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Sample records for basin west sumatra

  1. Exploration in the Ombilin Intermontane Basin, West Sumatra

    SciTech Connect

    Koning, T.

    1996-12-31

    The Ombilin Basin is a Tertiary intermontane basin located within the Barisan Mountain Range of Sumatra. Oil exploration commenced in the Ombilin Basin in the early 1980s when geological mapping was carried out, a synthetic aperture radar survey was flown, and a basin-wide geophysical survey was completed. This effort led to the drilling of Sinimar No. 1 to a total depth 3020 m. Sinimar No. 1 was a historic well in Indonesia`s oil industry since it was the first oil exploration well drilled in the Ombilin Basin and also the first well drilled in an intermontane basin in Indonesia. Oil, gas and condensate was tested in the well. An integrated interpretation of the well, geophysical and outcrop data indicates that despite its small areal size (30 km x 50 km), the Ombilin Basin is a deep pull-apart basin containing up to 4500 m of Tertiary sediments, ranging in age from Middle Eocene to Early Miocene. The basin currently is in an intermontane basin structural setting but it was also an intermontane basin during its Early Tertiary depositional history. During the Eocene, alluvial fans and massive debris flows were deposited on the basin margins and a large lake occupied the basin center. Fluvial deposition occurred in the basin during the Oligocene followed by deposition of marine shales, sandstones, and isolated reefs during the Miocene. Although the Ombilin Basin is located within Sumatra`s magmatic arc and is partially covered by volcanics from extinct and active volcanoes, the subsurface temperature gradients of 1.62 deg. F/100 ft. recorded in Sinimar No. I and 1.47 deg F/100 ft. measured in a deep (670 m) coal exploration core hole are significantly cooler than the average subsurface temperature gradients in the Sumatra back-arc basins. Organic-rich Eocene lacustrine shales are the likely source rocks for the hydrocarbons tested in Sinimar No. 1 and the oil seeps located along the basin margins.

  2. Exploration in the Ombilin Intermontane Basin, West Sumatra

    SciTech Connect

    Koning, T. Petroleum Co., Lagos )

    1996-01-01

    The Ombilin Basin is a Tertiary intermontane basin located within the Barisan Mountain Range of Sumatra. Oil exploration commenced in the Ombilin Basin in the early 1980s when geological mapping was carried out, a synthetic aperture radar survey was flown, and a basin-wide geophysical survey was completed. This effort led to the drilling of Sinimar No. 1 to a total depth 3020 m. Sinimar No. 1 was a historic well in Indonesia's oil industry since it was the first oil exploration well drilled in the Ombilin Basin and also the first well drilled in an intermontane basin in Indonesia. Oil, gas and condensate was tested in the well. An integrated interpretation of the well, geophysical and outcrop data indicates that despite its small areal size (30 km x 50 km), the Ombilin Basin is a deep pull-apart basin containing up to 4500 m of Tertiary sediments, ranging in age from Middle Eocene to Early Miocene. The basin currently is in an intermontane basin structural setting but it was also an intermontane basin during its Early Tertiary depositional history. During the Eocene, alluvial fans and massive debris flows were deposited on the basin margins and a large lake occupied the basin center. Fluvial deposition occurred in the basin during the Oligocene followed by deposition of marine shales, sandstones, and isolated reefs during the Miocene. Although the Ombilin Basin is located within Sumatra's magmatic arc and is partially covered by volcanics from extinct and active volcanoes, the subsurface temperature gradients of 1.62 deg. F/100 ft. recorded in Sinimar No. I and 1.47 deg F/100 ft. measured in a deep (670 m) coal exploration core hole are significantly cooler than the average subsurface temperature gradients in the Sumatra back-arc basins. Organic-rich Eocene lacustrine shales are the likely source rocks for the hydrocarbons tested in Sinimar No. 1 and the oil seeps located along the basin margins.

  3. Ichnological constraints on the depositional environment of the Sawahlunto Formation, Kandi, northwest Ombilin Basin, west Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Zonneveld, J.-P.; Zaim, Y.; Rizal, Y.; Ciochon, R. L.; Bettis, E. A.; Aswan; Gunnell, G. F.

    2012-02-01

    A low diversity trace fossil assemblage is described from the Oligocene Sawahlunto Formation near Kandi, in the northwestern part of the Ombilin Basin in western Sumatra, Indonesia. This trace fossil assemblage includes six ichnogenera attributed to invertebrate infaunal and epifaunal activities ( Arenicolites, Diplocraterion, Planolites, Monocraterion/ Skolithos and Coenobichnus) and two ichnotaxa attributed to vertebrate activity (avian footprints: two species of Aquatilavipes). Arenicolites, Diplocraterion and Monocraterion/ Skolithos record the suspension feeding activities of either arthropods (most likely amphipods) or vermiform organisms. Planolites reflects the presence of an infaunal deposit feeder. Coenobichnus records the walking activities of hermit crabs. Both the Coenobichnus and the avian footprints record the surficial detritus scavenging of epifaunal organisms within a subaerial setting. These traces occur within a fine-grained sandstone succession characterized by planar laminae and low-relief, asymmetrical, commonly mud-draped (locally bidirectional) ripples. The presence of traces attributable to suspension feeders implies deposition in a subaqueous setting. Their occurrence (particularly the presence of Arenicolites and Diplocraterion) in a sandstone bed characterized by mud-draped and bidirectional ripples implies emplacement in a tidally-influenced marine to marginal marine setting. Co-occurrence of these traces with well-preserved avian footprints ( Aquatilavipes) further implies periodic subaerial exposure. Thus, it is most likely that the Sawahlunto Formation near Kandi records deposition within an intertidal flat setting. Definitive evidence of marine influences in the Oligocene interval of the Ombilin Basin implies a more complex tectono-stratigraphic history than has previously been implied.

  4. Terrestrial heat flow in the tertiary basin of central Sumatra

    NASA Astrophysics Data System (ADS)

    Da Silva Carvalho, Humberto; Purwoko; Siswoyo; Thamrin, M.; Vacquier, Victor

    1980-10-01

    Heat flow at 170 locations in the Central Tertiary basin of Sumatra was determined from thermal gradients obtained from the extrapolated oil well bottom hole formation temperature and the assumed temperature of 80°F at the surface. The effective thermal conductivity of the whole rock column, by which the gradient is multiplied to get the heat flow was calculated from measurements on 273 specimens of the geologic section and inspection of 92 well logs. For the whole basin the gradient averaged 3.71 ± 1.04°F/ 100 ft (67.6°C/km) the conductivity 4.83 ± 0.31 mcal °C -1 cm -1 sec -1, giving an average heat flow of 3.27 ± 0.93 10-6 cal cm -2 sec -1 which is about twice the world average. The gradient and the heat flow vary inversely with the depth of the wells most of which bottom in the pre-Tertiary basement. This may result from the basement rocks being several times more conductive than the sediments. Mocel calculations on a narrow heat-flow anomaly which rises from a base level of 3.2 HFU to 8.8 HFU suggest that it can be caused by the intrusion less than 55,000 years ago of an igneous plug or laccolith no deeper than 3 km and 2.2 to 4.6 km wide. Using the gradients from the SEAPEX Geothermal Gradient Map and assuming a conductivity of 5 mcal cm -1 °C -1 sec -1, the heat flow in the North Sumatra basin, the South Sumatra Basin, Sunda Strait and West Java is 2.5 HFU, while in Java east of 110°E longitude it drops to 1.9 HFU. Since subduction off Sumatra dates back at least to the Cretaceous, compression of the Asian plate against the Benioff zone is preventing the opening of a back-arc basin. This does not preclude the possibility of occasional periods of crustal tension corresponding perhaps to episodes of transgression which allow magma to rise into the rocks underlying the basin.

  5. [The population of West Sumatra: a profile, trends, and projections].

    PubMed

    Kamaluddin, R

    1984-06-01

    A review of population trends in West Sumatra, Indonesia, is presented, together with projections up to 1990. The author notes that the population increased at a rate of about 2.21 percent per year between 1971 and 1980 and will continue to increase at about 2.12 percent per year up to 1990. The age composition of the population is expected to remain largely unchanged, with a high proportion of young adults and children. Urbanization levels are expected to remain relatively low and variations in spatial distribution to persist. The implications of these trends for development policy are considered.

  6. Basin modeling of Jambi Subbasin, South Sumatra, Indonesia

    SciTech Connect

    Halik, N. ); Wu, C. )

    1994-07-01

    The Jambi Subbasin is part of the South Sumatra Basin, a Tertiary back-arc basin formed by the collision between the Sundaland and Indian Plate. The Oligocene synrift Lahat Formation, and the Miocene postrift Talang Akar, Batu Raja, Gumai, and Air Benakat formations are stratigraphic intervals for potential hydrocarbon exploration. Most of the hydrocarbons have been produced from the Talang Akar and Air Benakat formations. Detailed age-depth relationship, paleobathymetry, and eustatic sea level were studied for 11 wells. Degrees of transgression and regression, and relative movement of fault blocks were predicted from rates of total and tectonic subsidence. The structural evolution of the Jambi Subbasin was reconstructed using the backstripping method. Results from the burial history modeling have helped in predicting thermal maturity, hydrocarbon generation, and structural development of the Jambi Subbasin. The timing of basement uplifting started from middle-late Miocene and reached the maximum in Pliocene-Pleistocene. Two hydrocarbon migration and accumulation mechanisms were proposed. In the depocenter, hydrocarbons were generated, migrated upward along faults, and trapped in the middle Miocene Air Benakat Formation, whereas in the basin flanks, hydrocarbons were migrated laterally from the depocenter and trapped in the Oligocene Talang Akar Formation. The methodology of this study can be applied to other subbasins in South Sumatra.

  7. Contemporary Minangkabau food culture in West Sumatra, Indonesia.

    PubMed

    Lipoeto, N I; Mmedsci; Agus, Z; Oenzil, F; Masrul, M; Wattanapenpaiboon, N

    2001-01-01

    Diet has a strong relationship with food culture and changes in it are likely to be involved in the pathogenesis of newly emergent degenerative diseases. To obtain in-depth opinions about the food culture of Minangkabau people, focus group discussions were conducted in a Minangkabau region, represented by four villages in West Sumatra, Indonesia, from January to March 1999. The members of the discussion groups were principally women aged from 35 to 82 years old. Minangkabau culture is matriarchal and matrilineal which accounts for female gender dominants in the discussions. Rice, fish, coconut and chilli are the basic ingredients of the Minangkabau meals. Meat, especially beef and chicken, is mainly prepared for special occasions; pork is not halal and therefore not eaten by Muslim Minangkabau people; and for reasons of taste preference and availability, lamb, goat and wild game are rarely eaten. However, rendang, a popular meat dish, has been identified as one of the Minangkabau food culture characteristic dishes. Vegetables are consumed daily. Fruit is mainly seasonal, although certain kinds of fruit, such as banana, papaya and citrus, can be found all year around. Coconut has an important role in Minangkabau food culture and is the main source of dietary fat. While almost all food items consumed by the Minangkabau can be cooked with coconut milk, fried food with coconut oil is considered to be a daily basic food. Desiccated coconut is also used as a food ingredient on about a weekly basis and in snack foods almost every day. Although there have been no changes in food preparation and there is a slight difference in taste preference between the young and the old generations, there has been a dramatic shift in food preferences, which is reflected in the changing percentage of energy consumed over the past 15 years. The traditional combination of rice, fish and coconut in Minangkabau culture goes back hundreds of years, long before the emergence of the degenerative

  8. Contemporary Minangkabau food culture in West Sumatra, Indonesia.

    PubMed

    Lipoeto, N I; Mmedsci; Agus, Z; Oenzil, F; Masrul, M; Wattanapenpaiboon, N

    2001-01-01

    Diet has a strong relationship with food culture and changes in it are likely to be involved in the pathogenesis of newly emergent degenerative diseases. To obtain in-depth opinions about the food culture of Minangkabau people, focus group discussions were conducted in a Minangkabau region, represented by four villages in West Sumatra, Indonesia, from January to March 1999. The members of the discussion groups were principally women aged from 35 to 82 years old. Minangkabau culture is matriarchal and matrilineal which accounts for female gender dominants in the discussions. Rice, fish, coconut and chilli are the basic ingredients of the Minangkabau meals. Meat, especially beef and chicken, is mainly prepared for special occasions; pork is not halal and therefore not eaten by Muslim Minangkabau people; and for reasons of taste preference and availability, lamb, goat and wild game are rarely eaten. However, rendang, a popular meat dish, has been identified as one of the Minangkabau food culture characteristic dishes. Vegetables are consumed daily. Fruit is mainly seasonal, although certain kinds of fruit, such as banana, papaya and citrus, can be found all year around. Coconut has an important role in Minangkabau food culture and is the main source of dietary fat. While almost all food items consumed by the Minangkabau can be cooked with coconut milk, fried food with coconut oil is considered to be a daily basic food. Desiccated coconut is also used as a food ingredient on about a weekly basis and in snack foods almost every day. Although there have been no changes in food preparation and there is a slight difference in taste preference between the young and the old generations, there has been a dramatic shift in food preferences, which is reflected in the changing percentage of energy consumed over the past 15 years. The traditional combination of rice, fish and coconut in Minangkabau culture goes back hundreds of years, long before the emergence of the degenerative

  9. Assessment of shale-oil resources of the Central Sumatra Basin, Indonesia, 2015

    USGS Publications Warehouse

    Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.

    2015-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 459 million barrels of shale oil, 275 billion cubic feet of associated gas, and 23 million barrels of natural gas liquids in the Central Sumatra Basin, Indonesia.

  10. Assessment of shale-oil resources of the Central Sumatra Basin, Indonesia, 2015

    USGS Publications Warehouse

    Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Leathers-Miller, Heidi M.

    2015-11-12

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 459 million barrels of shale oil, 275 billion cubic feet of associated gas, and 23 million barrels of natural gas liquids in the Central Sumatra Basin, Indonesia.

  11. Interannual variation of ocean heat content in outer Indonesian waters in warming ocean (Case study: West Sumatra waters)

    NASA Astrophysics Data System (ADS)

    Radjawane, Ivonne M.; Bernawis, Lamona I.; Priyono, Bayu; Fadli, Muh.; Putuhena, Hugo S.

    2015-09-01

    This research was intended observe of interannual variation of Ocean Heat Content (OHC) in outer Indonesian Water within the boundary of Indonesia Economic Exclusive Zone (EEZ) with study case focused West Sumatra waters that related to global ocean warming. The temperature data were obtained from ARGO floats as well as other observations data from 2002-2010. OHC was calculated following the equations adopted from Young et al.(2009) using a two-layer ocean models which are above and below the thermocline, where the heat content is calculated from the surface to depth of 28° C isotherm of upper thermocline.The results show trend of increasing OHC and varies interannual in West Sumatra water. The OHC ranges from 425 MJ/m2 to 4720 MJ/m2 in West Sumatra. The signal of OHC in West Sumatra influenced by Indian Ocean Dipole Mode phenomena. When positive IOD event occurs then decrease of OHC in West Sumatra due to decrease in SST over the areas.

  12. Fluctuation of diptera larvae in phytotelmata and relation with climate variation in West Sumatra Indonesia.

    PubMed

    Rosa, Emantis; Dahelmi; Salmah, Siti; Syamsuardi

    2014-07-01

    Research of fluctuations in Diptera's larvae in Phytotelmata had been conducted at three locations in West Sumatra, Indonesia; Padang, Bukittinggi and Payakumbuh; which aimed to determine the number and fluctuations Diptera larvae in Phytotelmata. The results obtained; the highest number of individual larvae Diptera in Phytotelmata was 7109 Aedes albopictus larvae (49.56%), followed by larvae of Culex tritaeniorhynchus with 2409 individuals (16.80%). Larvae fluctuated every month and tent to increase in November and December. There was no difference in the number of Diptera larvae individuals inhabiting pandan, taro, and pineapple, but there were significant differences between the three types of Phytotelmata (pandanus, taro and pineapple) with bamboo (p < 0.05). Number of individual larvae in Phytotelmata negatively correlated with temperature and rainfall, but positively correlated with humidity (r = 0.44: p < 0.05). PMID:26035947

  13. South Sumatra Basin Province, Indonesia; the Lahat/Talang Akar-Cenozoic total petroleum system

    USGS Publications Warehouse

    Bishop, Michele G.

    2000-01-01

    Oil and gas are produced from the onshore South Sumatra Basin Province. The province consists of Tertiary half-graben basins infilled with carbonate and clastic sedimentary rocks unconformably overlying pre-Tertiary metamorphic and igneous rocks. Eocene through lower Oligocene lacustrine shales and Oligocene through lower Miocene lacustrine and deltaic coaly shales are the mature source rocks. Reserves of 4.3 billion barrels of oil equivalent have been discovered in reservoirs that range from pre-Tertiary basement through upper Miocene sandstones and carbonates deposited as synrift strata and as marine shoreline, deltaic-fluvial, and deep-water strata. Carbonate and sandstone reservoirs produce oil and gas primarily from anticlinal traps of Plio-Pleistocene age. Stratigraphic trapping and faulting are important locally. Production is compartmentalized due to numerous intraformational seals. The regional marine shale seal, deposited by a maximum sea level highstand in early middle Miocene time, was faulted during post-depositional folding allowing migration of hydrocarbons to reservoirs above the seal. The province contains the Lahat/Talang Akar-Cenozoic total petroleum system with one assessment unit, South Sumatra.

  14. Forearc Basin Structure in the Andaman-Nicobar Segment of the Sumatra-Andaman Subduction Zone: Insight from High-Resolution Seismic Reflection Data

    NASA Astrophysics Data System (ADS)

    Moeremans, R. E.; Singh, S. C.

    2014-12-01

    The Andaman-Nicobar subduction is the northernmost segment of the Sumatra-Andaman subduction zone and marks the western boundary of the Andaman Sea, which is a complex backarc extensional basin. We present the interpretation of a new set of deep seismic reflection data acquired across the Andaman-Nicobar forearc basin, from 8°N to 11°N, to understand the structure and evolution of the forearc basin, focusing on how the obliquity of convergence affects deformation in the forearc, as well as on the Diligent (DF) and Eastern Margin Faults (EMF). Constraining the evolution of this basin, which is strongly related to the collision of India and Eurasia, can help shed light onto present-day deformation processes along this segment of the subduction zone, where convergence is highly oblique and little data is available. We find that he DF is a backthrust and corresponds to the Mentawai (MFZ) and West Andaman Fault (WAF) systems further south, offshore Sumatra. The DF is expressed as a series of mostly landward verging folds and faults, deforming the early to late Miocene sediments. The DF seems to root from the boundary between the accretionary complex and the continental backstop, where it meets the EMF. The EMF marks the western boundary of the forearc basin; it is associated with subsidence and is expressed as a deep piggyback basin, associated with recent Pliocene to Pleistocene subsidence at the western edge of the forearc basin. The eastern edge of the forearc basin is marked by the Invisible Bank (IB), which is thought to be tilted and uplifted continental crustal block. Subsidence along the EMF and uplift and tilting of the IB seem to be related to different opening phases in the Andaman Sea. The sliver Andaman-Nicobar Fault (ANF), which is the active northward extension of the Great Sumatra sliver Fault (GSF), lies to the east of the IB, and marks the boundary between continental crust underlying the forearc basin and crust accreted at the Andaman Sea Spreading

  15. K West Basin canister survey

    SciTech Connect

    Pitner, A.L.

    1998-08-26

    A survey was conducted of the K West Basin to determine the distribution of canister types that contain the irradiated N Reactor fuel. An underwater camera was used to conduct the survey during June 1998, and the results were recorded on videotape. A full row-by-row survey of the entire basin was performed, with the distinction between aluminum and stainless steel Mark 1 canisters made by the presence or absence of steel rings on the canister trunions (aluminum canisters have the steel rings). The results of the survey are presented in tables and figures. Grid maps of the three bays show the canister lid ID number and the canister type in each location that contained fuel. The following abbreviations are used in the grid maps for canister type designation: IA = Mark 1 aluminum, IS = Mark 1 stainless steel, and 2 = Mark 2 stainless steel. An overall summary of the canister distribution survey is presented in Table 1. The total number of canisters found to contain fuel was 3842, with 20% being Mark 1 Al, 25% being Mark 1 SS, and 55% being Mark 2 SS. The aluminum canisters were predominantly located in the East and West bays of the basin.

  16. Seismic and deformation precursory to the small explosions of Marapi Volcano, West Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Hidayat, D.; Patria, C.; Gunawan, H.; Taisne, B.; Nurfiani, D.; Avila, E. J.

    2015-12-01

    Marapi Volcano is one of the active volcanoes of Indonesia located near the city of Bukittinggi, West Sumatra, Indonesia. Its activity is characterized by small vulcanian explosions with occasional VEI 2 producing tephra and pyroclastic flows. Due to its activity, it is being monitored by Centre for Volcanology and Geological Hazard Mitigation (CVGHM). Four seismic stations consists of 2 broadband and 2 short period instruments have been established since 2009. In collaboration with CVGHM, Earth Observatory of Singapore added 5 seismic stations around the volcano in 2014, initially with short period instruments but later upgraded to broadbands. We added one tilt station at the summit of Marapi. These seismic and tilt stations are telemetered by 5.8GHz radio to Marapi Observatory Post where data are archived and displayed for Marapi observers for their daily volcanic activity monitoring work. We also archive the data in the EOS and CVGHM main offices. Here we are presenting examples of seismic and deformation data from Marapi prior, during, and after the vulcanian explosion. Our study attempt to understand the state of the volcano based on monitoring data and in order to enable us to better estimate the hazards associated with the future eruptions of this or similar volcano.

  17. Earthquake and tsunami hazard in West Sumatra: integrating science, outreach, and local stakeholder needs

    NASA Astrophysics Data System (ADS)

    McCaughey, J.; Lubis, A. M.; Huang, Z.; Yao, Y.; Hill, E. M.; Eriksson, S.; Sieh, K.

    2012-04-01

    The Earth Observatory of Singapore (EOS) is building partnerships with local to provincial government agencies, NGOs, and educators in West Sumatra to inform their policymaking, disaster-risk-reduction, and education efforts. Geodetic and paleoseismic studies show that an earthquake as large as M 8.8 is likely sometime in the coming decades on the Mentawai patch of the Sunda megathrust. This earthquake and its tsunami would be devastating for the Mentawai Islands and neighboring areas of the western Sumatra coast. The low-lying coastal Sumatran city of Padang (pop. ~800,000) has been the object of many research and outreach efforts, especially since 2004. Padang experienced deadly earthquakes in 2007 and 2009 that, though tragedies in their own right, served also as wake-up calls for a larger earthquake to come. However, there remain significant barriers to linking science to policy: extant hazard information is sometimes contradictory or confusing for non-scientists, while turnover of agency leadership and staff means that, in the words of one local advocate, "we keep having to start from zero." Both better hazard knowledge and major infrastructure changes are necessary for risk reduction in Padang. In contrast, the small, isolated villages on the outlying Mentawai Islands have received relatively fewer outreach efforts, yet many villages have the potential for timely evacuation with existing infrastructure. Therefore, knowledge alone can go far toward risk reduction. The tragic October 2010 Mentawai tsunami has inspired further disaster-risk reduction work by local stakeholders. In both locations, we are engaging policymakers and local NGOs, providing science to help inform their work. Through outreach contacts, the Mentawai government requested that we produce the first-ever tsunami hazard map for their islands; this aligns well with scientific interests at EOS. We will work with the Mentawai government on the presentation and explanation of the hazard map, as

  18. Sedimentology and diagenesis of a rift basin lacustrine sandstone: Pematang group, central Sumatra, Indonesia

    SciTech Connect

    Janks, J.S.; Kelley, P.A.; Williams, H.H.

    1986-05-01

    The Central Sumatra basin is a back-arc basin that formed during the Paleocene as a series of half-graben structures. These early formed half-graben structures were filled with nonmarine clastics and lacustrine sediments of the Pematang Group, sourced from local highland areas. The Pematang Group consists of the Lower Red Beds, Brown Shale, Coal Zone Member, and Lake Fill Formation (in ascending order). The Pematang Group sedimentology is intimately related to the regional and basinal tectonic development and history. Sandstones of the Pematang Group are predominantly sublitharenites and litharenites; feldspars are rare. Sandstone diagenesis is relatively uniform regardless of the depositional environment. Diagenetic modifications include compaction, early calcite and dolomite cementation, quartz overgrowth formation, unstable rock-fragment dissolution, kaolinite precipitation, siderite formation, and local illite formation. Secondary porosity accounts for up to 50% of the effective porosity and was created by rock-fragment dissolution. This dissolution is probably caused by the organic acids released during kerogen maturation. Stable isotope data from diagenetic siderite are presented.

  19. Geological Investigation and analysis in response to Earthquake Induced Landslide in West Sumatra

    NASA Astrophysics Data System (ADS)

    Karnawati, D.; Wilopo, W.; Salahudin, S.; Sudarno, I.; Burton, P.

    2009-12-01

    Substantial socio-economical loss occurred in response to the September 30. 2009 West Sumatra Earthquake with magnitude of 7.6. Damage of houses and engineered structures mostly occurred at the low land of alluvium sediments due to the ground amplification, whilst at the high land of mountain slopes several villages were buried by massive debris of rocks and soils. It was recorded that 1115 people died due to this disasters. Series of geological investigation was carried out by Geological Engineering Department of Gadjah Mada University, with the purpose to support the rehabilitation program. Based on this preliminary investigation it was identified that most of the house and engineered structural damages at the alluvial deposits mainly due to by the poor quality of such houses and engineered structures, which poorly resist the ground amplification, instead of due to the control of geological conditions. On the other hand, the existence and distribution of structural geology (faults and joints) at the mountaineous regions are significant in controlling the distribution of landslides, with the types of rock falls, debris flows and debris falls. Despite the landslide susceptibility mapping conducted by Geological Survey of Indonesia, more detailed investigation is required to be carried out in the region surrounding Maninjau Lake, in order to provide safer places for village relocation. Accordingly Gadjah Mada University in collaboration with the local university (Andalas University) as well as with the local Government of Agam Regency and the Geological Survey of Indonesia, serve the mission for conducting rather more detailed geological and landslide investigation. It is also crucial that the investigation (survey and mapping) on the social perception and expectation of local people living in this landslide susceptible area should also be carried out, to support the mitigation effort of any future potential earthquake induced landslides.

  20. Constructivist learning at the science-policy interface: tsunami science informing disaster policy in West Sumatra

    NASA Astrophysics Data System (ADS)

    McCaughey, J.; Dewi, P. R.; Natawidjaja, D. H.; Sieh, K. E.

    2012-12-01

    Science communication often falls short when it is based on the blank-slate assumption that if we can just get the message right, then the information will be received and understood as intended. In contrast, constructivist learning theory and practice suggest that we all actively construct our knowledge from a variety of information sources and through particular, novel associations with our prior knowledge. This constructed knowledge can be quite different from any of its original sources, such as a particular science communication. Successful communication requires carefully examining how people construct their knowledge of the topic of interest. Examples from our outreach work to connect hazard-science research with disaster-risk reduction practice in West Sumatra illustrate the mismatch between expert and stakeholder/public mental models of the characteristics of tsunamigenic earthquakes. There are incorrect conceptions that seawater always withdraws before a tsunami, and that a tsunami can be produced by an earthquake only if the epicenter is located at the ocean trench. These incorrect conceptions arise from generalizations based on recent, local earthquake experiences, as well as from unintended consequences of science outreach, science education, and, in one case, the way that tsunami modelling is graphically presented in scientific journals. We directly address these incorrect conceptions in our discussions with government officials and others; as a result, the local disaster-management agency has changed its policies to reflect an increased understanding of the hazard. This outreach success would not have been possible without eliciting the prior knowledge of our audiences through dialogue.

  1. Radiocarbon Content of Intermediate Waters off West Sumatra During the Last 45,000 Years

    NASA Astrophysics Data System (ADS)

    De Pol-Holz, R.; Mohtadi, M.; Southon, J. R.

    2014-12-01

    Radiocarbon content of intermediate waters originating from the Southern Ocean is held as a likely smoking gun of the events that triggered the atmospheric CO2 rise and its radiocarbon decline during the last glacial-interglacial transition. Late Glacial depleted radiocarbon water masses have been found at intermediate depths off the coast of Baja California, the Galapagos, the Arabian Sea, but not unequivocally elsewhere. Knowing the route of the old water is therefore central for the required mechanistic linkage of Southern Ocean processes and the atmospheric response. A common approach to search for the old water reservoir is the radiocarbon difference between planktonic and benthic foraminifera or 'apparent ventilation age'. Caveats of this approach are due to the fact that it relies strongly on the knowledge of the surface water reservoir age. In this study, we present a high-resolution radiocarbon difference between surface and intermediate depth waters off west Sumatra in the attempt to elucidate a possible route of the old water from its hypothetical source in the high latitudes near Antarctica on its way to the lower latitude sites where it has been observed. Samples come from core SO189-39KL (0°47'S, 99°55'E, 517 m), a 1350 cm hemipelagic sedimentary sequence that spans the last 45,000 years. Radiocarbon determinations were made at centennial time resolution on both planktonic and benthic species. Calibration of the planktonic radiocarbon as age control points allowed us to infer the Δ14C of the intermediate waters. Our results show that throughout the LGM and the entire deglaciation, radiocarbon content of intermediate depths in the area remained with an almost constant age difference with the contemporaneous atmosphere. Unless we have grossly underestimated the local planktonic reservoir age, our results discard this area as a probable route for the spreading of the old water along its way to northern latitudes. In light of recent evidence from the

  2. Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra

    NASA Astrophysics Data System (ADS)

    Gagan, Michael K.; Sosdian, Sindia M.; Scott-Gagan, Heather; Sieh, Kerry; Hantoro, Wahyoe S.; Natawidjaja, Danny H.; Briggs, Richard W.; Suwargadi, Bambang W.; Rifai, Hamdi

    2015-12-01

    The recent surge of megathrust earthquakes and tsunami disasters has highlighted the need for a comprehensive understanding of earthquake cycles along convergent plate boundaries. Space geodesy has been used to document recent crustal deformation patterns with unprecedented precision, however the production of long paleogeodetic records of vertical seafloor motion is still a major challenge. Here we show that carbon isotope ratios (δ13C) in the skeletons of massive Porites corals from west Sumatra record abrupt changes in light exposure resulting from coseismic seafloor displacements. Validation of the method is based on the coral δ13C response to uplift (and subsidence) produced by the March 2005 Mw 8.6 Nias-Simeulue earthquake, and uplift further south around Sipora Island during a M ∼ 8.4 megathrust earthquake in February 1797. At Nias, the average step-change in coral δ13C was 0.6 ± 0.1 ‰ /m for coseismic displacements of +1.8 m and -0.4 m in 2005. At Sipora, a distinct change in Porites microatoll growth morphology marks coseismic uplift of 0.7 m in 1797. In this shallow water setting, with a steep light attenuation gradient, the step-change in microatoll δ13C is 2.3 ‰ /m, nearly four times greater than for the Nias Porites. Considering the natural variability in coral skeletal δ13C, we show that the lower detection limit of the method is around 0.2 m of vertical seafloor motion. Analysis of vertical displacement for well-documented earthquakes suggests this sensitivity equates to shallow events exceeding Mw ∼ 7.2 in central megathrust and back-arc thrust fault settings. Our findings indicate that the coral 13C /12C paleogeodesy technique could be applied to convergent tectonic margins throughout the tropical western Pacific and eastern Indian oceans, which host prolific coral reefs, and some of the world's greatest earthquake catastrophes. While our focus here is the link between coral δ13C, light exposure and coseismic crustal deformation, the

  3. Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra

    USGS Publications Warehouse

    Gagan, Michael K.; Sosdian, Sindia M.; Scott-Gagan, Heather; Sieh, Kerry; Hantoro, Wahyoe S.; Natawidjaja, Danny H.; Briggs, Richard W.; Suwargadi, Bambang W.; Rifai, Hamdi

    2015-01-01

    The recent surge of megathrust earthquakes and tsunami disasters has highlighted the need for a comprehensive understanding of earthquake cycles along convergent plate boundaries. Space geodesy has been used to document recent crustal deformation patterns with unprecedented precision, however the production of long paleogeodetic records of vertical seafloor motion is still a major challenge. Here we show that carbon isotope ratios () in the skeletons of massive Porites   corals from west Sumatra record abrupt changes in light exposure resulting from coseismic seafloor displacements. Validation of the method is based on the coral  response to uplift (and subsidence) produced by the March 2005 Mw 8.6 Nias–Simeulue earthquake, and uplift further south around Sipora Island during a M∼8.4 megathrust earthquake in February 1797. At Nias, the average step-change in coral  was 0.6±0.1‰/m for coseismic displacements of +1.8 m and −0.4 m in 2005. At Sipora, a distinct change in Porites  microatoll growth morphology marks coseismic uplift of 0.7 m in 1797. In this shallow water setting, with a steep light attenuation gradient, the step-change in microatoll  is2.3‰/m, nearly four times greater than for the Nias Porites  . Considering the natural variability in coral skeletal , we show that the lower detection limit of the method is around 0.2 m of vertical seafloor motion. Analysis of vertical displacement for well-documented earthquakes suggests this sensitivity equates to shallow events exceedingMw∼7.2 in central megathrust and back-arc thrust fault settings. Our findings indicate that the coral  paleogeodesy technique could be applied to convergent tectonic margins throughout the tropical western Pacific and eastern Indian oceans, which host prolific coral reefs, and some of the world's greatest earthquake catastrophes. While our focus here is the link between coral , light exposure and coseismic crustal deformation, the same principles

  4. Male replacement and stability of territorial boundary in a group of agile gibbons (Hylobates agilis agilis) in West Sumatra, Indonesia.

    PubMed

    Koda, Hiroki; Oyakawa, Chisako; Nurulkamilah, Santi; Rizaldi; Sugiura, Hideki; Bakar, Amsir; Masataka, Nobuo

    2012-10-01

    We report membership change in a group of wild agile gibbons, Hylobates agilis agilis, in West Sumatra, Indonesia. During 6-month observational periods, we focused on a particular unit of individuals known as the B group. We confirmed that the group consisted of five individuals: one adult female, one adult male, one subadult male, one subadult female, and one infant male. During our observations, the resident adult male and the two subadult individuals dispersed or disappeared, and a new adult male took over the group. We examined the effects of the male replacement on the territorial boundary, using the auditory census technique. The boundary was stable. We also documented the succession of the home range. Our results indicate a flexible social structure in this species and contribute some useful data to an ongoing debate on their social dynamics.

  5. Hydrogeology of the West Siberian Basin

    SciTech Connect

    Foley, M.G.; Bradley, D.J.; Cole, C.R.

    1996-08-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in extensive radioactive contaminant releases to the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. We have assumed that ground-water flow in the West Siberian Basin is topographically driven, with recharge to the basin occurring in the highlands on the west, east, and south, and internal discharge localized in numerous river valleys and lakes that ultimately discharge north to the ocean. We are modeling the regional hydrogeology as three-dimensional, steady-state, saturated flow that is recharged from above. We acquired topographic, geologic, hydrostratigraphic, hydrogeologic, and water-balance data for the West Siberian Basin and constructed a regional water table. We correlated and combined 70 different rock types derived from published descriptions of West Siberian Basin rocks into 17 rock types appropriate for assignment of hydrogeologic properties on the basis of spatial heterogeneity and constituent (i.e., sand, silt, and clay) diversity. Examination of resulting three-dimensional assemblages of rock types showed that they were consistent with published and inferred paleogeography and depositional processes. Calibrating the basin`s moisture balance (i.e., recharge and discharge) to the derived water table determined plausible input parameter values for unknowns such as hydraulic conductivities. The general directions of calculated ground-water flow suggest that major rivers act as discharge areas, with upwelling below the rivers extending down into the basement rocks, and that ground-water divides that penetrate the entire thickness of the model are evident between major rivers.

  6. Tsunamis as geomorphic crises: Lessons from the December 26, 2004 tsunami in Lhok Nga, West Banda Aceh (Sumatra, Indonesia)

    NASA Astrophysics Data System (ADS)

    Paris, Raphaël; Wassmer, Patrick; Sartohadi, Junun; Lavigne, Franck; Barthomeuf, Benjamin; Desgages, Emilie; Grancher, Delphine; Baumert, Philippe; Vautier, Franck; Brunstein, Daniel; Gomez, Christopher

    2009-03-01

    Large tsunamis are major geomorphic crises, since they imply extensive erosion, sediment transport and deposition in a few minutes and over hundreds of kilometres of coast. Nevertheless, little is known about their geomorphologic imprints. The December 26, 2004 tsunami in Sumatra (Indonesia) was one of the largest and deadliest tsunamis in recorded human history. We present a description of the coastal erosion and boulder deposition induced by the 2004 tsunami in the Lhok Nga Bay, located to the West of Banda Aceh (northwest Sumatra). The geomorphological impact of the tsunami is evidenced by: beach erosion (some beaches have almost disappeared); destruction of sand barriers protecting the lagoons or at river mouths; numerous erosion escarpments typically in the order of 0.5-1.5 m when capped by soil and more than 2 m in dunes; bank erosion in the river beds (the retreat along the main river is in the order of 5-15 m, with local retreats exceeding 30 m); large scars typically 20-50 cm deep on slopes; dislodgement of blocks along fractures and structural ramps on cliffs. The upper limit of erosion appears as a continuous trimline at 20-30 m a.s.l., locally reaching 50 m. The erosional imprints of the tsunami extend to 500 m from the shoreline and exceed 2 km along riverbeds. The overall coastal retreat from Lampuuk to Leupung was 60 m (550,000 m 2) and locally exceeded 150 m. Over 276,000 m 3 of coastal sediments were eroded by the tsunami along the 9.2 km of sandy coast. The mean erosion rate of the beaches was ~ 30 m 3/m of coast and locally exceeded 80 m 3/m. The most eroded coasts were tangent to the tsunami wave train, which was coming from the southwest. The fringing reefs were not efficient in reducing the erosional impact of the tsunami. The 220 boulders measured range from 0.3 to 7.2 m large (typically 0.7-1.5 m), with weights from over 50 kg up to 85 t. We found one boulder, less than 1 m large, at 1 km from the coastline, but all the others were

  7. Controls on early retention and late enhancement of microporosity in reefal gas reservoirs, offshore north Sumatra basin

    SciTech Connect

    Moshier, S.O.

    1989-03-01

    Chalky lime-matrix texture is pervasive in 300 m of coralgal and skeletal carbonates in the NSB-A (North Sumatra basin-A) gas field (lower-middle Miocene), offshore northern Sumatra. Much of the reservoir quality can be attributed to matrix with abundant intercrystalline, vuggy, and channel-form micropores. Matrix is composed of calcite microrhombs which are interpreted to have developed during stabilization of the precursor mud. On the same shelf, the smaller NSB-H oil field is composed of more than 45-m thick buildup of similar lithofacies which lack abundant microporosity. In both fields, early diagenesis included dissolution of aragonitic skeletal material, matrix neomorphism, and precipitation of nonluminescent calcite followed by zoned, luminescent calcite cements. Stable isotopes from matrix reflect a more open or water-dominated matrix diagenesis at NSB-H field. More active flushing of oversaturated, organically charged meteoric waters was responsible for thorough matrix cementation and microporosity occlusion at NSB-H field. Calcite cements show progressive enrichment of iron and manganese and depletion of magnesium and strontium during growth. The matrix at NSB-H field contains iron-rich dolomite. At A field, remnant matrix microporosity and intraparticle microporosity in calcitic skeletal material were greatly enhanced after all phases of cementation. Some pore-rimming cements are partially dissolved. At NSB-H field, late-phase dissolution is limited to the vicinity of open fractures where matrix-calcite and dolomite crystals are leached. Reservoir brines have a limey marine origin but are depleted in Ca and Mg relative to seawater, and carbon dioxide accounts for 31% of reservoir gas. If present brines are carbonate undersaturated, they may be substantially enhanced microporosity at NSB-A field. Late-stage dissolution is insignificant at NSB-H field due to the lack of early formed matrix microporosity.

  8. Modeling the 2012 Wharton Basin Earthquakes off-Sumatra; Complete Lithospheric Failure (Invited)

    NASA Astrophysics Data System (ADS)

    Wei, S.; Helmberger, D. V.; Avouac, J.

    2013-12-01

    A sequence of large strike-slip earthquakes occurred west of Sunda Trench beneath the Wharton Basin. First reports indicate that the mainshock was extremely complex, involving three to four subevents (Mw>8) with a maze of aftershocks. We investigate slip models of the two largest earthquakes by joint inversion of regional and teleseismic waveform data. Using the Mw7.2 foreshock, we developed hybrid Green's Functions for the regional stations to approximate the mixture of oceanic and continental paths. The mainshock fault geometry is defined based on the back-projection results, point-source mechanisms, aftershock distribution and fine tune of grid searches. The fault system contains three faults, labeled F1 (89°/289° for dip/strike), F2 (74°/20°) and F3 (60°/310°). The inversion indicates that the main rupture consisted of a cascade of high stress drop asperities (up to 30MPa), extending as deep as 50 km. The rupture propagated smoothly from one fault to the next (F1, F2 and F3 in sequence) with rupture velocities of 2.0-2.5 km/s. The whole process lasted about 200s and the major moment release (>70%) took place on the N-S oriented F2. The Mw8.2 aftershock happened about 2hrs later on a N-S oriented fault with a relatively short duration (~60s) and also ruptured as deep as 50km. The slip distributions suggest that the earthquake sequence was part of a broad left-lateral shear zone between the Australian and Indian plates, and ruptured the whole lithosphere. These earthquakes apparently reactivated existing fracture zones and were probably triggered by unclamping of the great Sumatran earthquake of 2004.

  9. Modeling the 2012 Wharton basin earthquakes off-Sumatra: Complete lithospheric failure

    NASA Astrophysics Data System (ADS)

    Wei, Shengji; Helmberger, Don; Avouac, Jean-Philippe

    2013-07-01

    sequence of large strike-slip earthquakes occurred west of Sunda Trench beneath the Wharton Basin. First reports indicate that the main shock was extremely complex, involving three to four subevents (Mw > 8) with a maze of aftershocks. We investigate slip models of the two largest earthquakes by joint inversion of regional and teleseismic waveform data. Using the Mw7.2 foreshock, we developed hybrid Green's Functions for the regional stations to approximate the mixture of oceanic and continental paths. The main shock fault geometry is defined based on the back projection results, point-source mechanisms, aftershock distribution, and fine tune of grid searches. The fault system contains three faults, labeled F1 (89°/289° for dip/strike), F2 (74°/20°), and F3 (60°/310°). The inversion indicates that the main rupture consisted of a cascade of high-stress drop asperities (up to 30 MPa), extending as deep as 50 km. The rupture propagated smoothly from one fault to the next (F1, F2, and F3 in sequence) with rupture velocities of 2.0-2.5 km/s. The whole process lasted about 200 s, and the major moment release (>70%) took place on the N-S oriented F2. The Mw8.2 aftershock happened about 2 h later on a N-S oriented fault with a relatively short duration (~60 s) and also ruptured as deep as 50 km. The slip distributions suggest that the earthquake sequence was part of a broad left-lateral shear zone between the Australian and Indian plates and ruptured the whole lithosphere. These earthquakes apparently reactivated existing fracture zones and were probably triggered by unclamping of the great Sumatran earthquake of 2004.

  10. Dietary intake and the risk of coronary heart disease among the coconut-consuming Minangkabau in West Sumatra, Indonesia.

    PubMed

    Lipoeto, Nur I; Agus, Zulkarnain; Oenzil, Fadil; Wahlqvist, Mark; Wattanapenpaiboon, Naiyana

    2004-01-01

    Several nutrition and non-nutritional pathways are recognised in the development and occurrence of cardiovascular disease. In many populations, high intakes of saturated fat are associated with elevated serum cholesterol concentrations and increased coronary heart disease (CHD) mortality. However, several studies report that hyperlipidaemia and heart diseases are not common among populations who consume coconut, a source of saturated fat. A case-control study was conducted among the Minangkabau known to be high coconut consumers to examine the difference in food patterns and risk of coronary heart disease (CHD) between the coronary cases and their gender- and age-matched apparently healthy counterparts serving as controls. Eligible subjects with CHD were identified through the co-operation of five participating hospitals located in Padang and Bukittinggi in West Sumatra, Indonesia. A total of 93 eligible cases (62 men and 31 women) in the Case group and 189 subjects (113 men and 76 women) in the Control group were recruited. Information on the intakes of individual foods and dishes over the preceding 12 months was obtained using a semi-quantitative food frequency questionnaire. The Case groups had significantly higher intakes of meats, eggs, sugar, tea, coffee and fruits, but lower intakes of soy products, rice and cereals compared to the controls. Coconut consumption as flesh or milk was not different between cases and controls. The cases had significantly higher intakes of protein and cholesterol, but lower intake of carbohydrate. Similar intakes of saturated and unsaturated fatty acids between the cases and controls indicated that the consumption of total fat or saturated fat, including that from coconut, was not a predictor for CHD in this food culture. However, the intakes of animal foods, total protein, dietary cholesterol and less plant derived carbohydrates were predictors of CHD. PMID:15563444

  11. Dietary intake and the risk of coronary heart disease among the coconut-consuming Minangkabau in West Sumatra, Indonesia.

    PubMed

    Lipoeto, Nur I; Agus, Zulkarnain; Oenzil, Fadil; Wahlqvist, Mark; Wattanapenpaiboon, Naiyana

    2004-01-01

    Several nutrition and non-nutritional pathways are recognised in the development and occurrence of cardiovascular disease. In many populations, high intakes of saturated fat are associated with elevated serum cholesterol concentrations and increased coronary heart disease (CHD) mortality. However, several studies report that hyperlipidaemia and heart diseases are not common among populations who consume coconut, a source of saturated fat. A case-control study was conducted among the Minangkabau known to be high coconut consumers to examine the difference in food patterns and risk of coronary heart disease (CHD) between the coronary cases and their gender- and age-matched apparently healthy counterparts serving as controls. Eligible subjects with CHD were identified through the co-operation of five participating hospitals located in Padang and Bukittinggi in West Sumatra, Indonesia. A total of 93 eligible cases (62 men and 31 women) in the Case group and 189 subjects (113 men and 76 women) in the Control group were recruited. Information on the intakes of individual foods and dishes over the preceding 12 months was obtained using a semi-quantitative food frequency questionnaire. The Case groups had significantly higher intakes of meats, eggs, sugar, tea, coffee and fruits, but lower intakes of soy products, rice and cereals compared to the controls. Coconut consumption as flesh or milk was not different between cases and controls. The cases had significantly higher intakes of protein and cholesterol, but lower intake of carbohydrate. Similar intakes of saturated and unsaturated fatty acids between the cases and controls indicated that the consumption of total fat or saturated fat, including that from coconut, was not a predictor for CHD in this food culture. However, the intakes of animal foods, total protein, dietary cholesterol and less plant derived carbohydrates were predictors of CHD.

  12. View west of reserve basin of submarine trout and frigate ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west of reserve basin of submarine trout and frigate Edward E. McDonnell - Naval Base Philadelphia-Philadelphia Naval Shipyard, Reserve Basin & Marine Railway, League Island, Philadelphia, Philadelphia County, PA

  13. Geothermal resource of Sumatra

    SciTech Connect

    Hochstein, M.P. . Geothermal Inst.); Sudarman, Sayogi . Geothermal Section)

    1993-06-01

    There are at least 30 high temperatures systems (with inferred reservoir temperatures > 200 C) along the active Sumatra Arc that transfer heat from crustal intrusions to the surface. These systems, together with eleven active volcanoes, five degassing volcanoes and one caldera volcano (Lake Toba), are controlled by the Sumatra Fault Zone, an active mega shear zone that follows the median axis of the arc. At least half of the active and degassing volcanoes are associated with volcanic geothermal reservoirs containing magmatic gases and acid fluids. Large, low temperature resources exist in the Tertiary sedimentary basins of east Sumatra (back-arc region), where anomalously higher thermal gradients (up to 8 C/100 m) have been measured. Volcanic activity was not continuous during the Cenozoic; subduction and arc volcanism probably decreased after the Eocene as a result of a clockwise rotation of Sumatra. In the Late Miocene, subduction started again, and andesitic volcanism reached a new peak of intensity in the Pliocene and has been continuous ever since. Rhyolitic volcanism, which has produced voluminous ignimbrite flows, began later (Pliocene/Pleistocene). All known rhyolitic centers associated with ignimbrite flows appear to lie along the Sumatra Fault Zone.

  14. K West basin isolation barrier leak rate test

    SciTech Connect

    Whitehurst, R.; McCracken, K.; Papenfuss, J.N.

    1994-10-31

    This document establishes the procedure for performing the acceptance test on the two isolation barriers being installed in K West basin. This acceptance test procedure shall be used to: First establish a basin water loss rate prior to installation of the two isolation barriers between the main basin and the discharge chute in K-Basin West. Second, perform an acceptance test to verify an acceptable leakage rate through the barrier seals.

  15. Indonesia: Sumatra

    Atmospheric Science Data Center

    2013-04-16

    article title:  Smoke over Sumatra, Indonesia     View Larger Image ... the onset of a weak to moderate El Niño. The governments of Indonesia, Malaysia, and Brunei have agreed to ban open burning in plantation ...

  16. Anaerobic Oxidation of Methane at a Marine Methane Seep in a Forearc Sediment Basin off Sumatra, Indian Ocean

    PubMed Central

    Siegert, Michael; Krüger, Martin; Teichert, Barbara; Wiedicke, Michael; Schippers, Axel

    2011-01-01

    A cold methane seep was discovered in a forearc sediment basin off the island Sumatra, exhibiting a methane-seep adapted microbial community. A defined seep center of activity, like in mud volcanoes, was not discovered. The seep area was rather characterized by a patchy distribution of active spots. The relevance of anaerobic oxidation of methane (AOM) was reflected by 13C-depleted isotopic signatures of dissolved inorganic carbon. The anaerobic conversion of methane to CO2 was confirmed in a 13C-labeling experiment. Methane fueled a vital microbial community with cell numbers of up to 4 × 109 cells cm−3 sediment. The microbial community was analyzed by total cell counting, catalyzed reporter deposition–fluorescence in situ hybridization (CARD–FISH), quantitative real-time PCR (qPCR), and denaturing gradient gel electrophoresis (DGGE). CARD–FISH cell counts and qPCR measurements showed the presence of Bacteria and Archaea, but only small numbers of Eukarya. The archaeal community comprised largely members of ANME-1 and ANME-2. Furthermore, members of the Crenarchaeota were frequently detected in the DGGE analysis. Three major bacterial phylogenetic groups (δ-Proteobacteria, candidate division OP9, and Anaerolineaceae) were abundant across the study area. Several of these sequences were closely related to the genus Desulfococcus of the family Desulfobacteraceae, which is in good agreement with previously described AOM sites. In conclusion, the majority of the microbial community at the seep consisted of AOM-related microorganisms, while the relevance of higher hydrocarbons as microbial substrates was negligible. PMID:22207865

  17. CONSTRUCTION PROGRESS PHOTO SHOWING WEST STORAGE BASIN AT FUEL STORAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    CONSTRUCTION PROGRESS PHOTO SHOWING WEST STORAGE BASIN AT FUEL STORAGE BUILDING (CPP-603). INL PHOTO NUMBER NRTS-51-689. Unknown Photographer, 1950 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  18. The December 26, 2004, off the west coast of northern Sumatra, Indonesia, M W=9.0, earthquake and the critical-point-like model of earthquake preparation

    NASA Astrophysics Data System (ADS)

    Jiang, Chang-Sheng; Wu, Zhong-Liang

    2005-05-01

    Long-term seismic activity prior to the December 26, 2004, off the west coast of northern Sumatra, Indonesia, M W=9.0 earthquake was investigated using the Harvard CMT catalogue. It is observed that before this great earthquake, there exists an accelerating moment release (AMR) process with the temporal scale of a quarter century and the spatial scale of 1 500 km. Within this spatial range, the M W=9.0 event falls into the piece-wise power-law-like frequency-magnitude distribution. Therefore, in the perspective of the critical-point-like model of earthquake preparation, the failure to forecast/predict the approaching and/or the size of this earthquake is not due to the physically intrinsic unpredictability of earthquakes.

  19. 1. LOOKING TOWARD PLANE 9 WEST. BASIN HAS BEEN DRAINED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. LOOKING TOWARD PLANE 9 WEST. BASIN HAS BEEN DRAINED AND SLOPE OF PLANE 9 IS VISIBLE BETWEEN ROW OF TREES IN BACKGROUND. STONEWORK ON LEFT IS ABUTMENT TO BRIDGE THAT CROSSED OVER THE CANAL. - Morris Canal, Inclined Plane 9 West, Port Warren, Warren County, NJ

  20. Micropaleontology and biostratigraphy of the coastal basins of West Africa

    SciTech Connect

    Kogbe, C.A.; Mehes, K.

    1986-01-01

    This book is intended to meet the need for a single volume on descriptive micropaleontology of West African microfauna assemblage which is different from that of the Boreal, Mediterranean, Pacific and Atlantic regions. The contents include: Preface. Introduction. Systematics: West African foraminifera species: Systematic classification and description. Glossary for the foraminifera. Selected references for the foraminifera. The ostracoda: Systematic classification and description. Glossary for the ostracoda. Selected references for the ostracoda. Stratigraphic Sequences of the West African Coastal Basins: General review. Angola-Cuanza basin. Congo. Gabon. Cameroun-Douala basin. Nigeria. Togo-Benin basin. Ghana. Ivory Coast. Senegal. Appendix: Brief classification of foraminifera. Paleo-ecology of the foraminifera. Testing of samples. Collection of samples. Preparation of samples. Preparation of thin sections. Storage of microfossils. Methods of examination. Index.

  1. Vertical plate motions in the West Siberian Basin

    NASA Astrophysics Data System (ADS)

    Vibe, Yulia

    2014-05-01

    The West Siberian Basin is a sedimentary basin situated between the Ural Mountains and the Siberian Craton. The Basin has experienced several periods of subsidence and uplift since the arrival of the Siberian Traps c. 250 Ma. Although the Basin is extensively explored and hosts large reserves of Oil and Gas, the forces driving the vertical motions are poorly understood. In this work we attempt to analyse the amount, timing and location of subsidence and uplift in the Basin to shed light on the possible causes of these motions. A detailed description of sedimentary layers is published in a number of Soviet-era books and articles and serves as a basis for our research. This data is first converted into sediment grids through time. Subsequently, the sediments, the sediment load and the compaction are taken into account ('backstripping') to produce the depth of the Basin at respective time steps. With this technique we calculate the tectonic component of subsidence. Uncertainties related to uplift events are estimated by the unconformities in the stratigraphic charts. One of the possible driving forces of vertical motions is a change of force balance arising at plate boundaries. Since active plate tectonics have been absent from West Siberia since the formation of the Urengoy and Khodosey Rifts, c. 250Ma, we study the far-field tectonic effects as a potential driving mechanism. Indeed, some of the significant vertical events in the West Siberian Basin coincide with the major tectonic events around Siberia. An example is the spreading in the Arctic (Eurasian Basin) in the Eocene (56 Ma) which was synchronous with initiation of uplift events in the northern part of West Siberia. In the middle Oligocene (33 Ma), the northern and eastern parts of the basin were subjected to uplift as subsidence migrated southwards and the Basin rose above the sea level. This was coincident with the changes of plate motions in the northern North Atlantic and Indo-European collision.

  2. Geology and petroleum resources of West Siberian Basin, USSR

    SciTech Connect

    Clarke, J.W.; Klemme, H.D.; Peterson, J.A.

    1986-05-01

    The West Siberian basin occupies an area of approximately 3.3 million km/sup 2/ (1.3 million mi/sup 2/) in northwestern Siberia east of the Ural Mountains. Thickness of the Phanerozoic sedimentary cover ranges from approximately 3-5 km (10,000-15,000 ft) in the central area of the basin, to 8-12 km (25,000-40,000 ft) in the northern part. The basin is filled with approximately 10 million km/sup 3/ (2.4 million mi/sup 3/) of Mesozoic-Cenozoic clastic sedimentary rocks ranging in thickness from 3-4 km (10,000-13,000 ft) in the central area to 6-9 km (20,000-30,000 ft) in the north. The basement in the basin is Precambrian and Precambrian-Paleozoic granitic rocks and in places is highly metamorphosed Paleozoic sedimentary rocks. In other parts of the basin, Paleozoic carbonate and clastic rocks are only lightly metamorphosed and are targets for petroleum exploration. The Mesozoic-Cenozoic sedimentary basin fill was initiated in the northern part of the basin during the Triassic. By the Late Jurassic, marine clastic deposition had spread throughout the basin, and the basin configuration was established for the remainder of geologic time. Cretaceous and lower Tertiary rocks are primarily shallow marine shelf, coastal plain, and lowland clastic deposits formed during several transgressive-regressive phases. Major oil accumulations, mainly in Lower Cretaceous and Jurassic sandstone reservoirs, are located in the central and west-central parts of the basin. The largest reserves of natural gas in the world are located in the northern part of the basin, primarily in Upper Cretaceous (Cenomanian) sandstone reservoirs. In 1982, estimated cumulative production from the basin was approximately 10 billion bbl of oil. Estimated mean undiscovered resources (1981) are approximately 80 billion bbl of oil and 700 tcf of gas.

  3. Vertical plate motions in the West Siberian Basin

    NASA Astrophysics Data System (ADS)

    Vibe, Yulia; Clark, Stuart

    2015-04-01

    The West Siberian Basin is one of the world's largest sedimentary basins representing an important source of oil and gas. The Basin's history includes long periods of very slow subsidence coupled with periods of erosion and uplift. Despite that the Basin has been broadly explored the causes of these vertical motions are not yet understood. In this study we analyse the vertical motions by the means of backstripping. The new backstripping results refined by the paleo-water depth data give estimates of the subsidence and uplift rate. These results show a peculiar character of the vertical motions where the region of maximum subsidence migrated from the north to the south several times during the Basin's history. Such southward propagation of subsidence happened in the Late Jurassic, Aptian and in the Paleogene periods. The newly constrained local eustatic curve indicates that the Basin's vertical motions do not reflect the global sea level changes, but the more complicated tectonic processes. We put different data sets of the Basin's sediments and crust structure together with the new backstripping results in order to understand better the vertical motions and the processes underlying the irregular subsidence and uplift pattern of the West Siberian Basin

  4. Petroleum geology of South Sumatra, Indonesia

    SciTech Connect

    Woodside, P.R.

    1987-05-01

    The South Sumatra basin resulted from horst-graben structures formed from the end of Cretaceous to the early Tertiary. During the Pliocene-Pleistocene orogeny, prominent northwest-trending folds and strike-slip faults were formed within the basin. The depositional history of South Sumatra is similar to the prolific Central Sumatra basin; however, the reservoir sandstone facies in South Sumatra are less well developed. Four major orogenic events resulted in the present framework of the South Sumatra basin. These events occurred during (1) a mid-Mesozoic orogeny which metamorphosed, faulted, and uplifted previously deposited sediments into blocks; (2) the Late Cretaceous-early Oligocene tectonic event with resultant horsts and grabens that controlled Eocene sedimentation; (3) the late Oligocene-Miocene, a period of isostatic subsidence until its tectonic quiescence was broken by middle Miocene diastrophism in the Barisan Mountains and by minor structural movements; and (4) the widespread Pliocene-Pleistocene orogeny reflected in the shallow structures in the Tertiary sediments. The southwestern part of Sumatra corresponds to the uplifted range that folded during the Miocene. Only the Tertiary Lahat (Lamat) and Talang Akar formations were deposited in rugged pre-Tertiary topography. The contact between the Sumatra block and the Sunda-Java block is a north-south-trending right-lateral wrench fault. The anticlines within the South Sumatra basin can be grouped into three groups of anticlinal features. The major anticlinora consist of over 150 individual anticlines. To date, about 50 of the 100 structures tested have proved production. Shales in the upper Oligocene-lower Miocene Talang Akar and lower-middle Miocene Gumai (Telisa) Formations show excellent potential for oil generation.

  5. Livelihood Change and Livelihood Sustainability in the Uplands of Lembang Subwatershed, West Sumatra, Indonesia, in a Changing Natural Resource Management Context

    NASA Astrophysics Data System (ADS)

    Mahdi; Shivakoti, Ganesh P.; Schmidt-Vogt, Dietrich

    2009-01-01

    This paper analyzes livelihood change and livelihood sustainability of households in the upland part of the Lembang subwatershed, West Sumatra, in response to changes in the natural resource management context during the last decade. Using the sustainable livelihood framework (SLF), we measured livelihood changes at two separate points in time, 1996 and 2006, and assessed their environmental, economic, social, and institutional sustainability. We found that people with a low income had less access to capital assets than people from middle- and high-income groups. Our analysis revealed, however, that access to capital assets increased over time, and that poor households experienced economic improvement, indicating an overall increase in economic sustainability. Environmental sustainability, however, is threatened by intensive agricultural practices such as high agrochemical input and intensive soil tillage on steep slopes, leading to pollution and soil erosion. Social sustainability is also a matter of concern: while social exclusion has been reduced, income inequity has increased. Institutional sustainability is likely to remain uncertain, as local institutions for natural resource management are still weak, despite the fact that decentralization has been implemented during the last 8 years. External facilitation is needed to improve the livelihood of upland people while, at the same time, enhancing the sustainability of watershed management. Strengthening local institutions, conserving natural resources, and promoting environmentally sound agricultural practices are the three most important policies to be promoted within the watershed.

  6. Oil and Gas Resources of the West Siberian Basin, Russia

    EIA Publications

    1997-01-01

    Provides an assessment of the oil and gas potential of the West Siberian Basin of Russia. The report was prepared in cooperation with the U. S. Geological Survey (USGS) and is part of the Energy Information Administration's (EIA) Foreign Energy Supply Assessment Program (FESAP).

  7. Subsidence of the West Siberian Basin: Geophysical evidence for eclogitization

    NASA Astrophysics Data System (ADS)

    Cherepanova, Yulia; Artemieva, Irina M.

    2013-04-01

    The West Siberian basin is the world's largest intracratonic sedimentary basin. The basin basement consists of complexes of island arcs, terranes, micro-continents, and relict ocean basins which amalgamated during late Proterozoic-Paleozoic orogenic events up to the formation of the Pangea super-continent. The basin was affected by rifting and flood basalt eruption in the Permian-early Triassic (ca 250 Ma), which was floowed by rapid late Triassic (190 Ma) subsidence, as observed in borehole data from the axial part of the Ob rift (Saunders, 2005). Widely distributed subsidence of the north and central parts of the basin took place in the Jurassic with accumulation of 1,5- 3 km sediments. Two other subsidence episodes in the early Cretaceous and in the Late Cretaceous to Cenozoic led to deposition of 2-3 km of sediment in the north-eastern and axial parts. (Rudkevich, 1976). Most of the present-day West Siberian basin lacks surface topography, whereas the reliefs of the Moho and the top of the basement have amplitudes of ca. 20 km and 15 km, respectively (Cherepanova et al., 2012). Modeling suggests that the thermal lithosphere is 130km thick in the West Siberian basin, up-to 260 km in the Siberian craton further east, and 90 km in the axial part of the basin under the Ob rift (Artemieva and Mooney, 2001). Assuming local isostatic equilibrium and no effect of dynamic topography (which probably is a valid approximation for most of the region, except for the southern margin and the Urals), we examine the relative contributions of the crust and the lithospheric mantle to maintaining the surface topography. Lithosphere buoyancy is controlled by thicknesses and densities of the crust and the lithospheric mantle, and therefore by composition, metamorphic state, and temperature. Crustal thickness and density are constrained by our new regional crustal model, which is based on a quality-controlled compilation of all seismic models published in international and Russian

  8. Geochemistry, strontium isotope data, and potassium-argon ages of the andesite-rhyolite association in the Padang area, West Sumatra

    USGS Publications Warehouse

    Leo, G.W.; Hedge, C.E.; Marvin, R.F.

    1980-01-01

    Quaternary volcanoes in the Padang area on the west coast of Sumatra have produced two-pyroxene, calc-alkaline andesite and volumetrically subordinate rhyolitic and andesitic ash-flow tuffs. A sequence of andesite (pre-caldera), rhyolitic tuff and andesitic tuff, in decreasing order of age, is related to Maninjau caldera. Andesite compositions range from 55.0 to 61.2% SiO2 and from 1.13 to 2.05% K2O. Six K-Ar whole-rock age determinations on andesites show a range of 0.27 ?? 0.12 to 0.83 ?? 0.42 m.y.; a single determination on the rhyolitic ashflow tuff gave 0.28 ?? 0.12 m.y. Eight 57Sr/26Sr ratios on andesites and rhyolite tuff west of the Semangko fault zone are in the range 0.7056 - 0.7066. These ratios are higher than those elsewhere in the Sunda arc but are comparable to the Taupo volcanic zone of New Zealand and calc-alkaline volcanics of continental margins. An 87Sr/86Sr ratio of 0.7048 on G. Sirabungan east of the Semangko fault is similar to an earlier determination on nearby G. Marapi (0.7047), and agrees with 87Sr/86Sr ratios in the rest of the Sunda arc. The reason for this distribution of 87Sr/86Sr ratios is unknown. The high 87Sr/86Sr ratios are tentatively regarded to reflect a crustal source for the andesites, while moderately fractionated REE patterns with pronounced negative Eu anomalies suggest a residue enriched in plagioclase with hornblende and/or pyroxenes. Generation of associated andesite and rhyolite could have been caused by hydrous fractional melting of andesite or volcanogenic sediments under adiabatic decompression. ?? 1980.

  9. Analysis of Ignition Testing on K-West Basin Fuel

    SciTech Connect

    J. Abrefah; F.H. Huang; W.M. Gerry; W.J. Gray; S.C. Marschman; T.A. Thornton

    1999-08-10

    Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).

  10. Petroleum geology and resources of the West Siberian Basin, Russia

    USGS Publications Warehouse

    Ulmishek, Gregory F.

    2003-01-01

    The West Siberian basin is the largest petroleum basin in the world covering an area of about 2.2 million km2. The basin occupies a swampy plain between the Ural Mountains and the Yenisey River. On the north, the basin extends offshore into the southern Kara Sea. On the west, north, and east, the basin is surrounded by the Ural, Yenisey Ridge, and Turukhan-Igarka foldbelts that experienced major deformations during the Hercynian tectonic event and the Novaya Zemlya foldbelt that was deformed in early Cimmerian (Triassic) time. On the south, the folded Caledonian structures of the Central Kazakhstan and Altay-Sayan regions dip northward beneath the basin?s sedimentary cover. The basin is a relatively undeformed Mesozoic sag that overlies the Hercynian accreted terrane and the Early Triassic rift system. The basement is composed of foldbelts that were deformed in Late Carboniferous?Permian time during collision of the Siberian and Kazakhstan continents with the Russian craton. The basement also includes several microcontinental blocks with a relatively undeformed Paleozoic sedimentary sequence. The sedimentary succession of the basin is composed of Middle Triassic through Tertiary clastic rocks. The lower part of this succession is present only in the northern part of the basin; southward, progressively younger strata onlap the basement, so that in the southern areas the basement is overlain by Toarcian and younger rocks. The important stage in tectono-stratigraphic development of the basin was formation of a deep-water sea in Volgian?early Berriasian time. The sea covered more than one million km2 in the central basin area. Highly organic-rich siliceous shales of the Bazhenov Formation were deposited during this time in anoxic conditions on the sea bottom. Rocks of this formation have generated more than 80 percent of West Siberian oil reserves and probably a substantial part of its gas reserves. The deep-water basin was filled by prograding clastic clinoforms

  11. Oil and gas resources in the West Siberian Basin, Russia

    SciTech Connect

    1997-12-01

    The primary objective of this study is to assess the oil and gas potential of the West Siberian Basin of Russia. The study does not analyze the costs or technology necessary to achieve the estimates of the ultimate recoverable oil and gas. This study uses reservoir data to estimate recoverable oil and gas quantities which were aggregated to the field level. Field totals were summed to a basin total for discovered fields. An estimate of undiscovered oil and gas, from work of the US Geological Survey (USGS), was added to give a total basin resource volume. Recent production decline points out Russia`s need to continue development of its discovered recoverable oil and gas. Continued exploration is required to discover additional oil and gas that remains undiscovered in the basin.

  12. Tectonosedimentary history of the sedimentary basins in northern west Siberia

    SciTech Connect

    Kunin, N.Ya.; Segalovich, I.E. )

    1993-09-01

    Sedimentary basins of northern west Siberia belong to the Arctic tectonosedimentary province. This basin evolved dissimilarly compared to those in the Urengoy and more southern areas, which resulted in substantial differences in the geologic characteristics. Seismic surveys indicate that the basement surface in northern west Siberia occurs at great depths, in places exceeding 15 km. The depressions of the basement surfaces are filled with the thick Paleozoic and Mesozoic sequences. The paper discussed the results of seismostratigraphic analysis of more than 13,000 km of regional common-depth-point profiles. These profiles identified systems of east-west-trending and isometric structures in the region. Some of the structures are buried; others are mapped in the upper horizons of the sedimentary cover and decrease in magnitude with depth. Cretaceous marine sediments that were deposited under deep-water conditions and did not compensate for the tectonic subsidence are widely present in the region. Noncompensated sedimentation was the longest from the Late Jurassic to the Hauterivian-Barremian on the Gydan peninsula and in adjacent areas. The Jurassic section is dominate by ingressive marine sediments. Sediments that did not compensate for tectonic subsidence widely occurred in the Early Jurassic and resulted in deposition of petroleum source rocks. Triassic and Jurassic strata occur conformable in most of northern west Siberia. Significant deformation of the Triassic sediments are identified in the periphery of the Triassic marine basin. This indicates that surrounding structures were thrust against northern west Siberia at the Triassic and Jurassic time boundary. Isometric structures of high magnitude were formed during the Paleozoic structure stage and these structures continued to grow through the Triassic and Jurassic. These and other results of seismostratigraphic analysis suggest the high oil potential of the region.

  13. The stratigraphy of the Taoudeni basin, west Africa

    SciTech Connect

    Ratcliffe, K.T.; Moody, R.T.J. )

    1993-09-01

    The Taoudeni basin is one of the major structural units of the west African craton, with an areal extent in excess of 2,000,000 km[sup 2]. Sediment thicknesses can reach over 3000 m, but have an average thickness of 1250 m. The majority of the basin-fill sediments are Precambrian to Carboniferous, with Mesozoic rocks present in the eastern margin adjacent to the Adrar des Iforas. Due to the paucity of exploration in the Taoudoni basin, there are no detailed works on source potential, maturity, or reservoir quality. However, within the sediment pile, there are excellent potential reservoirs, in the form of poorly cemented sandstones, and apparently organic-rich sediments, which may have source potential. Three major Paleozoic tectono-sedimentary units are recognized within the basin, all of which are found in the Adrar de Mauritania, which is taken as the [open quotes]type section[close quotes] for the Taoudeni basin. Unit 1 (Upper Riphean) is composed of alternating sandstones, limestones, and mudstones, which show rapid lateral thickness variations. Units 2 and 3 are far more uniform in thickness and distribution. Unit 2 (late Precambrian-Lower Ordovician) is composed of shales and sandstones with minor limestones. The base of this unit is composed of the Triad, or the Eocambrian glacial deposits that can be correlated across west Africa. Unit 3 (Upper Oedovician-Devonian) is composed of a variety of lithofacies varying from a basal glacial unit through basinal graptolitic shales into shallow marine/continental deposits. Each of these units will be discussed in detail and the petroleum potential of the constituent lithofacies considered.

  14. Development of the central Carpathian Paleogene basin, west Carpathians, Slovakia

    SciTech Connect

    Nemcok, M. ); Neese, D.G. )

    1993-09-01

    The central Carpathian Paleogene basin, corresponding to one of the regions of Slovakia having a hydrocarbon potential, forms part of the Carpathian system. In the west Carpathians, synorogenic sediments, derived from the rising orogene, comprise an up to 3.5-km-thick sequence of Middle Eocene to Early Oligocene clastics. Flysch-type sediments dominate and are locally cut by canyon-focused submarine fans. The morphology of the floor of the central Carpathian Paleogene basin developed during the Albian and Maastrichtian in response to pre-Senonian nappe emplacement in the inner Carpathians and Late Cretaceous thrusting in the Pieniny Klippen belt. By the end of the Cretaceous, the inner Carpathians formed an emergent orogenic belt, providing a southern source for the sedimentary fill of the central Carpathian Paleogene basin. To the north, this basin was bounded by the Pieniny Klippen belt, forming at that time an irregular chain of islands, upheld by compressionally deformed pre-Tertiary rocks. Uplift of this northern barrier may explain the development of the central Carpathian Paleogene current system. Senonian shortening was subparallel to the present strike of the Pieniny Klippen belt. During the Paleogene and Miocene, shortening changed to a northern or northeastern direction. Differential shortening gave rise to the development of major strike-slip zones and numerous strike-slip faults that accommodated differential motion of thrust slices along the orogenic front. The northern, frontal portions of the basin were shortened by thrusting, whereas its basinal and proximal parts were affected by contemporaneous transtensional strike-slip faulting. Paleogene uplift of the frontal part of the evolving mountain belt is recorded by high-slump activity in areas of flysch deposition. A minimum of 2 km of sediments are missing from the basin due to Miocene erosion. At present, only structural remnants of the ancestral Paleogene basin are preserved.

  15. Gravity-driven structures and rift basin evolution: Rio Muni Basin, offshore equatorial West Africa

    SciTech Connect

    Turner, J.P.

    1995-08-01

    Offshore Equatorial Guinea, west Africa, gravity-driven nappes, more than 1 km thick and 15 km from head to toe, provide key evidence in reconstructing the late synrift: evolution of this part of the South Atlantic margin basin system. Furthermore, Aptian-Cenomanian carbonate and clastic rocks in the nappes` allochthonous hanging walls are attracting interest as a new exploration play in west Africa. The nappes exhibit a range of geometries that suggest they share many of the same deformation processes as thin-skin thrust and linked extensional fault systems. Not only are these structures significant in their own right, representing a rare example of gravity tectonics in the virtual absence of major halokinesis, but their presence may record an other-wise undetectable process active during the transition from a rift basin to a passive continental margin. A review of Equatorial Guinea in its pre-Atlantic configuration, alongside neighboring basins in Brazil (the Sergipe-Alagoas basin) and Gabon, suggests that gravity gliding was sustained by a relatively steep, westward paleoslope promoted by east-ward offset of the locus of thermal uplift from the rift basin (i.e., a simple shear model of basin formation). In contrast to gravity-driven structures in most postrift settings, the Equatorial Guinea nappes developed at the close of the Aptian-Albian synrift episode in response to a growing bathymetric deep caused by rapid subsidence outpacing restricted sedimentation.

  16. Fishing farmers or farming fishers? Fishing typology of inland small-scale fishing households and fisheries management in singkarak lake, west sumatra, indonesia.

    PubMed

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  17. Fishing Farmers or Farming Fishers? Fishing Typology of Inland Small-Scale Fishing Households and Fisheries Management in Singkarak Lake, West Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P.

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  18. Geophysical basin structure of the Cotonou (Dahomey/Benin) basin, West African Gulf of Guinea

    SciTech Connect

    Babalola, O.O. )

    1990-05-01

    The frontier Cotonou basin (or Dahomey/Benin embayment), situated west of the prolific Niger Delta basin, appears from seismic, gravity, and aeromagnetic interpretation, as a series of grabens and troughs confined on the west and east by the Romanche and the Chain fracture zones, respectively. The Keta trough of the western basin rim was formed by a 2700-m southeasterly downthrow of the Adina fault. This trough is separated by a north-northeasterly fault from the Lome-Anecho gravity high. Eastward, the arcuate Allada-Adjohon trough is abutted on its southern flank by the northwest-trending Nokue-Afowo trough and separated from the northwesterly Ikorodu trough by the 50-km-wide aeromagnetically inferred ro-Otta ridge. The Ikorodu trough is adjoined on the northwest by the Aiyetoro trough and on the southeast by the Yemoja offshore graben trending east northeast as the Seme oil-field structural trend. North of the regional northeasterly axial, gravity positive, structural divide (the continental precursor of the Charcot fracture zone) a series of half-grabens (notably the Aplahoue, Bohicon, and Keiou troughs), normal faulted eastward and downthrown in the west, dominate the landward western rim of the Cotonou basin. Graben-bounding faults control the upper valleys of the basin drainage, converge toward the regional intrabasin structural trend and continue into the Fenyi-koe fault and the Charcot fracture zone. These faults resulted from brittle dextral shear of continental crust oblique to local, preexisting north-northeast structural trends. In the eastern basin rim, preexisting north-northwest structural trends influenced the shearing stress regime to generate small, shallow, structurally bounded, east-northeast- and north-northwest trending grabens.

  19. SLUDGE RETRIEVAL FROM HANFORD K WEST BASIN SETTLER TANKS

    SciTech Connect

    ERPENBECK EG; LESHIKAR GA

    2011-01-13

    In 2010, an innovative, remotely operated retrieval system was deployed to successfully retrieve over 99.7% of the radioactive sludge from ten submerged tanks in Hanford's K-West Basin. As part of K-West Basin cleanup, the accumulated sludge needed to be removed from the 0.5 meter diameter by 5 meter long settler tanks and transferred approximately 45 meters to an underwater container for sampling and waste treatment. The abrasive, dense, non-homogeneous sludge was the product of the washing process of corroded nuclear fuel. It consists of small (less than 600 micron) particles of uranium metal, uranium oxide, and various other constituents, potentially agglomerated or cohesive after 10 years of storage. The Settler Tank Retrieval System (STRS) was developed to access, mobilize and pump out the sludge from each tank using a standardized process of retrieval head insertion, periodic high pressure water spray, retraction, and continuous pumping of the sludge. Blind operations were guided by monitoring flow rate, radiation levels in the sludge stream, and solids concentration. The technology developed and employed in the STRS can potentially be adapted to similar problematic waste tanks or pipes that must be remotely accessed to achieve mobilization and retrieval of the sludge within.

  20. Brachiopods, fusulines and palynomorphs of the Mengkarang Formation (Early Permian, Sumatra) and their palaeobiogeographical significance

    NASA Astrophysics Data System (ADS)

    Crippa, G.; Angiolini, L.; Van Waveren, I.; Crow, M. J.; Hasibuan, F.; Stephenson, M. H.; Ueno, K.

    2014-01-01

    Brachiopods, fusulines and palynomorphs from the Lower Permian Mengkarang Formation (Sumatra, Indonesia) have been studied in order to establish the palaeogeographical position and the palaeolatitude of the West Sumatra Block. The position of the West Sumatra Block within the Palaeo-Tethys and Panthalassa oceans and its relationships to their marginal landmasses, in particular the Gondwana supercontinent and the Cathaysian palaeogeographical area, currently is uncertain.

  1. Analysis of water from K west basin canisters (second campaign)

    SciTech Connect

    Trimble, D.J., Fluor Daniel Hanford

    1997-03-06

    Gas and liquid samples have been obtained from a selection of the approximately 3,820 spent fuel storage canisters in the K West Basin. The samples were taken to characterize the contents of the gas and water in the canisters. The data will provide source term information for two subprojects of the Spent Nuclear Fuel Project (SNFP) (Fulton 1994): the K Basins Integrated Water Treatment System subproject (Ball 1996) and the K Basins Fuel Retrieval System subproject (Waymire 1996). The barrels of ten canisters were sampled in 1995, and 50 canisters were sampled in a second campaign in 1996. The analysis results for the gas and liquid samples of the first campaign have been reported (Trimble 1995a; Trimble 1995b; Trimble 1996a; Trimble 1996b). An analysis of cesium-137 (137CS ) data from the second campaign samples was reported (Trimble and Welsh 1997), and the gas sample results are documented in Trimble 1997. This report documents the results of all analytes of liquid samples from the second campaign.

  2. Potential Multi Canister Overpack (MCO) Cask Drop in the K West Basin South Loadout Pit

    SciTech Connect

    POWERS, T.B.

    1999-12-09

    This calculation note documents the probabilistic calculation of a potential drop of a multi-canister overpack (MCO) cask or MCO cask and immersion pail at the K West Basin south loadout pit. The calculations are in support of the cask loading system (CLS) subproject alignment of CLS equipment in the K West Basin south loadout pit.

  3. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... subject to enforcement when it is activated. (2) Under general security zone regulations of 33 CFR 165.33... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; West Basin, Port... Guard District § 165.777 Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida....

  4. Reserve Growth in Oil Fields of West Siberian Basin, Russia

    USGS Publications Warehouse

    Verma, Mahendra K.; Ulmishek, Gregory F.

    2006-01-01

    Although reserve (or field) growth has proven to be an important factor contributing to new reserves in mature petroleum basins, it is still a poorly understood phenomenon. Limited studies show that the magnitude of reserve growth is controlled by several major factors, including (1) the reserve booking and reporting requirements in each country, (2) improvements in reservoir characterization and simulation, (3) application of enhanced oil recovery techniques, and (4) the discovery of new and extensions of known pools in discovered fields. Various combinations of these factors can affect the estimates of proven reserves in particular fields and may dictate repeated estimations of reserves during a field's life. This study explores the reserve growth in the 42 largest oil fields in the West Siberian Basin, which contain about 55 percent of the basin's total oil reserves. The West Siberian Basin occupies a vast swampy plain between the Ural Mountains and the Yenisey River, and extends offshore into the Kara Sea; it is the richest petroleum province in Russia. About 600 oil and gas fields with original reserves of 144 billion barrels of oil (BBO) and more than 1,200 trillion cubic feet of gas (TCFG) have been discovered. The principal oil reserves and most of the oil fields are in the southern half of the basin, whereas the northern half contains mainly gas reserves. Sedimentary strata in the basin consist of Upper Triassic through Tertiary clastic rocks. Most oil is produced from Neocomian (Lower Cretaceous) marine to deltaic sandstone reservoirs, although substantial oil reserves are also in the marine Upper Jurassic and continental to paralic Lower to Middle Jurassic sequences. The majority of oil fields are in structural traps, which are gentle, platform-type anticlines with closures ranging from several tens of meters to as much as 150 meters (490 feet). Fields producing from stratigraphic traps are generally smaller except for the giant Talin field which

  5. Seismic Stratigraphy of the Ross Island Flexural Basin, West Antarctica

    NASA Astrophysics Data System (ADS)

    Wenman, C. P.; Harry, D. L.; Jha, S.

    2014-12-01

    Marine seismic reflection data collected over the past 30+ years in the Ross Sea region of southwest Antarctica has been tied to the ANDRILL and CIROS boreholes to develop a seismic stratigraphic model that constrains the spatial and temporal evolution of the flexural basin surrounding Ross Island. Ross Island was formed from 4.6 Ma to present by extrusive volcanism in the Ross Sea at the southern end of the Terror Rift. Preliminary mapping has identified a hinge zone trending northeastward from Mt. Bird, separating the well-developed flexural moat on the west side of the island from sub-horizontal strata on the northeast and east sides. The flexural moat on the west and north-northwest sides of the island is approximately 40-45 km wide with sediment fill thickness of roughly 1100 m. Seismic lines to the east and northeast of the island do not indicate the presence of a flexural moat. Instead, the thickness of strata on the east side of the island that are time-equivalent to the infill of the flexural moat on the west side remains constant from the Coulman High westward to within ~28 km of Ross Island (the landward extent of the seismic data coverage). The concordant post-Miocene strata on the east and northeast sides of Ross Island imply either that the flexural basin does not extend more than ~28 km eastward from the Ross Island shoreline, or that the flexural basin is not present on that side of the island. The first scenario requires that the elastic strength of the lithosphere differ on either side of the hinge. The second scenario can be explained by a mechanical rupture in the lithosphere beneath Ross Island, with Ross Island acting as an end-load on a mechanical half-plate that forms the lithosphere beneath Ross Island and westward. In this model, the lithosphere east of Ross Island and the hinge forms a second half-plate, bearing little or none of the Ross Island volcanic load.

  6. Indonesia, Sumatra, Singapore

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This view shows the area around Northeastern Sumatra, Indonesia (1.0N, 104.0E). The city of Singapore and the Singapore Strait is in the center at the southern tip of the Malay Peninsula. The Singapore Strait is the eastern extension of the Strait of Malacca and separates the Malay Peninsula from Sumatra. Large sediment plumes from the rivers attest to the local soil erosion and industrial dumping ofd wastes.

  7. Tsunami Damage in Northwest Sumatra

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The island of Sumatra suffered from both the rumblings of the submarine earthquake and the tsunamis that were generated on December 26, 2004. Within minutes of the quake, the sea surged ashore, bringing destruction to the coasts of the northern Sumatra. This pair of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite shows the Aceh province of northern Sumatra, Indonesia, on December 17, 2004, before the quake (bottom), and on December 29, 2004 (top), three days after the catastrophe. Although MODIS was not specifically designed to make the very detailed observations that are usually necessary for mapping coastline changes, the sensor nevertheless observed obvious differences in the Sumatran coastline. On December 17, the green vegetation along the west coast appears to reach all the way to the sea, with only an occasional thin stretch of white that is likely sand. After the earthquake and tsunamis, the entire western coast is lined with a noticeable purplish-brown border. The brownish border could be deposited sand, or perhaps exposed soil that was stripped bare of vegetation when the large waves rushed ashore and then raced away. Another possibility is that parts of the coastline may have sunk as the sea floor near the plate boundary rose. On a moderate-resolution image such as this, the affected area may seem small, but each pixel in the full resolution image is 250 by 250 meters. In places the brown strip reaches inland roughly 13 pixels, equal to a distance of 3.25 kilometers, or about 2 miles. On the northern tip of the island (shown in the large image), the incursion is even larger. NASA images created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team and the Goddard Earth Sciences DAAC.

  8. Vertical deformation at western part of Sumatra

    SciTech Connect

    Febriyani, Caroline Prijatna, Kosasih Meilano, Irwan

    2015-04-24

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate.

  9. Vertical deformation at western part of Sumatra

    NASA Astrophysics Data System (ADS)

    Febriyani, Caroline; Prijatna, Kosasih; Meilano, Irwan

    2015-04-01

    This research tries to make advancement in GPS signal processing to estimate the interseismic vertical deformation field at western part of Sumatra Island. The data derived by Continuous Global Positioning System (CGPS) from Badan Informasi Geospasial (BIG) between 2010 and 2012. GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) software are used to process the GPS signal to estimate the vertical velocities of the CGPS station. In order to minimize noise due to atmospheric delay, Vienna Mapping Function 1 (VMF1) is used as atmospheric parameter model and include daily IONEX file provided by the Center for Orbit Determination in Europe (CODE) as well. It improves GAMIT daily position accuracy up to 0.8 mm. In a second step of processing, the GLOBK is used in order to estimate site positions and velocities in the ITRF08 reference frame. The result shows that the uncertainties of estimated displacement velocity at all CGPS stations are smaller than 1.5 mm/yr. The subsided deformation patterns are seen at the northern and southern part of west Sumatra. The vertical deformation at northern part of west Sumatra indicates postseismic phase associated with the 2010 and 2012 Northern Sumatra earthquakes and also the long-term postseismic associated with the 2004 and 2005 Northern Sumatra earthquakes. The uplifted deformation patterns are seen from Bukit Tinggi to Seblat which indicate a long-term interseismic phase after the 2007 Bengkulu earthquake and 2010 Mentawai earthquake. GANO station shows a subsidence at rate 12.25 mm/yr, indicating the overriding Indo-Australia Plate which is dragged down by the subducting Southeast Asian Plate.

  10. Overpressure history of fractures, West Maracaibo Basin, Venezuela

    SciTech Connect

    Vrolijk, P.J.; Pottorf, R.J.; Maze, W.B.

    1996-08-01

    Prediction of density of natural fractures in reservoir rocks requires evaluation of many factors, including the effective stress and thus fluid pressure conditions through time. In this study we use analyses of fluid inclusions in calcite-filled fractures with burial and thermal history models to assess the fluid pressure history and the causes of overpressure in the West Maracaibo Basin. We analyzed abundant oil-filled and rare aqueous fluid inclusions in calcite-filled fractures in the La Luna Formation source rock and in the underlying Cogollo Gp. carbonate reservoir. Our analyses of fluid inclusion homogenization temperatures and fluorescence properties lead us to the interpretation of near-lithostatic paleo-fluid pressures in La Luna Formation and near-lithostatic to hydrostatic fluid pressures in the Cogollo, Gp. fractures. Maturation and expulsion of oil from the La Luna Formation source rock is required to generate the large inferred excess pressures as compaction disequilibrium and thermal expansion of pore fluids from rapid Miocene burial are insufficient to achieve near-lithostatic conditions. This hypothesis is supported by the observation of decreasing paleo- and modern fluid pressures with depth beneath the La Luna Formation. Thus based on the wide occurrence of oil-filled inclusions in calcite-filled fractures and the high fluid pressures associated with trapped oils, we infer extensive rock fracture under overpressured conditions near maximum Miocene burial, during inferred late source rock yield, and during Miocene growth of structural traps.

  11. Lower and middle Guadalupian shelf carbonates, eastern margin of Central Basin platform, Permian basin, west Texas

    SciTech Connect

    Ward, R.F.; Chalcraft, R.G.

    1988-01-01

    Lower and middle Guadalupian shelf carbonates serve as the reservoir for a nearly continuous band of oil fields extending 100 mi along the eastern margin of the Central Basin platform of west Texas. Approximately 5 billion bbl of oil have been produced from stratigraphic-structural traps within the Upper Permian (Gaudalupian Series) dolomites of the San Andrea and Grayburg Formations in Upton, Crane, Ector, Pecos, and Andrews Counties, Texas. The San Andrea and Grayburg Formations are cyclical shallowing-upward carbonate sequences of open shelf through sabkha facies whose depositional strike parallels the eastern margin of the Central Basin platform. Porosity and permeability of reservoir rock are governed by diagenetic processes such as dolomitization, anhydrite porosity occlusion, leaching, silicification, and authigenic clay formation. Self sediments are primarily burrowed wackestones and packstones that locally contain pelletal, skeletal, and ooid grainstones. Typical subtidal shelf sediments are capped by algal-laminated dolomite, nodular anhydritic dolomite, and bedded anhydrite. The fauna is normally sparse and dominated by foraminifera and algae. Less common faunal components include pelecypods, crinoids, sponges, Bryozoa, brachiopods, gastropods, and coral that are associated with the development of small scattered patch reefs. Lowering the sea level during the early Guadalpian initiated basinward progradation of San Andres carbonate facies with hydrocarbon reservoirs best developed in shallow self fusulinid wackestones to packstone and oolitic grainstone. Reservoir dolomites of the Grayburg formation are present east of San Andres fields with optimal reservoir properties occurring near the San Andreas outer shelf margin.

  12. Seismicity of the Earth 1900-2012 Sumatra and vicinity

    USGS Publications Warehouse

    Hayes, Gavin P.; Bernardino, Melissa; Dannemann, Fransiska; Smoczyk, Gregory; Briggs, Richard W.; Benz, Harley M.; Furlong, Kevin P.; Villaseñor, Antonio

    2013-01-01

    The plate boundary southwest of Sumatra is part of a long tectonic collision zone that extends over 8,000 km from Papua, New Guinea, in the east to the Himalayan front in the west. The Sumatra-Andaman part of the collision zone forms a subduction zone plate boundary, which accommodates convergence between the Indo-Australia and Sunda plates. This convergence is responsible for the intense seismicity in Sumatra. The Sumatra Fault, a major transform structure that bisects Sumatra, accommodates the northwest-increasing lateral component of relative plate motion. Most strain accumulation and release between the two plates occurs along the Sunda megathrust. The increasingly oblique convergence moving northwest is accommodated by crustal seismicity along several transform and normal faults, including the Sumatra Fault. Plate-boundary related deformation is also not restricted to the subduction zone and overriding plate: the Indo-Australian plate actually comprises two somewhat independent plates (India and Australia) that are joined along a broad, actively deforming region that produces seismicity up to several hundred kilometers west of the trench. This deformation is exemplified by the recent April 2012 earthquake sequence, which includes the April 11 M 8.6 and M 8.2 strike-slip events and their subsequent aftershocks. Since 2004, much of the Sunda megathrust between the northern Andaman Islands and Enggano Island, a distance of more than 2,000 km, has ruptured in a series of large subduction zone earthquakes—most rupturing the plate boundary south of Banda Aceh. These events include the great M 9.1 earthquake of December 26, 2004; the M 8.6 Nias Island earthquake of March 28, 2005; and two earthquakes on September 12, 2007, of M 8.5 and M 7.9. On October 25, 2010, a M 7.8 on the shallow portion of the megathrust to the west of the Mentawai Islands caused a substantial tsunami on the west coast of those islands.

  13. Shallow subsurface morpho-tectonics at the Northern offshore Sumatra subduction system using high resolution reflection and refraction seismics

    NASA Astrophysics Data System (ADS)

    Ghosal, D.; Dibakar Ghosal*, S. C. Singh, A. P. S. Chauhan, H. Carton, N. D. Hananto

    2011-12-01

    The oblique subduction of Indo-Australian plate below the Eurosian plate regulates the subsurface geology of the Sumatra subduction system from south to north. Although many geological, geophysical and geodetic studies have been carried over since several decades nevertheless a high resolution subsurface image describing the detailed structural features over the Northern Sumatra is still missing. To scrutinize the northern part of this subduction system we had carried out a multi channel seismic (MCS) and OBS survey using a 12 km long streamer and 56 ocean bottom seismometers in 2006 and procured a high resolution deep seismic reflection and refraction data over a 500 km long profile mapping the whole subduction setting from the subduction front, forearc high and basin, Sumatra platform, Sumatra fault and volcanic arc. The acoustic basement along the profile is very complex because of its extremities lies in a range of 300 m to 5000 m. In order to overcome the imaging-intricacies caused due to the abrupt changes of water depth, we have downward continued the 12 km streamer data to the seafloor, which provides refraction arrivals from near zero offsets to 12 km, and subsequently a high-resolution travel time tomography keeping node spacing of 50m x 50m has accomplished to procure a detail velocity structure along the profile. We have conducted our analysis in two important areas at northern offshore Sumatra: (1) subduction front and accretionary settings and (2) forearc high and West Anadman Fault. Our main goal lies to observe the nature of shallow subsurface velocity distribution over these regions. Tomographic result of the subduction front demonstrates the changes in velocity gradient along up-dip. The 1D velocity gradients become shallower toward the subduction trench inferring the fact of lithification of accreted sediments around the accretionary wedge. At the forearc high adjacent to the Aceh basin a pile of 1 km thick low velocity sediments is underlain by

  14. Smoke over Sumatra, Indonesia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    At least once a year for a period lasting from a week to several months, northern Sumatra is obscured by smoke and haze produced by agricultural burning and forest fires. These data products from the Multi-angle Imaging SpectroRadiometer document the presence of airborne particulates on March 13, 2002, during Terra orbit 11880. On the left is an image acquired by MISR's 70-degree backward-viewing camera. On the right is a map of aerosol optical depth, a measure of the abundance of atmospheric particulates. This product utilized a test version of the MISR retrieval that incorporates an experimental set of aerosol mixtures. The haze has completely obscured northeastern Sumatra and part of the Strait of Malacca, which separates Sumatra and the Malaysian Peninsula. A northward gradient is apparent as the haze dissipates in the direction of the Malaysian landmass. Each panel covers an area of about 760 kilometers x 400 kilometers.

    Haze conditions had posed a health concern during late February (when schools in some parts of North Sumatra were closed), and worsened considerably in the first two weeks of March. By mid-March, local meteorology officials asked residents of North Sumatra's provincial capital, Medan, to minimize their outdoor activities and wear protective masks. Poor visibility at Medan airport forced a passenger plane to divert to Malaysia on March 14, and visibility reportedly ranged between 100 and 600 meters in some coastal towns southeast of Medan.

    The number and severity of this year's fires was exacerbated by dry weather conditions associated with the onset of a weak to moderate El Nino. The governments of Indonesia, Malaysia, and Brunei have agreed to ban open burning in plantation and forest areas. The enforcement of such fire bans, however, has proven to be an extremely challenging task.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra

  15. Hydrogeology of the West Branch Delaware River basin, Delaware County, New York

    USGS Publications Warehouse

    Reynolds, Richard J.

    2013-01-01

    In 2009, the U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, began a study of the hydrogeology of the West Branch Delaware River (Cannonsville Reservoir) watershed. There has been recent interest by energy companies in developing the natural gas reserves that are trapped within the Marcellus Shale, which is part of the Hamilton Group of Devonian age that underlies all the West Branch Delaware River Basin. Knowing the extent and thickness of stratified-drift (sand and gravel) aquifers within this basin can help State and Federal regulatory agencies evaluate any effects on these aquifers that gas-well drilling might produce. This report describes the hydrogeology of the 455-square-mile basin in the southwestern Catskill Mountain region of southeastern New York and includes a detailed surficial geologic map of the basin. Analysis of surficial geologic data indicates that the most widespread surficial geologic unit within the basin is till, which is present as deposits of ablation till in major stream valleys and as thick deposits of lodgment till that fill upland basins. Till and colluvium (remobilized till) cover about 89 percent of the West Branch Delaware River Basin, whereas stratified drift (outwash and ice-contact deposits) and alluvium account for 8.9 percent. The Cannonsville Reservoir occupies about 1.9 percent of the basin area. Large areas of outwash and ice-contact deposits occupy the West Branch Delaware River valley along its entire length. These deposits form a stratified-drift aquifer that ranges in thickness from 40 to 50 feet (ft) in the upper West Branch Delaware River valley, from 70 to 140 ft in the middle West Branch Delaware River valley, and from 60 to 70 ft in the lower West Branch Delaware River valley. The gas-bearing Marcellus Shale underlies the entire West Branch Delaware River Basin and ranges in thickness from 600 to 650 ft along the northern divide of the basin to 750 ft thick

  16. Assessment of undiscovered oil and gas resources of the West Siberian Basin Province, Russia, 2010

    USGS Publications Warehouse

    Klett, T.R.

    2011-01-01

    The U.S. Geological Survey, using a geology-based assessment methodology, estimated mean volumes of technically recoverable, conventional, undiscovered petroleum resources at 8 billion barrels of crude oil, 670 trillion cubic feet of natural gas, and 21 billion barrels of natural gas liquids for the West Siberian Basin Province in Russia as part of a program to estimate petroleum resources for priority basins throughout the world.

  17. Tectonic evolution of the West Florida Basin, Eastern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Gregg, Andrea Christine

    Basement geometry of the Eastern Gulf of Mexico developed following the breakup of Pangea and the opening of the Gulf of Mexico in Late Triassic time. Nine 2-D pre-stack depth migrated seismic profiles and a structural restoration provide insight into the evolution and development of the southern West Florida Basin, located west of the Florida Escarpment in the Eastern Gulf of Mexico. Seismic reflection profiles reveal basement structures probably developed following a combination of Late Triassic extension and extension and subsequent oceanic crust emplacement in Middle Jurassic time. During Late Triassic rifting, the West Florida Basin developed as a rift graben; however, the graben was later dissected during the Middle Jurassic drift episode. Absence of faulting, syn-rift deposition and sagging in the Lower Cretaceous seismic section indicates that extension and rotation of the Yucatan block must have stopped prior to Cretaceous time. After extension terminated and the Gulf of Mexico reached its modern day configuration, subsidence from lithospheric cooling and sediment loading dominated throughout Cretaceous time. A structural restoration confirms that following Late Triassic rifting, basement topography remains relatively elevated to the south in the West Florida Basin. Subsequent extension and subsidence further dissected the basement allowing for the deposition of Middle and Late Jurassic syn-rift and Cretaceous post-rift sediments. Because of the lack of well control in the West Florida Basin, seismic packages are correlated northward to the northern margin of the West Florida Basin and slope, the Tampa Embayment, and the Apalachicola Basin and southward to the Straits of Florida and Yucatan. Seismic interpretations reveal two syn-rift packages, Triassic-Jurassic (TJ) and Jurassic-Cretaceous (JK), and one post rift package, Early Cretaceous (EK), were deposited prior to the Mid-Cretaceous Sequence Boundary, a basin-wide unconformity that marks the

  18. K West Basin Integrated Water Treatment System (IWTS) E-F Annular Filter Vessel Accident Calculations

    SciTech Connect

    PIEPHO, M.G.

    2000-01-10

    Four bounding accidents postulated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing a hydrogen explosion, and a fire breaching filter vessel and enclosure. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.

  19. K West Basin Integrated Water Treatment System (IWTS) E-F Annular Filter Vessel Accident Calculations

    SciTech Connect

    RITTMANN, P.D.

    1999-10-07

    Three bounding accidents postdated for the K West Basin integrated water treatment system are evaluated against applicable risk evaluation guidelines. The accidents are a spray leak during fuel retrieval, spray leak during backflushing, and a hydrogen explosion. Event trees and accident probabilities are estimated. In all cases, the unmitigated dose consequences are below the risk evaluation guidelines.

  20. EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST/WEST TRUCK BAY AREA OF TRANSFER BASIN CORRIDOR OF FUEL STORAGE BUILDING (CPP-603). PHOTO TAKEN LOOKING NORTHWEST. INL PHOTO NUMBER HD-54-19-1. Mike Crane, Photographer, 8/2005 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  1. Glacial geology of the West Tensleep Drainage Basin, Bighorn Mountains, Wyoming

    SciTech Connect

    Burggraf, G.B.

    1980-08-01

    The glacial deposits of the West Tensleep Basin in the Bighorn Mountains of Wyoming are mapped and a relative chromology established. The deposits are correlated with the regional model as defined in the Wind River Mountains. A statistical analysis is performed on the density and weathering characteristics of the surficial boulders to determine their validity as indicators of relative age. (ACR)

  2. LIFE HISTORY MONITORING OF SALMONIDS IN THE WEST FORK SMITH RIVER, UMPQUA BASIN, OREGON

    EPA Science Inventory

    As a life-cycle monitoring basin for the Oregon Salmon Plan, the Oregon Department of Fish and Wildlife has estimated adult returns, distribution and smolt outmigration of coho, chinook and winter steelhead in the West Fork Smith River since 1998. In 2001/2002, the Environmenta...

  3. Tracing and age-dating injected groundwater of the west basin barrier project, Los Angeles, CA

    SciTech Connect

    Davisson, M L; Eaton, Gp; Hudson, G B; Koester, C

    1999-03-26

    This preliminary report summarizes results from isotopic data recently generated on water collected for the West Basin Municipal Water District (WBMWD). Samples comprised monitoring and production wells up to 3.5 miles form the injection barrier, in addition to barrier product and blend water.

  4. 40Ar/39Ar dates from the West Siberian Basin: Siberian flood basalt province doubled.

    PubMed

    Reichow, Marc K; Saunders, Andrew D; White, Rosalind V; Pringle, Malcolm S; Al'Mukhamedov, Alexander I; Medvedev, Alexander I; Kirda, Nikolay P

    2002-06-01

    Widespread basaltic volcanism occurred in the region of the West Siberian Basin in central Russia during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the basin reveal that the basalts were erupted 249.4 +/- 0.5 million years ago. This is synchronous with the bulk of the Siberian Traps, erupted further east on the Siberian Platform. The age and geochemical data confirm that the West Siberian Basin basalts are part of the Siberian Traps and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction. PMID:12052954

  5. Diverse super-giant petroleum deposits in the West Siberian oil-gas basin

    SciTech Connect

    Clarke, J.W.; Peterson, J.A. )

    1990-05-01

    The West Siberian sedimentary basin is a relatively uncomplicated basin where deposition has continued with little significant interruption during the almost 200 m.y. since the beginning of the Pliensbachian Age in the Early Jurassic. The petroleum deposits, however, are diverse, as exemplified by the Salym Samotlor, and Urengoy fields. During the Volgian Age, in the latest Jurassic, bituminous siliceous clays were deposited during a tectonic calm in an anoxic basin. These clays, now the cherty shale of the Bazhenov Formation were enriched in sapropelic organic matter and became source rock reservoir rock, and seal for the oil of Salym field. The oil occurs along fractures generated by the hydraulic effect of the generating oil. No significant water or gas accompanies the oil. Following the tectonic calm progradational deltaic deposits began to fill the sedimentary basin during the Early Cretaceous. Deltaic sands deposited on a mid-basin high were winnowed by currents that carried the finer material farther west. These sands became reservoirs whose source beds were either the distal pelitic facies to the west or the underlying bituminous Bazhenov Formation. The oil pools of Samotlor field which accounts for about 5% of the world production, are in these progradational sandstones. Deposition of sandy facies continued with little interruption through the Cenomanian after which clay was deposited during the Turonian in an anoxic environment similar to that of the Bazhenov. Urengoy field, probably the largest gas deposit in the world, occurs in the sandstones beneath the Turonian clays. The gas is almost pure methane and was sourced probably by both the humic organic matter in the rocks beneath and adjacent to the pool and by organic matter in the overlying Turonian bituminous clays. The source beds of the West Siberian basin are presently at those depths favorable for petroleum generation.

  6. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, X.; Qi, X.; Zheng, M.

    2015-12-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  7. Earthquake in a Maze: Compressional Rupture Branching During the 2012 Mw 8.6 Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Meng, L.; Ampuero, J.-P.; Stock, J.; Duputel, Z.; Luo, Y.; Tsai, V. C.

    2012-08-01

    Seismological observations of the 2012 moment magnitude 8.6 Sumatra earthquake reveal unprecedented complexity of dynamic rupture. The surprisingly large magnitude results from the combination of deep extent, high stress drop, and rupture of multiple faults. Back-projection source imaging indicates that the rupture occurred on distinct planes in an orthogonal conjugate fault system, with relatively slow rupture speed. The east-southeast-west-northwest ruptures add a new dimension to the seismotectonics of the Wharton Basin, which was previously thought to be controlled by north-south strike-slip faulting. The rupture turned twice into the compressive quadrant, against the preferred branching direction predicted by dynamic Coulomb stress calculations. Orthogonal faulting and compressional branching indicate that rupture was controlled by a pressure-insensitive strength of the deep oceanic lithosphere.

  8. Basin Characteristics for Selected Streamflow-Gaging Stations In and Near West Virginia

    USGS Publications Warehouse

    Paybins, Katherine S.

    2008-01-01

    Basin characteristics have long been used to develop equations describing streamflow. In the past, flow equations used in West Virginia were based on a few hand-calculated basin characteristics. More recently, the use of a Geographic Information System (GIS) to generate basin characteristics from existing datasets has refined the process for developing equations to describe flow values in the Mountain State. These basin characteristics are described in this document for streamflow-gaging stations in and near West Virginia. The GIS program developed in ArcGIS Workstation by Environmental Systems Research Institute (ESRI?) used data that included National Elevation Dataset (NED) at 1:24,000 scale, climate data from the National Oceanic and Atmospheric Agency (NOAA), streamlines from the National Hydrologic Dataset (NHD), and LandSat-based land-cover data (NLCD) for the period 1999-2003. Full automation of data generation was not achieved due to some inaccuracies in the elevation dataset, as well as inaccuracies in the streamflow-gage locations retrieved from the National Water Information System (NWIS). A Pearson?s correlation examination of the data indicates that several of the basin characteristics are correlated with drainage area. However, the GIS-generated data provide a consistent and documented set of basin characteristics for resource managers and researchers to use.

  9. Mathematical model of the West Bolsa Ground-water Basin, San Benito County, California

    USGS Publications Warehouse

    Faye, Robert E.

    1976-01-01

    Simulation of the West Bolsa ground-water basin hydrology in California had provided values of basin recharge and discharge and nodally distributed values of transmissivity and storage coefficient. Average net recharge from April 1945 to March 1969 was 6.2 cubic feet per second and occurred as subsurace recharge and infiltration of rain and minor streamflow. Discharge from the basin during the same period was 8.1 cubic feet per second and occurred as pumping and leakage from confined parts of the basin. Values of transmissivity used in the model generally range from 3,300 to 20,000 feet squared per day. Values of storage coefficient used in the model range from 0.0005 to 0.10. (Woodard-USGS)

  10. Deforestation in Sumatra

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Indonesia is rapidly losing its lowland forests to logging, much of it illegal. At present, logging is claiming the forests at a rate of nearly two million hectares (slightly less than 5 million acres: roughly the same area as the state of Massachusetts) each year. At this rate, the island of Sumatra will have no more lowland forests by 2005, a fate already befallen the island of Sulawesi. Indonesia's lowland forests are home to a wide variety of wildlife and are considered among the richest ecosystems in the world. Among the unique life forms in these forests are the Orangutan and the Sumatra Tiger. Sixteen percent of the entire world's bird species, eleven percent of its plants, and ten percent of all mammals on Earth call these forests home. Many are found nowhere else. In the two Landsat scenes shown above, the pattern of deforestation can be clearly discerned. Deep green in these images shows lush vegetation in the forest cover. In both scenes, deep and pale red shows areas where there is little or no vegetation, often bare ground from where forest has been completely stripped. The latter Landsat scene from 2001 not only shows extensive clear cut areas, but also new logging roads built into the remaining forest to facilitate future cutting. This lowland forest region is located on Indonesia's largest island, Sumatra, roughly 100 km southwest of the provincial capital of Jambi. The first image was acquired by Landsat 5's Thematic Mapper (TM) sensor on June 22, 1992, the second by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 14, 2001. Both are false-color composite images made using shortwave infrared, infrared, and green wavelengths. The area shown above is roughly 30 km x 22 km (19 miles x 14 miles). The large versions of these images show the same general area covering 60 km x 60 km. Images provided by the Tropical Rain Forest Information Center (TRFIC) through the Basic Science and Remote Sensing Initiative (BSRSI) based at Michigan

  11. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

    NASA Astrophysics Data System (ADS)

    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  12. Sedimentation and water quality in the West Branch Shade River basin, Ohio, 1983-85

    USGS Publications Warehouse

    Oblinger Childress, C. J.; Jones, R.L.

    1988-01-01

    Loss of channel conveyance from deposition of sediment from abandoned surface mines in the West Branch Shade River basin has resulted in frequent flooding. In addition, water quality in the West Branch Shade River and some of its tributaries is typical of streams affected by acid mine drainage. About 938 acres were surfaced mined and abandoned in West Branch Shade River basin. By the end of 1984, about 450 acres were reclaimed. The purpose of this study was to measure the effects of abandoned surface mines and their reclamation on suspended-sediment load, channel cross-section profile, and water quality of West Branch Shade River. Sediment data were collected from June 1983 through September 1985. Daily suspended-sediment samples were collected and continuous streamflow data were recorded at two locations in West Branch Shade River basin and one location in the unmined, East Branch Shade River basin. Water-quality samples were collected three times per year, from June 1983 through July 1986, at four locations in the West Branch Shade River basin and at one location in East Branch Shade River basin and at one location in East Branch Shade River basin. Stream-channel cross sections were surveyed at least twice per year at 10 locations. During the period of study, annual mean suspended-sediment concentration was unchanged for the unmined, East Branch Shade River basin; 0.28 ton per acre-foot of runoff in 1984 and 1985 water years. Annual suspended-sediment concentration, in tons per acre foot, in West Branch Shade River near Harrisonville, from 8.6 in 1984 water year to 0.15 in 1985 water year. In West Branch Shade River near Burlingham, where 48 percent of the abandoned mines were reclaimed by the end of 1984, annual mean suspended-sediment concentration was unchanged (0.5 ton per acre-foot of runoff) in 1984 and 1985 water years and was twice that of the unmined basin. Channel profiles, surveyed at each of the 10 cross sections, indicated scouring at two locations

  13. Data quality objectives for gas and liquid samples from sealed K West basin canisters (second campaign)

    SciTech Connect

    Makenas, B.J., Westinghouse Hanford

    1996-07-01

    Data Quality Objectives (DQOs) for gas and liquid sampling from the sealed canisters in K West Basin have been developed and are presented in this document. This sampling campaign supports the selection of canisters to provide fuel for hot cell examinations and provides an assessment of gas/liquid chemistry for comparison to the results of fuel element hot cell examinations. It also provides information applicable to water cleanup and air permits for the fuel handling associated with moving fuel to dry storage.

  14. Link between the northward extension of Great Sumatra Fault and continental rifting in the Andaman Sea: new results from seismic reflection studies

    NASA Astrophysics Data System (ADS)

    Singh, S. C.; Moeremans, R. E.; McArdle, J.; Johansen, K.

    2012-12-01

    The Great Sumatra Fault (GSF) traverses the main land Sumatra from Sunda Strait in the southeast to Banda Aceh in the northwest for about 1900 km, and defines the present day plate boundary between the Sunda Plate in the north and Burmese Sliver Plate in the south. It is formed due to the oblique subduction of the Indo-Australian Plate beneath the Sunda Plate. It has been well studied on land but is poorly studied north of Banda Aceh in the Andaman Sea. Its study is further complicated by the presence of volcanic arc in its vicinity and its interaction with the West Andaman Fault (WAF) further north. Here we present deep seismic reflection images along the northward extension of the GSF over 700 km until it joins the Andaman Spreading Centre and interpret these images in the light of earthquake, gravity and bathymetry data. We find that the GSF has two strands between Banda Aceh and Nicobar Island: a transpression in the south and a deep narrow active rift basin in the north dotted with volcanoes in the center, suggesting that the volcanic arc is coincident with the rifting. Further north of Nicobar Island, an active strike-slip fault cuts through a deep rifted basin until its intersection with Andaman Sea Spreading Centre. The volcanic arc lies just east of the basin. The western margin of this basin seems to be a rifted continental margin, tilted westward flooring the Andaman-Nicobar forearc basin, which was once a part of Malaya Peninsula, suggesting that a significant parts of the Andaman-Nicobar forearc system is underlain by the Sunda continental crust. The Andaman-Nicobar forearc basin is bounded in the west by backthrusts, similar to the West Andaman and Mentawai faults bounding the Aceh and Mentawai forearc basins in the south. The cluster of seismicity after the 2004 great Andaman-Sumatra earthquake just north of Nicobar Island coincides with the intersection of two NW-SE and N-S trending strike-slip fault systems. Some of hypocentre of these earthquakes

  15. Morrowan sedimentation in the Orogrande basin, west Texas and south-central New Mexico

    SciTech Connect

    Connolly, W.M.; Stanton, R.J. Jr.

    1986-03-01

    Morrowan strata in the Hueco and Franklin Mountains reflect deposition within a shallow, gradually subsiding, carbonate shelf lagoon. Postulated environments fluctuated between open shelf lagoon with localized shoaling, restricted inner shelf lagoon, and peritidal settings. Variations in depth were slight, probably not exceeding several tens of meters within the photic zone. The La Tuna Formation (Franklin Mountains) was deposited near the axis (center) of the Orogrande basin; the lower division of the Magdalena limestone (Hueco Mountains), 30 mi east, was deposited 20-30 mi west of the paleoshoreline. Physiographically, the Orogrande sea was a small gulf, offering a certain degree of protection from the Morrowan seaway to the south. Sedimentologically, it was a wide expanse of predominantly quiet-water carbonate sedimentation with subordinate argillaceous influex and coarser peripheral clastics. The Orogrande basin, a stratigraphic feature, corresponds to a blanket deposit of shallow epeiric carbonates. Climatic and orographic effects are invoked to explain the contrasting style of clastic sedimentation in the Delaware and orogrande basins, east and west of the Pedernal uplift. Analysis of Morrowan carbonates reveals no evidence of cyclicity, major transgressions or regressions, or local tectonic activity. Deposition was stable and in equilibrium with a gradually subsiding shallow basin. Based on lithologic, faunal, biostratigraphic, and paleogeographic criteria, the lower division is both laterally and temporally equivalent with the La Tuna Formation. Accordingly, the latter term is advocated in favor of the former, which lacks both priority and formal status.

  16. Basin-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China

    NASA Astrophysics Data System (ADS)

    Wu, Xiaozhi; He, Dengfa; Qi, Xuefeng

    2016-04-01

    Situated in northern Xinjiang, China, in NE-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar Basin on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane basins, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending NE-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate basin evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the basin basement property but also complex basin-mountain coupling relations, structures and basin superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar Basin. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of basin-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of basin superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas

  17. Impact of climate change on vegetation dynamics in a West African river basin

    NASA Astrophysics Data System (ADS)

    Sawada, Y.; Koike, T.

    2012-12-01

    Future changes in terrestrial biomass distribution under climate change will have a tremendous impact on water availability and land productivity in arid and semi-arid regions. Assessment of future change of biomass distribution in the regional or the river basin scale is strongly needed. An eco-hydrological model that fully couples a dynamic vegetation model (DVM) with a distributed biosphere hydrological model is applied to multi-model assessment of climate change impact on vegetation dynamics in a West African river basin. In addition, a distributed and auto optimization system of parameters in DVM is developed to make it possible to model a diversity of phonologies of plants by using different parameters in the different model grids. The simple carbon cycle modeling in a distributed hydrological model shows reliable accuracy in simulating the seasonal cycle of vegetation on the river basin scale. Model outputs indicate that generally, an extension of dry season duration and surface air temperature rising caused by climate change may cause a dieback of vegetation in West Africa. However, we get different seasonal and spatial changes of leaf area index and different mechanisms of the degradation when we used different general circulation models' outputs as meteorological forcing of the eco-hydrological model. Therefore, multi-model analysis like this study is important to deliver meaningful information to the society because we can discuss the uncertainties of our prediction by this methodology. This study makes it possible to discuss the impact of future change of terrestrial biomass on climate and water resources in the regional or the river basin scale although we need further sophistications of the system. Performance of the eco-hydrological model (WEB-DHM+DVM) in Volta River Basin, with basin-averaged leaf area index from model (blue solid line) and AVHRR satellite-derived product (red rectangles).

  18. The habitat of petroleum in the Brazilian marginal and west African basins: A biological marker investigation

    SciTech Connect

    Mello, M.R.; Soldan, A.L. ); Maxwell, J.R. ); Figueira, J. )

    1990-05-01

    A geochemical and biological marker investigation of a variety of oils from offshore Brazil and west Africa, ranging in age from Lower Cretaceous to Tertiary, has been done, with the following aims: (1) assessing the depositional environment of source rocks, (2) correlating the reservoired oils, (3) comparing the Brazilian oils with their west African counterparts. The approach was based in stable isotope data; bulk, elemental, and hydrous pyrolysis results; and molecular studies involving quantitative geological marker investigations of alkanes using GC-MS and GC-MS-MS. The results reveal similarities between groups of oils from each side of the Atlantic and suggest an origin from source rocks deposited in five types of depositional environment: lacustrine fresh water, lacustrine saline water, marine evaporitic/carbonate, restricted marine anoxic, and marine deltaic. In west Africa, the Upper Cretaceous marine anoxic succession (Cenomanian-Santonian) appears to be a major oil producer, but in Brazil it is generally immature. The Brazilian offshore oils have arisen mainly from the pre-salt sequence, whereas the African oils show a balance between origins from the pre-salt and marine sequences. The integration of the geochemical and geological data indicate that new frontiers of hydrocarbon exploration in the west African basins must consider the Tertiary reservoirs in the offshore area of Niger Delta, the reservoirs of the rift sequences in the shallow-water areas of south Gabon, Congo, and Cuanza basins, and the reservoirs from the drift sequences (post-salt) in the deep-water areas of Gabon, Congo Cabinda, and Cuanza basins.

  19. Assessment of Undiscovered Oil and Gas Resources of the West Siberian Basin Province, Russia, 2008

    USGS Publications Warehouse

    Schenk, Christopher J.; Bird, Kenneth J.; Charpentier, Ronald R.; Gautier, Donald L.; Houseknecht, David W.; Klett, Timothy R.; Moore, Thomas E.; Pawlewicz, Mark J.; Pitman, Janet K.; Tennyson, Marilyn E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the West Siberian Basin Province in Russia as part of the USGS Circum-Arctic Resource Appraisal program. This province is the largest petroleum basin in the world and has an areal extent of about 2.2 million square kilometers. It is a large rift-sag feature bounded to the west by the Ural fold belt, to the north by the Novaya Zemlya fold belt and North Siberian Sill, to the south by the Turgay Depression and Altay-Sayan fold belt, and to the east by the Yenisey Ridge, Turukhan-Igarka uplift, Yenisey-Khatanga Basin, and Taimyr High. The West Siberian Basin Province has a total discovered oil and gas volume of more than 360 billion barrels of oil equivalent (Ulmishek, 2000). Exploration has led to the discovery of tens of giant oil and gas fields, including the Urengoy gas field with more than 3500 trillion cubic feet of gas reserves and Samotlar oil field with reserves of nearly 28 billion barrels of oil (Ulmishek, 2003). This report summarizes the results of a reassessment of the undiscovered oil and gas potential of that part of the province north of the Arctic Circle; a previous assessment that included the entire province was completed in 2000 (Ulmishek, 2000). The total petroleum system (TPS) and assessment units (AU) defined by the USGS for the assessments in 2000 were adopted for this assessment. However, only those parts of the Aus lying wholly or partially north of the Arctic Circle were assessed for this study.

  20. Structural style of the Cuyo-Bolsones basin complex of west-central Argentina

    SciTech Connect

    Gollop, I.G. )

    1991-03-01

    The Cuyo-Bolsones basin complex is part of a mosaic of basinal features that lie in the eastern Andean foreland. Sedimentary section ranges from Ordovician to Tertiary in age with the main petroleum source and reservoir potential in Carboniferous to Triassic clastics. Thick conglomerate units and widespread unconformities of both Permo-Carboniferous and Triassic age as well as localized volcanics indicate several periods of violent tectonic activity during late Paleozoic to early Mesozoic times. Triassic and older sediments are affected by normal faulting which in basins directly south extends up into the Lower Cretaceous. In the Cuyo-Bolsones basinal area, however this ancient tensional regime is entirely overprinted by relatively recent thrusting. This thrusting is late Tertiary in age, generally from east to west with very substantial relief. These thrust sheets are cut in places by later northeast-southwest strike-slip fault zones producing some localized flower structures. Nearly all the oil discovered in the Cuyo basin is produced from Triassic clastic reservoirs in compressional anticlines related to this thrusting. The major thrusts are well defined seismically, and seismic interpretations fit easily on balanced sections.

  1. Upper Permian (Guadalupian) facies and their association with hydrocarbons - Permian basin, west Texas and New Mexico

    SciTech Connect

    Ward, R.F.; Kendall, C.G.S.C.; Harris, P.M.

    1986-03-01

    Outcrops of Guadalupian sedimentary rocks in the Permian basin of west Texas and southeastern New Mexico are a classic example of the facies relationships that span a carbonate shelf. In the subsurface, these rocks form classic hydrocarbon-facies taps. Proceeding from basin to the updip termination of the shelf, the facies are (1) deep-water basin, (2) an apron of allochthonous carbonates, (3) carbonate shelf margin or reef, (4) carbonate sand flats, (5) carbonate barrier islands, (6) lagoon, and (7) coastal playas and supratidal salt flats (sabkhas). Over a half century of exploration drilling has shown that hydrocarbons in the Permian rocks of the Permian basin have accumulated at the updip contact of the lagoonal dolomites and clastics with the coastal evaporites, and in the basinal channel-fill clastics. The shelf marginal (reef) facies contain cavernous porosity, but commonly are water saturated. These facies relationships and hydrocarbon occurrences provide an exploration model with which to explore and rank hydrocarbon potential in other carbonate provinces. 16 figures, 3 tables.

  2. California Basin study (CaBS): DOE west coast basin program

    SciTech Connect

    Small, L.F.

    1990-01-01

    The overall objective of our research continues to be elucidation of the transport pathways and transformations of organic matter in the California Basins region, with particular reference to the role of macrozooplankton in upper waters. We have concentrated on C and N pathways and fluxes to data, and will continue to investigate these further (seasonal aspects, and the role of zooplankton carnivory in zooplankton-medicated C and N flux, for example).

  3. A tectonically controlled basin-fill within the Valle del Cauca, West-Central Colombia

    SciTech Connect

    Rine, J.M.; Keith, J.F. Jr.; Alfonso, C.A.; Ballesteros, I.; Laverde, F.; Sacks, P.E.; Secor, D.T. Jr. ); Perez, V.E.; Bernal, I.; Cordoba, F.; Numpaque, L.E. )

    1993-02-01

    Tertiary strata of the Valle del Cauca reflect a forearc/foreland basin tectonic history spanning a period from pre-uplift of the Cordillera Central to initiation of uplift of the Cordillera Occidental. Stratigraphy of the Valle del Cauca begins with Jurassic-Cretaceous rocks of exotic and/or volcanic provenance and of oceanic origin. Unconformably overlying these are Eocene to Oligocene basal quartz-rich sandstones, shallow marine algal limestones, and fine-grained fluvial/deltaic mudstones and sandstones with coalbeds. These Eocene to Oligocene deposits represent a period of low tectonic activity. During late Oligocene to early Miocene, increased tectonic activity produced conglomeratic sediments which were transported from east to west, apparently derived from uplift of the Cordillera Central, and deposited within a fluvial to deltaic setting. East-west shortening of the Valle del Cauca basin folded the Eocene to early Miocene units, and additional uplift of the Cordillera Central during the later Miocene resulted in syn-tectonic deposition of alluvial fans. After additional fold and thrust deformation of the total Eocene-Miocene basin-fill, tectonic activity abated and Pliocene-Quaternary alluvial and lacustrine strata were deposited. Within the framework of this depositional and tectonic history of the Valle del Cauca, hydrocarbon exploration strategies can be formulated and evaluated.

  4. Effects of coal mining on the hydrologic environment of selected stream basins in southern West Virginia. Water resources investigation

    SciTech Connect

    Borchers, J.W.; Ehlke, T.A.; Mathes, M.V.; Downs, S.C.

    1991-01-01

    The study was undertaken to help answer questions about the effects of coal mining on streamflow characteristics, stream-water quality, ground-water flow and availability, ground-water quality, concentration, loading and types of suspended sediment in streams, and biological life in streams. Three mined basins and two unmined control basins in southern West Virginia were selected for study. The report defines the effects of coal mining on the hydrologic environment of small stream basins in southern West Virginia. It answers some of the questions that have been raised by coal companies, regulatory agencies, environmental groups, researchers, and the public. The report compares hydrologic data collected in unmined basins to data collected in deep-mined and surface-mined basins. The data include the measurement and description of precipitation, streamflow, ground-water levels, suspended sediment, stream and ground-water quality, and benthic invertebrate life in streams.

  5. Long-Term Water Balance of the Volta River Basin in West Africa

    NASA Astrophysics Data System (ADS)

    van de Giesen, N.; Andreini, M.; Taylor, J.; Steenhuis, T.

    2002-12-01

    The Volta River drains approximately 400,000 km2 of the semi-arid to sub-humid savanna of West Africa. Average rainfall is about 1000 mm per year. The interannual variation is relatively low with a coefficient of variation of 0.07. Most rainfall returns to the atmosphere as evapotranspiration and only 9% becomes available as river runoff. The interannual variation of river flow is much higher than that of rainfall and has a coefficient of variation of 0.57. In this presentation, the coupling between interannual variation in rainfall and runoff is examined. To a large extent, the high variability in river flow can be explained with the relatively small differences in rainfall between years; the watershed strongly amplifies the atmospheric input. The amplifying effect is, however, not constant over space and time. Over all, the basin received less rain than before in the past two decades. Some parts of the basin did indeed produce less runoff but other parts actually produced more runoff, most likely due to changes in landuse. No clear increase or decrease in the interannual variability could be found for different parts of the basin. To examine the interannual variability of water resources availability under future climates, the applicability of General Circulation Models (GCMs) was examined for West Africa. Comparison of historical and GCM rainfall data showed large discrepancies. Different approaches exist to adjust GCM rainfall with the aid of historical rainfall data but for West Africa some problems remained. This presentation concludes with a focus on differences in mid-term (2-10 years) persistence in annual river flow as produced by historical and GCM data.

  6. Predictive modeling of West Nile virus transmission risk in the Mediterranean Basin: how far from landing?

    PubMed

    Chevalier, Véronique; Tran, Annelise; Durand, Benoit

    2014-01-01

    The impact on human and horse health of West Nile fever (WNF) recently and dramatically increased in Europe and neighboring countries. Involving several mosquito and wild bird species, WNF epidemiology is complex. Despite the implementation of surveillance systems in several countries of concern, and due to a lack of knowledge, outbreak occurrence remains unpredictable. Statistical models may help identifying transmission risk factors. When spatialized, they provide tools to identify areas that are suitable for West Nile virus transmission. Mathematical models may be used to improve our understanding of epidemiological process involved, to evaluate the impact of environmental changes or test the efficiency of control measures. We propose a systematic literature review of publications aiming at modeling the processes involved in WNF transmission in the Mediterranean Basin. The relevance of the corresponding models as predictive tools for risk mapping, early warning and for the design of surveillance systems in a changing environment is analyzed. PMID:24362544

  7. Impact of future climate change on streamflow in the White Volta river basin, West Africa

    NASA Astrophysics Data System (ADS)

    Obuobie, E.; Diekkrüger, B.; Liebe, J.

    2009-04-01

    The Soil and Water Assessment Tool (SWAT) model was applied in the White Volta river basin, West Africa, to simulate the streamflow and to estimate the impact of future climate change on the streamflow. The White Volta river basin is one of the three major sub-basins of the Volta river basin, and drains an area of about 106,000 km2 mainly shared by the riparian countries, Burkina Faso and Ghana. The model was calibrated and validated using daily measured streamflow data from the stream gage at Nawuni, for the period 1980-2000. Impact of future climate change on streamflow was estimated by simulating streamflow of two time slices, the present (1990-2000) and future (2030-2039), using the calibrated SWAT model and stochastically generated daily climate series and comparing their mean annual values. The generated future climate series reflected monthly changes in precipitation and temperature forecasted by the meso-scale climate model MM5, which was downscaled from ECHAM4 scenario IS92a. The results show that SWAT is able to accurately reproduce the streamflow in the White Volta Basin. The coefficient of determination and Nash-Sutcliffe model efficiency were found to be, respectively, higher than 0.8 and 0.7, for both the calibration and validation periods. Compared to the present, the future mean annual streamflow and the annual coefficient of variation of the streamflow in the basin are expected to increase by 33% and 52%, respectively, as a result of future climate change.

  8. Thermal springs in the Payette River basin, west-central Idaho

    USGS Publications Warehouse

    Lewis, R.E.; Young, H.W.

    1980-01-01

    The Payette River basin, characterized by steep, rugged mountains and narrow river valleys, occupies an area of about 3 ,300 square miles in west-central Idaho. Predominant rock types in the basin include granitic rocks of the Idaho batholith and basalt flows of the Columbia River Basalt Group. Waters from thermal springs in the basin, temperatures of which range from 34 to 86 degrees Celsius, are sodium bicarbonate types and are slightly alkaline. Dissolved-solids concentrations range from 173 to 470 milligrams per liter. Reservoir temperatures determined from the sodium-potassium-calcium and silicic acid-corrected silica geothermometers range from 53 to 143 degrees Celsius. Tritium, present in concentrations between 0 and 2 tritium units, indicate sampled thermal waters are at least 100 years old and possibly more than 1,000 years old. Stable isotope data indicate it is unlikely any of the nonthermal waters sampled are representative of precipitation that recharges the thermal springs in the basin. Thermal springs discharged about 5,700 acre-feet of water in 1979. Associated convective heat flux is 1.1x10 to the 7th power calories per second. (USGS)

  9. Thermal springs in the Payette River basin, west-central Idaho

    SciTech Connect

    Lewis, R.E.; Young, H.W.

    1980-10-01

    The Payette River basin, characterized by steep, rugged mountains and narrow river valleys, occupies an area of about 3300 square miles in west-central Idaho. Predominant rock types in the basin include granitic rocks of the Idaho batholith and basalt flows of the Columbia River Basalt Group. Waters from thermal springs in the basin, temperatures of which range from 34/sup 0/ to 86/sup 0/ Celsius, are sodium bicarbonate type and are slightly alkaline. Dissolved-solids concentrations range from 173 to 470 milligrams per liter. Reservoir temperatures determined from the sodium-potassium-calcium, silicic acid-corrected silica, and sulfate-water isotope geothermometers range from 53/sup 0/ to 143/sup 0/ Celsius. Tritium, present in concentrations between 0 and 2 tritium units, indicate that sampled thermal waters are at least 100 years and possibly more than 1000 years old. Stable-isotope data indicate it is unlikely any of the nonthermal waters sampled are representative of precipitation that recharges the thermal springs in the basin. Thermal springs discharged about 5700 acre-feet of water in 1979. Associated convective heat flux is 1.1 x 10/sup 7/ calories per second.

  10. Flood of July 9-11, 1993, in the Raccoon River basin, west-central Iowa

    USGS Publications Warehouse

    Eash, D.A.; Koppensteiner, B.A.

    1997-01-01

    Water-surface-elevation profiles and peak discharges for the flood of July 9-11, 1993, in the Raccoon River Basin, west-central Iowa, are presented in this report. The profiles illustrate the 1993 flood along the Raccoon, North Raccoon, South Raccoon, and Middle Raccoon Rivers and along Brushy and Storm Creeks in the west-central Iowa counties of Carroll, Dallas, Greene, Guthrie, and Polk. Water-surface-elevation profiles for the floods of June 1947, March 1979, and June 29- July 1, 1986, in the Raccoon River Basin also are included in the report for comparative purposes. The July 9-11, 1993, flood is the largest known peak discharge at gaging stations Brushy Creek near Templeton (station number 05483318) 19,000 cubic feet per second, Middle Raccoon River near Bayard (station number 05483450) 27,500 cubic feet per second, Middle Raccoon River at Panora (station number 05483600) 22,400 cubic feet per second, South Raccoon River at Redfield (station number 05484000) 44,000 cubic feet per second, and Raccoon River at Van Meter (station number 05484500) 70,100 cubic feet per second. The peak discharges were, respectively, 1.5, 1.3, 1.1,1.2, and 1.3 times larger than calculated 100-year recurrence-interval discharges. The report provides information on flood stages and discharges and floodflow frequencies for streamflow-gaging stations in the Raccoon River Basin using flood information collected through 1996. A flood history summarizes rainfall conditions and damages for floods that occurred during 1947, 1958, 1979, 1986, 1990, and 1993. Information on temporary bench marks and reference points established in the Raccoon River Basin during 1976-79 and 1995-97 also is included in the report.

  11. Aerogeophysical evidence for complex subglacial geology below the Rutford drainage basin,WestAntarctica

    NASA Astrophysics Data System (ADS)

    Jones, P.; Ferraccioli, F.; Corr, H.; Smith, A. M.; King, E.; Vaughan, D.

    2003-12-01

    A significant part of the West Antarctic Ice Sheet appears to be imposed upon a complex and still largely unknown continental rift system, perhaps featuring sedimentary basins, thin crust and high heat flow. Subglacial geology has been postulated to strongly modulate the dynamics and stability of the ice sheet itself. Specifically, recent aerogeophysics collected over central West Antarctica at edge of the Whitmore Mountains crustal block show that narrow subglacial rift basins with thick sedimentary infill may control the onsets and lateral margins of ice streams. The British Antarctic Survey flew an aerogeophysical survey during the 2001-02 field season: the main aim was to investigate what factors control the location and dynamics of the onset region of the Rutford Ice stream. Airborne radar, aerogravity and aeromagnetic data were simultaneously collected over the drainage basin of the Rutford Ice Stream. The new bedrock elevation grid for the area shows that the Rutford Ice Stream is constrained by a deep bedrock trough with a N-S to NE-SW trend. The onset region appears however to lie within an E-W bedrock trough at the edge of the Ellsworth Mountains crustal block. Bouguer gravity maps do not reveal typical signatures for a coincident deep rift basin at this location. However, a sharp NE-SW trending gradient, likely separating crustal blocks with contrasting crustal thickness is revealed. Aeromagnetic data image NE-SW trends north of the Rutford Ice Stream. In the onset region, these trends appear to be truncated by a NNW-SSE trend, lying on strike with the Ellsworth Mountains. Hence, the new aerogeophysical data suggests greater complexity in the subglacial geology and structure of an onset region of an ice stream compared to previous investigations.

  12. Evaporite replacement within the Permian strata of the Bighorn Basin, Wyoming and the Delaware Basin, west Texas and New Mexico

    SciTech Connect

    Ulmer, D.S.; Scholle, P.A. )

    1992-01-01

    The Park City and Goose Egg Formations of the Big Horn Basin, Wyoming and the Seven Rivers, Yates and Tansill Formations of west Texas and New Mexico contain numerous examples of silicified and calcitized evaporites. Both areas show significant preserved interstitial evaporite, but on outcrop the discrete crystals and nodular evaporites have been extensively replaced. These replacements appear to be a multistage phenomenon. Field and petrographic evidence (matted fabrics in nodules; evaporite inclusions) indicate that silicification involved direct replacement of evaporites and probably occurred during earlier stages of burial. Calcitization, however, appears to be a much later phenomenon and involved precipitation of coarse crystals within evaporite molds. The calcites are typically free of evaporite inclusions. Isotopic analyses of these calcites give a wide range of values from [minus]6.04 to [minus]25.02 [per thousand] [delta][sup 18]O and +6.40 to [minus]25.26 [per thousand] [delta][sup 13]C, reflecting their complex diagenetic histories. In both localities, silicification of evaporites was completed by the end of hydrocarbon migration and emplacement. The extremely broad isotopic range of the calcites indicates that the calcitization occurred during a long period of progressive uplift and increased groundwater circulation associated with mid-Tertiary block faulting. The very light oxygen values within the Bighorn Basin were produced by thermochemical sulfate reduction during deepest burial of the region. Evaporite diagenesis in both the Bighorn and Delaware Basins is an ongoing process that started prior to hydrocarbon migration, continued over millions of years, and has the potential to do significant porosity change.

  13. Diatom distribution as an environmental indicator in surface sediments of the West Philippine Basin

    NASA Astrophysics Data System (ADS)

    Shen, Linnan; Chen, Min; Lan, Binbin; Qi, Hongshuai; Zhang, Aimei; Lan, Dongzhao; Fang, Qi

    2016-05-01

    The distribution of diatoms from surface sediments of the West Philippine Basin was analyzed, with 68 species and varieties of diatoms from 26 genera identified. Diatom abundance varied spatially, with the absolute abundance of diatoms ranging from 0 to 3.4×104 frustules/g. The seven tropical pelagic diatoms were Alveus marinus, Azpeitia africana, Azpeitia nodulifera, Hemidiscus cuneiformis, Hemidiscus cuneiformis var. ventricosus, Roperia tesselata and Rhizosolenia bergonii. The relative abundance of these species was greater than 20%, and their distribution pattern in the sediments was overlaid by the flow of the Kuroshio Current. Ethmodiscus rex was present at 159 stations, formed the most abundant and dominant species in the diatomaceous ooze, and thus referred to as Ethmodiscus ooze. Ethmodiscus rex was also a major contributor to primary production in the region. A principal component analysis was employed to explain the relationship between samples and variations in diatom species from the WPB. Four diatom assemblages were distinguished, representing different oceanographic conditions; their spatial distributions were closely related with the North Equatorial Current and Kuroshio Current patterns in the region. These diatom assemblages can therefore be useful in deciphering late Quaternary palaeoceanographic reconstructions of the West Philippine Basin.

  14. Age and tectonic evolution of the northwest corner of the West Philippine Basin

    NASA Astrophysics Data System (ADS)

    Doo, Wen-Bin; Hsu, Shu-Kun; Yeh, Yi-Ching; Tsai, Ching-Hui; Chang, Ching-Ming

    2015-09-01

    To understand the tectonic characteristics and age of the northwestern part of the West Philippine Basin (WPB), multi-beam bathymetry and geomagnetic data have been collected and analyzed. The seafloor morphology obviously shows NW-SE trending seafloor fabrics and NE-SW trending fracture zones, indicating a NE-SW seafloor spreading direction. An overlapping spreading center near 22°20'N and 125°E is identified. Besides, numerous seamounts indicate an excess supply of magma during or after the oceanic crust formation. A V-shaped seamount chain near 21°52'N and 124°26'E indicates a southeastward magma propagation and also indicates the location of the seafloor spreading ridge. On the basis of the newly collected geomagnetic data, the magnetic anomaly shows NW-SE trending magnetic lineations. Both bathymetry and geomagnetic data reveal NE-SW seafloor spreading features between the Gagua Ridge and the Luzon Okinawa fracture zone (LOFZ). Our magnetic age modeling indicates that the age of the northwestern corner of the WPB west of the LOFZ is between 47.5 to 54 Ma (without including overlapping spreading center), which is linked to the first spreading phase of the WPB to the east of the LOFZ. In addition, the age of the Huatung Basin is identified to be between 33 to 42 Ma, which is similar to the second spreading phase of the WPB.

  15. Dormant state of rifting below the Byrd Subglacial Basin, West Antarctica, implied by magnetotelluric (MT) profiling

    SciTech Connect

    Wannamaker, P.E.; Stodt, J.A.; Olsen, S.L.

    1996-10-01

    During the 1994{endash}1995 austral summer field season, we collected twelve, high-quality MT soundings over the Byrd Subglacial Basin of central West Antarctica (82{degree}36{prime}S lat., 118{degree}14{prime}W long. approx.) in the period range 0.01 s to 400 s. Ten equispaced sites in a 54 km profile cross regional aeromagnetic trends and complement seismic reflection and refraction results collected by others. Our purposes were to prove such measurements were feasible over the 2 km thick interior ice sheet, and to show from deep electrical resistivity whether the Byrd Basin comprises an active rift environment. The difficult acquisition of electric field data on ice was overcome using a custom electrometer system, with preamplifiers located at the electrode sites to buffer the high contact impedances of the ice as close to the source as possible. Two-dimensional modeling of the profile shows that resistivity of the deep crust and upper mantle is about 2000{endash}3000 ohm-m to 100 km depth or more. This is much higher than observed in active extensional regimes, suggesting that the current state of rifting, at least in this part of central West Antarctica, is dormant. {copyright} American Geophysical Union 1996

  16. Characterization of Suspect Fuel Rod Pieces from the 105 K West Basin

    SciTech Connect

    Delegard, Calvin H.; Schmidt, Andrew J.; Pool, Karl N.; Thornton, Brenda M.

    2006-07-25

    This report provides physical and radiochemical characterization results from examinations and laboratory analyses performed on {approx}0.55-inch diameter rod pieces found in the 105 K West (KW) Basin that were suspected to be from nuclear reactor fuel. The characterization results will be used to establish the technical basis for adding this material to the contents of one of the final Multi-Canister Overpacks (MCOs) that will be loaded out of the KW Basin in late FY2006 or at a later time depending on project priorities. Fifteen fuel rod pieces were found during the clean out of the KW Basin. Based on lack of specific credentials, documentation, or obvious serial numbers, none of the items could be positively identified nor could their sources or compositions be described. Item weights and dimensions measured in the KW Basin indicated densities consistent with the suspect fuel rods containing uranium dioxide (UO2), uranium metal, or being empty. Extensive review of the Hanford Site technical literature led to the postulation that these pieces likely were irradiated test fuel prepared to support of the development of the Hanford ''New Production Reactor'', later called N Reactor. To obtain definitive data on the composition of the suspect fuel, 4 representative fuel rod pieces, with densities corresponding to oxide fuel were selected from the 15 items, and shipped from the KW Basin to the Pacific Northwest National Laboratory's (PNNL) Radiological Processing Laboratory (RPL; also known at the 325 Building) for examinations and characterization. The three fuel rod that were characterized appear to contain slightly irradiated UO2 fuel, originally of natural enrichment, with zirconium cladding. The uranium-235 isotopic concentrations decreased by the irradiation and become slightly lower than the natural enrichment of 0.72% to range from 0.67 to 0.71 atom%. The plutonium concentrations, ranged from about 200 to 470 grams per metric ton of uranium and ranged in

  17. Techniques for simulating flood hydrographs and estimating flood volumes for ungaged basins in east and west Tennessee

    USGS Publications Warehouse

    Gamble, C.R.

    1989-01-01

    A dimensionless hydrograph developed for a variety of basin conditions in Georgia was tested for its applicability to streams in East and West Tennessee by comparing it to a similar dimensionless hydrograph developed for streams in East and West Tennessee. Hydrographs of observed discharge at 83 streams in East Tennessee and 38 in West Tennessee were used in the study. Statistical analyses were performed by comparing simulated (or computed) hydrographs, derived by application of the Georgia dimensionless hydrograph, and dimensionless hydrographs developed from Tennessee data, with the observed hydrographs at 50 and 75% of their peak-flow widths. Results of the tests indicate that the Georgia dimensionless hydrography is virtually the same as the one developed for streams in East Tennessee, but that it is different from the dimensionless hydrograph developed for streams in West Tennessee. Because of the extensive testing of the Georgia dimensionless hydrograph, it was determined to be applicable for East Tennessee, whereas the dimensionless hydrograph developed from data on streams in West Tennessee was determined to be applicable in West Tennessee. As part of the dimensionless hydrograph development, an average lagtime in hours for each study basin, and the volume in inches of flood runoff for each flood event were computed. By use of multiple-regression analysis, equations were developed that relate basin lagtime to drainage area size, basin length, and percent impervious area. Similarly, flood volumes were related to drainage area size, peak discharge, and basin lagtime. These equations, along with the appropriate dimensionless hydrograph, can be used to estimate a typical (average) flood hydrograph and volume for recurrence-intervals up to 100 years at any ungaged site draining less than 50 sq mi in East and West Tennessee. (USGS)

  18. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    SciTech Connect

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  19. Thermal Properties of West Siberian Sediments in Application to Basin and Petroleum Systems Modeling

    NASA Astrophysics Data System (ADS)

    Romushkevich, Raisa; Popov, Evgeny; Popov, Yury; Chekhonin, Evgeny; Myasnikov, Artem; Kazak, Andrey; Belenkaya, Irina; Zagranovskaya, Dzhuliya

    2016-04-01

    Quality of heat flow and rock thermal property data is the crucial question in basin and petroleum system modeling. A number of significant deviations in thermal conductivity values were observed during our integral geothermal study of West Siberian platform reporting that the corrections should be carried out in basin models. The experimental data including thermal anisotropy and heterogeneity measurements were obtained along of more than 15 000 core samples and about 4 500 core plugs. The measurements were performed in 1993-2015 with the optical scanning technique within the Continental Super-Deep Drilling Program (Russia) for scientific super-deep well Tyumenskaya SG-6, parametric super-deep well Yen-Yakhinskaya, and deep well Yarudeyskaya-38 as well as for 13 oil and gas fields in the West Siberia. Variations of the thermal conductivity tensor components in parallel and perpendicular direction to the layer stratification (assessed for 2D anisotropy model of the rock studied), volumetric heat capacity and thermal anisotropy coefficient values and average values of the thermal properties were the subject of statistical analysis for the uppermost deposits aged by: T3-J2 (200-165 Ma); J2-J3 (165-150 Ma); J3 (150-145 Ma); K1 (145-136 Ma); K1 (136-125 Ma); K1-K2 (125-94 Ma); K2-Pg+Ng+Q (94-0 Ma). Uncertainties caused by deviations of thermal conductivity data from its average values were found to be as high as 45 % leading to unexpected errors in the basin heat flow determinations. Also, the essential spatial-temporal variations in the thermal rock properties in the study area is proposed to be taken into account in thermo-hydrodynamic modeling of hydrocarbon recovery with thermal methods. The research work was done with financial support of the Russian Ministry of Education and Science (unique identification number RFMEFI58114X0008).

  20. Cenozoic uplift on the West Greenland margin: active sedimentary basins in quiet Archean terranes.

    NASA Astrophysics Data System (ADS)

    Jess, Scott; Stephenson, Randell; Brown, Roderick

    2016-04-01

    The North Atlantic is believed by some authors to have experienced tectonically induced uplift within the Cenozoic. Examination of evidence, onshore and offshore, has been interpreted to imply the presence of kilometre scale uplift across the margins of the Barents Sea, North Sea, Baffin Bay and Greenland Sea. Development of topography on the West Greenland margin (Baffin Bay), in particular, has been subject to much discussion and dispute. A series of low temperature thermochronological (AFT and AHe) studies onshore and interpretation of seismic architecture offshore have suggested uplift of the entire margin totalling ~3km. However, challenges to this work and recent analysis on the opposing margin (Baffin Island) have raised questions about the validity of this interpretation. The present work reviews and remodels the thermochronological data from onshore West Greenland with the aim of re-evaluating our understanding of the margin's history. New concepts within the discipline, such as effect of radiation damage on Helium diffusivity, contemporary modelling approaches and denudational mapping are all utilised to investigate alternative interpretations to this margins complex post rift evolution. In contrast to earlier studies our new approach indicates slow protracted cooling across much of the region; however, reworked sedimentary samples taken from the Cretaceous Nuussuaq Basin display periods of rapid reheating and cooling. These new models suggest the Nuussuaq Basin experienced a tectonically active Cenozoic, while the surrounding Archean basement remained quiet. Faults located within the basin appear to have been reactivated during the Palaeocene and Eocene, a period of well-documented inversion events throughout the North Atlantic, and may have resulted in subaerial kilometre scale uplift. This interpretation of the margin's evolution has wider implications for the treatment of low temperature thermochronological data and the geological history of the North

  1. Geology of oil fields and future exploration potential in west African Aptian Salt basin

    SciTech Connect

    Bignell, R.D.; Edwards, A.D.

    1987-05-01

    The Aptian Salt basin of west Africa, extends from Equatorial Guinea southward to Angola, contains recoverable reserves estimated at nearly 4 billion BOE, and is current producing 600,000 BOPD. The basin developed as a result of tensional forces between west Africa and South America initiated at the end of the Jurassic. The prospective sedimentary sequences ranged in age from Early Cretaceous (uppermost Jurassic in places) to Holocene and is divided by the Aptian transgressive sand and salt into a pre-salt, nonmarine, syn-rift sequence and a post-salt, marine, post-rift sequence. Both the pre- and post-salt sequences contain several successful exploration plays, the most prolific of which are the Early Cretaceous nonmarine sandstone fields in tilted fault blocks of Gabon and Cabinda; Early Cretaceous carbonate buildups on the margins of basement highs in Cabinda; Early Cretaceous transgressive marine sandstone fields in anticlines draped over basement highs in Gabon; Late Cretaceous shallow marine sandstone and carbonate fields in salt-related structures in the Congo, Zaire, Cabinda, and Angola; Late Cretaceous dolomites in structural/stratigraphic traps in Angola; Late Cretaceous/early Tertiary deltaic/estuarine sandstone traps formed by salt movement in Gabon, Cabinda, and angola; and Tertiary marine turbidite fields in Cabinda and Angola. Despite the exploration success in these trends, much of the basin is under or poorly explored. The major problems for exploration are the poor quality of seismic definition beneath the salt, which makes it difficult to predict pre-salt structure and stratigraphy, and the importance of a stratigraphic element in many of the post-salt traps, also difficult to detect on seismic.

  2. Cleanup Verification Package for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils

    SciTech Connect

    L. D. Habel

    2008-03-18

    This cleanup verification package documents completion of remedial action, sampling activities, and compliance with cleanup criteria for the 118-F-8:4 Fuel Storage Basin West Side Adjacent and Side Slope Soils. The rectangular-shaped concrete basin on the south side of the 105-F Reactor building served as an underwater collection, storage, and transfer facility for irradiated fuel elements discharged from the reactor.

  3. Influence of Transcontinental arch on Cretaceous listric-normal faulting, west flank, Denver basin

    SciTech Connect

    Davis, T.L.

    1983-08-01

    Seismic studies along the west flank of the Denver basin near Boulder and Greeley, Colorado illustrate the interrelationship between shallow listric-normal faulting in the Cretaceous and deeper basement-controlled faulting. Deeper fault systems, primarily associated with the Transcontinental arch, control the styles and causative mechanisms of listric-normal faulting that developed in the Cretaceous. Three major stratigraphic levels of listric-normal faulting occur in the Boulder-Greeley area. These tectonic sensitive intervals are present in the following Cretaceous formations: Laramie-Fox Hills-upper Pierre, middle Pierre Hygiene zone, and the Niobrara-Carlile-Greenhorn. Documentation of the listric-normal fault style reveals a Wattenberg high, a horst block or positive feature of the greater Transcontinental arch, was active in the east Boulder-Greeley area during Cretaceous time. Paleotectonic events associated with the Wattenberg high are traced through analysis of the listric-normal fault systems that occur in the area. These styles are important to recognize because of their stratigraphic and structural influence on Cretaceous petroleum reservoir systems in the Denver basin. Similar styles of listric-normal faulting occur in the Cretaceous in many Rocky Mountain foreland basins.

  4. Fluviomarine sequences in the Lower Cretaceous of the west Netherlands basin

    SciTech Connect

    Van Der Zwan, K. ); Den Hartog Jager, D.; De Klerk, C. )

    1993-09-01

    The Lower Cretaceous of the West Netherlands Basin contains fluvial deposits of the Delfland Group, overlain by shallow marine sediments of the Rijnland Group. Sequence stratigraphy was applied to both succession, to study the nature of the transgression and to identify possible reservoir-seal pairs. A total of six depositional sequences has been identified using extensive new biostratigraphy and sedimentology. Three of the sequences contain fluvial sediments only, two are mixed fluvial and marine, and one is fully marine. The typical thickness per sequence is 200-400 m. Characteristic for the fluvial sequences is an overall fining-upward pattern. The sequence boundaries have been correlated on logs and on regional seismic. Each of the main depositional settings displays a characteristic seismic facies, which has been used to reconstruct the sedimentological facies distribution. The results demonstrate that the source direction of the Delfland Group was predominantly southeast, controlled by the tectonic grain. Strong thickness variations within the lowermost sequence indicate syndepositional rifting, which confined the main channel systems. The major intervening flood-plain shales correspond to base-level highstands, which implies they can be correlated regionally and may act as intraformational seals. The marine transgression entered the basin from the north during the late Valanginian. By the early Barremian, it covered the entire basin. Retrograding barrier sands from the transgressive systems tract are the best reservoirs within the marine succession. In both fluvial and marine settings, the use of sequence stratigraphy has enabled recognition of several types stratigraphic traps.

  5. Dissolution of evaporites in and around the Delaware Basin, southeastern New Mexico and west Texas

    SciTech Connect

    Lambert, S.J.

    1983-03-01

    permian evaporites in the Ochoan Castile, Salado, and Rustler Formations in the Delaware Basin of southeast New Mexico and west Texas have been subjected to various degrees of dissolution (notably of halite and gypsum) through geologic time. Eastward tilting of the Delaware Basin has resulted in the exhumation and erosion of Ochoan rocks in the western part of the basin. Waters in the Capitan, Rustler, Castile, and Bell Canyon Formations have previously been proposed as agents or consequences of evaporite dissolution according to four principal models: solution-and-fill, phreatic dissolution, brine density flow, and stratabound dissolutin (along bedding planes). Several geomorphological features of positive and negative relief have previously been cited as indicators of evaporite dissolution. Brine density flow has been used to explain the selective dissolution of certain evaporite horizons during the late Cenozoic. A review of available geological data has revealed that: Halite deposition was probably not so extensive as formerly believed. Waters with potential to dissolve evaporites are in the Rustler and Capitan, but not in the Bell Canyon, Salado mine seeps, or the Castile brine reservoirs. Brine density flow has not been active in removing most of the missing halite, nor are point-source dissolution features likely to have their roots at the Bell Canyon. Major evaporite dissolution has not been confined to the late Cenozoic, but much of it took place during the Permian, Triassic, Jurassic, and Tertiary periods. The Bell Canyon Formation has been a sink for dissolution-derived brine.

  6. Detailed seafloor morphology in the epicentral region of the Great Sumatra-Andaman earthquake from the compilation of 2005-2006 French and British swath bathymetric data

    NASA Astrophysics Data System (ADS)

    Graindorge, D.; Klingelhoefer, F.; Sibuet, J.; Permana, H.; Dessa, J.; Singh, S.; Dean, S.; White, N.; Carton, H.; Chauhan, A.; Greenroyd, C. J.; Royle, G.; Aryawan, K. G.; Chaubey, A. K.; Galih, D. R.; Laesanpura, A.; Prihantono, J.; Shankar, U.; McNeill, L. C.; Henstock, T. J.; Tappin, D.

    2006-12-01

    The 26th December 2004 Great Sumatra Earthquake is the second largest earthquake (Mw=9.1) recorded during the past century. In order to investigate the sea-floor morphology and potentially recent fault activity related to the seismic activity, swath bathymetric mapping was conducted by the French vessel R/V Marion Dufresne during Sumatra-Aftershocks 2005 cruise and complemented during SAGER-OBS in 2006. The 2005 box was a 370 km x 75 km strip located between northern Sumatra and the Indonesia/India boundary (Sibuet et al, 2005). These data complemented the data acquired by HMS Scott (Henstock et al, 2006) earlier in 2005. This year, we filled the gap in the 2005 surveys and added two more boxes. Box A is located over the outer ridge and wedge, east of the area covered during the Sumatra Aftershocks cruise. Box B is in the vicinity of the epicentre and completes the existing data set on the outer ridge, north of the West Andaman Fault (WAF). These data, combined with the HMS Scott data represent about 70 percent of the surface area between west Simeulue Island and the India-Indonesia boundary, from the trench to north- west Sumatra. This dataset provides for the first time the detailed morphology of the vast epicentral region, which permits us to identify fine-scale as well large-scale geo-morphological features related to subduction processes. New data outline the major discontinuity of the deflection of the outer ridge where it crosses the WAF. As identified last year, some of the active deformation in the wedge and at the base of the outer ridge could be interpreted as the emergence of major splay faults that may accommodate part of the December 26th earthquake thrusting. Apart from thrusting, the upper part of the wedge shows folds and pull-apart basins that indicate a significant strike motion. To the south, the outer ridge is well developed in the continuity of Simeulue Island forming a 60 km wide, relatively smooth 1000 m deep plateau. The entire data

  7. Bathymetry Offshore Sumatra First Comprehensive map of International Data Sets

    NASA Astrophysics Data System (ADS)

    Gaedicke, C.; Ladage, S.; Soh, W.; Weinrebe, W.; Tappin, D. R.; Henstock, T.; McNeill, L.; Sibuet, J.; Klingelhoefer, F.; Singh, S.; Flueh, E.; Djajadihardja, Y.

    2006-12-01

    Knowledge of the bathymetry offshore Sumatra is of great importance for geohazard risk assessment, modelling of tsunami runup heights and development of tsunami early warning systems as well as for the general understanding of plate boundary processes and morphotectonic features. Since the devastating December 26, 2004 Sumatra-Andaman Islands earthquake and tsunami a number of marine expeditions, funded by Canada, France, Germany, India, Indonesia, Japan, United Kingdom and the United States have acquired bathymetric data over the southern part of the earthquake rupture zone but also along strike the whole Sunda trench. Here we present the first compilation of these bathymetric data sets as one bathymetric map. The bathymetric data acquired up to date covers a vast part of the trench, continental slope and in part also of the fore arc basins. The map incorporates the newest data sets from 2005 of the British high-resolution HMS SCOTT survey, the French Marion-Dufresene "Aftershocks" and the Japanese Natsushima cruises. While these surveys concentrated on the southern rupture zone of the Dec. 26th, 2004 earthquake, the German RV SONNE SeaCause and Sumatra cruises in 2005 and 2006 mapped the March 28th 2005 rupture area as well as large parts of the central Sunda trench and slope and in part the fore arc basins. Surveys reaching back to 1997 covering parts of the Sunda Strait and offshore southern Sumatra are also incorporated. A nearly complete coverage of the Sunda trench and slope area in the north is achieved. In the south data gaps on the slope still exist. This map compilation is a collaborative international effort initiated and partly funded by InterMARGINS. It is a major contribution to the Indonesian and international science community.

  8. Volcanic Explosions, Seismicity, and Debris from the West and North Mata Volcano Complex, NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Dziak, R. P.; Bohnenstiehl, D. R.; Baker, E. T.; Matsumoto, H.; Haxel, J.; Walker, S.; Fowler, M.

    2010-12-01

    The discovery of the explosively erupting deep-ocean West Mata volcano in the northeast Lau Basin offers an unprecedented opportunity for in situ and near-field studies of the hydroacoustic wavefield produced by a submarine arc volcano, as well as the relationship between gas-driven explosions and the formation of volcanic-hydrothermal plumes. From December 2009 to April 2010, we re-initiated acoustic monitoring of the West Mata system by deploying four hydrophone moorings in a diamond-shaped geometry encompassing the summit and a set of nearby volcanic edifices known as the North Matas. Recent water column surveys over the North Matas found intense volcanic plumes suggesting that one or more of these volcanoes may be in an active eruption phase similar to West Mata. Each mooring contained a single sound-channel moored hydrophone (~1000 m depth) with a sample-rate of 1 kHz. The southern mooring in the array also included two optical backscatter and temperature sensors (MAPRs) attached to the mooring line (at 1800 m (data lost due to a battery failure) and 2250 m (~300 mab) depth) to detect plumes of volcanic debris that detach from the flank of West Mata. The acoustic record shows that West Mata volcano was continually erupting during the 5-month period of the experiment, producing broadband explosions every few seconds and long episodes of both mono- and poly-chromatic volcanic tremor. The MAPR record shows at least four major and several minor events, lasting from days to >week, that may correspond to debris flows. In most cases these episodes begin with a turbidity spike that slowly decreases while also fluctuating between elevated and ambient levels with the semidiurnal tides, as indicated by the temperature record. This linked temperature-turbidity fluctuation requires the events to be thin (<~100 m?) lenses that vertically oscillate around the MAPR depth while dissipating. High turbidity values (0.15-5 NTU) in some events imply these debris flows regularly

  9. Crustal shear-wave velocity structure beneath Sumatra from receiver function modeling

    NASA Astrophysics Data System (ADS)

    Bora, Dipok K.; Borah, Kajaljyoti; Goyal, Ayush

    2016-05-01

    We estimated the shear-wave velocity structure and Vp/Vs ratio of the crust beneath the Sumatra region by inverting stacked receiver functions from five three-component broadband seismic stations, located in diverse geologic setting, using a well known non-linear direct search approach, Neighborhood Algorithm (NA). Inversion results show significant variation of sediment layer thicknesses from 1 km beneath the backarc basin (station BKNI and PMBI) to 3-7 km beneath the coastal part of Sumatra region (station LHMI and MNAI) and Nias island (station GSI). Average sediment layer shear velocity (Vss) beneath all the stations is observed to be less (∼1.35 km/s) and their corresponding Vp/Vs ratio is very high (∼2.2-3.0). Crustal thickness beneath Sumatra region varies between 27 and 35 km, with exception of 19 km beneath Nias island, with average crustal Vs ∼3.1-3.4 km/s (Vp/Vs ∼1.8). It is well known that thick sediments with low Vs (and high Vp/Vs) amplify seismic waves even from a small-magnitude earthquake, which can cause huge damage in the zone. This study can provide the useful information of the crust for the Sumatra region. Since, Sumatra is an earthquake prone zone, which suffered the strong shaking of Great Andaman-Sumatra earthquake; this study can also be helpful for seismic hazard assessment.

  10. Gravity Variations in the Rockall and Porcupine Basins West of Ireland: Evidence for a Linked Structural Development

    NASA Astrophysics Data System (ADS)

    Readman, P. W.; O'Reilly, B. M.

    2001-12-01

    The crustal structure of the large Mesozoic Rockall and Porcupine basins west of Ireland determines the broader scale behaviour of the free air gravity field in the region. Marine gravity surveys in the shallow shelf seas around Ireland together with satellite gravity data from the deeper ocean to the west are used to investigate the larger-scale crustal structure of these major basins. Crustal structure derived from wide-angle and vertical incidence seismic data is used to control the interpretation and modeling of gravity data. The Porcupine Basin is situated between the highly stretched crust of the Rockall Basin (where β = 5 to 6) and the thicker Proterozoic crust of the Irish mainland and shelf area, where the crust approaches 30 km in thickness. The crust of the south Porcupine Basin has undergone similar amounts of bulk stretching to that of the southern Rockall Basin and has very similar gravity patterns. The crust of the northern Porcupine Basin is less severely stretched and an axial gravity high is present due to anomalous density variations in the crust or upper mantle. The change in crustal geometry and gravity properties occurs across a distinctive set of NW-trending gravity lineaments, which may correlate with cross-basin crustal faults, controlling large-scale basin segmentation. Lithospheric stretching south of these gravity lineaments involved a large anticlockwise rotation of the southern part of the Porcupine High, while to the north the stretching involved a smaller antipathetic clockwise rotation of the northern Porcupine High. This pattern of tectonic block rotation controls the southward broadening of the Rockall Basin and suggests a strong structural linkage between these two large basins.

  11. Permian-triassic paleogeography and stratigraphy of the west Netherlands basin

    SciTech Connect

    Speksnijder, A. )

    1993-09-01

    During the Permian, the present West Netherlands basin (WNB) was situated at the southernmost margin of the southern Permian basin (SPB). The thickness of Rotilegende sandstones therefore is very much reduced in the WNB. The relatively thin deposits of the Fringe Zechstein in the WNB, however, also contrast strongly in sedimentary facies with thick evaporite/carbonate alternations in the main SPB to the north, although the classic cyclicity of Zechstein deposition still can be recognized. The Fringe Zechstein sediments are mainly siliciclastic and interfinger with both carbonates and anhydrites toward the evaporite basin. End members are thin clay layers that constitute potential seals to underlying Rotliegende reservoirs and relatively thick sandstones (over 100 m net sand) in the western part of the WNB. Nevertheless, favorable reservoir/seal configurations in the Fringe Zechstein seem to be sparse because only minor hydrocarbon occurrences have been proven in the area to date. The situation is dramatically different for the Triassic in the WNB. The [open quotes]Bunter[close quotes] gas play comprises thick Fringe Buntsandstein sandstones (up to 250 m), vertically sealed by carbonates and anhydritic clays of the Muschelkalk and Keuper formations. The Bunter sandstones are largely of the same age as the classic Volpriehausen, Detfurth, and Hardegsen alluvial sand/shale alternations recognized elsewhere, but the upper onlapping transgressive sands and silts correlate with evaporitic clays of the Roet basin to the north. A total volume of 65 x 10[sup 9]m[sup 3] of gas has so far been found in the Triassic Bunter sandstones of the WNB.

  12. Hazard categorization of 100K East and 100K West in-basin fuel characterization program activities. Revision 1

    SciTech Connect

    Alwardt, L.D.

    1995-02-28

    This report provides a hazard categorization of the 105 K East and 105 K West in-basin activities associated with the fuel sampling and transport preparations. It is limited to those characterization activities performed in the 105 KE and 105 KW fuel storage basin structures. The methodology of DOE standard DOE-STD-10227-92 is used. The report documents the determination that the in-basin activities associated with the fuel characterization program are classified as Hazard Category 3 (hazard analysis shows the potential for only significant localized consequences).

  13. Risk assessment of drain valve failure in the K-West basin south loadout pit

    SciTech Connect

    MORGAN, R.G.

    1999-06-23

    The drain valve located in the bottom of the K-West Basin South Loadout Pit (SLOP) could provide an additional leak path from the K Basins if the drain valve were damaged during construction, installation, or operation of the cask loading system. For the K-West Basin SLOP the immersion pail support structure (IPSS) has already been installed, but the immersion pail has not been installed in the IPSS. The objective of this analysis is to evaluate the risk of damaging the drain valve during the remaining installation activities or operation of the cask loading system. Valve damage, as used in this analysis, does not necessarily imply large amounts of the water will be released quickly from the basin, rather valve damage implies that the valve's integrity has been compromised. The analysis process is a risk-based uncertainty analysis where best engineering judgement is used to represent each variable in the analysis. The uncertainty associated with each variable is represented by a probability distribution. The uncertainty is propagated through the analysis by Monte Carlo convolution techniques. The corresponding results are developed as a probability distribution and the risk is expressed in terms of the corresponding complementary cumulative distribution function (''risk curve''). The total risk is the area under the ''risk curve''. The risk of potentially dropping a cask into or on the IPSS and damaging the drain valve is approximately 1 x 10{sup -4} to 2 x 10{sup -5} per year. The risk of objects falling behind the IPSS and damaging the valve is 3 x 10{sup -2} to 6 x 10{sup -3} per year. Both risks are expressed as drain value failure frequencies. The risk of objects falling behind the IPSS and damaging the valve can be significantly reduced by an impact limiter and/or installing a gating or plate over the area bounded by the back of the IPSS and the wall of the SLOP. With either of these actions there is a 90 percent confidence that the frequency of drain valve

  14. Seismotectonics of a diffuse plate boundary: Observations off the Sumatra-Andaman trench

    NASA Astrophysics Data System (ADS)

    Aderhold, K.; Abercrombie, R. E.

    2016-05-01

    The actively deforming Indo-Australian intraplate region off the Sumatra-Andaman trench hosted the largest strike-slip earthquake recorded by modern instruments, the 2012 Mw 8.6 Wharton Basin earthquake, closely followed by a Mw 8.2 aftershock. These two large events ruptured either parallel north-south trending faults or a series of north-south and nearly perpendicular east-west fault planes. No active east-west faults had been identified in the region prior to these earthquakes, and the seismic rupture for these two earthquakes extended past the 800°C isotherm for lithosphere of this age, deep into the oceanic mantle and possibly beyond the inferred transition to ductile failure. To investigate the seismic behavior of this region, we calculate moment tensors with teleseismic body waves for 6.0 ≤ Mw ≤ 8.0 intraplate strike-slip earthquakes. The centroid depths are located throughout the seismogenic mantle and could extend through the oceanic crust, but are generally well constrained by the 600°C isotherm and do not appear to rupture beyond the 800°C isotherm. We conclude that while many earthquakes are consistent with a thermal limit to depth, large magnitude earthquakes may be able to rupture typically aseismic zones. We also perform finite-fault modeling for Mw ≥ 7.0 earthquakes and find a slight preference for rupture on east-west oriented faults for the 2012 Mw 7.2 and 2005 Mw 7.2 earthquakes. This lends support for the presence of active east-west faults in this region, consistent with the majority of previously published models of the 2012 M8+ earthquakes.

  15. Hydrogeology and water quality of the West Valley Creek Basin, Chester County, Pennsylvania

    USGS Publications Warehouse

    Senior, L.A.; Sloto, R.A.; Reif, A.G.

    1997-01-01

    The West Valley Creek Basin drains 20.9 square miles in the Piedmont Physiographic Province of southeastern Pennsylvania and is partly underlain by carbonate rocks that are highly productive aquifers. The basin is undergoing rapid urbanization that includes changes in land use and increases in demand for public water supply and wastewater disposal. Ground water is the sole source of supply in the basin. West Valley Creek flows southwest in a 1.5-mile-wide valley that is underlain by folded and faulted carbonate rocks and trends east-northeast, parallel to regional geologic structures. The valley is flanked by hills underlain by quartzite and gneiss to the north and by phyllite and schist to the south. Surface water and ground water flow from the hills toward the center of the valley. Ground water in the valley flows west-southwest parallel to the course of the stream. Seepage investigations identified losing reaches in the headwaters area where streams are underlain by carbonate rocks and gaining reaches downstream. Tributaries contribute about 75 percent of streamflow. The ground-water and surface-water divides do not coincide in the carbonate valley. The ground-water divide is about 0.5 miles west of the surface-water divide at the eastern edge of the carbonate valley. Underflow to the east is about 1.1 inches per year. Quarry dewatering operations at the western edge of the valley may act partly as an artificial basin boundary, preventing underflow to the west. Water budgets for 1990, a year of normal precipitation (45.8 inches), and 1991, a year of sub-normal precipitation (41.5 inches), were calculated. Streamflow was 14.61 inches in 1990 and 12.08 inches in 1991. Evapotranspiration was estimated to range from 50 to 60 percent of precipitation. Base flow was about 62 percent of streamflow in both years. Exportation by sewer systems was about 3 inches from the basin and, at times, equaled base flow during the dry autumn of 1991. Recharge was estimated to be 18

  16. Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age

    PubMed Central

    2010-01-01

    Background The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA) derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far. Results Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C) and the West Eurasian haplogroups (H and K), whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals. Conclusion Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin. PMID:20163704

  17. Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarctica.

    PubMed

    Joughin, Ian; Smith, Benjamin E; Medley, Brooke

    2014-05-16

    Resting atop a deep marine basin, the West Antarctic Ice Sheet has long been considered prone to instability. Using a numerical model, we investigated the sensitivity of Thwaites Glacier to ocean melt and whether its unstable retreat is already under way. Our model reproduces observed losses when forced with ocean melt comparable to estimates. Simulated losses are moderate (<0.25 mm per year at sea level) over the 21st century but generally increase thereafter. Except possibly for the lowest-melt scenario, the simulations indicate that early-stage collapse has begun. Less certain is the time scale, with the onset of rapid (>1 mm per year of sea-level rise) collapse in the different simulations within the range of 200 to 900 years. PMID:24821948

  18. Testing of sludge coating adhesiveness on fuel elements in 105-K west basin

    SciTech Connect

    Maassen, D.P., Fluor Daniel Hanford

    1997-03-11

    This report summarizes the results from the first sludge adherence tests performed in the 105-K West Basin on N Reactor fuel. The outside surface of the outer fuel elements were brushed, using stainless steel wire brushes, to test the adhesiveness of various types of sludge coatings to the cladding`s surface. The majority of the sludge was removed by the wire brushes in this test but different types of sludge were more adhesive than others. Particularly, an orange rust-like sludge coating that was just slightly more adherent to the fuel`s cladding than the majority of the sludge coatings and a thick white vertical strip sludge coating that was much more difficult to remove. The test demonstrated that all of the sludge could be removed from the outer fuel elements` surfaces if the need arises.

  19. Physical characteristics of stream subbasins in the Pomme de Terre River Basin, west-central Minnesota

    USGS Publications Warehouse

    Lorenz, D.L.; Payne, G.A.

    1994-01-01

    Data describing the physical characteristics of stream subbasins upstream from selected points on streams in the Pomme de Terre River Basin, located in west-central Minnesota, are presented in this report. The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both lakes and wetlands, the main-channel length, and the main-channel slope. The points on the stream include outlets of subbasins of at least 5 square miles, outfalls of sewage treatment plants, and locations of U.S. Geological Survey low-flow, high-flow, and continuous-record gaging stations.

  20. Ground water for irrigation in the Viking Basin, west-central Minnesota

    USGS Publications Warehouse

    McBride, M.S.

    1975-01-01

    The Viking Basin consists of six glacial outwash areas in Douglas, Ottertail, and Todd Counties, west-central Minnesota. Total area is 340 square miles (880 square kilometres). Soils are sandy and excessively well-drained. Crops grown on the outwash would benefit from supplemental irrigation. Irrigation supplies can be obtained from wells in the surface outwash aquifer in significant parts of the large outwash areas near Carlos and Parkers Prairie and the small outwash area near Clotho. Irrigation supplies are unlikely in the outwash areas near Alexandria, Urbank, and Rose City. Major use of ground water for irrigation may lower ground-water levels sufficiently to affect lake and marsh levels and streamflow out of the irrigation areas. Water from the outwash is of excellent chemical quality for irrigation.

  1. Physical characteristics of stream subbasins in the Chippewa River basin, west-central Minnesota

    USGS Publications Warehouse

    Sanocki, C.A.; Krumrie, J.R.

    1994-01-01

    Data that describe the physical characteristics of stream subbasins upstream from selected points on streams in the Chippewa River Basin, located in west-central Minnesota, are presented in this report The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both lakes and wetlands, the main-channel length, and the main-channel slope. The points on the stream include outlets of subbasins of at least 5 square miles, outlets of sewage treatment plants, and locations of U.S. Geological Survey low-flow, high-flow, and continuous-record gaging stations.

  2. Palaeosol Control of Arsenic Pollution: The Bengal Basin in West Bengal, India.

    PubMed

    Ghosal, U; Sikdar, P K; McArthur, J M

    2015-01-01

    Groundwater in the Bengal Basin is badly polluted by arsenic (As) which adversely affects human health. To provide low-As groundwater for As mitigation, it was sought across 235 km(2) of central West Bengal, in the western part of the basin. By drilling 76 boreholes and chemical analysis of 535 water wells, groundwater with <10 µg/L As in shallow aquifers was found under one-third of a study area. The groundwater is in late Pleistocene palaeo-interfluvial aquifers of weathered brown sand that are capped by a palaeosol of red clay. The aquifers form two N-S trending lineaments that are bounded on the east by an As-polluted deep palaeo-channel aquifer and separated by a shallower palaeo-channel aquifer. The depth to the top of the palaeo-interfluvial aquifers is mostly between 35 and 38 m below ground level (mbgl). The palaeo-interfluvial aquifers are overlain by shallow palaeo-channel aquifers of gray sand in which groundwater is usually As-polluted. The palaeosol now protects the palaeo-interfluvial aquifers from downward migration of As-polluted groundwater in overlying shallow palaeo-channel aquifers. The depth to the palaeo-interfluvial aquifers of 35 to 38 mbgl makes the cost of their exploitation affordable to most of the rural poor of West Bengal, who can install a well cheaply to depths up to 60 mbgl. The protection against pollution afforded by the palaeosol means that the palaeo-interfluvial aquifers will provide a long-term source of low-As groundwater to mitigate As pollution of groundwater in the shallower, heavily used, palaeo-channel aquifers. This option for mitigation is cheap to employ and instantly available.

  3. Wake Vortices and Tropical Cyclogenesis Downstream of Sumatra over the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Fine, Caitlin Marie

    A myriad of processes acting singly or in concert may contribute to tropical cyclogenesis, including convectively coupled waves, breakdown of the inter-tropical convergence zone (ITCZ), or upper-level troughs. This thesis investigates the role that topographic effects from the island of Sumatra may play in initiating tropical cyclogenesis (TC genesis) in the eastern Indian Ocean. If easterly flow is split by the mountains of Sumatra, counter-rotating lee vortices may form downstream. Because Sumatra straddles the equator, though the wake vortices rotate in opposite directions, they will both be cyclonic when winds are easterly upon Sumatra, and may intensify further into tropical cyclones. The phenomenon of crossequatorial cyclone pairs, or "twin" tropical cyclones, in the Indian Ocean originating from Sumatra was first noted by Kuettner (1989). TC genesis appears to be particularly favored during the pre-onset phase of the Madden Julian Oscillation (MJO), when easterly flow encroaches upon Sumatra and the resulting cyclonic wake vortices encounter convectively coupled waves and enhanced moisture associated with the MJO in the Indian Ocean. Operational analysis data from the Year of Tropical Convection (YOTC) and Dynamics of the Madden Julian Oscillation (DYNAMO) campaigns were used to evaluate the impacts of Sumatra's topography upon the flow. The YOTC data encompass two years, from May 2008 to April 2010, while the special observing period of DYNAMO was conducted from October to December 2011. This research also presents three case studies of twin tropical cyclones west of Sumatra in the Indian Ocean, which were all determined to originate from Sumatran wake vortices and occurred between October and December of 2008, 2009, and 2011. Multiple cyclonic wake vortices and vorticity streamers were observed downstream of Sumatra during periods of easterly flow, most frequently between October and December. Froude numbers calculated for the region upstream of Sumatra

  4. GPS Analyses of the Sumatra-Andaman Earthquake

    NASA Astrophysics Data System (ADS)

    Khan, S. A.; Gudmundsson, Ólafur

    2005-03-01

    The Sumatra, Indonesia, earthquake on 26 December 2004 was one of the most devastating earthquakes in history. With a magnitude of Mw = 9.3 (revised based on normal-mode amplitudes by Stein and Okal, http://www.earth.northwestern.edu/people/seth/research/sumatra.html), it is the second largest earthquake recorded since 1900. It occurred about 100 km off the west coast of northern Sumatra, where the relatively dense Indo-Australian plate moves beneath the lighter Burma plate, resulting in stress accumulation. The average relative velocity of the two plates is about 6 cm/yr. On 26 December 2004, however, the two plates moved by a distance of several meters, releasing the stress accumulated over hundreds of years. The result was a devastating tsunami that hit coastlines across the Indian Ocean, killing about 300,000 people in Indonesia, Sri Lanka, India, Thailand, Burma, Malaysia, Somalia, and other countries (Guardian, 29 January 2005, http://www.guardian.co.uk/tsunami/story/0,15671,1380895,00.html).

  5. Characterization of Suspect Fuel Rod Pieces from the 105 K West Basin

    SciTech Connect

    Delegard, Calvin H.; Schmidt, Andrew J.; Pool, Karl N.; Thornton, Brenda M.

    2006-09-15

    This report provides physical and radiochemical characterization results from examinations and laboratory analyses performed on ~0.55-inch diameter rod pieces found in the 105 K West (KW) Basin that were suspected to be from nuclear reactor fuel. The characterization results will be used to establish the technical basis for adding this material to the contents of one of the final Multi-Canister Overpacks (MCOs) that will be loaded out of the KW Basin in late FY2006 or at a later time depending on project priorities. Fifteen fuel rod pieces were found during the clean out of the KW Basin. Based on lack of specific credentials, documentation, or obvious serial numbers, none of the items could be positively identified nor could their sources or compositions be described. Item weights and dimensions measured in the KW Basin indicated densities consistent with the suspect fuel rods containing uranium dioxide (UO2), uranium metal, or being empty. Extensive review of the Hanford Site technical literature led to the postulation that these pieces likely were irradiated test fuel prepared to support of the development of the Hanford “New Production Reactor,” later called N Reactor. To obtain definitive data on the composition of the suspect fuel, 4 representative fuel rod pieces, with densities corresponding to oxide fuel were selected from the 15 items, and shipped from the KW Basin to the Pacific Northwest National Laboratory’s (PNNL) Radiological Processing Laboratory (RPL; also known at the 325 Building) for examinations and characterization. The three fuel rod that were characterized appear to contain slightly irradiated UO2 fuel, originally of natural enrichment, with zirconium cladding. The uranium-235 isotopic concentrations decreased by the irradiation and become slightly lower than the natural enrichment of 0.72% to range from 0.67 to 0.71 atom%. The plutonium concentrations, ranged from about 200 to 470 grams per metric ton of uranium and ranged in Plutonium

  6. Linear sea-level response to abrupt ocean warming of major West Antarctic ice basin

    NASA Astrophysics Data System (ADS)

    Mengel, M.; Feldmann, J.; Levermann, A.

    2016-01-01

    Antarctica's contribution to global sea-level rise has recently been increasing. Whether its ice discharge will become unstable and decouple from anthropogenic forcing or increase linearly with the warming of the surrounding ocean is of fundamental importance. Under unabated greenhouse-gas emissions, ocean models indicate an abrupt intrusion of warm circumpolar deep water into the cavity below West Antarctica's Filchner-Ronne ice shelf within the next two centuries. The ice basin's retrograde bed slope would allow for an unstable ice-sheet retreat, but the buttressing of the large ice shelf and the narrow glacier troughs tend to inhibit such instability. It is unclear whether future ice loss will be dominated by ice instability or anthropogenic forcing. Here we show in regional and continental-scale ice-sheet simulations, which are capable of resolving unstable grounding-line retreat, that the sea-level response of the Filchner-Ronne ice basin is not dominated by ice instability and follows the strength of the forcing quasi-linearly. We find that the ice loss reduces after each pulse of projected warm water intrusion. The long-term sea-level contribution is approximately proportional to the total shelf-ice melt. Although the local instabilities might dominate the ice loss for weak oceanic warming, we find that the upper limit of ice discharge from the region is determined by the forcing and not by the marine ice-sheet instability.

  7. New insights into the inversion history of the West Natuna Basin

    SciTech Connect

    Ginger, D.C.; Pothecary, J.; Hedley, R.J.

    1994-07-01

    Late Eocene to mid-Oligocene transtensional rifting created a complex network of graben in the West Natuna and Malay basins. From the earliest Miocene, the grabens were inverted to form folds and wrench zones as a result of a right-lateral stress regime. The nature of the inversion is strongly controlled by the orientation of underlying rift faults with respect to the principal stress, [sigma][sub 1]. Rift basins with a strike oriented at a high angle to the principal stress form folds through reactivation of graben-bounding faults. In these rifts the synrift graben fill is inverted over the graben footwall, often along a fault with a convex upward geometry. The magnitude of inversion is closely correlated to the heave of the initial extensional faults; large extensional faults often have large inversion folds associated with them and vice versa. Within any one graben, inversion appears to commence at younger ages away from these large faults. The mechanisms of inversion fold development have been investigated using detailed interpretations of modern seismic data and a section balancing and restoration computer software package. Results of this work are presented in support of the conclusions documented in this paper. The original grabens were formed through extension of basement equivalent to [beta] = 1.05 to 1.30. In most grabens, at least some of the extension was removed by the subsequent inversion. Amounts of shortening range from 2 to 18%, equivalent to removal of between 40 and 100% of the original graben extension.

  8. Monthly streamflow prediction in the Volta Basin of West Africa: A SISO NARMAX polynomial modelling

    NASA Astrophysics Data System (ADS)

    Amisigo, B. A.; van de Giesen, N.; Rogers, C.; Andah, W. E. I.; Friesen, J.

    Single-input-single-output (SISO) non-linear system identification techniques were employed to model monthly catchment runoff at selected gauging sites in the Volta Basin of West Africa. NARMAX (Non-linear Autoregressive Moving Average with eXogenous Input) polynomial models were fitted to basin monthly rainfall and gauging station runoff data for each of the selected sites and used to predict monthly runoff at the sites. An error reduction ratio (ERR) algorithm was used to order regressors for various combinations of input, output and noise lags (various model structures) and the significant regressors for each model selected by applying an Akaike Information Criterion (AIC) to independent rainfall-runoff validation series. Model parameters were estimated from the Matlab REGRESS function (an orthogonal least squares method). In each case, the sub-model without noise terms was fitted first followed by a fitting of the noise model. The coefficient of determination ( R-squared), the Nash-Sutcliffe Efficiency criterion (NSE) and the F statistic for the estimation (training) series were used to evaluate the significance of fit of each model to this series while model selection from the range of models fitted for each gauging site was done by examining the NSEs and the AICs of the validation series. Monthly runoff predictions from the selected models were very good, and the polynomial models appeared to have captured a good part of the rainfall-runoff non-linearity. The results indicate that the NARMAX modelling framework is suitable for monthly river runoff prediction in the Volta Basin. The several good models made available by the NARMAX modelling framework could be useful in the selection of model structures that also provide insights into the physical behaviour of the catchment rainfall-runoff system.

  9. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Mendez, Daniel L.

    2001-05-08

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstone's of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover oil more economically through geologically based field development. This project was focused on East Ford field, a Delaware Mountain Group field that produced from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 9160, is operated by Oral Petco, Inc., as the East Ford unit. A CO2 flood was being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  10. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.

    2001-11-04

    The objective of this Class III project was demonstrate that reservoir characterization and enhanced oil recovery (EOR) by CO2 flood can increase production from slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico. Phase 1 of the project, reservoir characterization, focused on Geraldine Ford and East Ford fields, which are Delaware Mountain Group fields that produce from the upper Bell Canyon Formation (Ramsey sandstone). The demonstration phase of the project was a CO2 flood conducted in East Ford field, which is operated by Orla Petco, Inc., as the East Ford unit.

  11. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.

    2000-07-07

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstone's of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two main phases. The original objectives of the reservoir-characterization phase of the project were (1) to provide a detailed understanding of the architecture and heterogeneity of two representative fields of the Delaware Mountain Group, Geraldine Ford and Ford West, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, (2) to chose a demonstration area in one of the fields, and (3) to simulate a CO{sub 2} flood in the demonstration area.

  12. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Dutton, Shirley

    1999-11-09

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two main phases. The original objectives of the reservoir-characterization phase of the project were (1) to provide a detailed understanding of the architecture and heterogeneity of two representative fields of the Delaware Mountain Group, Geraldine Ford and Ford West, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, (2) to chose a demonstration area in one of the fields, and (3) to simulate a CO 2 flood in the demonstration area.

  13. Paleoenvironmental and tectonostratigraphic evolution of the west Cumberland Basin of Nova Scotia and New Brunswick during the Upper Mississippian

    NASA Astrophysics Data System (ADS)

    McLeod, Jason R.

    2010-06-01

    The Cumberland Basin, which spans the provinces of Nova Scotia and New Brunswick, contains one of the most complete stratigraphic records of upper Mississippian (Visean -- Namurian) strata within the Maritimes Basin. The paleoenvironmental and tectonostratigraphic evolution of these units is here assessed, as well as lateral variations and stratigraphic relationships between upper Mississippian units in the western half of the basin. This exercise resulted in necessary petrographic and stratigraphic correlations across the study area, and several redundancies and inconsistencies in the pre-existing stratigraphic nomenclature were identified and informally amended based on equivalencies and precedence. Three source areas were identified in the west Cumberland Basin during the upper Mississippian, and a paleogeographic model was created for that interval based on geophysical, paleocurrent, provenance and facies distribution data.

  14. Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Allander, Kip K.

    2009-01-01

    The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline

  15. Base-flow data for the Little West Fork Basin, Fort Campbell, Tennessee and Kentucky, 1993 and 1994

    USGS Publications Warehouse

    Ladd, D.E.

    1996-01-01

    Base-flow data were collected from selected sites within the Little West Fork Red River basin during high and low base-flow conditions in order to support a study of the source and movement of ground water that supplies the Fort Campbell Military Reservation. Stream and spring discharge, water temperature, and specific-conductance data were collected during low base-flow conditions from 64 sites on September 1 and 13, 1993, and from 64 sites on March 17 and 18, 1994. Discharge was greater during high base-flow conditions than low base-flow conditions. Major tributaries on the south side of the study area consistently had lower flow than the tributaries on the north side. Discharge data were used to categorize stream reaches and sub-basins. Stream reaches were categorized as gaining or losing, wet, dry, or unobserved for each base-flow measurement period. More dry stream reaches occurred during the two low base-flow periods than during the high base-flow period. Sub-basin areas with surplus or deficient flow were also defined. Many areas of deficient flow occurred near the headwaters of the Little West Fork basin under all base-flow conditions. Fewer areas of deficient flow occurred near the mouth of the basin. The flow per square mile for each major tributary basin in the study area was also calculated. The values of flow per square mile for the tributary basins in the northern part of the study area were greater than those for the tributary basins in the southern part of the study area under all base-flow conditions.

  16. Sedimentary response to orogenic exhumation in the northern rocky mountain basin and range province, flint creek basin, west-central Montana

    USGS Publications Warehouse

    Portner, R.A.; Hendrix, M.S.; Stalker, J.C.; Miggins, D.P.; Sheriff, S.D.

    2011-01-01

    Middle Eocene through Upper Miocene sedimentary and volcanic rocks of the Flint Creek basin in western Montana accumulated during a period of significant paleoclimatic change and extension across the northern Rocky Mountain Basin and Range province. Gravity modelling, borehole data, and geologic mapping from the Flint Creek basin indicate that subsidence was focused along an extensionally reactivated Sevier thrust fault, which accommodated up to 800 m of basin fill while relaying stress between the dextral transtensional Lewis and Clark lineament to the north and the Anaconda core complex to the south. Northwesterly paleocurrent indicators, foliated metamorphic lithics, 64 Ma (40Ar/39Ar) muscovite grains, and 76 Ma (U-Pb) zircons in a ca. 27 Ma arkosic sandstone are consistent with Oligocene exhumation and erosion of the Anaconda core complex. The core complex and volcanic and magmatic rocks in its hangingwall created an important drainage divide during the Paleogene shedding detritus to the NNW and ESE. Following a major period of Early Miocene tectonism and erosion, regional drainage networks were reorganized such that paleoflow in the Flint Creek basin flowed east into an internally drained saline lake system. Renewed tectonism during Middle to Late Miocene time reestablished a west-directed drainage that is recorded by fluvial strata within a Late Miocene paleovalley. These tectonic reorganizations and associated drainage divide explain observed discrepancies in provenance studies across the province. Regional correlation of unconformities and lithofacies mapping in the Flint Creek basin suggest that localized tectonism and relative base level fluctuations controlled lithostratigraphic architecture.

  17. Sampling and analysis plan for sludge located in fuel storage canisters of the 105-K West basin

    SciTech Connect

    Baker, R.B.

    1997-04-30

    This Sampling and Analysis Plan (SAP) provides direction for the first sampling of sludge from the K West Basin spent fuel canisters. The specially developed sampling equipment removes representative samples of sludge while maintaining the radioactive sample underwater in the basin pool (equipment is described in WHC-SD-SNF-SDD-004). Included are the basic background logic for sample selection, the overall laboratory analyses required and the laboratory reporting required. These are based on requirements put forth in the data quality objectives (WHC-SD-SNF-DQO-012) established for this sampling and characterization activity.

  18. Arsenic contamination in parts of Yamuna sub-basin, West Bengal.

    PubMed

    Joshi, Himanshu; Ghosh, A K; Singhal, D C; Kumar, Sudhir

    2003-10-01

    Arsenic rarely occurs in free state and is generally found in combination with Sulphur, Oxygen and Iron. In the environment, Arsenic occurs as a result of several inputs that contain this element in organic and inorganic forms. Arsenic is present in Coal, Lead, Zinc, Gold and Copper ores in the form of several minerals viz. Arsenopyrite (FeAsS), Orpiment (As2S3), Realgar (AsS), Arsenolite (As2O3) and Lollingite (FeAs2). The commonly existing species in groundwater are in two forms viz. Arsenite [As(III)] which is the reduced state of inorganic Arsenic and Arsenate [As(V)], which is the oxidized state of inorganic Arsenic, The As(III) form is more mobile and toxic for living organisms. Recently, the symptoms of chronic arsenic poisoning have been observed in many parts of West Bengal (India) and Bangladesh. In the present study, an integrated evaluation of hydrogeology and hydrochemistry has been carried out by processing the available data of Yamuna sub-basin (Part of Nadia and North 24 Parganas district) of West Bengal in order to understand the possible reason of arsenic pollution in the ground water. Arsenic has generally been observed in higher concentration in shallow aquifer. Northwestern region of the study area has been observed to be the most effected with premonsoon periods exhibiting higher concentration. Transmissivity values have been observed to vary inversely with arsenic concentrations. Arsenic values have not indicated any well defined association with many other constituents. Arsenic buildup could also not be conclusively related to lowering of ground water table of the study area.

  19. A Seismic Gap Study in the western offshore of Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Haridhi, H. A.; Rizal, S.; Ridha, M.; Lee, C.

    2011-12-01

    The extremely destructive earthquake in December 26th 2004 and by the resulting tsunami was the worst natural disasters in recorded human history. However, the tsunami earthquakes continue to strike the west coast of Sumatra in the last 8 years. There are at least 12 events, the earthquake Magnitude between M = 7 to 8.9. The tragedies continue to add up to the already damaged coastal zone. In 2010 (after 6 years of the 2004 event), an earthquake of a magnitude 7.8 resulting a destructive tsunami was also happened near Mentawai Island at west coast of West Sumatra Province. Several thousand of people died and many houses buried. In order to have a better understanding of the seismic stress distribution and prepare for a future study including an IODP drilling in this area, we adopt the previous studies by French, Japan and German together with the absolute gravity data and seismic networks by the IRIS and Taiwan Central Weather Bureau for this research. In the last eight years, the Sumatra region already experienced two domains of the tsunami earthquake swamps, one in the north of Sumatra and the other in the south. Here, we present broadband earthquake data from the IRIS-NEIC catalogue between 2004 and 2010. The result shows that there is a possible of seismic gap in the border of central - southern domain of Sumatra region. This region included in the Northern Sumatra Province near Batu Island. The historical earthquake along the Sumatra margin since 17th century showed that the last big rapture in this border of central - southern domain was occurred in 1797 by the magnitude of 8.8 (Lange et al., 2010). In the other hand, the free-air gravity anomaly (Barber et al., 2005) shows high values correspond to the N-S oceanic fracture zone. All the high value was found near the trench of Sumatra subduction zone and gradually lower value through the south. Regarding to the stress release of the subducting Indo-Australian Oceanic Plate beneath Eurasian Plate, we also

  20. Nuussuaq basin of west Greenland: Subsidence and structural inversion in an Albian - early Tertiary pull-apart basin

    SciTech Connect

    Tankard, A. ); Ng, T. ) Renner, T. )

    1996-01-01

    The western margin of Greenland consists of a complex of linked extensional basins which formed during opening of Labrador Sea and Baffin Bay in Albian - early Tertiary time. The Nuussuaq basin, which straddles Nuussuaq peninsula and Disko Island, is onshore. Its sedimentary succession is generally hidden beneath a cover of early Tertiary extrusives. Slim-hole exploration drilling has been based on an integrated basin analysis and magnetotelluric data acquisition. Nuussuaq basin developed at a left-lateral releasing stepover at the end of the Ungava fault, an interplate strike-slip fault zone. SW-directed extension was accommodated by several transfer faults which compartmented the Nuussuaq basin. Although the principal depocenter is only 1500 km[sup 2] in area, interpretation of the magnetotelluric: data shows basin depths greater than 10 km. Persistent overpressuring and the low resistivity lower basin fill are believed to be typical of a young basin which has subsided rapidly. The Cretaceous - lower Tertiary succession is indicative of a restricted, underfilled basin. In contrast, the mid-Paleocene paleogeography was controlled by dextral slip along the basement strike-slip fault zones, broadscale structural inversion of the earlier extensional faults, and widespread volcanism. Catastrophic crestal collapse of inversion anticlines is reflected in sudden incision and rapid filling of a suite of paleovalleys. In Paleocene time, the Nuussuag basin was generally overfilled and dominated by terrestrial depositional systems. Oil seeps are associated with crestal collapse and fracturing of inversion structures. Biomarkers suggest a source rock of Paleocene age.

  1. Nuussuaq basin of west Greenland: Subsidence and structural inversion in an Albian - early Tertiary pull-apart basin

    SciTech Connect

    Tankard, A.; Ng, T. Renner, T.

    1996-12-31

    The western margin of Greenland consists of a complex of linked extensional basins which formed during opening of Labrador Sea and Baffin Bay in Albian - early Tertiary time. The Nuussuaq basin, which straddles Nuussuaq peninsula and Disko Island, is onshore. Its sedimentary succession is generally hidden beneath a cover of early Tertiary extrusives. Slim-hole exploration drilling has been based on an integrated basin analysis and magnetotelluric data acquisition. Nuussuaq basin developed at a left-lateral releasing stepover at the end of the Ungava fault, an interplate strike-slip fault zone. SW-directed extension was accommodated by several transfer faults which compartmented the Nuussuaq basin. Although the principal depocenter is only 1500 km{sup 2} in area, interpretation of the magnetotelluric: data shows basin depths greater than 10 km. Persistent overpressuring and the low resistivity lower basin fill are believed to be typical of a young basin which has subsided rapidly. The Cretaceous - lower Tertiary succession is indicative of a restricted, underfilled basin. In contrast, the mid-Paleocene paleogeography was controlled by dextral slip along the basement strike-slip fault zones, broadscale structural inversion of the earlier extensional faults, and widespread volcanism. Catastrophic crestal collapse of inversion anticlines is reflected in sudden incision and rapid filling of a suite of paleovalleys. In Paleocene time, the Nuussuag basin was generally overfilled and dominated by terrestrial depositional systems. Oil seeps are associated with crestal collapse and fracturing of inversion structures. Biomarkers suggest a source rock of Paleocene age.

  2. Orbital forced rhythmites in the upper Lamar Limestone (Guadalupian) of the Delaware Basin, West Texas, USA

    NASA Astrophysics Data System (ADS)

    Jin, Y.; Xuan, C.; Noble, P. J.

    2010-12-01

    Gray scale data, radiolarian relative abundance, and three types of geochemical data (oxygen isotope of bulk carbonates, organic carbon isotope, and total organic carbon) collected from an ~8 m section of the upper Lamar Limestone (Guadalupian) in the Delaware Basin, West Texas, USA, show apparent rhythms that mimic orbital variations. Spectral analyses on the radiolarian relative abundance and geochemical data, using Blackman-Tukey, multi-taper, maximum entropy, and REDFIT (Schulz, M., Mudelsee, M., 2002, REDFIT: estimating red-noise spectra directly from unevenly spaced paleoclimatic time series. Comput. Geosci. 28, 421-426) methods, reveal a common period with cycle length of ~1.16 m. Another spectral peak, which corresponds to period with cycle length of ~5.50 m, appears to be common in power spectra of the geochemical proxies. Power spectra of the high-resolution gray scale data are dominated by periods that have cycle length around 1.2-1.6 m, 0.67 m, 0.24-0.31 m, 0.14-0.18 m, and 0.07-0.09 m. Wavelet analyses confirm the existence of these cycles, and suggest that the power of the dominant periods in these parameters varies through the section, presumably due to accumulation rate variations. Average spectral misfit calculation (Meyers, S.R., Sageman, B.B., 2007, Quantification of deep-time orbital forcing by average spectral misfit. Am. J. Sci. 307, 773-792) using dominant frequencies from the power spectra of the gray scale data implies that average accumulation rates of ~1.5 cm/kyr provide the best fit of the data to orbital frequencies. Statistic tests for rejecting the null hypothesis (no orbital signal), on a wide range of average accumulation rates, also suggest lowest significance levels of the tests for accumulation rates around 1.5 cm/kyr. The ~1.5 cm/kyr accumulation rates are within the accumulation rate range estimated for the Capitanian strata in the basin-margin facies of the Delaware Basin. The Lamar Limestone appears to record the eccentricity

  3. Basin Hydrology and Substrate Controls on Mountain Stream Morphology: Highlands of Southeastern West Virginia

    NASA Astrophysics Data System (ADS)

    Burks, T. W.; Springer, G. S.

    2004-12-01

    Evolution of mountain drainage basins across a broad spectrum of geologic, tectonic, and climatic conditions is an active area of investigation in the field of fluvial geomorphology. Mountain streams are typified by steep channel gradients (>0.002), high channel roughness, rapid changes in drainage area, and high spatial and low temporal variability in channel morphology, leading to complexities in landscape modeling relative to their lowland counterparts. Factors driving this recent investigative trend are the refinement and generation of digital topographic data and terrain analysis software, and more importantly, the demand for a multidiscipline approach to the assessment, restoration, and management of entire watersheds. A significant volume of research has been conducted in mountain drainage basins of the western United States, with particular attention paid to tectonically active regions of the Pacific Northwest, which also contain federally listed threatened and endangered salmonid populations. Brook trout (Salvelinus fontinalis), native to the highlands of the eastern margin of the Appalachian Plateau are impacted by acid rain deposition; however, geomorphic research into landscape modeling, applicable to restoration and management of lotic ecosystems of the eastern United States, is comparatively lacking. This current research explores the potential for modeling channel morphology in mountain streams; specifically, how downstream trends in channel substrate resistance and unit stream power effect the partitioning of mountain stream morphology along and downstream of the fluvial/colluvial transition. In order to address this issue, two mountain drainage basins in the headwaters of the Gauley River watershed on the Appalachian Plateau of southeastern West Virginia were chosen. The westerly flowing Cranberry (250 sqkm) and Cherry (429 sqkm) rivers incise gently northwestward dipping Carboniferous-aged strata (shale, minor coal, siltstone, sandstone, and

  4. Hazard categorization of 100K east and 100K west in-basin fuel characterization program activities

    SciTech Connect

    Alwardt, L.D.

    1994-11-16

    This report documents the determination that the in-basin activities at 105 K East (KE) and 105 K West (KW) on the Hanford Reservation associated with the fuel characterization program are classified as Hazard Category 3 (hazard analysis shows the potential for only significant localized consequences). Potential accident consequences, a description of significant activities around the site, and hazard identification and management were explored.

  5. West Siberian basin hydrogeology - regional framework for contaminant migration from injected wastes

    SciTech Connect

    Foley, M.G.

    1994-05-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated site hydrogeology. Calibration studies of the regional hydrogeologic computer model suggest that most precipitation entering the ground-water system moves in the near-surface part of the system and discharges to surface waters relatively near its point of infiltration. This means that wastes discharged to the surface and near-surface may not be isolated as well as previously thought, since the wastes may be carried to the surface by gradually rising ground waters.

  6. Intercomparison of Evapotranspiration Over the Savannah Volta Basin in West Africa Using Remote Sensing Data

    PubMed Central

    Opoku-Duah, S.; Donoghue, D.N.M.; Burt, T. P.

    2008-01-01

    This paper compares evapotranspiration estimates from two complementary satellite sensors – NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and ESA's ENVISAT Advanced Along-Track Scanning Radiometer (AATSR) over the savannah area of the Volta basin in West Africa. This was achieved through solving for evapotranspiration on the basis of the regional energy balance equation, which was computationally-driven by the Surface Energy Balance Algorithm for Land algorithm (SEBAL). The results showed that both sensors are potentially good sources of evapotranspiration estimates over large heterogeneous landscapes. The MODIS sensor measured daily evapotranspiration reasonably well with a strong spatial correlation (R2=0.71) with Landsat ETM+ but underperformed with deviations up to ∼2.0 mm day-1, when compared with local eddy correlation observations and the Penman-Monteith method mainly because of scale mismatch. The AATSR sensor produced much poorer correlations (R2=0.13) with Landsat ETM+ and conventional ET methods also because of differences in atmospheric correction and sensor calibration over land.

  7. Eruptive modes and hiatus of volcanism at West Mata seamount, NE Lau basin: 1996-2012

    NASA Astrophysics Data System (ADS)

    Embley, Robert W.; Merle, Susan G.; Baker, Edward T.; Rubin, Kenneth H.; Lupton, John E.; Resing, Joseph A.; Dziak, Robert P.; Lilley, Marvin D.; Chadwick, William W.; Shank, T.; Greene, Ron; Walker, Sharon L.; Haxel, Joseph; Olson, Eric; Baumberger, Tamara

    2014-10-01

    present multiple lines of evidence for years to decade-long changes in the location and character of volcanic activity at West Mata seamount in the NE Lau basin over a 16 year period, and a hiatus in summit eruptions from early 2011 to at least September 2012. Boninite lava and pyroclasts were observed erupting from its summit in 2009, and hydroacoustic data from a succession of hydrophones moored nearby show near-continuous eruptive activity from January 2009 to early 2011. Successive differencing of seven multibeam bathymetric surveys of the volcano made in the 1996-2012 period reveals a pattern of extended constructional volcanism on the summit and northwest flank punctuated by eruptions along the volcano's WSW rift zone (WSWRZ). Away from the summit, the volumetrically largest eruption during the observational period occurred between May 2010 and November 2011 at ˜2920 m depth near the base of the WSWRZ. The (nearly) equally long ENE rift zone did not experience any volcanic activity during the 1996-2012 period. The cessation of summit volcanism recorded on the moored hydrophone was accompanied or followed by the formation of a small summit crater and a landslide on the eastern flank. Water column sensors, analysis of gas samples in the overlying hydrothermal plume and dives with a remotely operated vehicle in September 2012 confirmed that the summit eruption had ceased. Based on the historical eruption rates calculated using the bathymetric differencing technique, the volcano could be as young as several thousand years.

  8. Epidemiology of west nile in europe and in the mediterranean basin.

    PubMed

    Calistri, Paolo; Giovannini, Armando; Hubalek, Zdenek; Ionescu, Aurelia; Monaco, Federica; Savini, Giovanni; Lelli, Rossella

    2010-01-01

    In the last 30 years several cases of West Nile (WN) virus infection were reported in horses and humans in Europe and in the Mediterranean Basin. Most of them were determined by strains of the Lineage 1 included in the European Mediterranean/Kenyan cluster. Strains of this cluster are characterised by a moderate pathogenicity for horses and humans and limited or no pathogenicity for birds. In recent years, however, WN cases determined by strains grouped in the Israeli/American cluster of Lineage 1 or in the lineage 2 have been reported in Hungary and Austria. The role of migrating birds in introducing new viruses to Europe has been often demonstrated. The migratory birds, which may be infected in their African wintering places, carry the virus northward to European sites during spring migrations. In the past, the virus introduction determined occasional cases of WN. In the recent years, new epidemiological scenarios are developing. In few occasions it has been evidenced the capability of WNV strains of overwintering by using local birds and mosquitoes. Species of Culex amongst mosquitoes and magpies (Pica pica), carrion crows (Corvus corone) and rock pigeons (Columba livia) amongst resident birds are the most probable species involved in this hypothetical WND endemic cycle.

  9. Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

    NASA Astrophysics Data System (ADS)

    Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

    2009-04-01

    Drained thaw lake basins in Western Siberia have a local name "khasyreis" [1]. Khasyreis as well as lakes, ponds and frozen mounds are invariable element of sub-arctic frozen peat bogs - palsas and tundra landscapes. In some areas of West-Siberian sub-arctic khasyreis occupy up to 40-50% of total lake area. Sometimes their concentration is so high that we call such places ‘khasyrei's fields". Khasyreis are part of the natural cycle of palsa complex development [1], but their origin is not continuous and uniform in time and, according to our opinion, there were periods of more intensive lake drainage and khasyrei development accordingly. These times were corresponding with epochs of climatic warming and today we have faced with one of them. So, last years this process was sufficiently activated in the south part of West-Siberian sub-arctic [2]. It was discovered that in the zone of continuous permafrost thermokarst lakes have expanded their areas by about 10-12%, but in the zone of discontinuous permafrost the process of their drainage prevails. These features are connected with the thickness of peat layers which gradually decreases to the North, and thus have reduced the opportunity for lake drainage in northern areas. The most typical way of khasyrei origin is their drainage to the bigger lakes which are always situated on the lower levels and works as a collecting funnels providing drainage of smaller lakes. The lower level of the big lake appeared when the lake takes a critical mass of water enough for subsidence of the lake bottom due to the melting of underlaying rocks [2]. Another one way of lake drainage is the lake intercept by any river. Lake drainage to the subsurface (underlaying rocks) as some authors think [3, 4] is not possible in Western Siberia, because the thickness of permafrost is at list 500 m here being safe confining bed. We mark out few stages of khasyrei development: freshly drained, young, mature and old. This row reflects stages of

  10. Middle-Miocene counterclockwise rotation of rocks from west-central Nevada; implications for Basin and Range extension

    SciTech Connect

    Hudson, M.R.; Geissman, J.W.

    1985-01-01

    Drilling and geophysical data from Dixie Valley and Fallon Basin of west-central Nevada have shown that dip-slip normal faults accommodated post-Miocene Basin and Range extension in this area, but the presence of an earlier, less-understood phase of Basin and Range deformation is suggested in the adjacent West Humboldt, Stillwater, and Clan Alpine Ranges where the late-Miocene basalts lie in angular unconformity on Oligocene to early-Miocene ash-flow tuffs. Paleomagnetic components obtained from the tuffs and underlying gabbroic and basaltic rocks of the Jurassic Humboldt Lopolith have declinations that are statistically different and counterclockwise from the expected Oligo-Miocene and Jurassic directions for the area. Paleomagnetic components from the late-Miocene basalts statistically overlap their expected direction. These data imply that the rocks were rotated counterclockwise during middle-Miocene. The common association of such rotations with strike-slip faulting suggests that this earlier phase of Basin and Range extension was largely a strike-slip faulting deformation. If so, the total amount of extension in the area may be significantly larger than estimates based solely on the moderate tilts (<30/sup 0/) of the ranges.

  11. Late Pliocene and Early Pleistocene Temperature Reconstructions from Paleolakes of the West Turkana and North Awash Basins, East Africa

    NASA Astrophysics Data System (ADS)

    Castañeda, I. S.; Thompson-Munson, M.; Lupien, R.; Russell, J. M.

    2015-12-01

    The Hominin Sites and Paleolakes Drilling Project (HSPDP) aims to reconstruct past environments of the East African Rift Valley from locations in close proximity to some of the world's most important fossil hominin and artifact sites. In this study, we investigate sediments from the West Turkana and North Awash Basins, which were recently drilled as part of the HSPDP. The North Awash Basin contains abundant early hominin fossils and the lakebeds of the Hadar Formation (~3.6 to ~2.9 Ma) will provide a record of climate variability during the Pliocene, prior to the intensification of Northern Hemisphere glaciation at ~2.7 Ma. The lakebeds of the Turkana Basin are Early Pleistocene in age (~1.9 to ~1.45 Ma) and span the interval that includes some the earliest fossils of Homo rudolfensis and H. ergaster/erectus. Here we examine the organic geochemistry of West Turkana and North Awash Basin sediments and investigate the use of proxies based on isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs) to reconstruct temperature, including TEX86 and the methylation and cyclization (MBT and CBT) ratios and relative abundances of branched GDGTs. We also examine variability in the abundances and ratios of plant leaf waxes (n-alkanes) to provide insight into past vegetation changes on the East African landscape.

  12. Variation in forearc basin development along the Sunda Arc, Indonesia

    NASA Astrophysics Data System (ADS)

    van der Werff, W.

    The present forearc basin configuration along the Sunda Arc initially appears to have been controlled by extension and differential subsidence of basement blocks in response to the late Eocene collision of India with Asia. The late Oligocene increase in convergence between the South-east Asian and Indian Plates associated with a new pulse of subduction, resulted in basement uplift and the formation of a regional unconformity that can be recognized along the entire Sunda Arc. From the early to late Miocene, the Sumba and Savu forearc sectors along the eastern Sunda Arc may have been characterized by forearc extension. Submarine fan deposition on the arcward side of the evolving accretionary prism represents the first phase in forearc basin deposition. These fans were subsequently covered by basin and slope sediments derived from the evolving magmatic arc. Structural response to increased late Miocene compression varied along strike of the Sunda Arc. North of Bali, Lombok and Sumbawa, the incipient collision between Australia and the western Banda Arc caused back-arc thrusting and basin inversion. Towards the south of Java, an increase in both the size of the accretionary prism and convergence rates resulted in uplift and large scale folding of the outer forearc basin strata. Along the west coast of Sumatra, increased compression resulted in uplift along the inner side of the forearc along older transcurrent faults. Uplift of West Sumatra was followed by the deposition of a westward prograding sequence of terrigenous sediments that resulted in the development of a broad shelf. Initial forearc basin subsidence relates to the age of the subducting oceanic lithosphere, on top of which the basin is situated. Along the western Sunda Arc, both fexural loading of the evolving accretionary prism, and across arc strike-slip faulting represent additional factors that result in forearc subsidence.

  13. Timing the structural events in the Palaeoproterozoic Bolé-Nangodi belt terrane and adjacent Maluwe basin, West African craton, in central-west Ghana

    NASA Astrophysics Data System (ADS)

    de Kock, G. S.; Théveniaut, H.; Botha, P. M. W.; Gyapong, W.

    2012-04-01

    deposited concordantly on the submerged Sunyani strata after a hiatus of 20 million years. After cessation of the NW-SE-directed compression the early Tanina Suite intruded as batholiths, dykes and sheets and produced garnet, staurolite, sillimanite and kyanite in their thermal aureoles. Docking of the Sunyani basin produced the DE2 thrust related folding and stacking in the deformed and granitoid invaded Maluwe basin as well as the single stage sin- and anticlinoria in the Sunyani and Banda Groups. In the Maluwe basin the Abulembire fragment acted as a resistor and the approaching front rotated anticlockwise and clockwise around the barrier to form west- and north-directed piggy-back thrust-stacking and deformation of the Tanina Suite granitoids. Due to the low metamorphic conditions the DE2 fabric is limited to crenulation cleavages in the more psammitic and pelitic units. The fold axes are double plunging (N-S and E-W) up to 60° with the axial planar fabric subvertical. Post-D2 tectonic relaxation has allowed the emplacement of the last Tanina Suite calc-alkaline melts and was succeeded by N-S extension fracturing (DE3) along which mantle derived Wakawaka gabbroids and syenite intruded. The DE1 folding occurred between 2125 and 2122 Ma and DE2 before 2119 Ma. The tectonic relaxation occurred at 2118 Ma. Around 2100 Ma, NE-SW directed strike-slip shearing (DE4), fractured the Bolé-Nangodi terrane and enhanced the basin-belt boundary. Along the boundary, the displacement was dextral along vertical faults but, southward, it became more east-over-west thrust related. Associated tension gashes are filled with vein quartz and pegmatite and typical of the brittle sector of the crust. Tectonism in this part of the intraoceanic accretionary arc back-arc complex was concluded by limited, right-lateral strike-slip (DE5) movement which formed some breccias.

  14. Unreviewed safety question evaluation of 100K East and 100K West in-basin fuel characterization program activities

    SciTech Connect

    Alwardt, L.D.

    1995-01-12

    The purpose of this report is to provide the basis for answers to an Unreviewed Safety Question (USQ) safety evaluation of the 105K East (KE) and 105K West (KW) in-basin activities associated with the fuel characterization program as described in the characterization shipping plan. The significant activities that are common to both 105 KE and 105 KW basins are the movement of canisters from their main basin storage locations (or potentially from the 105 KE Tech View Pit if a dump table is available) to the south loadout pit transfer channel, hydrogen generation testing in the single element fuel container, loading the single element fuel container into the shipping cask, loading of the shipping cask onto a flat-bed trailer, return of the test fuel elements or element pieces from the 327 facility, placement of the fuel elements back into Mark 2 canisters, and placement of the canisters in the main storage basin. Decapping of canisters in the south loadout pit transfer channel and re-encapsulation of canisters are activities specific to the 105 KW basin. The scope of this safety evaluation includes only those characterization fuel shipment activities performed in the 105 KE and 105 KW fuel storage basin structures up to installation of the overpack. The packaging safety evaluation report governs the shipment of the fuel elements. The K Basins Plant Review Committee has determined that the in-basin activities associated with the fuel characterization program fuel shipments are bounded by the current safety envelop and do not constitute an unreviewed safety question. This determination is documented on Attachment 1.

  15. Basin development and structure of the area covered by Tertiary basalts, offshore central West Greenland - implications of subvolcanic plays

    SciTech Connect

    Whittaker, R.C.; Bate, K.J.; Chalmers, J.A. )

    1996-01-01

    The West Greenland shelf area between 68[degrees] and 72[degrees] is covered by Lower Tertiary basalts and has so far proved difficult to explore seismically compared to the offshore basins farther north (Melville Bay) and south (southern West Greenland). A first seismic and geological interpretation of the basalt area has lead to a better understanding of the tectonic events during the Tertiary and their implications for hydrocarbon exploration. After a period of extension accompanied by basalt volcanic in the Paleocene, a period of transpression occurred related to sea-floor spreading in the Labrador Sea and Baffin Bay. The crests of the anticlines formed were then eroded and transgressive marine sediments infilled the irregular topography and formed a number of restricted basins. Strike-slip faulting continued throughout the Eocene. Ongoing geophysical studies, including acquisition of additional seismic data in 1995, are aimed at improving seismic resolution beneath the basalts and deter- mining the structure and nature of the underlying sedimentary section. It has been possible, locally, to interpret horizons beneath the Paleocene volcanics where a thick sedimentary section is inferred to be present. The geological development of this succession has to be extrapolated from offshore southern West Greenland and the nearby onshore Nuussuaq basin. Active exploration including drilling started in the onshore basin in 1995 after the discovery of hydrocarbons in basalts at the surface and in shallow wells. The most promising play concept is subbasaltic reservoir sandstones with a mid- Cretaceous marine or a Paleocene deltaic oil-prone source rock. A possible post - basaltic play has also been identified and several large structural leads have been identified by mapping the Top Paleocene Volcanics horizon.

  16. Basin development and structure of the area covered by Tertiary basalts, offshore central West Greenland - implications of subvolcanic plays

    SciTech Connect

    Whittaker, R.C.; Bate, K.J.; Chalmers, J.A.

    1996-12-31

    The West Greenland shelf area between 68{degrees} and 72{degrees} is covered by Lower Tertiary basalts and has so far proved difficult to explore seismically compared to the offshore basins farther north (Melville Bay) and south (southern West Greenland). A first seismic and geological interpretation of the basalt area has lead to a better understanding of the tectonic events during the Tertiary and their implications for hydrocarbon exploration. After a period of extension accompanied by basalt volcanic in the Paleocene, a period of transpression occurred related to sea-floor spreading in the Labrador Sea and Baffin Bay. The crests of the anticlines formed were then eroded and transgressive marine sediments infilled the irregular topography and formed a number of restricted basins. Strike-slip faulting continued throughout the Eocene. Ongoing geophysical studies, including acquisition of additional seismic data in 1995, are aimed at improving seismic resolution beneath the basalts and deter- mining the structure and nature of the underlying sedimentary section. It has been possible, locally, to interpret horizons beneath the Paleocene volcanics where a thick sedimentary section is inferred to be present. The geological development of this succession has to be extrapolated from offshore southern West Greenland and the nearby onshore Nuussuaq basin. Active exploration including drilling started in the onshore basin in 1995 after the discovery of hydrocarbons in basalts at the surface and in shallow wells. The most promising play concept is subbasaltic reservoir sandstones with a mid- Cretaceous marine or a Paleocene deltaic oil-prone source rock. A possible post - basaltic play has also been identified and several large structural leads have been identified by mapping the Top Paleocene Volcanics horizon.

  17. Problems of phytostratigraphy and the correlation of the Lower Jurassic continental sediments in West Siberia and Kuznetsk and Kansk-Achinsk basins

    SciTech Connect

    Mogutcheva, N.K.

    2009-06-15

    Paleofloral and palynological records of Lower Jurassic sediments in West Siberia, Kuznetsk (Kuzbass), and Kansk-Achinsk basins and their correlation are discussed. In a number of recent papers dedicated to the Jurassic stratigraphy of Siberia this problem is ambiguously treated. The reference palynological scale has been developed for the Jurassic West Siberian sediments and an uninterrupted succession of floral assemblages associated with it and with regional stratigraphic units has been recognized. On this basis the scheme of the correlation between the Lower Jurassic sediments of the Kansk-Achinsk and Kuznetsk basins and West Siberia permitting a better age estimate of coal-bearing deposits, is proposed.

  18. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin), Class III

    SciTech Connect

    Dutton, Shirley P.; Flanders, William A.; Zirczy, Helena H.

    2000-05-24

    The objective of this Class 3 project was to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Phase 1 of the project, reservoir characterization, was completed this year, and Phase 2 began. The project is focused on East Ford field, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit. A CO{sub 2} flood is being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  19. Sensitivity study of reference crop evapotranspiration during growing season in the West Liao River basin, China

    NASA Astrophysics Data System (ADS)

    Gao, Zhendong; He, Junshi; Dong, Kebao; Bian, Xiaodong; Li, Xiang

    2016-05-01

    We have analyzed the trends of reference crop evapotranspiration (ET0) through the Penman-Monteith model and climate factors in the West Liao River basin using the Mann-Kendall test after removing the effect of significant lag-1 serial correlation from the time series of the data by trend-free pre-whitening. The changing characteristics of the sensitivity coefficients and the spatial distribution during growing season are investigated, and the correlation between the sensitivity coefficients with elevation and the key climate factors by relative contribution and stepwise regression methods are evaluated. A significant overall increase in air temperature, and a significant decrease in wind speed, solar radiation, sunshine duration, relative humidity, and a slight decrease in ET0 are observed. Sensitivity analysis shows that ET0 is most sensitive to solar radiation, followed by relative humidity. In contrast, ET0 is least sensitive to the average air temperature. The sensitivity coefficients for the maximum and minimum air temperature and relative humidity have a significant negative correlation with elevation, while the coefficients for other variables are not strongly correlated with elevation. The spatial distribution of the sensitivity coefficients for wind speed and solar radiation is opposite, i.e., in regions where the sensitivity coefficients for wind speed are high; the sensitivity coefficients for solar radiation are low and vice versa. The sensitivity for relative humidity and average air temperature is region specific in the plain area. However, ET0 is most sensitive to the climate change in regions of high elevation. Wind speed is the most dominant contributor followed by solar radiation. Average air temperature contributes the least. The stepwise regression analysis indicates that wind speed is the foremost dominant variable influencing ET0. Relative contribution and stepwise regression analysis can be used to determine the main variables affecting ET0

  20. Moho depth and crustal structure of the Siberian Craton and the West Siberian Basin: An appraisal of existing seismic data

    NASA Astrophysics Data System (ADS)

    Cherepanova, Yulia; Artemieva, Irina M.; Thybo, Hans

    2013-04-01

    We present a digital model of the crustal structure of the Archean-Proterozoic Siberian craton and the Paleozoic-Mesozoic West Siberian basin, based on seismic profiles published since 1960 in international and Russian journals, books, theses and reports. Data quality was assessed and quantitatively assigned to each profile based on acquisition and interpretation method and completeness of the model. The database represents major improvement in coverage and resolution with a nominal sample interval of 50 km before interpolation onto a uniform grid. It includes depth to Moho, thickness and average P-wave velocity of five crustal layers (sediments, and upper, middle, lower, and lowermost crust) and Pn velocity. Results are presented in maps and cross-sections, which demonstrate strong crustal heterogeneity. Crustal structure shows weak correlation with tectono-thermal age and strong correlation with tectonic setting. Sedimentary thickness varies from 0-3 km in stable craton to 10-20 km in extended regions. Typical Moho depths are 44-46 km in stable Archean crust, 40-42 km in Proterozoic craton and Neoproterozoic/Paleozoic orogens, 35-38 km in extended cratonic crust, and 38-40 km in the West Siberian basin. Average crustal velocity is ~6.2-6.4 km/s, ranging from <5.8 km/s in deep sedimentary basins to ~6.6 km/s around the up-to 54 km thick Anabar shield crust. The cratonic crust generally consists of three layers and has no high-velocity lowermost crust (Vp~7.4 km/s), which is observed only in magmatic areas. Upper mantle Pn velocities are generally ~8.2 km/s in the craton and West Siberian Basin, lower in Baikalian and Caledonian areas, higher in the Tunguska and Viluy basins, and abnormally high (8.6-8.9 km/s) around kimberlite fields. We provide an extensive summary of the tectonic and geodynamic evolution of the region and discuss the origin of crustal heterogeneity and processes of crustal evolution in Precambrian cratons and major Phanerozoic basins and rift

  1. Coseismic topography deformation at Sumatra

    NASA Astrophysics Data System (ADS)

    Tong, Xinyue; Lavier, Luc; Tan, Eh

    2016-04-01

    Subduction zones produce the largest earthquakes. However, our understanding of earthquakes' spatial-temporal occurrence and tectonic deformation at convergent margin is limited. Traditional view for subduction earthquake cycle contain three stages: Interseismic - superposition of steady elastic strain accumulation and occasional short-duration aseismic strain release, Coseismic - rapid opposite-direction release of accumulated elastic strain, and Postseismic - superposition of afterslips and viscoelastic flow in mantle wedge and lower crust. However, the way strain accumulated interseismically which is related to the generation of long-term deformation and uplift in the forearc region is still a matter of debate. Moreover, when integrated over time, coseismic uplift poorly matches the longer-term vertical deformation. To better understand these relationships, we investigate numerically how coseismic slip and long-term deformation (vertical uplift) accumulate and interact at subduction zones by using a robust, adaptive, multi-dimensional, finite element method solver, Dynearthsol3D, on a 2D continuum viscoelastoplastic model. We set the conditions in this model to a realistic convergent margin setting that resembles Sumatra region. By introducing bathymetric features, this research also explore mechanisms that could explain how strain accumulation in space and time is modified by the presence of large asperities at the subduction interface.

  2. Coseismic Topography Deformation at Sumatra

    NASA Astrophysics Data System (ADS)

    Tong, X.; Lavier, L. L.; Tan, E.

    2015-12-01

    Subduction zones produce the largest earthquakes. However, our understanding of earthquakes' spatial-temporal occurrence and tectonic deformation at convergent margin is limited. Traditional view for subduction earthquake cycle contain three stages: Interseismic - superposition of steady elastic strain accumulation and occasional short-duration aseismic strain release, Coseismic - rapid opposite-direction release of accumulated elastic strain, and Postseismic - superposition of afterslips and viscoelastic flow in mantle wedge and lower crust. However, the way strain accumulated interseismically which is related to the generation of long-term deformation and uplift in the forearc region is still a matter of debate. Moreover, when integrated over time, coseismic uplift poorly matches the longer-term vertical deformation. To better understand these relationships, we investigate numerically how coseismic slip and long-term deformation (vertical uplift) accumulate and interact at subduction zones by using a robust, adaptive, multi-dimensional, finite element method solver, Dynearthsol3D, on a 2D continuum viscoelastoplastic model. We set the conditions in this model to a realistic convergent margin setting that resembles Sumatra region. By introducing bathymetric features, this research also explore mechanisms that could explain how strain accumulation in space and time is modified by the presence of large asperities at the subduction interface.

  3. Tsunami Generation from the 2004 Sumatra-Andaman Earthquake

    NASA Astrophysics Data System (ADS)

    Satake, K.

    2005-12-01

    The tsunami caused by the December 26, 2004, Sumatra earthquake (Mw 9.1) propagated across the Indian Ocean and caused the worst tsunami disaster. Factors contributed to the tragedy include the giant size of the earthquake, absence of both tsunami warning system and long-term forecast of future earthquakes in the Indian Ocean. Seismological developments since 1960, when the Chilean earthquake (Mw 9.5) caused Pacific-wide tsunami damage, make it possible to estimate the earthquake source parameters within minutes after the occurrence and utilize it for the tsunami warning purposes. The length of the tsunami source of the December Sumatra-Andaman earthquake is enigmatic. The aftershock zone extended from west of Sumatra through Nicobar Islands all the way to Andaman Islands; the total length is over 1,200 km. The seismic wave analyses indicate the southern half ruptured in rather rapidly while the northern half did slowly. Sea level changes in Andaman and Nicobar Islands indicate that the coseismic crustal deformation extended to Andaman Islands. The tsunami source size was estimated to be about 700 km long from the tsunami arrival times recorded on tide gauges, but the northern end was not well constrained. The tsunami heights in Indian Ocean, captured by Jason-1 and other satellites, support that the tsunami source was about 1,100 km long. For more accurate tsunami computations requires detailed shallow bathymetry data. To document the 2004 tsunami, many scientists from all over the world visited the affected coasts. From Japan alone, several survey teams visited coasts of Indonesia, Thailand, Myanmar, India and Sri Lanka, with collaborators in each country. The tsunami heights in Sumatra Island, particularly around Band Aceh, were mostly larger than 20 m with the maximum of 30 m. The tsunami heights along the Andaman Sea coast were highly variable; they were 5 to 15 m in Thailand but less than 3 m in Myanmar. In fact, the tsunami damage and casualties, reportedly

  4. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Second quarterly report, 1995

    SciTech Connect

    Dutton, S.P.

    1995-06-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine Unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation.

  5. Assessment of Undiscovered Oil and Gas Resources of the Permian Basin Province of West Texas and Southeast New Mexico, 2007

    USGS Publications Warehouse

    Schenk, Christopher J.; Pollastro, Richard M.; Cook, Troy A.; Pawlewicz, Mark J.; Klett, Timothy R.; Charpentier, Ronald R.; Cook, Harry E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the Permian Basin Province of west Texas and southeast New Mexico. The assessment was geology based and used the total petroleum system concept. The geologic elements of a total petroleum system are petroleum source rocks (quality, source rock maturation, generation, and migration), reservoir rocks (sequence stratigraphy, petrophysical properties), and traps (trap formation and timing). This study assessed potential for technically recoverable resources in new field discoveries only; field growth (or reserve growth) of conventional oil and gas fields was not included. Using this methodology, the U.S. Geological Survey estimated a mean of 41 trillion cubic feet of undiscovered natural gas and a mean of 1.3 billion barrels of undiscovered oil in the Permian Basin Province.

  6. In search of a Silurian Total Petroleum System in the Appalachian Basin of New York, Ohio, Pennsylvania, and West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.; Swezey, Christopher S.; Trippi, Michael H.; Lentz, Erika E.; Avary, K. Lee; Harper, John A.; Kappel, William M.; Rea, Ronald G.

    2007-01-01

    This report provides an evaluation of the source rock potential of Silurian strata in the U.S. portion of the northern Appalachian Basin, using new TOC and RockEval data. The study area consists of all or parts of New York, Ohio, Pennsylvania, and West Virginia. The stratigraphic intervals that were sampled for this study are as follows: 1) the Lower Silurian Cabot Head Shale, Rochester Shale, and Rose Hill Formation; 2) the Lower and Upper Silurian McKenzie Limestone, Lockport Dolomite, and Eramosa Member of the Lockport Group; and 3) the Upper Silurian Wills Creek Formation, Tonoloway Limestone, Salina Group, and Bass Islands Dolomite. These Silurian stratigraphic intervals were chosen because they are cited in previous publications as potential source rocks, they are easily identified and relatively continuous across the basin, and they contain beds of dark gray to black shale and (or) black argillaceous limestone and dolomite.

  7. Gas hydrates in the Messoyakha gas field of the West Siberian Basin - a re-examination of the geologic evidence

    USGS Publications Warehouse

    Collett, Timothy S.; Ginsburg, Gabriel D.; ,

    1997-01-01

    The amount of natural gas within the gas hydrate accumulations of the world is believed to greatly exceed the volume of known conventional natural gas reserves. The hydrocarbon production history of the Russian Messoyakha field, located in the West Siberian Basin, has been used as evidence that gas hydrates are an immediate source of natural gas that can be produced by conventional means. Re-examination of available geologic, geochemical, and hydrocarbon production data suggests, however, that gas hydrates may not have contributed to gas production in the Messoyakha field. More field and laboratory studies are needed to assess the historical contribution of gas hydrate production in the Messoyakha field.

  8. Gas hydrates in the Messoyakha gas field of the West Siberian Basin - A re-examination of the geologic evidence

    USGS Publications Warehouse

    Collett, T.S.; Ginsburg, G.D.

    1998-01-01

    The amount of natural gas within the gas hydrate accumulations of the world is believed to greatly exceed the volume of known conventional natural gas reserves. The hydrocarbon production history of the Russian Messoyakha field, located in the West Siberian Basin, has been used as evidence that gas hydrates are an immediate source of natural gas that can be produced by conventional means. Re-examination of available geologic, geochemical and hydrocarbon production data suggests, however, that gas hydrates may not have contributed to gas production in the Messoyakha field. More field and laboratory studies are needed to assess the historical contribution of gas hydrate production in the Messoyakha field.

  9. New insights on aerosol sources and properties of Organics in the west Mediterranean basin

    NASA Astrophysics Data System (ADS)

    Nicolas, José B.; Sciare, Jean; Petit, Jean-Eudes; Bonnaire, Nicolas; Féron, Anais; Dulac, François; Hamonou, Eric; Gros, Valérie; Mallet, Marc; Lambert, Dominique; Sauvage, Stéphane; Léonardis, Thierry; Tison, Emmanuel; Colomb, Aurélie; Fresney, Evelyn; Pichon, Jean-Marc; Bouvier, Laetitia; Bourrianne, Thierry; Roberts, Gregory

    2013-04-01

    The Mediterranean basin exhibits high PM concentrations for a marine area, in particular during the dry season (summer), associated with high photochemistry. The large population of the basin is impacted by both natural and anthropogenic aerosols of various sources from Europe and North Africa. Simulations predict significant climate changes in that area, with less precipitation and hotter temperatures, reinforced by an increasing anthropogenic pressure, which will be linked by higher emissions of pollutants and also by higher impacts on the health. Nevertheless the aerosol models in that area currently suffer from large uncertainties, due to a lack of knowledge in organic aerosol (OA) sources and processes. As part of the French program ChArMEx (The Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr), a 5-week intensive campaign has been performed in June - July 2012 at the new Cape Corsica station (see Dulac et al. in that session), and aiming at a better characterization of anthropogenic versus biogenic aerosols, long range transport versus local influence, with a focus on fine OA. A complete instrumental strategy was deployed thanks to the contribution of a large French community: PM1 concentration every 6 min with a TEOM-FDMS 1405 (Thermo), major aerosol components in PM1 every 30 min (Organics, SO4, NO3, NH4) by Aerosol Chemical Speciation Monitor (Aerodyne), Equivalent Black Carbon every 5 min with a 7-? aethalometer AE31 (Magee Scientific), on-line major anions and cations (incl. light organics like oxalate & MSA) every 10 min with Particle-Into-Liquid Sampler (PILS, Metrohm) coupled with Ion Chromatographs (Dionex), on-line water-soluble organic carbon (WSOC) every 4 min with a PILS (Applikon) coupled with a Total Organic Carbon instrument (Ionics). Filter sampling in PM2.5 and PM10 was also performed every 12h for quality purposes (PM, EC/OC, ions) and for complementary measurements (metals by ICP-MS and organic tracers by LC

  10. Deciphering the mid-Carboniferous eustatic event in the central Appalachian foreland basin, southern West Virginia, USA

    USGS Publications Warehouse

    Blake, B.M.; Beuthin, J.D.

    2008-01-01

    A prominent unconformity, present across shallow shelf areas of the Euramerican paleoequatorial basins, is used to demark the boundary between the Mississippian and Pennsylvanian subsystems. This unconformity, the mid-Carboniferous eustatic event, is generally attributed to a major glacio-eustatic sea-level fall. Although a Mississippian-Pennsylvanian unconformity is recognized throughout most of the Appalachian region, the record of the mid-Carboniferous eustatic event in the structurally deepest part of the basin has been controversial. Based on early reports that suggested the most complete Pennsylvanian section was present in southern West Virginia, various conceptual depositional models postulated continuous sedimentation between the youngest Mississippian Bluestone Formation and the oldest Penn-sylvanian Pocahontas Formation. In contrast, tabular-erosion models envisioned axial drainage systems that evolved in response to changing basin dynamics. These models predicted a Mississippian-Pennsylvanian unconformity. All these models suffered from a lack of biostratigraphic control. The presence of a sub-Pocahontas paleovalley, herein named the Lashmeet paleovalley, has been confirmed in southern West Virginia. The Lashmeet paleovalley was incised over 35 m into Bluestone strata and filled by lithic sands derived from the Appalachian orogen to the northeast and east. The polygenetic Green Valley paleosol complex marks the Bluestone-Pocahontas contact on associated interfluves. Together, these features indicate a substantial period of subaerial exposure and argue strongly in favor of a Mississippian-Pennsylvanian unconformity. Paleontologic data from the Bluestone Formation, including marine invertebrates and conodonts from the marine Bramwell Member and paleofloral data, support a late, but not latest, Arnsbergian age assignment. Marine fossils are not known from the Pocahontas Formation, but macrofloral and palynomorph taxa support a Langsettian age for most of

  11. Hydrologic and water-quality conditions in the Horse Creek Basin, west-central Florida, October 1992-February 1995

    USGS Publications Warehouse

    Lewelling, B.R.

    1997-01-01

    A baseline study of the 241-square-mile Horse Creek basin was undertaken from October 1992 to February 1995 to assess the hydrologic and water-quality conditions of one of the last remaining undeveloped basins in west-central Florida. During the period of the study, much of the basin remained in a natural state, except for limited areas of cattle and citrus production and phosphate mining. Rainfall in 1993 and 1994 in the Horse Creek basin was 8 and 31 percent, respectively, above the 30-year long-term average. The lowest and highest maximum instantaneous peak discharge of the six daily discharge stations occurred at the Buzzard Roost Branch and the Horse Creek near Arcadia stations with 185 to 4,180 cubic feet per second, respectively. The Horse Creek near Arcadia station had the lowest number of no-flow days with zero days and the Brushy Creek station had the highest number with 113 days. During the study, the West Fork Horse Creek subbasin had the highest daily mean discharge per square mile with 30.6 cubic feet per second per square mile, and the largest runoff coefficient of 43.7 percent. The Buzzard Roost Branch subbasin had the lowest daily mean discharge per square mile with 5.05 cubic feet per second per square mile, and Brushy Creek and Brandy Branch shared the lowest runoff coefficient of 0.6 percent. Brandy Branch had the highest monthly mean runoff in both 1993 and 1994 with 11.48 and 19.28 inches, respectively. During the high-baseflow seepage run, seepage gains were 8.87 cubic feet per second along the 43-mile Horse Creek channel. However, during the low-baseflow seepage run, seepage losses were 0.88 cubic foot per second. Three methods were used to estimate average annual ground-water recharge in the Horse Creek basin: (1) well hydrograph, (2) chloride mass balance, and (3) streamflow hydrograph. Estimated average annual recharge using these three methods ranged from 3.6 to 8.7 inches. The high percentage of carbonate plus bicarbonate analyzed at

  12. Deep infrasound radiated by the Sumatra earthquake and tsunami

    NASA Astrophysics Data System (ADS)

    Garcés, M.; Caron, P.; Hetzer, C.; Le Pichon, A.; Bass, H.; Drob, D.; Bhattacharyya, J.

    Infrasound arrays in the Pacific and Indian oceans that are part of the International Monitoring System (IMS) of the Comprehensive Nuclear Test Ban Treaty (CTBT) recorded distinct signatures associated with the 26 December 2004 Sumatra earthquake (M/9, http://earthquake.usgs.gov/) and tsunami. Although the radiation of infrasound from large continental earthquakes is established [e.g., Le Pichon et al., 2003], the results presented in the present article indicate that islands undergoing significant surface displacements from submarine earthquakes can produce infrasound.Far more intriguing is the possibility that the initiation and propagation of a tsunami may produce low-frequency sound near the source as well as along coastlines and basins. Since distant sound effectively propagates at ˜300 m/s and tsunamis propagate at ˜200 m/s, precursory sound could potentially be used as a discriminant for tsunami genesis.

  13. Using Spatial Information Technologies as Monitoring Devices in International Watershed Conservation along the Senegal River Basin of West Africa

    PubMed Central

    Merem, Edmund C.; Twumasi, Yaw A.

    2008-01-01

    In this paper, we present the applications of spatial technologies—Geographic Information Systems (GIS) and remote sensing—in the international monitoring of river basins particularly analyzing the ecological, hydrological, and socio-economic issues along the Senegal River. The literature on multinational water crisis has for decades focused on mediation aspects of trans-boundary watershed management resulting in limited emphasis placed on the application of advances in geo-spatial information technologies in multinational watershed conservation in the arid areas of the West African sub-region within the Senegal River Basin for decision-making and monitoring. While the basin offers life support in a complex ecosystem that stretches across different nations in a mostly desert region characterized by water scarcity and subsistence economies, there exists recurrent environmental stress induced by both socio-economic and physical factors. Part of the problems consists of flooding, drought and limited access to sufficient quantities of water. These remain particularly sensitive issues that are crucial for the health of a rapidly growing population and the economy. The problems are further compounded due to the threats of climate change and the resultant degradation of almost the region’s entire natural resources base. While the pace at which the institutional framework for managing the waters offers opportunities for hydro electricity and irrigated agriculture through the proliferation of dams, it has raised other serious concerns in the region. Even where data exists for confronting these issues, some of them are incompatible and dispersed among different agencies. This not only widens the geo-spatial data gaps, but it hinders the ability to monitor water problems along the basin. This study will fill that gap in research through mix scale methods built on descriptive statistics, GIS and remote sensing techniques by generating spatially referenced data to

  14. Using spatial information technologies as monitoring devices in international watershed conservation along the Senegal River Basin of West Africa.

    PubMed

    Merem, Edmund C; Twumasi, Yaw A

    2008-12-01

    In this paper, we present the applications of spatial technologies-Geographic Information Systems (GIS) and remote sensing-in the international monitoring of river basins particularly analyzing the ecological, hydrological, and socio-economic issues along the Senegal River. The literature on multinational water crisis has for decades focused on mediation aspects of trans-boundary watershed management resulting in limited emphasis placed on the application of advances in geo-spatial information technologies in multinational watershed conservation in the arid areas of the West African sub-region within the Senegal River Basin for decision-making and monitoring. While the basin offers life support in a complex ecosystem that stretches across different nations in a mostly desert region characterized by water scarcity and subsistence economies, there exists recurrent environmental stress induced by both socio-economic and physical factors. Part of the problems consists of flooding, drought and limited access to sufficient quantities of water. These remain particularly sensitive issues that are crucial for the health of a rapidly growing population and the economy. The problems are further compounded due to the threats of climate change and the resultant degradation of almost the region's entire natural resources base. While the pace at which the institutional framework for managing the waters offers opportunities for hydro electricity and irrigated agriculture through the proliferation of dams, it has raised other serious concerns in the region. Even where data exists for confronting these issues, some of them are incompatible and dispersed among different agencies. This not only widens the geo-spatial data gaps, but it hinders the ability to monitor water problems along the basin. This study will fill that gap in research through mix scale methods built on descriptive statistics, GIS and remote sensing techniques by generating spatially referenced data to supplement

  15. Stabilization of large drainage basins over geological time scales: Cenozoic West Africa, hot spot swell growth, and the Niger River

    NASA Astrophysics Data System (ADS)

    Chardon, Dominique; Grimaud, Jean-Louis; Rouby, Delphine; Beauvais, Anicet; Christophoul, Frédéric

    2016-03-01

    Reconstructing the evolving geometry of large river catchments over geological time scales is crucial to constraining yields to sedimentary basins. In the case of Africa, it should further help deciphering the response of large cratonic sediment routing systems to Cenozoic growth of the basin-and-swell topography of the continent. Mapping of dated and regionally correlated lateritic paleolandscape remnants complemented by onshore sedimentological archives allows the reconstruction of two physiographic configurations of West Africa in the Paleogene. Those reconstructions show that the geometry of the drainage is stabilized by the late early Oligocene (29 Ma) and probably by the end of the Eocene (34 Ma), allowing to effectively link the inland morphoclimatic record to offshore sedimentation since that time, particularly in the case of the Niger catchment—delta system. Mid-Eocene paleogeography reveals the antiquity of the Senegambia catchment back to at least 45 Ma and suggests that a marginal upwarp forming a continental divide preexisted early Oligocene connection of the Niger and Volta catchments to the Equatorial Atlantic Ocean. Such a drainage rearrangement was primarily enhanced by the topographic growth of the Hoggar hot spot swell and caused a stratigraphic turnover along the Equatorial margin of West Africa.

  16. Precambrian basement geology of the Permian basin region of west Texas and Eastern New Mexico: A geophysical perspective

    SciTech Connect

    Adams, D.C.; Keller, G.R.

    1996-03-01

    Because most of the Permian basin region of west Texas and southern New Mexico is covered by Phanerozoic rocks, other means must be found to examine the Precambrian upper crustal geology of the region. We have combined geologic information on the Precambrian from outcrops and wells with geophysical information from gravity and magnetic surveys in an integrated analysis of the history and structure of basement rocks in the region. Geophysical anomalies can be related to six Precambrian events: formation of the Early Proterozoic outer tectonic belt, igneous activity in the southern Granite-Rhyolite province, an episode of pre-Grenville extension, the Grenville orogeny, rifting to form the Delaware aulacogen, and Eocambrian rifting to form the early Paleozoic continental margin. Two geophysical features were studied in detail: the Abilene gravity minimum and the Central Basin platform gravity high. The Abilene gravity minimum is shown to extend from the Delaware basin across north-central Texas and is interpreted to be caused by a granitic batholith similar in size to the Sierra Nevada batholith in California and Nevada. This batholith appears to be related to formation of the southern Granite- Rhyolite province, possibly as a continental margin arc batholith. Because of this interpretation, we have located the Grenville tectonic front southward from its commonly quoted position, closer to the Llano uplift. Middle Proterozoic mafic intrusions are found to core the Central Basin platform and the Roosevelt uplift. These intrusions formed at about 1.1 Ga and are related in time to both the Mid-Continent rift system and the Grenville orogeny in Texas. Precambrian basement structures and changes in lithology have influenced the structure and stratigraphy in the overlying Permian basin, and thus have potential exploration significance.

  17. Origin of diverse geochemical signatures in igneous rocks from the West Philippine Basin: Implications for tectonic models

    NASA Astrophysics Data System (ADS)

    Hickey-Vargas, Rosemary; Savov, Ivan P.; Bizimis, Michael; Ishii, Teruaki; Fujioka, Kantaro

    The West Philippine Basin (WPB), formed by seafloor spreading between 60 and 35 Ma, provides an excellent case study of relationships between basin tectonics and magma chemistry. At 48 Ma, the Izu-Bonin-Mariana (IBM) arc formed along the basin edge, orthogonal to the active spreading center; thus, WPB development is a key issue for this Margins Subduction Factory focus area. WPB basalts from the main spreading stage are normal to enriched mid-ocean ridge basalt (MORB) with an Indian Ocean MORB isotopic signature. Basalts from the Benham Rise and locations near the western Central Basin Spreading Center (CBSC) at 50-35 Ma are geochemically identical to oceanic island basalts. Late-stage CBSC basalts (35-26 Ma) are isotopically like main spreading-stage MORB, with widely varying and decoupled trace element enrichments. Based on basalt geochemistry, the WPB could be a trapped fragment of ancient Indian/Tethyan ocean ridge, as proposed in some models for the initiation of the IBM arc, or it could be a back-arc basin, provided plate configurations allowed replenishment of sub-Indian Ocean asthenosphere. Ocean island basalts were formed by decompression melting of an enriched source beneath the western CBSC, mixing with normal MORB sources to form enriched MORB. This was a transitory feature (15 Ma) related to spreading, rather than a deep-seated plume, and probably did not affect the early IBM arc. Magma formed in small, deep-seated batches as the extension waned. That CBSC activity continued for 22 Ma after the initiation of the IBM arc indicates that forces related to an additional subduction system influenced the WPB.

  18. Santa Barbara and Ventura basins: Tectonics, structure, sedimentation, oilfields along an east-west transect

    SciTech Connect

    Sylvester, A.G.; Brown, G.C.

    1988-01-01

    The Santa Barbara and Ventura basins are tectonically active and are economically important because millions of barrels of oil were produced there since the 1800s. This guidebook focuses on structural and sedimentological aspects of two main structural tends in the basin: the Rincon-Ventura anticlinorium, and the Oakridge-South Mountain uplift. Section One of the publication is a roadlog which summarizes geologic features. Section Two focuses on the sedimentation of the principal reservoirs and source rocks in the main oil fields in the two basins. Section Three presents four original papers on the oil fields and tectonic evolution of the area.

  19. Probability of Potential Multi-Canister Overpack Loading System Drop of Proof Load in the K West Basin South Loadout Pit

    SciTech Connect

    SHULTZ, M.V.

    2000-01-20

    This document presents the results of a probabilistic analysis of the potential for load drop during the load test of the K West Basin South Loadout Pit Gantry. The calculations are in support of the cask loading system (CLS) subproject load test of the gantry. The purpose of this calculation note is to document the probabilistic calculation of the per lift potential for drop of a test load by the Multi-Canister Overpack (MCO) Loading System (MLS) during load testing at the K West Basin south loadout pit. The MLS subproject needs to load test the MLS in the K West Basin south loadout pit. To perform this test, a basket mockup weighing approximately 4,500 lb (125% of a fully loaded MCO basket accounting for water displacement) needs to be used for one or more load tests. The test load will comprise a standard basket lifting attachment with several ring-shaped steel segments to provide the required weight. The test load will exceed the K Basin Safety Analysis Report (WHC-SD-WM-SAR-062) (SAR) allowances for load drop in the K West Basin south loadout pit. This probabilistic calculation will be used as part of the basis for seeking U.S. Department of Energy approval to use an MLS test weight that exceeds SAR allowances.

  20. Sedimentation and water quality in the West Branch Shade River basin, Ohio, 1984 water year

    USGS Publications Warehouse

    Childress, C.J.; Jones, R.L.

    1985-01-01

    Sedimentation in, and flooding of, the West Branch Shade River and its tributaries have been major concerns of residents and State and local officials. The area was extensively surface mined for coal between the mid-1940 's and the early 1960's. Reclamation efforts immediately after mining were unsuccessful. The results have been elevated sediment loads and the subsequent loss of channel conveyance. Two sediment and stream gaging stations were established on West Branch Shade River in the area of past mining to provide data to evaluate the effectiveness of current reclamation activities on reducing sediment loads. A third station was established on the East Branch Shade River in an unmined area as a control. From October 1983 through September 1984, the annual suspended sediment yield/acre-ft of runoff was approximately two times as high for West Branch Shade River (0.51 ton/acre-ft of runoff) as for East Branch Shade River (0.28 ton/acre-ft). In addition, water quality of West Branch indicates that acidity is higher, pH is lower, and concentrations of dissolved sulfate and metals are higher than for East Branch. The concentration of coal in bed material increased in the downstream direction along West Branch Shade River. The concentration downstream in the West Branch was more than 20 times greater than in the East Branch. (Author 's abstract)

  1. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Shirley P. Dutton

    1998-04-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields was completed, a pilot area of approximately 1 mi 2 in one of the fields was chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the demonstration area, (2) demonstrate that economically significant unrecovered oil can be recovered by a CO 2 flood of the demonstration area, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery CO 2 flood and well-completion program will be developed. Through technology transfer workshops and other presentations, the knowledge gained in this study can then be applied to increase production from the more than 100 other Delaware Mountain Group reservoirs.

  2. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope, and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Shirley P. Dutton

    1997-04-30

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi 2 in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO 2 flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Through technology transfer workshops and other presentations, the knowledge gained in the comparative study of these two fields can then be applied to increase production from the more

  3. Simulation of Water Quality in the Tull Creek and West Neck Creek Watersheds, Currituck Sound Basin, North Carolina and Virginia

    USGS Publications Warehouse

    Garcia, Ana Maria

    2009-01-01

    A study of the Currituck Sound was initiated in 2005 to evaluate the water chemistry of the Sound and assess the effectiveness of management strategies. As part of this study, the Soil and Water Assessment Tool (SWAT) model was used to simulate current sediment and nutrient loadings for two distinct watersheds in the Currituck Sound basin and to determine the consequences of different water-quality management scenarios. The watersheds studied were (1) Tull Creek watershed, which has extensive row-crop cultivation and artificial drainage, and (2) West Neck Creek watershed, which drains urban areas in and around Virginia Beach, Virginia. The model simulated monthly streamflows with Nash-Sutcliffe model efficiency coefficients of 0.83 and 0.76 for Tull Creek and West Neck Creek, respectively. The daily sediment concentration coefficient of determination was 0.19 for Tull Creek and 0.36 for West Neck Creek. The coefficient of determination for total nitrogen was 0.26 for both watersheds and for dissolved phosphorus was 0.4 for Tull Creek and 0.03 for West Neck Creek. The model was used to estimate current (2006-2007) sediment and nutrient yields for the two watersheds. Total suspended-solids yield was 56 percent lower in the urban watershed than in the agricultural watershed. Total nitrogen export was 45 percent lower, and total phosphorus was 43 percent lower in the urban watershed than in the agricultural watershed. A management scenario with filter strips bordering the main channels was simulated for Tull Creek. The Soil and Water Assessment Tool model estimated a total suspended-solids yield reduction of 54 percent and total nitrogen and total phosphorus reductions of 21 percent and 29 percent, respectively, for the Tull Creek watershed.

  4. Analysis of Submarine Landslides at West Mata Volcano, NE Lau Basin, Using Hydroacoustic Data

    NASA Astrophysics Data System (ADS)

    Caplan-Auerbach, J.; Dziak, R. P.; Chadwick, B.; Lau, T. K. A.; Bohnenstiehl, D. R.

    2014-12-01

    Hundreds of submarine landslides were detected by a network of moored hydrophones near the erupting West Mata submarine volcano during a five month deployment in 2010-2011. The landslides are identifiable by their spectral characteristics, including a low frequency onset and extended broadband coda. All hydroacoustic signals at West Mata exhibit spectral banding due to interference of direct and surface-reflected waves (the Lloyd's Mirror effect), but in landslide signals the bands change frequency over the duration of the signal. This shows that the source is propagating, and the timing between direct and reflected arrivals is changing. We use the change in spectral content to estimate source and terminus depths and average propagation velocity. Landslides were only weakly recorded on a hydrophone to the south of West Mata suggesting that the events took place on the volcano's north flank, a region known from bathymetric mapping to have experienced significant mass wasting. We propose that the few landslides that did not exhibit spectral banding failed over a large source area and depth range and represent the largest West Mata slides. West Mata landslides occurred frequently during the eruption, suggesting that they may be triggered by loading of fragmental material on the volcano's flanks. While the slides occurred throughout the duration of the deployment, events tend to cluster in time, possibly indicating sequential or retrogressive failures.

  5. Genesis of the West Siberian Basin and its petroleum geology: a recent interpretation

    USGS Publications Warehouse

    Clarke, J.W.

    1994-01-01

    From Late Carboniferous through Middle Jurassic time, the region of West Siberia passed through orogenic, rift, and early platform stages. The Early-Middle Jurassic was a time of cyclical marine and continental deposition. It is suggested that: (a) the oil in the Lower Cretaceous Neocomian sandstones was sourced by bituminous clays that interfinger with these sandstones on the west; and (b) that Upper Cretaceous Cenomanian gas was sourced in part by deeply buried Paleozoics and by overlying Upper Cretaceous Turonian clays. Predicted discoveries in West Siberia include several thousand small fields with reserves of less than 10 million tons, 250 to 300 medium-sized fields, and several large fields with 30 to 100 million tons. -from Author

  6. Seismic signatures of Upper Messinian events in the West Sardinian margin and the East Liguro-Provençal basin

    NASA Astrophysics Data System (ADS)

    Del Ben, Anna; Geletti, Riccardo; Mocnik, Arianna; Zgur, Fabrizio

    2014-05-01

    A new seismic dataset acquired in Autumn 2010 on the West Sardinian margin and Eastern Liguro-Provençal basin (WS10 project) has provided important new information concerning the Messinian events. In particular, the good seismic resolution allows a well definition of the seismic facies of the Upper Unit (UU), which represents the upper sequence of the " Messinian trilogy ", well known in the Mediterranean literature. The trilogy includes also the main seismically transparent salt sequence, that reaches a thickness of some hundreds of meters , called Mobile Unit (MU), and the generally high amplitude reflectors of the Lower Unit (LU), that is not yet calibrated in the West Mediterranean region. As shown by the DSDP boreholes in the passive margins of the Balearic basin, the UU is represented by an alternation of gypsum, halite and marls, highlighted on the seismic profiles by a package of high amplitude about parallel reflectors. Within the UU we have identified a transparent seismic thickness that, specially due to some diapiric structures, we have interpreted as a salt layer. Its seismically continuous and regular extent, testifies its primary deposition, which necessarily implies a drawdown of the sea level during the deposition of the UU. The UU locally terminates at the foot of the slope, where the Messinian events are marked by the erosional surface (MES), characterized by clear toplap of the pre-Messinian sequences. Sometimes the UU is present on the lower slope, where it is gradually onlapping the thin and often deformed MU or, if the MU is completely moved toward the basin, directly onlaps the pre-MU sequence. The UU on the lower slope is locally topped by an erosional surface, that laterally converges, toward east, in the MES. Alternatively, along other seismic profiles,the top of the Messinian sequence is concordant with both the Lower Pliocene and the last UU reflectors but, in some cases, a clear erosional truncation is recognizable inner the UU. These

  7. Geohydrology, Geochemistry, and Ground-Water Simulation-Optimization of the Central and West Coast Basins, Los Angeles County, California

    USGS Publications Warehouse

    Reichard, Eric G.; Land, Michael; Crawford, Steven M.; Johnson, Tyler D.; Everett, Rhett; Kulshan, Trayle V.; Ponti, Daniel J.; Halford, Keith L.; Johnson, Theodore A.; Paybins, Katherine S.; Nishikawa, Tracy

    2003-01-01

    Historical ground-water development of the Central and West Coast Basins in Los Angeles County, California through the first half of the 20th century caused large water-level declines and induced seawater intrusion. Because of this, the basins were adjudicated and numerous ground-water management activities were implemented, including increased water spreading, construction of injection barriers, increased delivery of imported water, and increased use of reclaimed water. In order to improve the scientific basis for these water management activities, an extensive data collection program was undertaken, geohydrological and geochemical analyses were conducted, and ground-water flow simulation and optimization models were developed. In this project, extensive hydraulic, geologic, and chemical data were collected from new multiple-well monitoring sites. On the basis of these data and data compiled and collected from existing wells, the regional geohydrologic framework was characterized. For the purposes of modeling, the three-dimensional aquifer system was divided into four aquifer systems?the Recent, Lakewood, Upper San Pedro, and Lower San Pedro aquifer systems. Most pumpage in the two basins is from the Upper San Pedro aquifer system. Assessment of the three-dimensional geochemical data provides insight into the sources of recharge and the movement and age of ground water in the study area. Major-ion data indicate the chemical character of water containing less than 500 mg/L dissolved solids generally grades from calcium-bicarbonate/sulfate to sodium bicarbonate. Sodium-chloride water, high in dissolved solids, is present in wells near the coast. Stable isotopes of oxygen and hydrogen provide information on sources of recharge to the basin, including imported water and water originating in the San Fernando Valley, San Gabriel Valley, and the coastal plain and surrounding hills. Tritium and carbon-14 data provide information on relative ground-water ages. Water with

  8. Inelastic yielding and forebulge shape across a modern foreland basin: North West Shelf of Australia, Timor Sea

    NASA Astrophysics Data System (ADS)

    Lorenzo, Juan M.; O'Brien, Geoffrey W.; Stewart, Jonathan; Tandon, Kush

    The Timor Trough is a modern ‘underfilled’ foreland basin created by partial subduction of the outer north west continental shelf of Australia beneath Timor Island in the Outer Banda Arc of eastern Indonesia during the Cenozoic. A change of the effective elastic thickness (EET) of the continental foreland lithosphere from ˜80±20 km to ˜25 km over a distance of ˜300 km explains (1) the high curvature (˜10-7 m-1) on the outer Trough wall, (2) the low shelf forebulge (˜200 m) as measured along a reference base Pliocene unconformity, and (3) observed gravity. An inelastically yielding quartzite-quartz-diorite-dunite continental rheology can explain the EET gradient. New, shallow crustal (<8 km), seismic reflection images indicate that Jurassic basement normal faults are reactivated during bending of the foreland.

  9. Spatio-Temporal Identification of Areas Suitable for West Nile Disease in the Mediterranean Basin and Central Europe

    PubMed Central

    Conte, Annamaria; Candeloro, Luca; Ippoliti, Carla; Monaco, Federica; De Massis, Fabrizio; Bruno, Rossana; Di Sabatino, Daria; Danzetta, Maria Luisa; Benjelloun, Abdennasser; Belkadi, Bouchra; El Harrak, Mehdi; Declich, Silvia; Rizzo, Caterina; Hammami, Salah; Ben Hassine, Thameur; Calistri, Paolo; Savini, Giovanni

    2015-01-01

    West Nile virus (WNV) is a mosquito-transmitted Flavivirus belonging to the Japanese encephalitis antigenic complex of the Flaviviridae family. Its spread in the Mediterranean basin and the Balkans poses a significant risk to human health and forces public health officials to constantly monitor the virus transmission to ensure prompt application of preventive measures. In this context, predictive tools indicating the areas and periods at major risk of WNV transmission are of paramount importance. Spatial analysis approaches, which use environmental and climatic variables to find suitable habitats for WNV spread, can enhance predictive techniques. Using the Mahalanobis Distance statistic, areas ecologically most suitable for sustaining WNV transmission were identified in the Mediterranean basin and Central Europe. About 270 human and equine clinical cases notified in Italy, Greece, Portugal, Morocco, and Tunisia, between 2008 and 2012, have been considered. The environmental variables included in the model were altitude, slope, night time Land Surface Temperature, Normalized Difference Vegetation Index, Enhanced Vegetation Index, and daily temperature range. Seasonality of mosquito population has been modelled and included in the analyses to produce monthly maps of suitable areas for West Nile Disease. Between May and July, the most suitable areas are located in Tunisia, Libya, Egypt, and North Cyprus. Summer/Autumn months, particularly between August and October, characterize the suitability in Italy, France, Spain, the Balkan countries, Morocco, North Tunisia, the Mediterranean coast of Africa, and the Middle East. The persistence of suitable conditions in December is confined to the coastal areas of Morocco, Tunisia, Libya, Egypt, and Israel. PMID:26717483

  10. Geothermal reservoir properties of the Rotliegend (Permocarboniferous) sediments in the Saar Nahe Basin (South-West Germany)

    NASA Astrophysics Data System (ADS)

    Aretz, A.; Bär, K.; Sass, I.

    2012-04-01

    The geothermal potential of the Rotliegend (Permocarboniferous) in the Northern Upper Rhine Graben and the Saar-Nahe-Basin (Germany) has been shown in large scale regional studies. To further assess the geothermal potential of the different lithostratigraphical units and facies types within this Variscan intramontane basin, knowledge of their thermophysical and hydraulic properties is indispensable. Where the Cenozoic Upper Rhine Graben crosses the Permocarboniferous molasse basin, the top of the up to two kilometers thick Permocarboniferous deposits is located at a depth of one to three kilometers and is overlain by Tertiary and Quaternary sediments. Therefore, the reservoir temperatures exceed 150°C, making it suitable for geothermal power production. Lithologically the Permocarboniferous deposits consist of different formations and facies types including fine, middle and coarse grained sandstones, arcosic sandstones, siltstones, volcanics and carbonates. Within the framework of the study presented here, outcrop analogue studies west of the Graben in the Saar-Nahe-Basin, and east of the Graben in the Wetterau and the Wetterau-Fulda-Basin are conducted. Each lithostratigraphic formation and lithofacies type is sampled in various outcrops to generate a statistically sufficient amount of samples of the different sedimentary rocks in order to determine their petrophysical, sedimentological and geochemical characteristics. The petrophysical parameters measured include the porosity, permeability, density, thermal conductivity, thermal diffusivity and uniaxial compressive strength. So far, the petrophysical properties of samples of more than 70 locations have been measured in our lab facilities, showing a clear correlation with the facies type. Excluding the coarse grained sandstones of the Donnersberg formation at the beginning of the Nahe-subgroup of the Upper Rotliegend, the geothermal reservoir properties are more suitable in the Glan-subgroup of the Lower

  11. Fuel Cost Estimation for Sumatra Grid System

    NASA Astrophysics Data System (ADS)

    Liun, Edwaren

    2010-06-01

    Sumatra has a high growth rate electricity energy demand from the first decade in this century. At the medium of this decade the growth is 11% per annum. On the other side capability of Government of Indonesia cq. PLN authority is limited, while many and most old existing power plants will be retired. The electricity demand growth of Sumatra is increasing the fuel consumption for several next decades. Based on several cases by vary growth scenarios and economic parameters, it shown that some kinds of fossil fuel keep to be required until next several decades. Although Sumatra has abundant coal resource, however, the other fuel types such as fuel oil, diesel, gas and nuclear are needed. On the Base Scenario and discount rate of 10%, the Sumatra System will require 11.6 million tones of coal until 2030 producing 866 TWh with cost of US10558 million. Nuclear plants produce about 501 TWh or 32% by cost of US3.1 billion. On the High Scenario and discount rate 10%, the coal consumption becomes 486.6 million tones by fuel cost of US12.7 billion producing 1033 TWh electricity energy. Nuclear fuel cost required in this scenario is US7.06 billion. The other fuel in large amount consumed is natural gas for combined cycle plants by cost of US1.38 billion producing 11.7 TWh of electricity energy on the Base Scenario and discount rate of 10%. In the High Scenario and discount rate 10% coal plants take role in power generation in Sumatra producing about 866 TWh or 54% of electricity energy. Coal consumption will be the highest on the Base Scenario with discount rate of 12% producing 756 TWh and required cost of US17.1 billion. Nuclear plants will not applicable in this scenario due to its un-competitiveness. The fuel cost will depend on nuclear power role in Sumatra system. Fuel cost will increase correspond to the increasing of coal consumption on the case where nuclear power plants not appear.

  12. West Atlantic mesozoic carbonates: comparison of Baltimore Canyon and offshore Nova Scotian basins

    SciTech Connect

    Eliuk, L.S.; Cearley, S.C.; Levesque, R.

    1986-05-01

    Results of exploratory drilling, by Shell Offshore Inc., and its partners, of the Late Jurassic-Early Cretaceous carbonate margin of the Baltimore Canyon (BC) basin can be interpreted directly from the better understood, time-equivalent Nova Scotian (NS) basin stratigraphy. The BC paleomargin was constructed in a depositional cycle of three successive stages: Oxfordian-early Kimmeridgian progradation, Kimmeridgian-Berriasian aggradation, Berriasian-Valanginian drowning. The upper two stages in NS are the Baccaro and Artimon members of the Abenaki formation. The progradation of the lower sequence in BC results from high clastic input and has a parallel (not age equivalent) in NS only in proximity to the Sable Island paleodelta. Both basins have similar, complementary, shelf-edge environments that form a single water-depth-controlled biotic zonation. This zonation is: shallow-water stromatoporoid-hexacoral biostromes and reefs; deeper water stromatactis and thrombolitic mud mounds; and deep-water lithistid sponge reefs. Associated environments are oncolitic reef flats, reef-apron skeletal sands, slope reef debris from sponge and coral reefs, and back-reef mollusk-rich skeletal and skeletal-oolitic sands. Major differences between the basins are the pinnacle reefs of BC and the contrast between the mud-rich skeletal and nonskeletal megafacies of NS versus the dominantly skeletal sand-rich BC sediments. The higher subsidence rates of BC may explain both differences.

  13. Cambarus (Puncticambarus) smilax, a new species of crayfish (Crustacea: Decapoda: Cambaridae) from the Greenbrier River basin of West Virginia

    USGS Publications Warehouse

    Loughman, Zachary J.; Simon, Thomas P.; Welsh, Stuart

    2011-01-01

    Cambarus (Puncticambarus) smilax is a stream-dwelling crayfish that appears to be endemic to the Greenbrier River basin in the Valley and Ridge province of West Virginia. Within the Greenbrier system it occurs primarily in tributaries to the Greenbrier mainstem, with stable populations in the East and West Fork, and Thorny, Knapp, and Deer creeks. The new species is morphologically most similar to C. (P.) robustus, from which it can be distinguished by a combination of the following characters: adult palm length comprising 73–76% of palm width as opposed to 63–70% in C. (P.)robustus; ventral surface of chela of cheliped with 0–2 subpalmar tubercles compared to 3–6 subpalmar tubercles in C. (P.) robustus; lack of tubercles on the dorsal surface of chela; longer, more tapering, less rectangular rostrum (47–52% rostrum width/length ratio) compared to C. (P.) robustusshorter, less tapering rectangular rostrum (54–63% rostrum width/length ratio); and the central projection of the form-I male gonopod curved ≤90 degrees to the shaft.

  14. Geochemical evidence for sundering of the West Mariana arc in miocene ash from the Parece Vela Basin

    NASA Astrophysics Data System (ADS)

    Warner, Russell J.; Flower, Martin F. J.; Rodolfo, Kelvin S.

    1987-10-01

    Glass and mineral fragments from discrete volcanic ash layers were sampled from DSDP/IPOD Site 450 in the Parece Vela Basin, Philippine Sea and analyzed by electron microprobe. The ashes are interpreted as eruptive products of the adjacent West Mariana arc system between 25 and 14 Ma B.P., and have compositions between basaltic andesite and rhyolite, and rarely, boninite. 'Continuous' chemical trends appear to reflect mixing of mafic and silicic magmas. 'Discontinuous' trends between these end-members are relatively few, and are consistent with 'liquid lines' produced by fractional crystallization. Andesitic tephra become progressively richer in MgO and CaO through the middle Miocene, while boninite appears towards the end of the sequence, between 14 and 15 Ma B.P. Coeval rhyolitic glasses become richer in K 2O and Na 2O, with maximum concentrations at about 15 Ma B.P. Chronologic changes in fractionation type and composition of parent magmas are interpreted to reflect the subaerial volcanic evolution of the West Mariana arc. The appearance of boninite is believed to signal early stages of arc sundering, and corresponds temporally with regional uplift of the sea floor above the carbonate compensation depth, precursor to a new pulse of back-arc spreading.

  15. Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico

    SciTech Connect

    Hoak, T.; Sundberg, K.; Ortoleva, P.

    1998-12-31

    The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

  16. Analysis of Marine Magnetic Field Anomaly Profiles of the West Philippine Basin to Infer Its Style of Opening

    NASA Astrophysics Data System (ADS)

    Choe, Hanjin; Lee, Sang-Mook

    2016-04-01

    The West Philippine Basin (WPB), located on the Philippine Sea Plate, is considered to have undergone a rapid opening during the Eocene. However, the detailed opening of the WPB and its relationship with surrounding basins were rather uncertain in the existing plate reconstruction models because of their sparse coverage. This study re-examines the opening using the sea surface marine magnetic anomaly data that were added to the database over the last several decades. Detailed rotation poles were computed different stages using Gplates program. According to our analysis, WPB started to open in NE-SW direction as early as the early Eocene (> 53 Ma) but changed gradually to N-S direction around 45 Ma. It appears that the spreading was not uniform, evidenced by jumps in the spreading axis and along-axis discontinuities with an average speed greater than previous reported. The spreading appears to have slowed down around 37 Ma and finally ceasing at around 25 Ma. The spreading was not symmetric between north and south, and this apparent asymmetry becomes notable towards the end of the opening.

  17. Comparison of West African and Congo Basin Monkeypox Viruses in BALB/c and C57BL/6 Mice

    PubMed Central

    Hutson, Christina L.; Abel, Jason A.; Carroll, Darin S.; Olson, Victoria A.; Braden, Zachary H.; Hughes, Christine M.; Dillon, Michael; Hopkins, Consuelo; Karem, Kevin L.; Damon, Inger K.; Osorio, Jorge E.

    2010-01-01

    Although monkeypox virus (MPXV) studies in wild rodents and non-human primates have generated important knowledge regarding MPXV pathogenesis and inferences about disease transmission, it might be easier to dissect the importance of virulence factors and correlates of protection to MPXV in an inbred mouse model. Herein, we compared the two clades of MPXV via two routes of infection in the BALB/c and C57BL/6 inbred mice strains. Our studies show that similar to previous animal studies, the Congo Basin strain of MPXV was more virulent than West African MPXV in both mouse strains as evidenced by clinical signs. Although animals did not develop lesions as seen in human MPX infections, localized signs were apparent with the foot pad route of inoculation, primarily in the form of edema at the site of inoculation; while the Congo Basin intranasal route of infection led to generalized symptoms, primarily weight loss. We have determined that future studies with MPXV and laboratory mice would be very beneficial in understanding the pathogenesis of MPXV, in particular if used in in vivo imaging studies. Although this mouse model may not suffice as a model of human MPX disease, with an appropriate inbred mouse model, we can unravel many unknown aspects of MPX pathogenesis, including virulence factors, disease progression in rodent hosts, and viral shedding from infected animals. In addition, such a model can be utilized to test antivirals and the next generation of orthopoxvirus vaccines for their ability to alter the course of disease. PMID:20111702

  18. The Structure and Evolution of the Sabratah Basin, West Offshore Libya.

    NASA Astrophysics Data System (ADS)

    Reeh, G. A.; Reston, T. J.

    2014-12-01

    The Sabratah Basin is situated on the continental margin of Africa. In this presentation we use a series of grids of 3D seismic data, supported by potential field data, to document the structure and evolution of the basin. Although the basin is thought to be underlain by Paleozoic rocks, the oldest encountered in wells are Triassic in age. These are continental passing upwards into evaporites, a sequence thought to represent the progressive subsidence of the margin during major Mesozoic extension related to the opening of the Tethyan Ocean. Continued subsidence through the Jurassic and Early Cretaceous led to the deposition of marine sequences. The basin deepens towards the northeast, as the crust thins in the same direction. Crustal thinning in this direction is supported by an increase from southwest to northeast in the gravity. However, since the Late Cretaceous, there has been compression between Africa and Europe as a result of the Alpine collision, causing the inversion of the former extensional features, and creating en echelon folds trending ENE-WSW and segmented by en echelon northwest trending right-lateral faults. The geometries we observe are consistent with a right lateral shear roughly parallel to the continental margin. The Bouguer gravity anomaly map of the Sabratah Basin has relatively a smooth gradient with gravity increasing seaward to the northeast. The strong southwest-to-northeast increase in gravity values is probably related to the seaward swallowing of Moho as the crust thins in the that direction. This gradient is interrupted by two local gravity anomalies associated with magnetic anomalies and bounded the Sabratah basin, the WNW trending Jarrafa anomaly to the NE and to the SW the NS trending Jeffara anomaly with varying amplitudes. The high density and magnetisation of the source bodies indicates that they probably comprise mafic igneous rock. The depth to magnetic source estimated by source parameter imaging (SPI) and Euler

  19. Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin

    PubMed Central

    Feldmann, Johannes; Levermann, Anders

    2015-01-01

    The future evolution of the Antarctic Ice Sheet represents the largest uncertainty in sea-level projections of this and upcoming centuries. Recently, satellite observations and high-resolution simulations have suggested the initiation of an ice-sheet instability in the Amundsen Sea sector of West Antarctica, caused by the last decades’ enhanced basal ice-shelf melting. Whether this localized destabilization will yield a full discharge of marine ice from West Antarctica, associated with a global sea-level rise of more than 3 m, or whether the ice loss is limited by ice dynamics and topographic features, is unclear. Here we show that in the Parallel Ice Sheet Model, a local destabilization causes a complete disintegration of the marine ice in West Antarctica. In our simulations, at 5-km horizontal resolution, the region disequilibrates after 60 y of currently observed melt rates. Thereafter, the marine ice-sheet instability fully unfolds and is not halted by topographic features. In fact, the ice loss in Amundsen Sea sector shifts the catchment's ice divide toward the Filchner–Ronne and Ross ice shelves, which initiates grounding-line retreat there. Our simulations suggest that if a destabilization of Amundsen Sea sector has indeed been initiated, Antarctica will irrevocably contribute at least 3 m to global sea-level rise during the coming centuries to millennia. PMID:26578762

  20. Collapse of the West Antarctic Ice Sheet after local destabilization of the Amundsen Basin.

    PubMed

    Feldmann, Johannes; Levermann, Anders

    2015-11-17

    The future evolution of the Antarctic Ice Sheet represents the largest uncertainty in sea-level projections of this and upcoming centuries. Recently, satellite observations and high-resolution simulations have suggested the initiation of an ice-sheet instability in the Amundsen Sea sector of West Antarctica, caused by the last decades' enhanced basal ice-shelf melting. Whether this localized destabilization will yield a full discharge of marine ice from West Antarctica, associated with a global sea-level rise of more than 3 m, or whether the ice loss is limited by ice dynamics and topographic features, is unclear. Here we show that in the Parallel Ice Sheet Model, a local destabilization causes a complete disintegration of the marine ice in West Antarctica. In our simulations, at 5-km horizontal resolution, the region disequilibrates after 60 y of currently observed melt rates. Thereafter, the marine ice-sheet instability fully unfolds and is not halted by topographic features. In fact, the ice loss in Amundsen Sea sector shifts the catchment's ice divide toward the Filchner-Ronne and Ross ice shelves, which initiates grounding-line retreat there. Our simulations suggest that if a destabilization of Amundsen Sea sector has indeed been initiated, Antarctica will irrevocably contribute at least 3 m to global sea-level rise during the coming centuries to millennia. PMID:26578762

  1. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope, and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Shirley P. Dutton

    1998-07-31

    The objective of this Class 3 project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two main phases. The original objectives of the reservoir-characterization phase of the project were (1) to provide a detailed understanding of the architecture and heterogeneity of two representative fields of the Delaware Mountain Group, Geraldine Ford and Ford West, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, (2) to chose a demonstration area in one of the fields, and (3) to simulate a CO 2 flood in the demonstration area. The Bureau's industry partner for the initial Phase 1 of the project was Conoco, Inc.. After the reservoir characterization and simulation of an area at the northern end of the Ford Geraldine unit were completed, Conoco decided not to proceed to Phase 2, installation of a CO 2 flood in the demonstration area. This decision by Conoco provides an opportunity for a more extensive field demonstration in East Ford field, with Orla Petco as the industry partner. East Ford field is immediately adjacent to the Ford Geraldine unit and produces from the same Ramsey sandstone channel. Phase 1 of the project has been expanded to include reservoir characterization of East Ford field. This additional reservoir-characterization task provides an excellent opportunity to test the transferability of the geologic model and log-interpretation methods developed during reservoir characterization of the Ford Geraldine unit to another Delaware sandstone field. The objectives of the implementation phase of the project remain the same, to (1) apply the knowledge gained from reservoir characterization and

  2. Acceptance testing of the eddy current probes for measurement of aluminum hydroxide coating thickness on K West Basin fuel elements

    SciTech Connect

    Pitner, A.L.

    1998-08-21

    During a recent visual inspection campaign of fuel elements stored in the K West Basin, it was noted that fuel elements contained in sealed aluminum canisters had a heavy translucent type coating on their surfaces (Pitner 1997a). Subsequent sampling of this coating in a hot cell (Pitner 1997b) and analysis of the material identified it as aluminum hydroxide. Because of the relatively high water content of this material, safety related concerns are raised with respect to long term storage of this fuel in Multi-Canister Overpacks (MCOs). A campaign in the basin is planned to demonstrate whether this coating can be removed by mechanical brushing (Bridges 1998). Part of this campaign involves before-and-after measurements of the coating thickness to determine the effectiveness of coating removal by the brushing machine. Measurements of the as-deposited coating thickness on multiple fuel elements are also expected to provide total coating inventory information needed for MCO safety evaluations. The measurement technique must be capable of measuring coating thicknesses on the order of several mils, with a measurement accuracy of 0.5 mil. Several different methods for quantitatively measuring these thin coatings were considered in selecting the most promising approach. Ultrasonic measurement was investigated, but it was determined that due to the thin coating depth and the high water content of the material, the signal would likely pass directly through to the cladding without ever sensing the coating surface. X-ray fluorescence was also identified as a candidate technique, but would not work because the high gamma background from the irradiated fuel would swamp out the low energy aluminum signal. Laser interferometry could possibly be applied, but considerable development would be required and it was considered to be high risk on a short term basis. The consensus reached was that standard eddy current techniques for coating thickness measurement had the best chance for

  3. Porosity evolution in reservoir sandstones in the West-Central San Joaquin basin, California

    SciTech Connect

    Horton, R.A. Jr.; McCullough, P.T.; Houghton, B.D.; Pennell, D.A.; Dunwoody, J.A. III; Menzie, R.J. Jr.

    1995-04-01

    Miocene reservoir sands (feldspathic and lithic arenites) in central San Joaquin basin oil fields show similar trends in porosity development despite differences in depositional environment, pore-fluid chemistry, and burial history. Burial and tectonic compaction caused grain rotation, deformation of altered lithics, and extensive fracturing of brittle grains, thereby eliminating most primary porosity. Diagenetic fluids, infiltrating along fractures in grains, reacted with freshly exposed mineral surfaces causing extensive leaching of framework components. All major grain types were affected but preferential removal of feldspars and lithics resulted in changes in QFL ratios. With continued compaction angular remnants of partially disolved grains were rotated and rearranged while secondary intergranular and moldic porosity collapsed to form secondary intergranular porosity. This resulted in reservoir sands that are less well sorted, more angular, and mineralogically more mature than they were at deposition. Such changes appear to widespread in the San Joaquin basin and may be more important than is generally acknowledged.

  4. Seismology: energy radiation from the Sumatra earthquake.

    PubMed

    Ni, Sidao; Kanamori, Hiroo; Helmberger, Don

    2005-03-31

    We determined the duration of high-frequency energy radiation from Indonesia's great Sumatra-Andaman earthquake (26 December 2004) to be about 500 seconds. This duration can be translated into a rupture length of about 1,200 km, which is more than twice as long as that inferred from body-wave analyses performed soon after the event. Our analysis was able rapidly to define the extent of rupture, thereby aiding the assessment of seismic hazard in the immediate future.

  5. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    SciTech Connect

    Andrew G. Cole; George B. Asquith; Jose I. Guzman; Mark D. Barton; Mohammad A. Malik; Shirley P. Dutton; Sigrid J. Clift

    1998-04-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based enhanced oil recovery. The study focused on the Ford Geraldine unit, which produces from the upper Bell Canyon Formation (Ramsey sandstone). Reservoirs in this and other Delaware Mountain Group fields have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Outcrop analogs were studied to better interpret the depositional processes that formed the reservoirs at the Ford Geraldine unit and to determine the dimensions of reservoir sandstone bodies. Facies relationships and bedding architecture within a single genetic unit exposed in outcrop in Culberson County, Texas, suggest that the sandstones were deposited in a system of channels and levees with attached lobes that initially prograded basinward, aggraded, and then turned around and stepped back toward the shelf. Channel sandstones are 10 to 60 ft thick and 300 to 3,000 ft wide. The flanking levees have a wedge-shaped geometry and are composed of interbedded sandstone and siltstone; thickness varies from 3 to 20 ft and length from several hundred to several thousands of feet. The lobe sandstones are broad lens-shaped bodies; thicknesses range up to 30 ft with aspect ratios (width/thickness) of 100 to 10,000. Lobe sandstones may be interstratified with laminated siltstones.

  6. Gravity and magnetic studies of crustal structure across the Porcupine basin west of Ireland

    NASA Astrophysics Data System (ADS)

    Conroy, J. J.; Brock, A.

    1989-07-01

    Gravity, magnetic and seismic data from a profile across the Porcupine basin are used to suggest a model for the crustal structure in the region. The 280 km long profile bears WSW off the southwest coast of Ireland, and overlaps partially with the COOLE 3A and 3B lines of Makris et al. [13]. The gravity data are processed to produce an isostatic residual anomaly which is then modelled by two-and-a-half dimensional methods using the seismic data to provide geometrical constraints. Similar modelling techniques are used for the magnetic data. The final model shows crystalline crust which thins from 28 km at the eastern end of the profile to less than 8 km beneath the central part of the basin. The thinned crust is intruded by dense magnetic bodies, whilst the eastern margin is underlain by a large low-density body which is assumed to be a granite. These new findings have parallels in other basins on thinned and rifted crust.

  7. Effects of underground mining and mine collapse on the hydrology of selected basins in West Virginia

    USGS Publications Warehouse

    Hobba, William A.

    1993-01-01

    The effects of underground mining and mine collapse on areal hydrology were determined at one site where the mined bed of coal lies above major streams and at two sites where the bed of coal lies below major streams. Subsidence cracks observed at land surface generally run parallel to predominant joint sets in the rocks. The mining and subsidence cracks increase hydraulic conductivity and interconnection of water-bearing rock units, which in turn cause increased infiltration of precipitation and surface water, decreased evapotranspiration, and higher base flows in some small streams. Water levels in observation wells in mined areas fluctuate as much as 100 ft annually. Both gaining and losing streams are found in mined areas. Mine pumpage and drainage can cause diversion of water underground from one basin to another. Areal and single-well aquifer tests indicated that near-surface rocks have higher transmissivity in a mine-subsided basin than in unmined basins. Increased infiltration and circulation through shallow subsurface rocks increase dissolved mineral loads in streams, as do treated and untreated contributions from mine pumpage and drainage. Abandoned and flooded underground mines make good reservoirs because of their increased transmissivity and storage. Subsidence cracks were not detectable by thermal imagery, but springs and seeps were detectable.

  8. Relation between ground water and surface water in the Hillsborough River basin, west-central Florida

    USGS Publications Warehouse

    Wolansky, R.M.; Thompson, T.H.

    1987-01-01

    The relation between groundwater and surface water in the Hillsborough River basin was defined through the use of: seismic-reflection profiling along selected reaches of the Hillsborough River, and evaluation of streamflow, rainfall, groundwater levels, water quality, and geologic data. Major municipal well fields in the basin are Morris Bridge and Cypress Creek where an averages of 15.3 and 30.0 million gal/day (mgd), respectively, were pumped in 1980. Mean annual rainfall for the study area is 53.7 inches. Average rainfall for 1980, determined from eight rainfall stations, was 49.7 inches. Evapotranspiration, corrected for the 5% of the basin that is standing water, was 35.7 in/year. The principal geohydrologic units in the basin are the surficial aquifer, the intermediate aquifer and confining beds, the Upper Floridan aquifer, the middle confining unit, and the Lower Floridan aquifer. Total pumpage of groundwater in 1980 was 98.18 mgd. The surficial aquifer and the intermediate aquifer are not used for major groundwater supply in the basin. Continuous marine seismic-reflection data collected along selected reaches of the Hillsborough River were interpreted to define the riverbed profile, the thickness of surficial deposits, and the top of persistent limestone. Major areas of groundwater discharge near the Hillsborough River and its tributaries are the wetlands adjacent to the river between the Zephyrhills gaging stations and Fletcher Avenue and the wetlands adjacent to Cypress Creek. An estimated 20 mgd seeps upward from the Upper Floridan aquifer within those wetland areas. The runoff/sq mi is greater at the Zephyrhills station than at Morris Bridge. However, results of groundwater flow models and potentiometric-surface maps indicate that groundwater is flowing upward along the Hillsborough River between the Zephyrhills gage and the Morris Bridge gage. This upward leakage is lost to evapotranspiration. An aquifer test conducted in 1978 at the Morris Bridge well

  9. Evapotranspiration from the Lower Walker River Basin, West-Central Nevada, Water Years 2005-07

    USGS Publications Warehouse

    Allander, Kip K.; Smith, J. LaRue; Johnson, Michael J.

    2009-01-01

    Evapotranspiration is the ultimate path of outflow of nearly all water from the Lower Walker River basin. Walker Lake is the terminus of the topographically closed Walker River basin, and the lake level has been declining at an average rate of about 1.6 feet per year (ft/yr) since 1917. As a result of the declining lake level, dissolved-solids concentrations are increasingly threatening the fishery and ecosystem health of the lake. Uncertainties in the water budget components of the Lower Walker River basin led the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, to undertake an investigation to refine estimates of the water budget. Evapotranspiration from the Lower Walker River basin represents a major component of this water budget. The specific objectives of this report are to provide estimates of total and net evapotranspiration for water years 2005-07 for areas in the Lower Walker River basin in which annual evapotranspiration exceeds annual precipitation, and to summarize these results for areas of similar vegetation and soil characteristics, hydrographic subareas, and Walker Lake and Weber Reservoir. The three hydrographic subareas include the area along Walker River north of Walker Lake, the area of and adjacent to Walker Lake, and the area south of Walker Lake. Areas of annual evapotranspiration exceeding annual precipitation were identified and mapped in the field and were further delineated using remote-sensing analysis. These areas were classified into 10 evapotranspiration units. A network of 11 evapotranspiration stations was operated in natural and agricultural vegetation and on Walker Lake. Measured evapotranspiration rates ranged from 0.5 ft/yr at a sparsely vegetated desert shrub site to 5.0 ft/yr from Walker Lake. The greatest evapotranspiration rate on land was 4.1 ft/yr at an irrigated alfalfa field, and the greatest rate for natural vegetation was 3.9 ft/yr in a riparian community along Walker River. At an

  10. Relationships between Variscan strike-slip faults in the Paleozoic basement and oil-gas deposits in its Mesozoic-Cenozoic cover: West Siberian sedimentary basin as example

    SciTech Connect

    Clauzon, G.; Rubino, J.L.

    1995-08-01

    The West-Siberian Sedimentary Basin was filled during Mesozoic and Cenozoic. Polychronous compressive and extensional deformations and strike-slip faulting occurred at the time of sedimentary basin formation. Late Variscan (Late Permian-Early Triassic) strike-slips in the basement took place as a result of N-S compression of the Central Asian Fold Belt. Strike-slips form wide and continuous shear zones which coincide with large oil and gas fields in the cover. Some strike-slips controlled distribution and formation of Permian and Triassic-Jurassic compressional and extensional local structures in the lower stage of the cover and anticlines in the upper stage of the cover. All these structures reveal potential oil and gas resources. In the Triassic, some of the N-S and SW-NE trending strike-slip faults in the axial part of the West Siberian Sedimentary Basin were transformed into graben-rift structures of the Koltogorsk-Urengoy Rift Belt. These transtension structures occurred as a result of N-S compression and reactivation of the Late Variscan faults. The largest oil and gas fields have been formed in the cover above the Koltogorsk-Urengoy Rift Belt of the West Siberian Sedimentary Basin.

  11. Geologic Controls of Hydrocarbon Occurrence in the Appalachian Basin in Eastern Tennessee, Southwestern Virginia, Eastern Kentucky, and Southern West Virginia

    SciTech Connect

    Hatcher, Robert D

    2005-11-30

    This report summarizes the accomplishments of a three-year program to investigate the geologic controls of hydrocarbon occurrence in the southern Appalachian basin in eastern Tennessee, southwestern Virginia, eastern Kentucky, and southern West Virginia. The project: (1) employed the petroleum system approach to understand the geologic controls of hydrocarbons; (2) attempted to characterize the P-T parameters driving petroleum evolution; (3) attempted to obtain more quantitative definitions of reservoir architecture and identify new traps; (4) is worked with USGS and industry partners to develop new play concepts and geophysical log standards for subsurface correlation; and (5) geochemically characterized the hydrocarbons (cooperatively with USGS). Third-year results include: All project milestones have been met and addressed. We also have disseminated this research and related information through presentations at professional meetings, convening a major workshop in August 2003, and the publication of results. Our work in geophysical log correlation in the Middle Ordovician units is bearing fruit in recognition that the criteria developed locally in Tennessee and southern Kentucky are more extendible than anticipated earlier. We have identified a major 60 mi-long structure in the western part of the Valley and Ridge thrust belt that has been successfully tested by a local independent and is now producing commercial amounts of hydrocarbons. If this structure is productive along strike, it will be one of the largest producing structures in the Appalachians. We are completing a more quantitative structural reconstruction of the Valley and Ridge and Cumberland Plateau than has been made before. This should yield major dividends in future exploration in the southern Appalachian basin. Our work in mapping, retrodeformation, and modeling of the Sevier basin is a major component of the understanding of the Ordovician petroleum system in this region. Prior to our

  12. Trends and Projections of Climatic Extremes in the Black Volta Basin, West Africa: Towards Climate Change Adaptation.

    NASA Astrophysics Data System (ADS)

    Aziz, F.

    2015-12-01

    The water resources of the Black Volta Basin in West Africa constitute a major resource for the four countries (Burkina Faso, Ghana, Côte d'Ivoire, Mali) that share it. For Burkina Faso and Ghana, the river is the main natural resource around which the development of the diverse sectors of the two economies is built. Whereas Ghana relies heavily on the river for energy, land-locked Burkina Faso continuously develops the water for agricultural purposes. Such important role of the river makes it an element around which there are potential conflicts: either among riparian countries or within the individual countries themselves. This study documents the changes in temperature and precipitation extremes in the Black Volta Basin region for the past (1981-2010) and makes projections for the mid-late 21st century (2051-2080) under two emission scenarios; RCP 2.6 and RCP 8.5. The Expert Team on Climate Change Detection and Indices (ETCCDI) temperature- and precipitation-based indices are computed with the RClimdex software. Observed daily records and downscaled CORDEX data of precipitation and maximum and minimum temperatures are used for historical and future trend analysis respectively. In general low emission scenarios show increases in the cold extremes. The region shows a consistent pattern of trends in hot extremes for the 1990's. An increasing trend in hot extremes is expected in the future under RCP 8.5 while RCP 2.5 shows reductions in hot extremes. Regardless of the emission scenario, projections show more frequent hot nights in the 21st century. Generally, the region shows variability in trends for future extreme precipitation indices with only a few of the trends being statistically significant (5% level). Results obtained provide a basic and first step to understanding how climatic extremes have been changing in the Volta Basin region and gives an idea of what to expect in the future. Such studies will also help in making informed decisions on water management

  13. Prototype Tsunami Evacuation Park in Padang, West Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Tucker, B. E.; Cedillos, V.; Deierlein, G.; Di Mauro, M.; Kornberg, K.

    2012-12-01

    Padang, Indonesia, a city of some 900,000 people, half of whom live close to the coast and within a five-meter elevation above sea level, has one of the highest tsunami risks in the world due to its close offshore thrust-fault seismic hazard, flat terrain and dense population. There is a high probability that a tsunami will strike the shores of Padang, flooding half of the area of the city, within the next 30 years. If that tsunami occurred today, it is estimated that several hundred thousand people would die, as they could not reach safe ground in the ~30 minute interval between the earthquake's occurrence and the tsunami's arrival. Padang's needs have been amply demonstrated: after earthquakes in 2007, 2009, 2011 and 2012, citizens, thinking that those earthquakes might cause a tsunami, tried to evacuate in cars and motorbikes, which created traffic jams, and most could not reach safe ground in 30 minutes. Since 2008, GeoHazards International (GHI) and Stanford University have studied a range of options for improving this situation, including ways to accelerate evacuation to high ground with pedestrian bridges and widened roads, and means of "vertical" evacuation in multi-story buildings, mosques, pedestrian overpasses, and Tsunami Evacuation Parks (TEPs), which are man-made hills with recreation facilities on top. TEPs proved most practical and cost-effective for Padang, given the available budget, technology and time. The Earth Observatory Singapore (EOS) developed an agent-based model that simulates pedestrian and vehicular evacuation to assess tsunami risk and risk reduction interventions in Southeast Asia. EOS applied this model to analyze the effectiveness in Padang of TEPs over other tsunami risk management approaches in terms of evacuation times and the number of people saved. The model shows that only ~24,000 people (20% of the total population) in the northern part of Padang can reach safe ground within 30 minutes, if people evacuate using cars and motorbikes immediately after the earthquake. If one TEP is built, ~46,000 could reach safe ground within 30 minutes, and if three were built ~72,000 could. GHI has acquired permission to build a prototype TEP in the northern part of Padang that would accommodate about 25,000 people during the time of a tsunami. This would cost about 4.7 million, amounting to a cost-per-life-saved of ~US200, far lower than the per capita cost of the other options. The cost of replication should be less. This interdisciplinary, international effort demonstrated that TEPs offer the best option for Padang because they have the potential to save thousands of lives, are relatively simple to build and maintain, invite everyday recreational use by the community, and have attracted strong Indonesian government support as a possible means to manage the country's tsunami risk.

  14. Hydrocarbon accumulation on rifted Continental Margin - examples of oil migration pathways, west African salt basins

    SciTech Connect

    Blackwelder, B.W.

    1989-03-01

    Examination of the oil fields in the Gabon, Lower Congo, and Cuanza basins allows modeling of oil migration and a more accurate ranking of prospects using geologic risk factors. Oil accumulations in these basins are in strata deposited during Cretaceous rift and drift phases, thus providing a diversity of geologic settings to examine. Oil accumulations in rift deposits are located on large faulted anticlines or in truncated units atop horst features. Many of these oil fields were sourced from adjacent organic shales along short direct migration paths. In Areas where source rock is more remote to fields or to prospective structures, faulting and continuity of reservoir rock are important to the migration of hydrocarbons. Because Aptian salts separate rift-related deposits from those of the drift stage, salt evacuation and faulting of the salt residuum are necessary for oil migration from the pre-salt sequences into the post-salt section. Oil migration within post-salt strata is complicated by the presence of salt walls and faulted carbonate platforms. Hydrocarbon shows in wells drilled throughout this area provide critical data for evaluating hydrocarbon migration pathways. Such evaluation in combination with modeling and mapping of the organic-rich units, maturation, reservoir facies, structural configurations, and seals in existing fields allows assessment of different plays. Based on this information, new play types and prospective structures can be ranked with respect to geologic risk.

  15. Ground-water quality of coastal aquifer systems in the West Coast Basin, Los Angeles County, California, 1999-2002

    USGS Publications Warehouse

    Land, Michael; Reichard, Eric G.; Crawford, Steven M.; Everett, Rhett; Newhouse, Mark W.; Williams, Colin F.

    2004-01-01

    The extensive use of ground water throughout the Central and West Coast Basins of Los Angeles County during the first half of the 20th century resulted in declining water levels, widespread seawater intrusion, and deterioration of water quality along most reaches of the coast. In order to control seawater intrusion in the West Coast Basin, freshwater is injected into a series of wells at two seawater barrier projects. In order to better understand the processes of seawater intrusion and the efficiency of current barrier operation, data were collected from multiple-well monitoring sites installed by the U.S. Geological Survey, from local observation wells, and from production wells. The occurrence and areal extent of native, saline, and recently injected ground water near the coast were defined through the collection and analysis of inorganic and isotopic water-quality data and geophysical logs. Most water in the West Coast Basin with a dissolved-solids concentration less than 500 milligrams per liter generally has a sodium-bicarbonate to sodium/calcium-bicarbonate character. Water with a dissolved-solids concentration greater than 1,000 milligrams per liter also contains variable amounts of calcium and sodium, but chloride is predominant. Most of these high-dissolved-solids wells are perforated in the Upper aquifer systems; several have dissolved-chloride values near that of seawater. Elevated chloride concentrations were measured at many wells in both the Upper and Lower aquifer systems inland from the barrier projects. Although water levels have increased in many wells over the last 30 years, some of the wells do not show a corresponding decrease in dissolved chloride. A detailed assessment of saline ground water was provided by examining the ratios of chloride to bromide, iodide, and boron. Seawater-freshwater mixing lines were constructed using all three ratios. These ion ratios also identify water affected by mixing with injected imported water and oil

  16. Variations of lead isotopes and airborne particulate concentrations from the Kozani basin, West Macedonia, Greece.

    PubMed

    Charalampides, G; Manoliadis, O; Triantafyllou, A

    2002-03-01

    The spread and variation in 206Pb/207Pb ratios make Pb isotopes a powerful tool when it comes to detecting trends in airborne particulates originating mainly from power plants. This study was conducted to determine the source of pollution in Kozani area, an affected industrial area. Lead isotopic ratios of air filters under certain meteorological conditions were compared to Pb isotope analyses sampled from lignite mines, but also to Pb isotope analyses of cultivations in soil originating from the reclamation of old abandoned lignite-mines. The particles taken into consideration have an aerodynamic diameter less than 10 microm (PM10). The measurements were carried out in a central part of the town of Kozani, West Macedonia, for one year observation period. The lead isotope values of air filters and of wheat in the Kozani area are between the values of lignite Pb and of Greek gasoline.

  17. Environmental geology for land use and regional planning in the Bandung Basin, West Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Suhari, S.; Siebenhüner, M.

    The demand on land and natural resources in the Greater Bandung area increases rapidly with increasing population and economic growth. Land use changes and over-exploitation of natural resources have significantly caused negative environmental impacts. In the period 1989-1993, an Indonesian-German technical cooperation project between the Directorate of Environmental Geology (Indonesia) and the Federal Institute for Geosciences and Natural Resources (Germany) has been conducting a study to improve the conservation and management of the natural resources for regional planning in the Bandung Basin. The Bandung Basin consists of a plain which is surrounded by a mountainous chain. The mountainous area is mostly dominated by Quaternary volcanic products such as lava, breccia, agglomerate, lahar, tuff, and andesite intrusions. The plain comprises thick alluvial deposits of river and lacustrine origin. Tertiary sediments only cover the western part of the basin. The Quaternary volcanic products do not only produce fertile agricultural soils but also are the important source of various construction materials and act as groundwater recharge. From the environmental geology point of view, the physical development,of the Greater Bandung area faces various constraints. These include conflict among urban development, agricultural land, groundwater protection, extraction of mineral resources, and potential waste disposal sites. In addition, some areas are restricted for development due to: (a) their poor foundation characteristics; (b) location in flood prone areas; and (c) geological hazards such as landslides and lahar flows. Operation of many existing and abandoned waste disposal dumping facilities in geologically unfavorable areas has contaminated both the groundwater and surface water. Improper exploitation technique in many quarries and pits has also endangered the environment, such as destabilization of slope, increasing danger of landslides and erosion, and increasing

  18. Detection and attribution of climate change at regional scale: case study of Karkheh river basin in the west of Iran

    NASA Astrophysics Data System (ADS)

    Zohrabi, Narges; Goodarzi, Elahe; Massah Bavani, Alireza; Najafi, Husain

    2016-09-01

    This research aims at providing a statistical framework for detection and attribution of climate variability and change at regional scale when at least 30 years of observation data are available. While extensive research has been done on detecting significant observed trends in hydroclimate variables and attribution to anthropogenic greenhouse gas emissions in large continents, less attention has been paid for regional scale analysis. The latter is mainly important for adaptation to climate change in different sectors including but not limited to energy, agriculture, and water resources planning and management, and it is still an open discussion in many countries including the West Asian ones. In the absence of regional climate models, an informative framework is suggested providing useful insights for policymakers. It benefits from general flexibility, not being computationally expensive, and applying several trend tests to analyze temporal variations in temperature and precipitation (gradual and step changes). The framework is implemented for a very important river basin in the west of Iran. In general, some increasing and decreasing trends of the interannual precipitation and temperature have been detected. For precipitation annual time series, a reducing step was seen around 1996 compared with the gradual change in most of the stations, which have not experience a dramatical change. The range of natural forcing is found to be ±76 % for precipitation and ±1.4 °C for temperature considering a two-dimensional diagram of precipitation and temperature anomalies from 1000-year control run of global climate model (GCM). Findings out of applying the proposed framework may provide useful insights into how to approach structural and non-structural climate change adaptation strategies from central governments.

  19. Subsurface geometry and growth history of the Warfield Structure in South-Central West Virginia, Central Appalachian basin

    SciTech Connect

    Gao, D.; Shumaker, R.C. )

    1994-08-01

    The Warfield structure is located at the eastern margin of Rome trough in south-central West Virginia, an intersection area between the 38th parallel and the Burning Springs lineaments in the central Appalachian basin. Using SURFACE III and MCS contouring packages, structure maps of upper Paleozoic horizons were completed by retrieving, editing, and contouring over 6000 shallow wells from the database of the DEAM (Data Editing and Management) software package. The Warfield anticline is horizontal at the Mississippian horizons, with a generally northeast-trending closure and a northwest-dipping axial plane, but at the Devonian level the closure is lost as the fold plunges northeastward. Structures from the Oriskany horizon to the basement were interpolated based on seismic and well data with a multisurface STACK procedure of the MCS package, and demonstrate a constrained half graben underneath the Warfield anticline with a 38th parallel and the north-south-trending Burning Springs lineaments. Based on preliminary results from subsurface mapping, digitization, and quantitative analysis of seismic time sections as well as computer modeling for the magnetic/gravity anomalies, the authors postulate that the geometry and growth history of the Warfield structure were genetically controlled by a wedge-shaped basement fault system in which the strike-slip displacement along both the eastwest-trending and the north-south-trending faults, and the dip-slip displacement on the northeast-trending faults occurred synchronously in response to the episodic movement of a wedge-shaped basement block bounded by the east-west-trending 38th parallel and the north-south-trending Burning Springs lineaments as well as the northeast-trending trough-margin faults throughout the Paleozoic.

  20. Distribution, lithology and ages of late Cenozoic volcanism on the eastern margin of the Great Basin, West-Central Utah

    SciTech Connect

    Nash, W.P.

    1986-01-01

    The eastern margin of the Basin and Range province in central Utah is the locus of late Cenozoic volcanic activity and has witnessed several volcanic episodes within the last three million years. The Twin Peaks volcanic center became active 2.7 m.y. ago producing rhyodacite and rhyolite from a shallow silicic magma body accompanied by voluminous eruptions of basalt. Between about 1 and 0.3 m.y. ago there were eruptions of high silica rhyolite from a deep-seated magma source beneath the Mineral Mountains together with primitive and strongly fractionated mafic magmas of the Cove Fort subprovince. Within this volcanic area are two localities, Roosevelt Hot Springs and Sulfurdale, which have high temperature waters at or near the surface. To the north in the Black Rock Desert, volcanism extended from 1.5 m.y to only several hundred years ago. The activity was dominated by basaltic eruptions, but the area contains the youngest known rhyolite body in Utah (0.4 m.y.). Volcanic vents are located along major crustal discontinuities in the Black Rock Desert, along ring fracture systems at Twin Peaks, and are aligned along trends of north-south normal faulting in the Mineral Mountains and Cove Fort areas. The localization of volcanism is consistent with high strain rates on a regional scale associated with extension of the Basin and Range. The variety of lithologies observed is consistent with a model of fundamentally basaltic magmatism which augments melting in the lower crust to produce silicic magmas. The majority of the mafic magmas that reach the surface are modified by fractionation with the most primitive varieties erupted to the west.

  1. A petroliferous transform-margin basin, Cote d'Ivoire, West Africa

    SciTech Connect

    Harms, J.C. ); Bruso, J.M. Jr.; Wallace, R.L.; Canales, J.A. )

    1996-01-01

    Break-up transform margins, formed by large dominantly strike-slip faults as continents separate, are distinct in structural style and stratigraphic sequence from subduction or purely extensional margins. A continental margin defined by such a transform zone is sharp, precipitous, and places an essentially complete continental crust abruptly against oceanic or highly attenuated continental crust. Structures develop in stress fields dominated by horizontal translation, with an overprint of uplift and subsidence related to thermal effects of a laterally migrating asthenosphere plume. Stratigraphic sequences begin with relatively deep-water lacustrine deposits and are followed by marine conditions as ocean connections develop. Because bathymetry tends to be steep across the transform zone, marine deposits along this zone represent slope environments with many erosional canyons and canyons fills, and these facies are vertically stacked through time. The offshore Cote d'Ivoire Basin is an excellent example of a transform margin documented by more than 110 wells, an extensive 2-D seismic grid, a growing number of 3-D surveys, and several productive fields. The sedimentary section exceeds 5000m, beginning with Aptian( )-Albian deep lacustrine facies. Marine incursion occurred in the Albian, followed by deformation, uplift, and erosion in later Albian. A series of major uplifts developed offshore along strands of the St. Paul fracture zone. The uplifts contain many SE-trending normal splay faults. The uplifts and NE-tilted fault blocks are the major petroleum targets within the Albian section. Upper Cretaceous petroleum traps are mainly related to stratigraphic variations caused by submarine canyon cutting and filling. The Cote d'lvoire Basin provides a valuable model of transform margin processes and petroleum occurrences.

  2. A petroliferous transform-margin basin, Cote d`Ivoire, West Africa

    SciTech Connect

    Harms, J.C.; Bruso, J.M. Jr.; Wallace, R.L.; Canales, J.A.

    1996-12-31

    Break-up transform margins, formed by large dominantly strike-slip faults as continents separate, are distinct in structural style and stratigraphic sequence from subduction or purely extensional margins. A continental margin defined by such a transform zone is sharp, precipitous, and places an essentially complete continental crust abruptly against oceanic or highly attenuated continental crust. Structures develop in stress fields dominated by horizontal translation, with an overprint of uplift and subsidence related to thermal effects of a laterally migrating asthenosphere plume. Stratigraphic sequences begin with relatively deep-water lacustrine deposits and are followed by marine conditions as ocean connections develop. Because bathymetry tends to be steep across the transform zone, marine deposits along this zone represent slope environments with many erosional canyons and canyons fills, and these facies are vertically stacked through time. The offshore Cote d`Ivoire Basin is an excellent example of a transform margin documented by more than 110 wells, an extensive 2-D seismic grid, a growing number of 3-D surveys, and several productive fields. The sedimentary section exceeds 5000m, beginning with Aptian(?)-Albian deep lacustrine facies. Marine incursion occurred in the Albian, followed by deformation, uplift, and erosion in later Albian. A series of major uplifts developed offshore along strands of the St. Paul fracture zone. The uplifts contain many SE-trending normal splay faults. The uplifts and NE-tilted fault blocks are the major petroleum targets within the Albian section. Upper Cretaceous petroleum traps are mainly related to stratigraphic variations caused by submarine canyon cutting and filling. The Cote d`lvoire Basin provides a valuable model of transform margin processes and petroleum occurrences.

  3. Structural Constraints and Earthquake Recurrence Estimates for the West Tahoe-Dollar Point Fault, Lake Tahoe Basin, California

    NASA Astrophysics Data System (ADS)

    Maloney, J. M.; Driscoll, N. W.; Kent, G.; Brothers, D. S.; Baskin, R. L.; Babcock, J. M.; Noble, P. J.; Karlin, R. E.

    2011-12-01

    Previous work in the Lake Tahoe Basin (LTB), California, identified the West Tahoe-Dollar Point Fault (WTDPF) as the most hazardous fault in the region. Onshore and offshore geophysical mapping delineated three segments of the WTDPF extending along the western margin of the LTB. The rupture patterns between the three WTDPF segments remain poorly understood. Fallen Leaf Lake (FLL), Cascade Lake, and Emerald Bay are three sub-basins of the LTB, located south of Lake Tahoe, that provide an opportunity to image primary earthquake deformation along the WTDPF and associated landslide deposits. We present results from recent (June 2011) high-resolution seismic CHIRP surveys in FLL and Cascade Lake, as well as complete multibeam swath bathymetry coverage of FLL. Radiocarbon dates obtained from the new piston cores acquired in FLL provide age constraints on the older FLL slide deposits and build on and complement previous work that dated the most recent event (MRE) in Fallen Leaf Lake at ~4.1-4.5 k.y. BP. The CHIRP data beneath FLL image slide deposits that appear to correlate with contemporaneous slide deposits in Emerald Bay and Lake Tahoe. A major slide imaged in FLL CHIRP data is slightly younger than the Tsoyowata ash (7950-7730 cal yrs BP) identified in sediment cores and appears synchronous with a major Lake Tahoe slide deposit (7890-7190 cal yrs BP). The equivalent age of these slides suggests the penultimate earthquake on the WTDPF may have triggered them. If correct, we postulate a recurrence interval of ~3-4 k.y. These results suggest the FLL segment of the WTDPF is near its seismic recurrence cycle. Additionally, CHIRP profiles acquired in Cascade Lake image the WTDPF for the first time in this sub-basin, which is located near the transition zone between the FLL and Rubicon Point Sections of the WTDPF. We observe two fault-strands trending N45°W across southern Cascade Lake for ~450 m. The strands produce scarps of ~5 m and ~2.7 m, respectively, on the lake

  4. Water quality of groundwater and stream base flow in the Marcellus Shale Gas Field of the Monongahela River Basin, West Virginia, 2011-12

    USGS Publications Warehouse

    Chambers, Douglas B.; Kozar, Mark D.; Messinger, Terence; Mulder, Michon L.; Pelak, Adam J.; White, Jeremy S.

    2015-01-01

    This study provides a baseline of water-quality conditions in the Monongahela River Basin in West Virginia during the early phases of development of the Marcellus Shale gas field. Although not all inclusive, the results of this study provide a set of reliable water-quality data against which future data sets can be compared and the effects of shale-gas development may be determined.

  5. Coalbed methane-produced water quality and its management options in Raniganj Basin, West Bengal, India

    NASA Astrophysics Data System (ADS)

    Mendhe, Vinod Atmaram; Mishra, Subhashree; Varma, Atul Kumar; Singh, Awanindra Pratap

    2015-09-01

    Coalbed methane (CBM) recovery is associated with production of large quantity of groundwater. The coal seams are depressurized by pumping of water for regular and consistent gas production. Usually, CBM operators need to pump >10 m3 of water per day from one well, which depends on the aquifer characteristics, drainage and recharge pattern. In India, 32 CBM blocks have been awarded for exploration and production, out of which six blocks are commercially producing methane gas at 0.5 million metric standard cubic feet per day. Large amount of water is being produced from CBM producing blocks, but no specific information or data are available for geochemical properties of CBM-produced water and its suitable disposal or utilization options for better management. CBM operators are in infancy and searching for the suitable solutions for optimal management of produced water. CBM- and mine-produced water needs to be handled considering its physical and geochemical assessment, because it may have environmental as well as long-term impact on aquifer. Investigations were carried out to evaluate geochemical and hydrogeological conditions of CBM blocks in Raniganj Basin. Totally, 15 water samples from CBM well head and nine water samples from mine disposal head were collected from Raniganj Basin. The chemical signature of produced water reveals high sodium and bicarbonate concentrations with low calcium and magnesium, and very low sulphate in CBM water. It is comprehend that CBM water is mainly of Na-HCO3 type and coal mine water is of Ca-Mg-SO4 and HCO3-Cl-SO4 type. The comparative studies are also carried out for CBM- and mine-produced water considering the geochemical properties, aquifer type, depth of occurrence and lithological formations. Suitable options like impounding, reverse osmosis, irrigation and industrial use after prerequisite treatments are suggested. However, use of this huge volume of CBM- and mine-produced water for irrigation or other beneficial purposes

  6. Regional hydrostratigraphy and groundwater flow modeling in the arsenic-affected areas of the western Bengal basin, West Bengal, India

    NASA Astrophysics Data System (ADS)

    Mukherjee, Abhijit; Fryar, Alan E.; Howell, Paul D.

    2007-11-01

    The first documented interpretation of the regional-scale hydrostratigraphy and groundwater flow is presented for a ˜21,000-km2 area of the arsenic-affected districts of West Bengal [Murshidabad, Nadia, North 24 Parganas and South 24 Parganas (including Calcutta)], India. A hydrostratigraphic model demonstrates the presence of a continuous, semi-confined sand aquifer underlain by a thick clay aquitard. The aquifer thickens toward the east and south. In the south, discontinuous clay layers locally divide the near-surface aquifer into several deeper, laterally connected, confined aquifers. Eight 22-layer model scenarios of regional groundwater flow were developed based on the observed topography, seasonal conditions, and inferred hydrostratigraphy. The models suggest the existence of seasonally variable, regional, north-south flow across the basin prior to the onset of extensive pumping in the 1970s. Pumping has severely distorted the flow pattern, inducing high vertical hydraulic gradients across wide cones of depression. Pumping has also increased total recharge (including irrigational return flow), inflow from rivers, and sea water intrusion. Consequently, downward flow of arsenic contaminated shallow groundwater appears to have resulted in contamination of previously safe aquifers by a combination of mechanical mixing and changes in chemical equilibrium.

  7. Impacts of increased CO2 on the hydrologic response over the Xijiang (West River) basin, South China

    NASA Astrophysics Data System (ADS)

    Niu, Jun; Sivakumar, Bellie; Chen, Ji

    2013-11-01

    Increases in atmospheric carbon dioxide (CO2) concentration levels may affect terrestrial hydrologic processes through changes in evapotranspiration. This study assesses the hydrologic response to the elevated CO2 levels for the Xijiang (West River) basin in South China by applying the Variable Infiltration Capacity (VIC) model. The standard VIC model is modified by incorporating a mechanistic description of vegetation-type specific responses of both stomatal resistance and leaf area increase based on plant physiological studies. The dynamic (monthly) rises of CO2 concentration are introduced to estimate the historical impacts of increased CO2 over the past two decades (1991-2010). The cropland is identified as the most important contributor in the response of streamflow increase for the region. For a doubled atmospheric CO2 concentration scenario (660 ppm), the streamflow might rise about 3% (i.e. 21.8 mm/yr) under the baseline climatic conditions. Decreases in evapotranspiration and associated streamflow increases in response to ambient CO2 exposures are expected to episodically increase the frequency and severity of flood and affect flow-dependent aquatic biota in forested watersheds.

  8. Thermal maturity patterns (CAI and %Ro) in the Ordovician and Devonian rocks of the Appalachian basin in West Virginia

    USGS Publications Warehouse

    Repetski, John E.; Ryder, Robert T.; Avary, Katharine Lee; Trippi, Michael H.

    2005-01-01

    The objective of this study is to enhance existing thermal maturity maps in West Virginia by establishing: 1) new subsurface CAI data points for the Ordovician and Devonian and 2) new %Ro and Rock Eval subsurface data points for Middle and Upper Devonian black shale units. Thermal maturity values for the Ordovician and Devonian strata are of major interest because they contain the source rocks for most of the oil and natural gas resources in the basin. Thermal maturity patterns of the Middle Ordovician Trenton Limestone are evaluated here because they closely approximate those of the overlying Ordovician Utica Shale that is believed to be the source rock for the regional oil and gas accumulation in Lower Silurian sandstones (Ryder and others, 1998) and for natural gas fields in fractured dolomite reservoirs of the Ordovician Black River-Trenton Limestones. Improved CAI-based thermal maturity maps of the Ordovician are important to identify areas of optimum gas generation from the Utica Shale and to provide constraints for interpreting the origin of oil and gas in the Lower Silurian regional accumulation and Ordovician Black River-Trenton fields. Thermal maturity maps of the Devonian will better constrain burial history-petroleum generation models of the Utica Shale, as well as place limitations on the origin of regional oil and gas accumulations in Upper Devonian sandstone and Middle to Upper Devonian black shale.

  9. Volcanic morphology of West Mata Volcano, NE Lau Basin, based on high-resolution bathymetry and depth changes

    NASA Astrophysics Data System (ADS)

    Clague, David A.; Paduan, Jennifer B.; Caress, David W.; Thomas, Hans; Chadwick, William W., Jr.; Merle, Susan G.

    2011-11-01

    High-resolution (1.5 m) mapping from the autonomous underwater vehicle (AUV) D. Allan B. of West Mata Volcano in the northern Lau Basin is used to identify the processes that construct and modify the volcano. The surface consists largely of volcaniclastic debris that forms smooth slopes to the NW and SE, with smaller lava flows forming gently sloping plateaus concentrated along the ENE and WSW rift zones, and more elongate flows radiating from the summit. Two active volcanic vents, Prometheus and Hades, are located ˜50 and ˜150 m WSW of the 1159 m summit, respectively, and are slightly NW of the ridgeline so the most abundant clastic deposits are emplaced on the NW flank. This eruptive activity and the location of vents appears to have been persistent for more than a decade, based on comparison of ship-based bathymetric surveys in 1996 and 2008-2010, which show positive depth changes up to 96 m on the summit and north flank of the volcano. The widespread distribution of clastic deposits downslope from the rift zones, as well as from the current vents, suggests that pyroclastic activity occurs at least as deep as 2200 m. The similar morphology of additional nearby volcanoes suggests that they too have abundant pyroclastic deposits.

  10. Hydrogeology and ground-water flow, fractured Mesozoic structural-basin rocks, Stony Brook, Beden Brook, and Jacobs Creek drainage basins, west-central New Jersey

    USGS Publications Warehouse

    Lewis, Jean C.; Jacobsen, Eric

    1995-01-01

    This study was undertaken to characterize ground- water flow in the Stony Brook, Beden Brook, and Jacobs Creek drainage basins in west-central New Jersey. The 89-square-mile study area is underlain by dipping beds of fractured siltstone, shale, and sandstone and by massive diabase sills. In all of the rocks, the density of interconnected fractures decreases with depth. A major fault extends through the study area, and rocks on both sides of the fault are extensively fractured. The average annual rates of precipitation and ground-water recharge in the study area are 45.07 inches and 8.58 inches, respectively. The rate of recharge to diabase rocks is about one-half the rate of recharge to other rocks. Part of the surface runoff from diabase rocks enters the ground-water system where it encounters more permeable rocks. Most ground water in the study area follows short, shallow flow paths. A three- dimensional finite-difference model of ground-water flow was developed to test hypotheses concerning geologic features that control ground-water flow in the study area. The decrease in the density of interconnected fractures with depth was represented by dividing the model into two layers with different hydraulic conductivity. The pinching out of water- bearing beds in the dip direction at land surface and at depth was simulated as a lower hydraulic conductivity in the dip direction than in the strike direction. This model can be used to analyze ground-water flow if the area of interest is more than about 0.5 square mile.

  11. Vulnerability and adaptation to climate change in the Comoe River Basin (West Africa).

    PubMed

    Yéo, Wonnan Eugène; Goula, Bi Tié Albert; Diekkrüger, Bernd; Afouda, Abel

    2016-01-01

    Climate change is impacting water users in many sectors: water supply, farming, industry, hydropower, fishing, housing, navigation and health. Existing situations, like population growth, movement of populations from rural to urban areas, poverty and pollution can aggravate the impacts of climate change. The aim of the study is to evaluate the vulnerability of different water user groups to climate change and define communities' adaptation strategies in the Comoe River Basin. Information was collected on communities' concerns and perception on changes in climate and potential adaptation measures and strategies. Results show that 95 % of the sample in the study communities had heard of it and are aware that climate change is occurring. They have been experiencing changes in economic activity and cropping pattern, reduced water level in rivers, crop failure, delay in cropping season, new pests and diseases, food insecurity, drop in income and decline in crop yield. Results also show that communities employ various adaptation strategies including crops diversification, substitution and calendar redefinition, agroforestry, borrowing from friends and money lenders and increasing fertilizer application.

  12. Vulnerability and adaptation to climate change in the Comoe River Basin (West Africa).

    PubMed

    Yéo, Wonnan Eugène; Goula, Bi Tié Albert; Diekkrüger, Bernd; Afouda, Abel

    2016-01-01

    Climate change is impacting water users in many sectors: water supply, farming, industry, hydropower, fishing, housing, navigation and health. Existing situations, like population growth, movement of populations from rural to urban areas, poverty and pollution can aggravate the impacts of climate change. The aim of the study is to evaluate the vulnerability of different water user groups to climate change and define communities' adaptation strategies in the Comoe River Basin. Information was collected on communities' concerns and perception on changes in climate and potential adaptation measures and strategies. Results show that 95 % of the sample in the study communities had heard of it and are aware that climate change is occurring. They have been experiencing changes in economic activity and cropping pattern, reduced water level in rivers, crop failure, delay in cropping season, new pests and diseases, food insecurity, drop in income and decline in crop yield. Results also show that communities employ various adaptation strategies including crops diversification, substitution and calendar redefinition, agroforestry, borrowing from friends and money lenders and increasing fertilizer application. PMID:27386296

  13. Distribution and seasonality of selected hydrocarbons and halocarbons over the western Pacific basin during PEM-West A and PEM-West B

    NASA Astrophysics Data System (ADS)

    Blake, Nicola J.; Blake, Donald R.; Chen, Tai-Yih; Collins, James E.; Sachse, Glen W.; Anderson, Bruce E.; Rowland, F. Sherwood

    1997-12-01

    Nonmethane hydrocarbons (NMHCs) and halocarbons were measured in the troposphere over the northwestern Pacific as part of the airborne component of NASA's Pacific Exploratory Mission-West Phase B (PEM-West B). This study took place in late winter of 1994, a period characterized by maximum outflow from the Asian continent. The results are compared to those from Pacific Exploratory Mission-West Phase A (PEM-West A), which was flown in the same region during late summer of 1991, when flow from the subtropical western Pacific dominated the lower troposphere. Mixing ratios of NMHCs, tetrachloroethene (C2Cl4), and methyl bromide (CH3Br) were significantly higher during PEM-West B than during PEM-West A, particularly at latitudes north of 25°N and altitudes lower than 6 km. The primary reasons for these higher ambient concentrations were the seasonal increase in the atmospheric lifetimes of trace gases controlled by HO radical reactions, and the more frequent input of continental air masses. During PEM-West B, air masses of continental origin observed north of 25°N latitude were augmented with urban signature gases such as C2Cl4. By contrast, more southerly continental outflow had characteristics associated with combustion sources such as biomass burning, including wood fuel burning. During the summer PEM-West A period, the spatial distribution of methyl iodide (CH3I) was consistent with effective oceanic sources at all latitudes, being especially strong in tropical and subtropical regions. At low latitudes, PEM-West B CH3I mixing ratios in the lower troposphere were similar to PEM-West A, but at latitudes greater than about 25°N PEM-West B concentrations were significantly reduced. Equatorial regions exhibited enhanced CH3I mixing ratios extending into the upper tropical troposphere, consistent with fast vertical transport of air from the tropical marine boundary layer.

  14. Distribution and Seasonality of Selected Hydrocarbons and Halocarbons over the Western Pacific Basin During PEM-West A and PEM-West B

    NASA Technical Reports Server (NTRS)

    Blake, Nicola J.; Blake, Donald R.; Chen, Tai-Yih; Collins, James E., Jr.; Sachse, Glen W.; Anderson, Bruce E.; Rowland, F. Sherwood

    1997-01-01

    Nonmethane hydrocarbons (NMHCs) and halocarbons were measured in the troposphere over the northwestern Pacific as part of the airborne component of NASA's Pacific Exploratory Mission-West Phase B (PEM-West B). This study took place in late winter of 1994, a period characterized by maximum outflow from the Asian continent. The results are compared to those from Pacific Exploratory Mission-West Phase A (PEM-West A), which was flown in the same region during late summer of 1991, when flow from the subtropical western Pacific dominated the lower troposphere. Mixing ratios of NMHCs, tetrachloroethene (C2Cl4), and methyl bromide (CH3Br) were significantly higher during PEM-West B than during PEM-West A, particularly at latitudes north of 25 deg N and altitudes lower than 6 km. The primary reasons for these higher ambient concentrations were the seasonal increase in the atmospheric lifetimes of trace gases controlled by HO radical reactions, and the more frequent input of continental air masses. During PEM-West B, air masses of continental origin observed north of 25 deg N latitude were augmented with urban signature gases such as C2Cl4. By contrast, more southerly continental outflow had characteristics associated with combustion sources such as biomass burning, including wood fuel burning. During the summer PEM-West A period, the spatial distribution of methyl iodide (CH3I) was consistent with effective oceanic sources at all latitudes, being especially strong in tropical and subtropical regions. At low latitudes, PEM-West B CH3I mixing ratios in the lower troposphere were similar to PEM-West A, but at latitudes greater than about 25 deg N PEM-West B concentrations were significantly reduced. Equatorial regions exhibited enhanced CH3I mixing ratios extending into the upper tropical troposphere, consistent with fast vertical transport of air from the tropical marine boundary layer.

  15. Sediment and water-quality data for the West Branch Shade and East Branch Shade River basins, Ohio, 1983 water year

    USGS Publications Warehouse

    Childress, C.J.; Jones, R.L.

    1985-01-01

    Sedimentation in and flooding of the West Branch Shade River and its tributaries have been major concerns of residents and State and local officials. The area was extensively surface mined for coal between the mid-1940's and the early 1960's. Reclamation efforts immediately after mining were unsuccessful. The results have been elevated sediment loads and the subsequent loss of channel conveyance. Two sediment and stream-gaging stations were established on the West Branch Shade River and one station was established on the East Branch Shade River. These three stations will provide data to evalute the effectiveness of current reclamation activties on reducing sediment loads. From June Through September 1983, suspended-sediment yield was 18 times higher in West Branch (218 tons/mi2) than East Branch (12 tons/mi2) Shade River. In addition, acidity is higher, pH is lower, and concentrations of dissolved sulfate and metals are higher in the West Branch Shade River basin than in the East Branch Shade river basins.

  16. V/Ni ratio in crude oil fractions from the west Venezuelan Basin: Correlation studies

    SciTech Connect

    Lo Monaco, S.; Lopez, L.; Rojas, A.; Lira, A.

    1996-08-01

    This study presents the analyses of S and the metals Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr within the fractions of saturated hydrocarbons, aromatic hydrocarbons and resins, and the IR spectroscopy analysis of these fractions for crudes of the Mara and Mara Oeste fields of the Maracaibo basin. These results are discussed as related to their implications in oil-oil correlation, and studies of the possible metal-organic associations, and are compared with previous studies which analyzed S, V, and Ni in the total crude and its asphaltene and maltene fractions. In the saturated fraction, elements Zn, Fe, Mn, Cu, Ni and Sr were detected. In the aromatic fraction, in addition to the before mentioned elements, Cr and Ni were also detected; while in the resins elements Cr, Zn, Fe, Cu, Ni, Mo, V and Sr were detected. S was detected in the three fractions studied, and IR spectra show bands that may be related to organic compounds that contain S. IR results for the aromatic hydrocarbons and the resins indicate the presence of carboxylic groups which can serve as ligands for metals in such fractions. The larger number of elements detected within resins, as well as their higher concentration vs. saturated and aromatic hydrocarbons, may be due to the structure of the resins and their greater ability to form organometallic complexes. The relatively constant V/Ni ratios in crudes (11 +/- 1), maltene (15 +/- 1), asphaltenes (15 +/- 1) and resins (11 +/- 1) give support to a single group of crudes. These results indicate that the V/Ni ratio determined for the whole crude or its fractions may be used as a correlation parameter.

  17. Tsunami damage in Aceh Province, Sumatra

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The island of Sumatra suffered from both the rumblings of the submarine earthquake and the tsunamis that were generated on December 26, 2004. Within minutes of the quake, the sea surged ashore, bringing destruction to the coasts of northern Sumatra. This pair of natural-color images from Landsat 7's Enhanced Thematic Mapper Plus (ETM+) instrument shows a small area along the Sumatran coast in Aceh province where the tsunami smashed its way ashore. In this region, the wave cut a swath of near-total destruction 1.5 kilometers (roughly one mile) in most places, but penetrating farther in many others. Some of these deeper paths of destruction can be seen especially dramatically in the larger-area ETM+ images linked to above. (North is up in these larger images.) ETM+ collects data at roughly 30 meter resolution, complimenting sensors like NASA's MODIS (onboard both Terra and Aqua satellites) which observed this area at 250-meter resolution to give a wide view and ultra-high-resolution sensors like Space Imaging's IKONOS, which observed the same region at 4-meter resolution to give a detailed, smaller-area view. NASA images created by Jesse Allen, Earth Observatory, using data provided courtesy of the Landsat 7 Science Project Office

  18. Integrated assessment of groundwater resources in the Ouémé basin, Benin, West Africa

    NASA Astrophysics Data System (ADS)

    Barthel, R.; Sonneveld, B. G. J. S.; Götzinger, J.; Keyzer, M. A.; Pande, S.; Printz, A.; Gaiser, T.

    An integrated assessment of groundwater resources in Benin, West Africa was performed within the framework of the EC-funded research project RIVERTWIN ( www.rivertwin.org). The assessment included a spatial analysis of groundwater relevant parameters taken from more than 4000 wells stored in a countrywide water database (BDI - Banque des Données Intégrée) and an estimation of the spatial and temporal distribution of groundwater recharge using a modified version of the hydrological model HBV. Additionally, a socio-economic assessment of the impacts of groundwater availability and accessibility on national health issues as well as an assessment of groundwater development costs was carried out. The analysis revealed particularly unfavourable conditions for groundwater use in the northern part of the country where groundwater recharge during the wet season does not lead to the formation of persistent groundwater storage in its shallow, unconfined aquifers. Poor storage capacity and hydraulic properties of the deeper fractured aquifers additionally limit the capacity of individual wells to capture groundwater recharge. Including climate change scenarios forecasting less precipitation (generated from global climate models (GCM) based on IPCC scenarios) indicates that the situation in water scarce regions will worsen, as recharge volumes lessen and occur over a shorter time period. Drilling more wells may be a limited option to capture larger portions of the recharge, since the capture zone and therefore the regional influence of existing wells is rather small. In the south, deeper confined aquifers guarantee better and more reliable yields, yet the lack of long-term monitoring and groundwater age data does not allow an appraisal of the limits of the sustainable use of these aquifers. Finally, it has been shown that access to suitable aquifers and diarrhea prevalence are spatially correlated. Access to groundwater is thereby not only a function of aquifer suitability

  19. Hydroclimatology of the Volta River Basin in West Africa: Trends and variability from 1901 to 2002

    NASA Astrophysics Data System (ADS)

    Oguntunde, Philip G.; Friesen, Jan; van de Giesen, Nick; Savenije, Hubert H. G.

    Long-term historical records of rainfall ( P), runoff ( Q) and other climatic factors were used to investigate hydrological variability and trends in the Volta River Basin over the period 1901-2002. Potential ( Ep) and actual evaporation ( E), rainfall variability index ( δ), Budyko’s aridity index ( IA), evaporation ratio ( CE) and runoff ratio ( CQ) were estimated from the available hydroclimatological records. Mann-Kendall trend analysis and non-parametric Sen’s slope estimates were performed on the respective time series variables to detect monotonic trend direction and magnitude of change over time. Rainfall variability index showed that 1968 was the wettest year ( δ = +1.75) while 1983 was the driest ( δ = -3.03), with the last three decades being drier than any other comparable period in the hydrological history of the Volta. An increase of 0.2 mm/yr 2 ( P < 0.05) was observed in Ep for the 1901-1969 sub-series while an increased of 1.8 mm/yr 2 ( P < 0.01) was recorded since 1970. Rainfall increased at the rate of 0.7 mm/yr 2 or 49 mm/yr between 1901 and 1969, whereas a decrease of 0.2 mm/yr 2 (6 mm/yr) was estimated for 1970-2002 sub-series. Runoff increased significantly at the rate of 0.8 mm/yr (23 mm/yr) since 1970. Runoff before dam construction was higher (87.5 mm/yr) and more varied (CV = 41.5%) than the post-dam period with value of 73.5 mm/yr (CV = 23.9%). A 10% relative decrease in P resulted in a 16% decrease in Q between 1936 and 1998. Since 1970, all the months showed increasing runoff trends with significant slopes ( P < 0.05) in 9 out of the 12 months. Possible causes, such as climate change and land cover change, on the detected changes in hydroclimatology are briefly discussed.

  20. TECHNOLOGY DEVELOPMENT AND DEPLOYMENT OF SYSTEMS FOR THE RETRIEVAL AND PROCESSING OF REMOTE-HANDLED SLUDGE FROM HANFORD K-WEST FUEL STORAGE BASIN

    SciTech Connect

    RAYMOND RE

    2011-12-27

    In 2011, significant progress was made in developing and deploying technologies to remove, transport, and interim store remote-handled sludge from the 105-K West Fuel Storage Basin on the Hanford Site in south-central Washington State. The sludge in the 105-K West Basin is an accumulation of degraded spent nuclear fuel and other debris that collected during long-term underwater storage of the spent fuel. In 2010, an innovative, remotely operated retrieval system was used to successfully retrieve over 99.7% of the radioactive sludge from 10 submerged temporary storage containers in the K West Basin. In 2011, a full-scale prototype facility was completed for use in technology development, design qualification testing, and operator training on systems used to retrieve, transport, and store highly radioactive K Basin sludge. In this facility, three separate systems for characterizing, retrieving, pretreating, and processing remote-handled sludge were developed. Two of these systems were successfully deployed in 2011. One of these systems was used to pretreat knockout pot sludge as part of the 105-K West Basin cleanup. Knockout pot sludge contains pieces of degraded uranium fuel ranging in size from 600 {mu}m to 6350 {mu}m mixed with pieces of inert material, such as aluminum wire and graphite, in the same size range. The 2011 pretreatment campaign successfully removed most of the inert material from the sludge stream and significantly reduced the remaining volume of knockout pot product material. Removing the inert material significantly minimized the waste stream and reduced costs by reducing the number of transportation and storage containers. Removing the inert material also improved worker safety by reducing the number of remote-handled shipments. Also in 2011, technology development and final design were completed on the system to remove knockout pot material from the basin and transport the material to an onsite facility for interim storage. This system is

  1. Predicting the downstream impact of ensembles of small reservoirs with special reference to the Volta Basin, West Africa

    NASA Astrophysics Data System (ADS)

    van de Giesen, N.; Andreini, M.; Liebe, J.; Steenhuis, T.; Huber-Lee, A.

    2005-12-01

    After a strong reduction in investments in water infrastructure in Sub-Saharan Africa, we now see a revival and increased interest to start water-related projects. The global political willingness to work towards the UN millennium goals are an important driver behind this recent development. Large scale irrigation projects, such as were constructed at tremendous costs in the 1970's and early 1980's, are no longer seen as the way forward. Instead, the construction of a large number of small, village-level irrigation schemes is thought to be a more effective way to improve food production. Such small schemes would fit better in existing and functioning governance structures. An important question now becomes what the cumulative (downstream) impact is of a large number of small irrigation projects, especially when they threaten to deplete transboundary water resources. The Volta Basin in West Africa is a transboundary river catchment, divided over six countries. Of these six countries, upstream Burkina Faso and downstream Ghana are the most important and cover 43% and 42% of the basin, respectively. In Burkina Faso (and also North Ghana), small reservoirs and associated irrigation schemes are already an important means to improve the livelihoods of the rural population. In fact, over two thousand such schemes have already been constructed in Burkina Faso and further construction is to be expected in the light of the UN millennium goals. The cumulative impact of these schemes would affect the Akosombo Reservoir, one of the largest manmade lakes in the world and an important motor behind the economic development in (South) Ghana. This presentation will put forward an analytical framework that allows for the impact assessment of (large) ensembles of small reservoirs. It will be shown that despite their relatively low water use efficiencies, the overall impact remains low compared to the impact of large dams. The tools developed can be used in similar settings elsewhere

  2. West African Climate and Linkages with the Atlantic Ocean, the Mediterranean Basin and Eurasia

    NASA Astrophysics Data System (ADS)

    Paz, S.; Tourre, Y. M.

    2010-09-01

    Large-scale Atlantic, Mediterranean and European climate conditions are not independent from anomalous rainfall patterns over the Sahel. Sahelian droughts are indeed linked to low-frequency climate variability in the North Atlantic i.e., multi-decadal (MDO) and quasi-decadal (QDO). As such, linkages (significant correlations) were investigated for the 1926-2006 period between the Sahelian rainfall and the following Atlantic climate indices: 1. Atlantic Multi-decadal Oscillation (AMO) 2. Atlantic Meridional Mode (AMM, SST and Wind) 3. North Africa-West Asia index (NAWA, and NA & WA poles) 4. Multi-Decadal Oscillation (MDO) 5. Quasi-Decadal Oscillation (QDO) 6. Tropical North Atlantic (TNA, SST), 7. Tropical South Atlantic (TSA, SST) The main results are: Significant relationships (0.05 level, Z-test) were detected between the spring NA pole of the NAWA index and summer Sahelian rainfall of the same year. Correlations (r = 0.54/0.43) were found between the winter AMO and summer Sahelian rainfall indices for the 1950-2006 and 1926-2006 periods, respectively. During the 20th century, the north Atlantic SST anomalies have changed phases three times. The last cooling phase (between 1968 and 1995) resulted in the long-lasting drought in the Sahel. This is also the period when the Azores anticyclone was displaced anomalously south-eastward and the ITCZ further south. It is also found that the cooling over the northern latitudes of Eurasia is associated with a warming tendency over the Sahel. Correlations between fall AMO and summer NA (r = 0.57/0.63) were found for the 1950-2006 period. Significant correlation were detected between summer AMM (wind and SST) and the Sahelian rainfall (r = 0.65 and 0.42 respectively). Linkages were also found with TNA-TSA (summer and fall). MDO/AMO and QDO SST/SLP displayed coherent patterns during the spatio-temporal evolution of the low-frequency climate signals. These findings add more insight on the variability of northern atmospheric

  3. Ground-water quality in the Appalachian Plateaus, Kanawha River basin, West Virginia

    USGS Publications Warehouse

    Sheets, Charlynn J.; Kozar, Mark D.

    2000-01-01

    Water samples collected from 30 privately-owned and small public-supply wells in the Appalachian Plateaus of the Kanawha River Basin were analyzed for a wide range of constituents, including bacteria, major ions, nutrients, trace elements, radon, pesticides, and volatile organic compounds. Concentrations of most constituents from samples analyzed did not exceed U.S. Environmental Protection Agency (USEPA) standards. Constituents that exceeded drinking-water standards in at least one sample were total coliform bacteria, Escherichia coli (E. coli), iron, manganese, and sulfate. Total coliform bacteria were present in samples from five sites, and E. coli were present at only one site. USEPA secondary maximum contaminant levels (SMCLs) were exceeded for three constituents -- sulfate exceeded the SMCL of 250 mg/L (milligrams per liter) in samples from 2 of 30 wells; iron exceeded the SMCL of 300 ?g/L (micrograms per liter) in samples from 12 of the wells, and manganese exceeded the SMCL of 50 ?g/L in samples from 17 of the wells sampled. None of the samples contained concentrations of nutrients that exceeded the USEPA maximum contaminant levels (MCLs) for these constituents. The maximum concentration of nitrate detected was only 4.1 mg/L, which is below the MCL of 10 mg/L. Concentrations of nitrate in precipitation and shallow ground water are similar, potentially indicating that precipitation may be a source of nitrate in shallow ground water in the study area. Radon concentrations exceeded the recently proposed maximum contaminant level of 300 pCi/L at 50 percent of the sites sampled. The median concentration of radon was only 290 pCi/L. Radon-222 is a naturally occurring, carcinogenic, radioactive decay product of uranium. Concentrations, however, did not exceed the alternate maximum contaminant level (AMCL) for radon of 4,000 pCi/L in any of the 30 samples. Arsenic concentrations exceeded the proposed MCL of 5?g/L at 4 of the 30 sites. No samples exceeded the

  4. Future Water Resources Assessment for West African River Basins Under Climate Change, Population Growth and Irrigation Development

    NASA Astrophysics Data System (ADS)

    Wisser, D.; Ibrahim, B.; Proussevitch, A. A.

    2014-12-01

    West Africa economies rely on rain-fed agriculture and are extremely vulnerable to changes in precipitation. Results from the most recent generation of regional climate models suggest increases in rainy season rainfall variability (delayed rainy season onset, increased probability of dry spells, shorter rainy season duration) despite a moderate increase in rainy season total precipitation. These changes could potentially have detrimental effects on crop yield and food security. Additional pressures on water resources come from increased demand as a result of high population growth rates (~3% per year). Increased water storage and irrigation can help improve crop yields but future assessments of water resources are needed to prioritize irrigation development as an adaptation option. Increased water abstraction, in turn can impact water availability in downstream regions so that an integrated assessment of future water availability and demand is needed. We use a set of 15 RCM outputs from the CORDEX data archive to drive WBMplus, a hydrological model and simulate water availability under climate change. Based on estimated water constraints, we develop scenarios to expand irrigated areas (from the current 1% of all croplands) and calculate the effects on water scarcity, taking into account increased demand for domestic consumption and livestock water demand, at a spatial resolution of 10 km. Results around the 2050's indicate large potential to develop irrigated areas on ground and surface water and increase local water storage without increasing water scarcity downstream for many river basins in the region that could help alleviate pressures on the cropping systems and thereby increase food security.

  5. Source potential of the Zairian onshore pre-salt subbasins of the West African Aptian salt basin

    SciTech Connect

    Swirydczuk, K.; Tshiband, D.; Nyimi, M.; Musombo, I.; Mbalambala, K.

    1996-08-01

    Three pre-salt subbasins are located onshore in Zaire in the Congo-Cabinda Basin. Production exists to the west, and extensive outcrops of Mavuma tar sands are located immediately to the east of these subbasins. Five pre-salt wells confirmed that thick Barremian lacustrine claystones of the Bucomazi Formation form the main source horizon in all the subbasins. Upper Bucomazi claystones average 4% and reach 12% TOC. Lower Bucomazi claystones average 2% (high of 6%). A mixed Type I/Type II algal oil-prone kerogen predominates. Up to 1% TOC is present in claystones in the underlying Lucula section. Dry pyrolysis shows significant differences in kerogen kinetics from subbasin to subbasin. R{sub o} and T{sub max} were used to model heat flow through time. Ages were from biostratigraphic analyses and radiometric dating of thin volcanics within the Lucula and Bucomazi formations. Apatite fission track analyses provided control on uplift history. Pseudowells were used in maturation modelling to predict source rock maturity in the subbasins. The upper Bucomazi is immature except in the deeper parts of two of the subbasins. The Lower - Bucomazi and Upper Lucula are mature in all subbasins and in the deepest subbasins are overmature. Oil generation occurred shortly after deposition of the Loeme Salt. Analyses of Lindu oil support this early migration. Estimates of oil that may have been generated in the eastern-most subbasin suggest that extensive Mavuma tar sands, which have been typed to lacustrine source, could have been sourced from this subbasin.

  6. Magnitudes, nature, and effects of point and nonpoint discharges in the Chattahoochee River Basin, Atlanta to West Point Dam, Georgia

    USGS Publications Warehouse

    Stamer, J.K.; Cherry, Rodney N.; Faye, R.E.; Kleckner, R.L.

    1979-01-01

    During the period April 1975 to June 1978, the U.S. Geological Survey conducted a river-quality assessment of the Upper Chattahoochee River basin in Georgia. One objective of the study was to assess the magnitudes, nature, and effects of point and non-point discharges in the Chattahoochee River basin from Atlanta to the West Point Dam. On an average annual basis and during the storm period of March 1215, 1976, non-point-source loads for most constituents analyzed were larger than point-source loads at the Whitesburg station, located on the Chattahoochee River about 40 river miles downstream of Atlanta. Most of the non-point-source constituent loads in the Atlanta-to-Whitesburg reach were from urban areas. Average annual point-source discharges accounted for about 50 percent of the dissolved nitrogen, total nitrogen, and total phosphorus loads, and about 70 percent of the dissolved phosphorus loads at Whitesburg. During weekends, power generation at the upstream Buford Dam hydroelectric facility is minimal. Streamflow at the Atlanta station during dry-weather weekends is estimated to be about 1,200 ft3/s (cubic feet per second). Average daily dissolved-oxygen concentrations of less than 5.0 mg/L (milligrams per liter) occurred often in the river, about 20 river miles downstream from Atlanta during these periods from May to November. During a low-flow period, June 1-2, 1977, five municipal point sources contributed 63 percent of the ultimate biochemical oxygen demand, 97 percent of the ammonium nitrogen, 78 percent of the total nitrogen, and 90 percent of the total phosphorus loads at the Franklin station, at the upstream end of West Point Lake. Average daily concentrations of 13 mg/L of ultimate biochemical oxygen demand and 1.8 mg/L of ammonium nitrogen were observed about 2 river miles downstream from two of the municipal point sources. Carbonaceous and nitrogenous oxygen demands caused dissolved-oxygen concentrations between 4.1 and 5.0 mg/L to occur in a 22-mile

  7. Genetic comparison of Glossina tachinoides populations in three river basins of the Upper West Region of Ghana and implications for tsetse control.

    PubMed

    Adam, Y; Bouyer, J; Dayo, G-K; Mahama, C I; Vreysen, M J B; Cecchi, G; Abd-Alla, A M M; Solano, P; Ravel, S; de Meeûs, T

    2014-12-01

    Tsetse flies are the cyclical vectors of African animal trypanosomosis (AAT) and human African trypanosomosis (HAT). In March 2010, the Government of Ghana initiated a large scale integrated tsetse eradication campaign in the Upper West Region (UWR) (≈18,000 km(2)) under the umbrella of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC). We investigated the structuring of Glossina tachinoides populations within and between the three main river basins of the target area in the UWR. Out of a total sample of 884 flies, a sub-sample of 266 was genotyped at nine microsatellite loci. The significance of the different hierarchical levels was tested using Yang's parameters estimated with Weir and Cockerham's method. A significant effect of traps within groups (pooling traps no more than 3 km distant from each other), of groups within river basins and of river basins within the whole target area was observed. Isolation by distance between traps was highly significant. A local density of 0.48-0.61 flies/m(2) was estimated and a dispersal distance that approximated 11 m per generation [CI 9, 17]. No significant sex-biased dispersal was detected. Dispersal distances of G. tachinoides in the UWR were relatively low, possibly as a result of the fragmentation of the habitat and the seasonality of the Kulpawn and Sissili rivers. Moreover, very high fly population densities were observed in the sample sites, which potentially reduces dispersal at constant habitat saturation, because the probability that migrants can established is reduced (density dependent dispersal). However, the observed spatial dispersal was deemed sufficient for a G. tachinoides-cleared area to be reinvaded from neighboring populations in adjacent river basins. These data corroborate results from other population genetics studies in West Africa, which indicate that G. tachinoides populations from different river basins cannot be considered isolated. PMID:24709401

  8. Genetic comparison of Glossina tachinoides populations in three river basins of the Upper West Region of Ghana and implications for tsetse control.

    PubMed

    Adam, Y; Bouyer, J; Dayo, G-K; Mahama, C I; Vreysen, M J B; Cecchi, G; Abd-Alla, A M M; Solano, P; Ravel, S; de Meeûs, T

    2014-12-01

    Tsetse flies are the cyclical vectors of African animal trypanosomosis (AAT) and human African trypanosomosis (HAT). In March 2010, the Government of Ghana initiated a large scale integrated tsetse eradication campaign in the Upper West Region (UWR) (≈18,000 km(2)) under the umbrella of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC). We investigated the structuring of Glossina tachinoides populations within and between the three main river basins of the target area in the UWR. Out of a total sample of 884 flies, a sub-sample of 266 was genotyped at nine microsatellite loci. The significance of the different hierarchical levels was tested using Yang's parameters estimated with Weir and Cockerham's method. A significant effect of traps within groups (pooling traps no more than 3 km distant from each other), of groups within river basins and of river basins within the whole target area was observed. Isolation by distance between traps was highly significant. A local density of 0.48-0.61 flies/m(2) was estimated and a dispersal distance that approximated 11 m per generation [CI 9, 17]. No significant sex-biased dispersal was detected. Dispersal distances of G. tachinoides in the UWR were relatively low, possibly as a result of the fragmentation of the habitat and the seasonality of the Kulpawn and Sissili rivers. Moreover, very high fly population densities were observed in the sample sites, which potentially reduces dispersal at constant habitat saturation, because the probability that migrants can established is reduced (density dependent dispersal). However, the observed spatial dispersal was deemed sufficient for a G. tachinoides-cleared area to be reinvaded from neighboring populations in adjacent river basins. These data corroborate results from other population genetics studies in West Africa, which indicate that G. tachinoides populations from different river basins cannot be considered isolated.

  9. Benthic invertebrate communities and their responses to selected environmental factors in the Kanawha River basin, West Virginia, Virginia, and North Carolina

    USGS Publications Warehouse

    Chambers, Douglas B.; Messinger, Terence

    2001-01-01

    The effects of selected environmental factors on the composition and structure of benthic invertebrate communities in the Kanawha River Basin of West Virginia, Virginia and North Carolina were investigated in 1997 and 1998. Environmental factors investigated include physiography, land-use pattern, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics. Land-use patterns investigated include coal mining, agriculture, and low intensity rural-residential patterns, at four main stem and seven tributary sites throughout the basin. Of the 37 sites sampled, basin size and physiography most strongly affected benthic invertebrate-community structure. Land-use practices also affected invertebrate community structure in these basins. The basins that differed most from the minimally affected reference condition were those basins in which coal mining was the dominant nonforest land use, as determined by comparing invertebrate- community metric values among sites. Basins in which agriculture was important were more similar to the reference condition. The effect of coal mining upon benthic invertebrate communities was further studied at 29 sites and the relations among invertebrate communities and the selected environmental factors of land use, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics analyzed. Division of coal-mining synoptic-survey sites based on invertebrate-community composition resulted in two groups?one with more than an average production of 9,000 tons of coal per square mile per year since 1980, and one with lesser or no recent coal production. The group with significant recent coal production showed higher levels of community impairment than the group with little or no recent coal production. Median particle size of streambed sediment, and specific conductance and sulfate concentration of streamwater were most strongly correlated with effects on invertebrate communities. These characteristics were

  10. Calibration parameters used to simulate streamflow from application of the Hydrologic Simulation Program-FORTRAN Model (HSPF) to mountainous basins containing coal mines in West Virginia

    USGS Publications Warehouse

    Atkins, John T.; Wiley, Jeffrey B.; Paybins, Katherine S.

    2005-01-01

    This report presents the Hydrologic Simulation Program-FORTRAN Model (HSPF) parameters for eight basins in the coal-mining region of West Virginia. The magnitude and characteristics of model parameters from this study will assist users of HSPF in simulating streamflow at other basins in the coal-mining region of West Virginia. The parameter for nominal capacity of the upper-zone storage, UZSN, increased from south to north. The increase in UZSN with the increase in basin latitude could be due to decreasing slopes, decreasing rockiness of the soils, and increasing soil depths from south to north. A special action was given to the parameter for fraction of ground-water inflow that flows to inactive ground water, DEEPFR. The basis for this special action was related to the seasonal movement of the water table and transpiration from trees. The models were most sensitive to DEEPFR and the parameter for interception storage capacity, CEPSC. The models were also fairly sensitive to the parameter for an index representing the infiltration capacity of the soil, INFILT; the parameter for indicating the behavior of the ground-water recession flow, KVARY; the parameter for the basic ground-water recession rate, AGWRC; the parameter for nominal capacity of the upper zone storage, UZSN; the parameter for the interflow inflow, INTFW; the parameter for the interflow recession constant, IRC; and the parameter for lower zone evapotranspiration, LZETP.

  11. Depositional setting of Ordovician and Cambrian rocks in central Appalachian basin along a section from Morrow County, Ohio, to Calhoun County, West Virginia

    SciTech Connect

    Ryder, R.T.

    1988-08-01

    A 200-mi (320 km) long restored stratigraphic section from Morrow County, Ohio, to Calhoun County, West Virginia, contrasts Ordovician and Cambrian rocks deposited on a relatively stable shelf with those deposited in rift and postrift basins. Lithologic data are from commercial logs and from detailed descriptions of cores in five of the nine drill holes used to construct the section. Particularly instructive was the 2,352 ft (717 m) of core from the Hope Natural Gas 9634 Power Oil basement test in Wood County, West Virginia. Rift basin deposits are dominated by medium to dark-gray argillaceous limestone, argillaceous siltstone, and by green-gray to black shale of probable subtidal origin. Dolomite is the dominant rock type in the postrift basin and adjacent stable shelf deposits. The upper part of the postrift sequence, composed of the Middle Ordovician Black River Limestone, the Middle Ordovician Trenton Limestone, and Middle and Upper Ordovician Antes (Utica) Shale with a high organic content, represents deposition in gradually deepening water on an open shelf.

  12. Slope Stability: Factor of Safety along the Seismically Active Continental Slope Offshore Sumatra

    NASA Astrophysics Data System (ADS)

    Patton, J. R.; Goldfinger, C.; Djadjadihardja, Y.; None, U.

    2013-12-01

    g. Arias intensities of 0.4-1.7 to 7.9-33 m/s are estimated for the M = 6 and M = 9 events, respectively, are expected in the source regions of piggyback basins for local slope failures. Typical sites have Dn means of 0.1, 1.6, 7.7, and 16 cm for earthquakes of M = 6, 7, 8, and 9; suggested thresholds for displacement range between 5 and 10 cm. Thus the observed turbidite stratigraphy in the Sumatra piggyback basins can be explained by local ground motions during earthquakes with magnitude greater than ~7, given the static stability and low sedimentation rates. The paleoseismic data to date suggest a repeat time of 240 years, insufficient to destabilize slopes though sediment accumulation alone.

  13. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  14. Estimation of postseismic deformation parameters from continuous GPS data in northern Sumatra after the 2004 Sumatra-Andaman earthquake

    NASA Astrophysics Data System (ADS)

    Anugrah, Bimar; Meilano, Irwan; Gunawan, Endra; Efendi, Joni

    2015-12-01

    Continuous global positioning system (GPS) in northern Sumatra detected signal of the ongoing physical process of postseismic deformation after the M9.2 2004 Sumatra-Andaman earthquake. We analyze the characteristics of postseismic deformation of the 2004 earthquake based on GPS networks operated by BIG, and the others named AGNeSS, and SuGAr networks located in northern Sumatra. We use a simple analytical logarithmic and exponential function to evaluate the postseismic deformation parameters of the 2004 earthquake. We find that GPS data in northern Sumatra during time periods of 2005-2012 are fit better using the logarithmic function with τlog of 104.2 ± 0.1 than using the exponential function. Our result clearly indicates that other physical mechanisms of postseismic deformation should be taken into account rather than a single physical mechanism of afterslip only.

  15. The Volta Basin Water Allocation System: assessing the impact of small-scale reservoir development on the water resources of the Volta basin, West Africa

    NASA Astrophysics Data System (ADS)

    Leemhuis, C.; Jung, G.; Kasei, R.; Liebe, J.

    2009-08-01

    In the Volta Basin, infrastructure watershed development with respect to the impact of climate conditions is hotly debated due to the lack of adequate tools to model the consequences of such development. There is an ongoing debate on the impact of further development of small and medium scale reservoirs on the water level of Lake Volta, which is essential for hydropower generation at the Akosombo power plant. The GLOWA Volta Project (GVP) has developed a Volta Basin Water Allocation System (VB-WAS), a decision support tool that allows assessing the impact of infrastructure development in the basin on the availability of current and future water resources, given the current or future climate conditions. The simulated historic and future discharge time series of the joint climate-hydrological modeling approach (MM5/WaSiM-ETH) serve as input data for a river basin management model (MIKE BASIN). MIKE BASIN uses a network approach, and allows fast simulations of water allocation and of the consequences of different development scenarios on the available water resources. The impact of the expansion of small and medium scale reservoirs on the stored volume of Lake Volta has been quantified and assessed in comparison with the impact of climate variability on the water resources of the basin.

  16. Calculation and interpretation of crustal shortening along the Central Basin Platform, West Texas: A method to calculate basement motion for modeling input

    SciTech Connect

    Hoak, T.E. |; Sundberg, K.R.; Ortoleva, P.

    1998-12-31

    The analysis carried out in the Chemical Interaction of Rocks and Fluids Basin (CIRFB) model describes the chemical and physical evolution of the entire system. One aspect of this is the deformation of the rocks, and its treatment with a rigorous flow and rheological model. This type of analysis depends on knowing the state of the model domain`s boundaries as functions of time. In the Andrews and Ector County areas of the Central Basin Platform of West Texas, the authors calculate this shortening with a simple interpretation of the basic motion and a restoration of the Ellenburger formation. Despite its simplicity, this calculation reveals two distinct periods of shortening/extension, a relatively uniform directionality to all the deformation, and the localization of deformation effects to the immediate vicinities of the major faults in the area. Conclusions are drawn regarding the appropriate expressions of these boundary conditions in the CIRFB model and possible implications for exploration.

  17. An integrated model for the tectonic development of the frontal Brooks Range and Colville Basin 250 km west of the Trans-Alaska Crustal Transect

    USGS Publications Warehouse

    Cole, F.; Bird, K.J.; Toro, J.; Roure, F.; O'Sullivan, P. B.; Pawlewicz, M.; Howell, D.G.

    1997-01-01

    We present a kinematic model for the sequence of deformation and sedimentation in the frontal Brooks Range and adjacent Colville Basin in the Etivluk River region, 250 km west of the Trans-Alaska Crustal Transect (TACT). The model is based on a tectonic subsidence analysis of the foreland basin, combined with structural, stratigraphic, and thermal studies of the northern edge of the Brooks Range thrust belt. We interpret six discrete tectonic events that led to the present-day configuration of the thrust belt in this area: (1) emplacement of ophiolitic allochthons over the distal continental margin rocks in Valanginian time, hundreds of kilometers south of this study, (2) Hauterivian uplift of the Barrow Arch rift margin, affecting the northern part of the Colville Basin, (3) Barremian contraction involving emplacement of distal continental margin and ophiolitic allochthons onto the Endicott Mountains allochthon and creation of a southward dipping flexural basin on the North Slope autochthon, (4) mid-Cretaceous exhumation of imbricated rocks in the Brooks Range during northward propagation of the thrust front into the foreland, (5) minor thrusting in Late Cretaceous-Paleocene in the northern foreland to the northern limit of contractional structures, and (6) regional exhumation of the orogen and the foreland in Paleocene-Eocene time. This sequence of deformation agrees well with a simple model of a forward propagating thrust system. Copyright 1997 by the American Geophysical Union.

  18. A comprehensive model of postseismic deformation of the 2004 Sumatra-Andaman earthquake deduced from GPS observations in northern Sumatra

    NASA Astrophysics Data System (ADS)

    Gunawan, Endra; Sagiya, Takeshi; Ito, Takeo; Kimata, Fumiaki; Tabei, Takao; Ohta, Yusaku; Meilano, Irwan; Abidin, Hasanuddin Z.; Agustan; Nurdin, Irwandi; Sugiyanto, Didik

    2014-07-01

    We investigate the postseismic deformation of the 2004 Sumatra-Andaman earthquake (SAE) using 5 years of Global Positioning System (GPS) data located in northern Sumatra. Continuous GPS data from northern Sumatra suggest that the relaxation time in the vertical displacement is longer than horizontal displacements. This implies that there are multiple physical mechanisms that control the postseismic deformation, which refer to afterslip and viscoelastic relaxation. In this study, we introduce an analysis strategy of postseismic deformation to simultaneously calculate multiple mechanisms of afterslip and viscoelastic relaxation. The afterslip inversion results indicate that the distribution of the afterslip and the coseismic slip are compensatory of each other. Also, afterslip has a limited contribution to vertical deformation in northern Sumatra. In our rheology model, we use a gravitational Maxwell viscoelastic response and the result indicates that the elastic layer thickness is 65 ± 5 km and the Maxwell viscosity is 8.0 ± 1.0 × 1018 Pa s. We find that afterslip plus Maxwell viscoelastic relaxation are appropriate to explain the deformation in northern Sumatra. We also find that our rheology model reproduces the long-term features of the GPS time series in Thailand. Applying our rheology model to the data in Andaman Islands our afterslip estimation is located at the down-dip part of the plate boundary. Finally, we showed that our rheology model is applicable to the GPS datasets of postseismic deformation of the 2004 SAE located in northern Sumatra, Thailand, and Andaman-Nicobar, respectively.

  19. In search of a Silurian total petroleum system in the Appalachian basin of New York, Ohio, Pennsylvania, and West Virginia: Chapter G.11 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ryder, Robert T.; Swezey, Christopher S.; Trippi, Michael H.; Lentz, Erika E.; Avary, K. Lee; Harper, John A.; Kappel, William M.; Rea, Ronald G.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Although the TOC analyses in this study indicate that good to very good source rocks are present in the Salina Group and Wills Creek Formation of southwestern Pennsylvania and northern West Virginia, data are insufficient to propose a new Silurian total petroleum system in the Appalachian basin. However, the analytical results of this investigation are encouraging enough to undertake more systematic studies of the source rock potential of the Salina Group, Wills Creek Formation, and perhaps the Tonoloway Formation (Limestone) and McKenzie Limestone (or Member).

  20. Evidence for Cambrian petroleum source rocks in the Rome trough of West Virginia and Kentucky, Appalachian basin: Chapter G.8 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ryder, Robert T.; Harris, David C.; Gerome, Paul; Hainsworth, Timothy J.; Burruss, Robert A.; Lillis, Paul G.; Jarvie, Daniel M.; Pawlewicz, Mark J.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The bitumen extract from the Rogersville Shale compares very closely with oils or condensates from Cambrian reservoirs in the Carson Associates No. 1 Kazee well, Homer gas field, Elliott County, Ky.; the Inland No. 529 White well, Boyd County, Ky.; and the Miller No. 1 well, Wolfe County, Ky. These favorable oil-source rock correlations suggest a new petroleum system in the Appalachian basin that is characterized by a Conasauga Group source rock and Rome Formation and Conasauga Group reservoirs. This petroleum system probably extends along the Rome trough from eastern Kentucky to at least central West Virginia.

  1. Geologic sources and concentrations of selenium in the West-Central Denver Basin, including the Toll Gate Creek watershed, Aurora, Colorado, 2003-2007

    USGS Publications Warehouse

    Paschke, Suzanne S.; Walton-Day, Katie; Beck, Jennifer A.; Webbers, Ank; Dupree, Jean A.

    2014-01-01

    Toll Gate Creek, in the west-central part of the Denver Basin, is a perennial stream in which concentrations of dissolved selenium have consistently exceeded the Colorado aquatic-life standard of 4.6 micrograms per liter. Recent studies of selenium in Toll Gate Creek identified the Denver lignite zone of the non-marine Cretaceous to Tertiary-aged (Paleocene) Denver Formation underlying the watershed as the geologic source of dissolved selenium to shallow ground-water and surface water. Previous work led to this study by the U.S. Geological Survey, in cooperation with the City of Aurora Utilities Department, which investigated geologic sources of selenium and selenium concentrations in the watershed. This report documents the occurrence of selenium-bearing rocks and groundwater within the Cretaceous- to Tertiary-aged Denver Formation in the west-central part of the Denver Basin, including the Toll Gate Creek watershed. The report presents background information on geochemical processes controlling selenium concentrations in the aquatic environment and possible geologic sources of selenium; the hydrogeologic setting of the watershed; selenium results from groundwater-sampling programs; and chemical analyses of solids samples as evidence that weathering of the Denver Formation is a geologic source of selenium to groundwater and surface water in the west-central part of the Denver Basin, including Toll Gate Creek. Analyses of water samples collected from 61 water-table wells in 2003 and from 19 water-table wells in 2007 indicate dissolved selenium concentrations in groundwater in the west-central Denver Basin frequently exceeded the Colorado aquatic-life standard and in some locations exceeded the primary drinking-water standard of 50 micrograms per liter. The greatest selenium concentrations were associated with oxidized groundwater samples from wells completed in bedrock materials. Selenium analysis of geologic core samples indicates that total selenium

  2. Nighttime lights time series of tsunami damage, recovery, and economic metrics in Sumatra, Indonesia.

    PubMed

    Gillespie, Thomas W; Frankenberg, Elizabeth; Chum, Kai Fung; Thomas, Duncan

    2014-01-01

    On 26 December 2004, a magnitude 9.2 earthquake off the west coast of the northern Sumatra, Indonesia resulted in 160,000 Indonesians killed. We examine the Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) nighttime light imagery brightness values for 307 communities in the Study of the Tsunami Aftermath and Recovery (STAR), a household survey in Sumatra from 2004 to 2008. We examined night light time series between the annual brightness and extent of damage, economic metrics collected from STAR households and aggregated to the community level. There were significant changes in brightness values from 2004 to 2008 with a significant drop in brightness values in 2005 due to the tsunami and pre-tsunami nighttime light values returning in 2006 for all damage zones. There were significant relationships between the nighttime imagery brightness and per capita expenditures, and spending on energy and on food. Results suggest that Defense Meteorological Satellite Program nighttime light imagery can be used to capture the impacts and recovery from the tsunami and other natural disasters and estimate time series economic metrics at the community level in developing countries.

  3. Burial and thermal history of the central Appalachian basin, based on three 2-D models of Ohio, Pennsylvania, and West Virginia

    USGS Publications Warehouse

    Rowan, Elisabeth L.

    2006-01-01

    Introduction: Three regional-scale, cross sectional (2-D) burial and thermal history models are presented for the central Appalachian basin based on the detailed geologic cross sections of Ryder and others (2004), Crangle and others (2005), and Ryder, R.T., written communication. The models integrate the available thermal and geologic information to constrain the burial, uplift, and erosion history of the region. The models are restricted to the relatively undeformed part of the basin and extend from the Rome trough in West Virginia and Pennsylvania northwestward to the Findlay arch in Ohio. This study expands the scope of previous work by Rowan and others (2004) which presented a preliminary burial/thermal history model for a cross section (E-E') through West Virginia and Ohio. In the current study, the burial/thermal history model for E-E' is revised, and integrated with results of two additional cross sectional models (D-D' and C-C'). The burial/thermal history models provide calculated thermal maturity (Ro%) values for the entire stratigraphic sequence, including hydrocarbon source rocks, along each of the three cross sections. In contrast, the Ro and conodont CAI data available in the literature are sparse and limited to specific stratigraphic intervals. The burial/thermal history models also provide the regional temperature and pressure framework that is needed to model hydrocarbon migration.

  4. Parasitology survey in northern Sumatra, Indonesia.

    PubMed

    Cross, J H; Clarke, M D; Cole, W C; Lien, J C; Partono, F; Joesoef, A; Kosin, E H

    1976-06-01

    A parasitology survey was conducted in five villages in North Sumatra, Indonesia. A total of 3,207 blood smears, 2,066 stool specimens and 969 sera were examined. Sixty (1.9%) inhabitants had malaria (Plasmodium vivax 41, P. falciparum 19), and 20 had Brugia malayi microfilaraemia. The most common intestinal helminths were Trichuris trichiura (87%), Ascaris lumbricoides (75%) and hookworm (58%). Other helminths found in low numbers were Enterobius vermicularis, Strongyloides stercoralis, Taenia sp., Fasciolid, Dicrocoeliid and Echinostoma sp. eggs. Entamoeba coli (25%) was the most common intestinal protozoa followed by Endolimax nana (8%), Entamoeba histolytica (7%), Giardia lamblia (6%), Iodamoeba bütschlii (5%), Entamoeba hartmanni (1%) and Chilomastix mesnili (1%). The amoeba prevalence rate was 31 per cent. Testing of sera for Entamoeba histolytica and Toxoplasma gondii antibodies by the indirect haemagglutination test demonstrated positive reactors in 13 per cent and nine per cent of the population respectively. The greatest number of seropositives for Toxoplasma gondii was at elevations of sea level to five meters and the lowest number at elevations of 5OO-1,000 meters. PMID:950682

  5. Relating seasonal dynamics of enhanced vegetation index to the recycling of water in two endorheic river basins in north-west China

    NASA Astrophysics Data System (ADS)

    Matin, M. A.; Bourque, C. P.-A.

    2015-08-01

    This study associates the dynamics of enhanced vegetation index in lowland desert oases to the recycling of water in two endorheic (hydrologically closed) river basins in Gansu Province, north-west China, along a gradient of elevation zones and land cover types. Each river basin was subdivided into four elevation zones representative of (i) oasis plains and foothills, and (ii) low-, (iii) mid-, and (iv) high-mountain elevations. Comparison of monthly vegetation phenology with precipitation and snowmelt dynamics within the same basins over a 10-year period (2000-2009) suggested that the onset of the precipitation season (cumulative % precipitation > 7-8 %) in the mountains, typically in late April to early May, was triggered by the greening of vegetation and increased production of water vapour at the base of the mountains. Seasonal evolution of in-mountain precipitation correlated fairly well with the temporal variation in oasis-vegetation coverage and phenology characterised by monthly enhanced vegetation index, yielding coefficients of determination of 0.65 and 0.85 for the two basins. Convergent cross-mapping of related time series indicated bi-directional causality (feedback) between the two variables. Comparisons between same-zone monthly precipitation amounts and enhanced vegetation index provided weaker correlations. Start of the growing season in the oases was shown to coincide with favourable spring warming and discharge of meltwater from low- to mid-elevations of the Qilian Mountains (zones 1 and 2) in mid-to-late March. In terms of plant requirement for water, mid-seasonal development of oasis vegetation was seen to be controlled to a greater extent by the production of rain in the mountains. Comparison of water volumes associated with in-basin production of rainfall and snowmelt with that associated with evaporation seemed to suggest that about 90 % of the available liquid water (i.e. mostly in the form of direct rainfall and snowmelt in the mountains

  6. Geochemistry and petrology of selected coal samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    USGS Publications Warehouse

    Belkin, H.E.; Tewalt, S.J.; Hower, J.C.; Stucker, J.D.; O'Keefe, J. M. K.

    2009-01-01

    Indonesia has become the world's largest exporter of thermal coal and is a major supplier to the Asian coal market, particularly as the People's Republic of China is now (2007) and perhaps may remain a net importer of coal. Indonesia has had a long history of coal production, mainly in Sumatra and Kalimantan, but only in the last two decades have government and commercial forces resulted in a remarkable coal boom. A recent assessment of Indonesian coal-bed methane (CBM) potential has motivated active CBM exploration. Most of the coal is Paleogene and Neogene, low to moderate rank and has low ash yield and sulfur (generally < 10 and < 1??wt.%, respectively). Active tectonic and igneous activity has resulted in significant rank increase in some coal basins. Eight coal samples are described that represent the major export and/or resource potential of Sumatra, Kalimantan, Sulawesi, and Papua. Detailed geochemistry, including proximate and ultimate analysis, sulfur forms, and major, minor, and trace element determinations are presented. Organic petrology and vitrinite reflectance data reflect various precursor flora assemblages and rank variations, including sample composites from active igneous and tectonic areas. A comparison of Hazardous Air Pollutants (HAPs) elements abundance with world and US averages show that the Indonesian coals have low combustion pollution potential.

  7. Relations of Principal Components Analysis Site Scores to Algal-Biomass, Habitat, Basin-Characteristics, Nutrient, and Biological-Community Data in the West Fork White River Basin, Indiana, 2001

    USGS Publications Warehouse

    Frey, Jeffrey W.; Caskey, Brian J.; Lowe, B. Scott

    2007-01-01

    Data were gathered from July through September 2001 at 34 randomly selected sites in the West Fork White River Basin, Indiana for algal biomass, habitat, nutrients, and biological communities (fish and invertebrates). Basin characteristics (drainage area and land use) and biological-community attributes and metric scores were determined for the basin of each sampling site. Yearly Principal Components Analysis site scores were calculated for algal biomass (periphyton and seston). The yearly Principal Components Analysis site scores for the first axis (PC1) were related, using Spearman's rho, to the seasonal algal-biomass, basin-characteristics, habitat, seasonal nutrient, biological-community attribute and metric score data. The periphyton PC1 site score, which was most influenced by ash-free dry mass, was negatively related to one (percent closed canopy) of nine habitat variables examined. Of the 43 fish-community attributes and metric scores examined, the periphyton PC1 was positively related to one fish-community attribute (percent tolerant). Of the 21 invertebrate-community attributes and metric scores examined, the periphyton PC1 was positively related to one attribute (Ephemeroptera, Plecoptera, and Trichoptera (EPT) index) and one metric score (EPT index metric score). The periphyton PC1 was not related to the five basin-characteristic or 12 nutrient variables examined. The seston PC1 site score, which was most influenced by particulate organic carbon, was negatively related to two of the 12 nutrient variables examined: total Kjeldahl nitrogen (July) and total phosphorus (July). Of the 43 fish-community attributes and metric scores examined, the seston PC1 was negatively related to one attribute (large-river percent). Of the 21 invertebrate-community attributes and metric scores examined, the seston PC1 was negatively related to one attribute (EPT-to-total ratio). The seston PC1 was not related to the five basin-characteristics or nine habitat variables

  8. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

    USGS Publications Warehouse

    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  9. Multi-phase Uplift of the Indo-Burman Ranges and Western Thrust Belt of Minbu Sub-basin (West Myanmar): Constraints from Apatite Fission Track Data

    NASA Astrophysics Data System (ADS)

    Zhang, P.; Qiu, H.; Mei, L.

    2015-12-01

    The forearc regions in active continental margins are important keys to analysis geodynamic processes such as oceanic crust oblique subduction, mechanism of subduction zone, and sediments recycling. The West Myanmar, interpreted as forearc silver, is the archetype example of such forearc regions subordinate to Sunda arc-trench system, and is widely debated when and how its forearc regions formed. A total of twenty-two samples were obtained from the Indo-Burman Ranges and western thrust belt of Minbu Sub-basin along Taungup-Prome Road in Southwestern Myanmar (Figure 1), and five sandstone samples of them were performed at Apatite to Zircon, Inc. Three samples (M3, M5, and M11) collected from Eocene flysch and metamorphic core at the Indo-Burman Ranges revealed apatite fission track (AFT) ages ranging from 19 to 9 Ma and 6.5 to 2 Ma. Two samples (M20 and M21) acquired from the western thrust belt of Minbu Sub-basin yielded AFT ages ranging from 28 to 13.5 Ma and 7.5 to 3.5 Ma. Time-temperature models based on AFT data suggest four major Cenozoic cooling episodes, Late Oligocene, Early to Middle Miocene, Late Miocene, and Pliocene to Pleistocene. The first to third episode, models suggest the metamorphic core of the Indo-Burman Ranges has experienced multi-phase rapidly uplifted during the early construction of the forearc regions. The latest episode, on which this study focused, indicated a fast westward growth of the Palaeogene accretionary wedge and a eastward propagation deformation of folding and thrusting of the western thrust belt of Minbu Sub-basin. We argued that above multi-phase uplifted and deformation of the forearc regions were results of India/West Burma plate's faster oblique convergence and faster sedimentation along the India/Eurasia suture zone.

  10. Coral radiocarbon records of Indian Ocean water mass mixing and wind-induced upwelling along the coast of Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Grumet, N. S.; Abram, N. J.; Beck, J. W.; Dunbar, R. B.; Gagan, M. K.; Guilderson, T. P.; Hantoro, W. S.; Suwargadi, B. W.

    2004-05-01

    Radiocarbon (14C) in the skeletal aragonite of annually banded corals track radiocarbon concentrations in dissolved inorganic carbon (DIC) in surface seawater. As a result of nuclear weapons testing in the 1950s, oceanic uptake of excess 14C in the atmosphere has increased the contrast between surface and deep ocean 14C concentrations. We present accelerator mass spectrometric (AMS) measurements of 14C/12C ratios (Δ14C) in Porites corals from the Mentawai Islands, Sumatra (0°S, 98°E) and Watamu, Kenya (3°S, 39°E) to document the temporal and spatial evolution of the 14C zonal gradient in the tropical Indian Ocean. The rise in Δ14C in the Sumatra coral, in response to the maximum in nuclear weapons testing, is delayed by 2-3 years relative to the rise in coral Δ14C from the coast of Kenya. Kenya coral Δ14C values rise quickly because surface waters are in prolonged contact with the atmosphere. In contrast, wind-induced upwelling and rapid mixing along the coast of Sumatra entrains 14C-depleted water from the subsurface, which dilutes the effect of the uptake of bomb-produced 14C by the surface ocean. Bimonthly AMS Δ14C measurements on the Mentawai coral reveal mainly interannual variability with minor seasonal variability. Singular spectrum analysis of the Sumatra coral Δ14C record reveals a significant 3-year periodicity. These results lend support to the concept that interannual variability in Indian Ocean upwelling and sea surface temperatures is related to ENSO-like teleconnections over the Indo-Pacific basin.

  11. Mid-level synoptic analysis of flood-generating systems in South-west of Iran (case study: Dalaki watershed river basin)

    NASA Astrophysics Data System (ADS)

    Sabziparvar, A. A.; Parandeh, A.; Lashkari, H.; Yazdanpanah, H.

    2010-11-01

    Flood is known as one of the most distractive natural disaster worldwide. Therefore, its prediction is of great importance from the socio-economical point of view. Despite the great improvement in computational techniques and numerical weather prediction approaches, so far, in Iran, an acceptable flood prediction method has not yet been introduced. The main aim of this study is to recognize and classify the patterns of synoptic systems leading to torrential rainfalls in a watershed basin located in south-west of Iran. In this research, 20 major floods characterized by high rainfall intensities and severe damage were selected. The pattern, extension, and the direction of movement of the selected synoptic maps from surface to 500 hPa pressure levels were identified. Furthermore, the position of cyclones, anti-cyclones and mid-level trough lines were carefully tracked and classified into different groups. The results show that the major severe floods occurring in Dalaki watershed river basin are mainly influenced by strengthening of the center of Sudan heat low (SHL) and the coincidence moisture feeding by the Indian Ocean and Mediterranean Sea. It was found that simultaneous merging of the SHL system and Mediterranean frontal system would intensify the flood intensities over the basin. The mean positions of high pressures, low pressures, the Red Sea trough lines and 1015 hPa isobars of the major floods are also discussed.

  12. Evaluation of baseline ground-water conditions in the Mosteiros, Ribeira Paul, and Ribeira Faja Basins, Republic of Cape Verde, West Africa, 2005-06

    USGS Publications Warehouse

    Heilweil, Victor M.; Earle, John D.; Cederberg, Jay R.; Messer, Mickey M.; Jorgensen, Brent E.; Verstraeten, Ingrid M.; Moura, Miguel A.; Querido, Arrigo; Spencer,; Osorio, Tatiana

    2006-01-01

    This report documents current (2005-06) baseline ground-water conditions in three basins within the West African Republic of Cape Verde (Mosteiros on Fogo, Ribeira Paul on Santo Ant?o, and Ribeira Faj? on S?o Nicolau) based on existing data and additional data collected during this study. Ground-water conditions (indicators) include ground-water levels, ground-water recharge altitude, ground-water discharge amounts, ground-water age (residence time), and ground-water quality. These indicators are needed to evaluate (1) long-term changes in ground-water resources or water quality caused by planned ground-water development associated with agricultural projects in these basins, and (2) the feasibility of artificial recharge as a mitigation strategy to offset the potentially declining water levels associated with increased ground-water development. Ground-water levels in all three basins vary from less than a few meters to more than 170 meters below land surface. Continuous recorder and electric tape measurements at three monitoring wells (one per basin) showed variations between August 2005 and June 2006 of as much as 1.8 meters. Few historical water-level data were available for the Mosteiros or Ribeira Paul Basins. Historical records from Ribeira Faj? indicate very large ground-water declines during the 1980s and early 1990s, associated with dewatering of the Galleria Faj? tunnel. More-recent data indicate that ground-water levels in Ribeira Faj? have reached a new equilibrium, remaining fairly constant since the late 1990s. Because of the scarcity of observation wells within each basin, water-level data were combined with other techniques to evaluate ground-water conditions. These techniques include the quantification of ground-water discharge (well withdrawals, spring discharge, seepage to springs, and gallery drainage), field water-quality measurements, and the use of environmental tracers to evaluate sources of aquifer recharge, flow paths, and ground

  13. Permian plate margin volcanism and tuffs in adjacent basins of west Gondwana: Age constraints and common characteristics

    NASA Astrophysics Data System (ADS)

    López-Gamundí, Oscar

    2006-12-01

    Increasing evidence of Permian volcanic activity along the South American portion of the Gondwana proto-Pacific margin has directed attention to its potential presence in the stratigraphic record of adjacent basins. In recent years, tuffaceous horizons have been identified in late Early Permian-through Middle Permian (280-260 Ma) sections of the Paraná Basin (Brazil, Paraguay, and Uruguay). Farther south and closer to the magmatic tract developed along the continental margin, in the San Rafael and Sauce Grande basins of Argentina, tuffs are present in the Early to Middle Permian section. This tuff-rich interval can be correlated with the appearance of widespread tuffs in the Karoo Basin. Although magmatic activity along the proto-Pacific plate margin was continuous during the Late Paleozoic, Choiyoi silicic volcanism along the Andean Cordillera and its equivalent in Patagonia peaked between the late Early Permian and Middle Permian, when extensive rhyolitic ignimbrites and consanguineous airborne tuffaceous material erupted in the northern Patagonian region. The San Rafael orogenic phase (SROP) interrupted sedimentation along the southwestern segment of the Gondwana margin (i.e., Frontal Cordillera, San Rafael Basin), induced cratonward thrusting (i.e., Ventana and Cape foldbelts), and triggered accelerated subsidence in the adjacent basins (Sauce Grande and Karoo) located inboard of the deformation front. This accelerated subsidence favored the preservation of tuffaceous horizons in the syntectonic successions. The age constraints and similarities in composition between the volcanics along the continental margin and the tuffaceous horizons in the San Rafael, Sauce Grande, Paraná, and Karoo basins strongly suggest a genetic linkage between the two episodes. Radiometric ages from tuffs in the San Rafael, Paraná, and Karoo basins indicate an intensely tuffaceous interval between 280 and 260 Ma.

  14. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, west Texas (Delaware Basin). Annual progress report, March 31, 1995--March 31, 1996

    SciTech Connect

    Dutton, S.P.; Hovorka, S.D.; Cole, A.G.

    1996-08-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based field development. Reservoirs in the Delaware Mountain Group have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Detailed correlations of the Ramsey sandstone reservoirs in Geraldine Ford field suggest that lateral sandstone continuity is less than interpreted by previous studies. The degree of lateral heterogeneity in the reservoir sandstones suggests that they were deposited by eolian-derived turbidites. According to the eolian-derived turbidite model, sand dunes migrated across the exposed shelf to the shelf break during sea-level lowstands and provided well sorted sand for turbidity currents or grain flows into the deep basin.

  15. Space Radar Image of Central Sumatra, Indonesia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is a radar image of the central part of the island of Sumatra in Indonesia that shows how the tropical rainforest typical of this country is being impacted by human activity. Native forest appears in green in this image, while prominent pink areas represent places where the native forest has been cleared. The large rectangular areas have been cleared for palm oil plantations. The bright pink zones are areas that have been cleared since 1989, while the dark pink zones are areas that were cleared before 1989. These radar data were processed as part of an effort to assist oil and gas companies working in the area to assess the environmental impact of both their drilling operations and the activities of the local population. Radar images are useful in these areas because heavy cloud cover and the persistent smoke and haze associated with deforestation have prevented usable visible-light imagery from being acquired since 1989. The dark shapes in the upper right (northeast) corner of the image are a chain of lakes in flat coastal marshes. This image was acquired in October 1994 by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour. Environmental changes can be easily documented by comparing this image with visible-light data that were acquired in previous years by the Landsat satellite. The image is centered at 0.9 degrees north latitude and 101.3 degrees east longitude. The area shown is 50 kilometers by 100 kilometers (31 miles by 62 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received; blue is L-band vertically transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  16. Epidemic dengue transmission in southern Sumatra, Indonesia.

    PubMed

    Corwin, A L; Larasati, R P; Bangs, M J; Wuryadi, S; Arjoso, S; Sukri, N; Listyaningsih, E; Hartati, S; Namursa, R; Anwar, Z; Chandra, S; Loho, B; Ahmad, H; Campbell, J R; Porter, K R

    2001-01-01

    An outbreak of dengue fever (DF), dengue haemorrhagic fever (DHF), and dengue shock syndrome (DSS) in the city of Palembang, south Sumatra, Indonesia was investigated to (i) validate epidemic occurrence, (ii) confirm dengue virus aetiology and associated serotype(s), (iii) provide a demonstrable measure of community impact, and (iv) identify causative relationship (if any) with climatic El Niño Southern Oscillation (ENSO) influences. Trend analysis based on a 6-year retrospective review of hospital records demonstrates a 3-fold increase in clinical cases for the outbreak period (January-April 1998), relative to historical records. In the 2 hospitals surveyed, the monthly mean number of outbreak-related dengue cases over 4 months was 833 (range 650-995 cases/month); the mean monthly value for the previous 72 months was 107 (range 14-779 cases/month). An apparent trend in epidemic transmission was observed, evolving from a 5-year cyclic phenomenon to an annual occurrence, often indistinguishable from one year to the next. The proportional distribution of clinical outbreak cases into DF, DHF and DSS diagnostic categories was 24%, 66%, and 10%, respectively. The population aged 10-19 years accounted for the largest (35%) proportion of hospitalized DHF cases, followed by children aged 5-9 years (25%) and children aged 4 years (16%). Serum samples obtained during acute illness from 221 hospitalized patients were examined using serology, RT-PCR, and virus isolation in cell culture: 59% of samples had laboratory evidence of a dengue infection. All 4 dengue virus serotypes (DEN 1-4) were identified in epidemic circulation, with DEN 3 predominating (43%). DEN 1 was the principal serotype associated with less severe dengue illness, suggesting that virulence may be, in part, a function of infecting serotype. The climatic influence of ENSO on rainfall and temperature in the months leading up to and during the outbreak was dramatic, and is likely to contribute to favourable

  17. Successful Deployment of System for the Storage and Retrieval of Spent/Used Nuclear Fuel from Hanford K-West Fuel Storage Basin-13051

    SciTech Connect

    Quintero, Roger; Smith, Sahid; Blackford, Leonard Ty; Johnson, Mike W.; Raymond, Richard; Sullivan, Neal; Sloughter, Jim

    2013-07-01

    In 2012, a system was deployed to remove, transport, and interim store chemically reactive and highly radioactive sludge material from the Hanford Site's 105-K West Fuel Storage Basin that will be managed as spent/used nuclear fuel. The Knockout Pot (KOP) sludge in the 105-K West Basin was a legacy issue resulting from the spent nuclear fuel (SNF) washing process applied to 2200 metric tons of highly degraded fuel elements following long-term underwater storage. The washing process removed uranium metal and other non-uranium constituents that could pass through a screen with 0.25-inch openings; larger pieces are, by definition, SNF or fuel scrap. When originally retrieved, KOP sludge contained pieces of degraded uranium fuel ranging from 600 microns (μm) to 6350 μm mixed with inert material such as aluminum hydroxide, aluminum wire, and graphite in the same size range. In 2011, a system was developed, tested, successfully deployed and operated to pre-treat KOP sludge as part of 105-K West Basin cleanup. The pretreatment process successfully removed the vast majority of inert material from the KOP sludge stream and reduced the remaining volume of material by approximately 65 percent, down to approximately 50 liters of material requiring management as used fuel. The removal of inert material resulted in significant waste minimization and project cost savings because of the reduced number of transportation/storage containers and improvement in worker safety. The improvement in worker safety is a result of shorter operating times and reduced number of remote handled shipments to the site fuel storage facility. Additionally in 2011, technology development, final design, and cold testing was completed on the system to be used in processing and packaging the remaining KOP material for removal from the basin in much the same manner spent fuel was removed. This system was deployed and successfully operated from June through September 2012, to remove and package the last

  18. Hydrogeologic comparison of an acidic-lake basin with a neutral-lake basin in the West-Central Adirondack Mountains, New York

    USGS Publications Warehouse

    Peters, N.E.; Murdoch, Peter S.

    1985-01-01

    Two small headwater lake basins that receive similar amounts of acidic atmospheric deposition have significantly different lake outflow pH values; pH at Panther Lake (neutral) ranges from about 4.7 to 7; that at Woods Lake (acidic) ranges from about 4.3 to 5. A hydrologic analysis, which included monthly water budgets, hydrograph analysis, examination of flow duration and runoff recession curves, calculation of ground-water storage, and an analysis of lateral flow capacity of the soil, indicates that differences in lakewater pH can be attributed to differences in the ground-water contribution to the lakes. A larger percentage of the water discharged from the neutral lake is derived from ground water than that from the acidic lake. Ground water has a higher pH resulting from a sufficiently long residence time for neutralizing chemical reactions to occur with the till. The difference in ground-water contribution is attributed to a more extensive distribution of thick till (<3m) in the neutral-lake basin than in the acidic-lake basin; average thickness of till in the neutral-lake basin is 24m whereas that in the other is 2.3m. During the snowmelt period, as much as three months of accumulated precipitation may be released within two weeks causing the lateral flow capacity of the deeper mineral soil to be exceeded in the neutral-lake basin. This excess water moves over and through the shallow acidic soil horizons and causes the lakewater pH to decrease during snowmelt.Two small headwater lake basins that receive similar amounts of acidic atmospheric deposition have significantly different lake outflow pH values; pH at Panther Lake (neutral) ranges from about 4. 7 to 7; that at Woods Lake (acidic) ranges from about 4. 3 to 5. A hydrologic analysis, which included monthly water budgets, hydrograph analysis, examination of flow duration and runoff recession curves, calculation of ground-water storage, and an analysis of lateral flow capacity of the soil, indicates that

  19. Preliminary Results of Paleotsunami Deposits Along the Sunda Megathrust, Simeulue Island, Sumatra

    NASA Astrophysics Data System (ADS)

    Whitlow, K. F.; Yulianto, E.; Fujino, S.; Sieh, K.

    2006-12-01

    Although great megathrust earthquakes have been previously documented by coral microatoll studies, the timing of past tsunamis on Simeulue Island, west Sumatra, are poorly documented. According to local residents and our recent reconnaissance, a large megathrust earthquake along the Sunda arc occurred in 1907 and generated a tsunami along the west coast of Sumatra. U/Th dates from a microatoll offshore from one of our field localities, Busong Bay, show an event that occurred in 1799. Our recent studies have identified candidate paleotsunami deposits at three different locations on Simeulue Island between 2o and 3o N at Inor, Busong Bay, and Langi Bay. Shallow excavations at each site exposed candidate tsunami deposits. At Inor, excavations made parallel to a river that runs perpendicular to the ocean document the inland extent of past tsunamis. At both Busong Bay and Langi Bay, excavations were made parallel to the shoreline. Diatom and grain size analyses of candidate tsunami deposits will help to determine if the sand layers are marine or terrestrially derived. Coral blocks at Busong Bay and Langi Bay may have been deposited by recent (2004) and past tsunamis. U/Th dating of a buried coral boulder found on a candidate tsunami sand in a trench exposure at Busang Bay will constrain the age of the Simeulue Island paleotsunami deposit. AMS radiocarbon dating of woody fragments from peat layers will also help to constrain the age of the candidate paleotsunami deposit. By constraining the age of the paleotsunami deposit, we will determine recurrence intervals for the portion of the Sumatran subduction zone that broke in 2004. Characterizing depositional settings and the origin of candidate tsunami deposits (marine or terrestrial) will help to understand tsunami preservation in the geologic record.

  20. Geologic Cross Section D-D' Through the Appalachian Basin from the Findlay Arch, Sandusky County, Ohio, to the Valley and Ridge Province, Hardy County, West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.; Crangle, Robert D.; Trippi, Michael H.; Swezey, Christopher S.; Lentz, Erika E.; Rowan, Elisabeth L.; Hope, Rebecca S.

    2009-01-01

    Geologic cross section D-D' is the second in a series of cross sections constructed by the U.S. Geological Survey to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section D-D' provides a regional view of the structural and stratigraphic framework of the Appalachian basin from the Findlay arch in northwestern Ohio to the Valley and Ridge province in eastern West Virginia, a distance of approximately 290 miles. The information shown on the cross section is based on geological and geophysical data from 13 deep drill holes, several of which penetrate the Paleozoic sedimentary rocks of the basin and bottom in Mesoproterozoic (Grenville-age) crystalline basement rocks. This cross section is a companion to cross section E-E' (Ryder and others, 2008) that is located about 25 to 50 mi to the southwest. Although specific petroleum systems in the Appalachian basin are not identified on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and preferred migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on information shown on the cross section. Cross section D-D' lacks the detail to illustrate key elements of coal systems (such as paleoclimate, coal quality, and coal rank), but it does provide a general geologic framework (stratigraphic units and general rock types) for the coal-bearing section. Also, cross section D-D' may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste or for the sequestration of carbon dioxide.

  1. Analysis of characteristics of simulated flows from small surface-mined and undisturbed Appalachian watersheds in the Tug Fork basin of Kentucky, Virginia, and West Virginia

    USGS Publications Warehouse

    Scott, A.G.

    1984-01-01

    Hydrologic and climatologic data were collected at 10 small, mined and unmined watersheds in the Tug Fork basin of Kentucky, Virginia, and West Virginia. These data included continuous records of discharge, precipitation, and air temperature. Daily records of sediment concentrations and sediment discharges were also obtained and periodic observations of water-quality data taken. A compilation of all these data is presented. The observed climatic and hydrologic data from these basins were used to calibrate the U.S. Geological Survey Precipitation-Runoff Modeling System for each watershed. The calibrated models of each basin were then used with a set of nearby, long-term climatic data to simulate a long record of stream-flow. A 68-year record of daily streamflow and 57 years of annual peaks were simulated for each site. These simulated records were analyzed to obtain flood-frequency curves, flow-duration curves, mean-annual discharges, and the 7-day, 10-year low flow for each site. The flow characteristics computed from the simulated records of discharge were analyzed graphically and statistically by regression analysis to investigate the degree of relationship and to define the relationship between mining and runoff. For this sample of small basins, peak flows, discharges for 10- and 50-percent flow durations, and mean-annual flows are directly related to percent of drainage area disturbed (measured from aerial photos) and drainage area. Percent of drainage area disturbed is generally a more statistically significant estimator of discharge than drainage area, particularly for peak flows of higher recurrence intervals. (USGS)

  2. Rupture process of the 2004 Sumatra-Andaman earthquake.

    PubMed

    Ammon, Charles J; Ji, Chen; Thio, Hong-Kie; Robinson, David; Ni, Sidao; Hjorleifsdottir, Vala; Kanamori, Hiroo; Lay, Thorne; Das, Shamita; Helmberger, Don; Ichinose, Gene; Polet, Jascha; Wald, David

    2005-05-20

    The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough. Peak displacements reached approximately 15 meters along a 600-kilometer segment of the plate boundary offshore of northwestern Sumatra and the southern Nicobar islands. Slip was less in the northern 400 to 500 kilometers of the aftershock zone, and at least some slip in that region may have occurred on a time scale beyond the seismic band.

  3. Stratigraphic Framework and Depositional Sequences in the Lower Silurian Regional Oil and Gas Accumulation, Appalachian Basin: From Licking County, Ohio, to Fayette County, West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.

    2006-01-01

    The Lower Silurian regional oil and gas accumulation was named by Ryder and Zagorski (2003) for a 400-mile (mi)-long by 200-mi-wide hydrocarbon accumulation in the central Appalachian basin of the Eastern United States and Ontario, Canada. From the early 1880s to 2000, approximately 300 to 400 million barrels of oil and eight to nine trillion cubic feet of gas have been produced from the Lower Silurian regional oil and gas accumulation (Miller, 1975; McCormac and others, 1996; Harper and others, 1999). Dominant reservoirs in the regional accumulation are the Lower Silurian 'Clinton' and Medina sandstones in Ohio and westernmost West Virginia and coeval rocks in the Lower Silurian Medina Group (Grimsby Sandstone (Formation) and Whirlpool Sandstone) in northwestern Pennsylvania and western New York. A secondary reservoir is the Upper Ordovician(?) and Lower Silurian Tuscarora Sandstone in central Pennsylvania and central West Virginia, a more proximal eastern facies of the 'Clinton' sandstone and Medina Group (Yeakel, 1962; Cotter, 1982, 1983; Castle, 1998). The Lower Silurian regional oil and gas accumulation is subdivided by Ryder and Zagorski (2003) into the following three parts: (1) an easternmost part consisting of local gas-bearing sandstone units in the Tuscarora Sandstone that is included with the basin-center accumulation; (2) an eastern part consisting predominantly of gas-bearing 'Clinton' sandstone-Medina Group sandstones that have many characteristics of a basin-center accumulation (Davis, 1984; Zagorski, 1988, 1991; Law and Spencer, 1993); and (3) a western part consisting of oil- and gas-bearing 'Clinton' sandstone-Medina Group sandstones that is a conventional accumulation with hybrid features of a basin-center accumulation (Zagorski, 1999). With the notable exception of the offshore part of Lake Erie (de Witt, 1993), the supply of oil and (or) gas in the hybrid-conventional part of the regional accumulation continues to decline because of the many

  4. California Basin study (CaBS): DOE west coast basin program. Progress report 8, 15 November 1989--14 November 1990

    SciTech Connect

    Small, L.F.

    1990-12-31

    The overall objective of our research continues to be elucidation of the transport pathways and transformations of organic matter in the California Basins region, with particular reference to the role of macrozooplankton in upper waters. We have concentrated on C and N pathways and fluxes to data, and will continue to investigate these further (seasonal aspects, and the role of zooplankton carnivory in zooplankton-medicated C and N flux, for example).

  5. Physical characteristics of stream subbasins in the upper Minnesota River basin, west-central Minnesota, northeastern South Dakota and southeastern North Dakota

    USGS Publications Warehouse

    Sanocki, C.A.

    1995-01-01

    Data that describe the physical characteristics of stream subbasins upstream from selected points on streams in the Upper Minnesota River Basin, located in west-central Minnesota, north-eastern South Dakota, and southeastern North Dakota, are presented in this report. The physical characteristics are the drainage area of the subbasin, the percentage area of the subbasin covered only by lakes, the percentage area of the subbasin covered by both laker and wetlands, the main-channel length, and the main-channel slope. The points on the stream include outlets of subbasins of at least 5 square miles, outlets of sewage treatment plants, and locations of U.S. Geological Survey low-flow, highflow, and continuous-record gaging stations.

  6. Water quality assessment for indirect potable reuse: a new methodology for controlling trace organic compounds at the West Basin Water Recycling Plant (California, USA).

    PubMed

    Levine, B; Reich, K; Sheilds, P; Suffet, I H; Lazarova, V

    2001-01-01

    The West Basin Water Recycling plant (California; USA) was built to increase the region's water resource availability. The plant influent is produced at Los Angeles Hyperion wastewater treatment plant and is treated through two parallel treatment processes depending on the end use: (1) Title 22 water for industrial and urban use, and (2) barrier treatment for groundwater recharge. A new methodology was applied to monitor the fate of base neutral compounds in the water barrier treatment train. The methodology included large sample volumes coupled with integrated chromatographic analysis (ICA). Data indicated a 25% increase in concentration of base neutral compounds after RO pretreatment, followed by a 70% removal efficiency after RO. The increase in concentration after RO pretreatment appears to be linked to the use of lime clarification.

  7. The development of a comprehensive regional digital geospatial database for geothermal exploration in the West-Central Great Basin, U.S.A.

    SciTech Connect

    Nash, G.D.; Hernandez, M.W.

    1996-08-01

    The Earth Sciences and Resources Institute, Geomatics Laboratory, (EGL), Department of Civil and Environmental Engineering, University of Utah, has compiled and initiated the use of a comprehensive digital geospatial database for geothermal exploration in the west-central Great Basin, U.S.A. The database consists of hydrothermal alteration, lineament, recent earthquake, aeromagnetic, gravity, hot spring, mining district, heat flow, geochemical, and geologic unit digital maps in a GIS format. Several problems were encountered during the development of this geospatial database. These primarily included (1) data availability and coverage of the study area, (2) data accuracy (both spatial and thematic), (3) inconsistent data formats, and (4) a lack of metadata. These problems were all overcome satisfactorily. The data are currently being used to create a regional geothermal potential model for the study area.

  8. Data quality objectives for sampling of sludge from the K West and K East Basin floor and from other Basin areas

    SciTech Connect

    MAKENAS, B.J.

    1998-10-21

    This document addresses the characterization strategy for those types of sludge not previously characterized or discussed in previous DQO documents. It seeks to ascertain those characteristics of uncharacterized Sludge which are unique with respect to the properties already determined for canister and K East Basin floor Sludge. Also recent decisions have resulted in the need for treatment of the Sludge prior to its currently identified disposal path to the Hanford waste tanks. This has resulted in a need for process development testing for the treatment system development.

  9. Forest Fruit Production Is Higher on Sumatra Than on Borneo

    PubMed Central

    Wich, Serge A.; Vogel, Erin R.; Larsen, Michael D.; Fredriksson, Gabriella; Leighton, Mark; Yeager, Carey P.; Brearley, Francis Q.; van Schaik, Carel P.; Marshall, Andrew J.

    2011-01-01

    Background Various studies have shown that the population densities of a number of forest vertebrates, such as orangutans, are higher on Sumatra than Borneo, and that several species exhibit smaller body sizes on Borneo than Sumatra and mainland Southeast Asia. It has been suggested that differences in forest fruit productivity between the islands can explain these patterns. Here we present a large-scale comparison of forest fruit production between the islands to test this hypothesis. Methodology/Principal Findings Data on fruit production were collated from Sumatran and Bornean sites. At six sites we assessed fruit production in three forest types: riverine, peat swamp and dryland forests. We compared fruit production using time-series models during different periods of overall fruit production and in different tree size classes. We examined overall island differences and differences specifically for fruiting period and tree size class. The results of these analyses indicate that overall the Sumatran forests are more productive than those on Borneo. This difference remains when each of the three forest types (dryland, riverine, and peat) are examined separately. The difference also holds over most tree sizes and fruiting periods. Conclusions/Significance Our results provide strong support for the hypothesis that forest fruit productivity is higher on Sumatra than Borneo. This difference is most likely the result of the overall younger and more volcanic soils on Sumatra than Borneo. These results contribute to our understanding of the determinants of faunal density and the evolution of body size on both islands. PMID:21738627

  10. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, July 1 - September 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-10-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sup 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Accomplishments for this past quarter are discussed.

  11. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, October 1 - December 31, 1996

    SciTech Connect

    Dutton, S.P.

    1997-01-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and recovery technology identification and analysis.

  12. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, April 1,1996 - June 30, 1996

    SciTech Connect

    Dutton, S.P.

    1996-07-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir- characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Progress to date is summarized for reservoir characterization.

  13. Geologic Cross Section E-E' through the Appalachian Basin from the Findlay Arch, Wood County, Ohio, to the Valley and Ridge Province, Pendleton County, West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.; Swezey, Christopher S.; Crangle, Robert D.; Trippi, Michael H.

    2008-01-01

    Geologic cross section E-E' is the first in a series of cross sections planned by the U.S. Geological Survey (USGS) to document and improve understanding of the geologic framework and petroleum systems of the Appalachian basin. Cross section E-E' provides a regional view of the structural and stratigraphic framework of the basin from the Findlay arch in northwestern Ohio to the Valley and Ridge province in eastern West Virginia, a distance of approximately 380 miles (mi) (fig. 1, on sheet 1). Cross section E-E' updates earlier geologic cross sections through the central Appalachian basin by Renfro and Feray (1970), Bennison (1978), and Bally and Snelson (1980) and a stratigraphic cross section by Colton (1970). Although other published cross sections through parts of the basin show more structural detail (for example, Shumaker, 1985; Kulander and Dean, 1986) and stratigraphic detail (for example, Ryder, 1992; de Witt and others, 1993; Hettinger, 2001), these other cross sections are of more limited extent geographically and stratigraphically. Although specific petroleum systems in the Appalachian basin are not identified on the cross section, many of their key elements (such as source rocks, reservoir rocks, seals, and traps) can be inferred from lithologic units, unconformities, and geologic structures shown on the cross section. Other aspects of petroleum systems (such as the timing of petroleum generation and preferred migration pathways) may be evaluated by burial history, thermal history, and fluid flow models based on information shown on the cross section. Cross section E-E' lacks the detail to illustrate key elements of coal systems (such as paleoclimate, coal quality, and coal rank), but it does provide a general framework (stratigraphic units and general rock types) for the coal-bearing section. Also, cross section E-E' may be used as a reconnaissance tool to identify plausible geologic structures and strata for the subsurface storage of liquid waste (for

  14. Adsorption Kinetics of CO2, CH4, and their Equimolar Mixture on Coal from the Black Warrior Basin, West-Central Alabama

    SciTech Connect

    Gruszkiewicz, Miroslaw {Mirek} S; Naney, Michael {Mike} T; Blencoe, James {Jim} G; Cole, David R; Pashin, Jack C.; Carroll, Richard E.

    2009-01-01

    Laboratory experiments were conducted to investigate the adsorption kinetic behavior of pure and mixed gases (CO2, CH4, approximately equimolar CO2 + CH4 mixtures, and He) on a coal sample obtained from the Black Warrior Basin at the Littleton Mine (Twin Pine Coal Company), Jefferson County, west-central Alabama. The sample was from the Mary Lee coal zone of the Pottsville Formation (Lower Pennsylvanian). Experiments with three size fractions (45-150 m, 1-2 mm, and 5-10 mm) of crushed coal were performed at 40 C and 35 C over a pressure range of 1.4 6.9 MPa to simulate coalbed methane reservoir conditions in the Black Warrior Basin and provide data relevant for enhanced coalbed methane recovery operations. The following key observations were made: (1) CO2 adsorption on both dry and water-saturated coal is much more rapid than CH4 adsorption; (2) water saturation decreases the rates of CO2 and CH4 adsorption on coal surfaces, but it appears to have minimal effects on the final magnitude of CO2 or CH4 adsorption if the coal is not previously exposed to CO2; (3) retention of adsorbed CO2 on coal surfaces is significant even with extreme pressure cycling; and (4) adsorption is significantly faster for the 45-150 m size fraction compared to the two coarser fractions.

  15. Adsorption kinetics of CO2, CH4, and their equimolar mixture on coal from the Black Warrior Basin, West-Central Alabama

    USGS Publications Warehouse

    Gruszkiewicz, M.S.; Naney, M.T.; Blencoe, J.G.; Cole, D.R.; Pashin, J.C.; Carroll, R.E.

    2009-01-01

    Laboratory experiments were conducted to investigate the adsorption kinetic behavior of pure and mixed gases (CO2, CH4, approximately equimolar CO2 + CH4 mixtures, and He) on a coal sample obtained from the Black Warrior Basin at the Littleton Mine (Twin Pine Coal Company), Jefferson County, west-central Alabama. The sample was from the Mary Lee coal zone of the Pottsville Formation (Lower Pennsylvanian). Experiments with three size fractions (45-150????m, 1-2??mm, and 5-10??mm) of crushed coal were performed at 40????C and 35????C over a pressure range of 1.4-6.9??MPa to simulate coalbed methane reservoir conditions in the Black Warrior Basin and provide data relevant for enhanced coalbed methane recovery operations. The following key observations were made: (1) CO2 adsorption on both dry and water-saturated coal is much more rapid than CH4 adsorption; (2) water saturation decreases the rates of CO2 and CH4 adsorption on coal surfaces, but it appears to have minimal effects on the final magnitude of CO2 or CH4 adsorption if the coal is not previously exposed to CO2; (3) retention of adsorbed CO2 on coal surfaces is significant even with extreme pressure cycling; and (4) adsorption is significantly faster for the 45-150????m size fraction compared to the two coarser fractions. ?? 2008 Elsevier B.V.

  16. Spatial distribution of Hydrocarbon Reservoirs in the West Korea Bay Basin in the northern part of the Yellow Sea, estimated by 3D gravity forward modeling

    NASA Astrophysics Data System (ADS)

    Choi, Sungchan; Ryu, In-Chang; Götze, H.-J.; Chae, Y.

    2016-10-01

    Although an amount of hydrocarbon has been discovered in the West Korea Bay Basin (WKBB), located in the North Korean offshore area, geophysical investigations associated with these hydrocarbon reservoirs are not permitted because of the current geopolitical situation. Interpretation of satellite- derived potential field data can be alternatively used to image the three-dimensional (3D) density distribution in the sedimentary basin associated with hydrocarbon deposits. We interpreted the TRIDENT satellite-derived gravity field data to provide detailed insights into the spatial distribution of sedimentary density structures in the WKBB. We used 3D forward density modeling for the interpretation that incorporated constraints from existing geological and geophysical information. The gravity data interpretation and the 3D forward modeling showed that there are two modeled areas in the central subbasin that are characterized by very low density structures, with a maximum density of about 2000 kg/m3, indicating some type of hydrocarbon reservoir. One of the anticipated hydrocarbon reservoirs is located in the southern part of the central subbasin with a volume of about 250 km3 at a depth of about 3000 m in the Cretaceous/Jurassic layer. The other hydrocarbon reservoir should exist in the northern part of the central subbasin, with an average volume of about 300 km3 at a depth of about 2500 m.

  17. Structural controls on Ochoan salt dissolution and Delaware Mountain Group oil field permeability trends in the Delaware basin, west Texas and southeast New Mexico

    SciTech Connect

    Zaengle, J.F.; Lohmann, K.C. )

    1991-03-01

    A Landsat TM image of the Delaware basin, west Texas and southeast New Mexico, reveals geomorphic lineaments and tonal anomalies with preferred northwest-southeast and northeast-southwest orientations. Lineament orientations are the same as the trend of joints and fractures observed in Delaware Mountain exposures and from subsurface borehole break-out and televiewer data. These data suggest that lineament trends are controlled by subsurface joints and fractures. Petrographic data indicate that Delaware Mountain Group porosity/permeability development is controlled in large part by the occurrence of calcite/dolomite cement and chlorite/corrensite clays. The unimodality of grain size, sorting, and framework grain mineralogy, along with the virtual absence of detrital clays, favors a diagenetic control on cementation patterns. These observations coupled with formation water chemistry, and cement carbon-oxygen isotope and fluid inclusion data suggest that the occurrence of Delaware Mountain Group cements is related to diagenetic alteration by waters that have dissolved Ochoan halite and potash salts. Hydrodynamic fluid flow along joint and fracture systems coupled with rock-water interactions are proposed that account for the coincidence of salt dissolution fronts and oil field permeability barriers as well as formation water chemical trends and cement isotopic signatures. Preliminary data suggest fracture systems provide conduits for hydrodynamic fluid flow capable of extensive Ochoan salt dissolution and the transport of reactive solutions to remote horizons both laterally and vertically in the basin.

  18. Effects of groundwater lateral flow on land surface processes: a case study in Heihe River Basin, north-west of China

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Zeng, Y.; Yu, Y.

    2015-12-01

    As an important component of hydrologic cycle, groundwater is affected by topography, vegetation, climate condition, and anthropogenic activity. Groundwater horizontal convergence and divergence and vertical interaction with soil water result in variations of soil moisture, water and energy exchanges between the land surface and the atmosphere, which ultimately influences climate. In this work, a two-dimensional groundwater lateral flow scheme based on groundwater mass equation, is developed and incorporated into the land surface model CLM4.5 to investigate effects of groundwater lateral flow on land surface processes in a river basin. A 30-year simulation with groundwater lateral flow and a control run without the horizontal movement are conducted over Heihe River Basin, north-west China, from 1979 to 2012 using the developed model. Results show that with groundwater lateral flow, equilibrium distribution of groundwater table shows more spatial variability following topography rather than the water balance between local precipitation and evapotranspiration, and are much closer to well observations especially over middle reaches area. Along with shallower groundwater table over piedmont areas in the middle reaches, increased soil moisture is shown which alleviates the underestimation of CLM4.5 at here. Changes in evapotranspiration are occurred and it is mainly controlled by the variation of local surface soil moisture, since water is the major limitation factor of evapotranspiration over this arid area. Besides, groundwater lateral flow can change the distribution of surface runoff by changing the saturated area fraction of each model grid cell. Energy cycle also responds to the changes of hydrological cycle which redistributes the sensible heat flux and latent heat flux in the entire basin.

  19. Petroleum systems characterization and ages in the Neuquen Basin (Triassic-to-Tertiary), West-Central Andes, Argentina

    SciTech Connect

    Legarreta, L.; Gulisano, C.A.; Orchuela, I.; Minnti, S.A.

    1996-08-01

    The Neuquen Basin, implanted on the western margin of the South American Plate evolved from Late Triassic-Early Jurassic as a set of isolated troughs, some of them connected to the {open_quotes}Pacific Ocean,{close_quotes} to an intra-arc to back-arc marine setting in Early-Late Jurassic. At the present day, a 7-km-thick succession of clastics, carbonates, evaporates, and volcanic rocks is preserved in between the eastern side of the Andean folded belt and the South American hinterland, affected by gentle deformation. On the southeastern margin of the basin occurs a relatively complex structural trend, as a result of the inversion tectonics related to an E-W regional strike-slip, fault. Five source-rock intervals are documented, the oldest consists of dark shales accumulated in a lacustrine environment (L. Triassic-E. Jurassic) and the others contain Type I and II organic matter as a consequence of anoxic conditions associated with marine flooding events that took place during the Jurassic and Early Cretaceous. The presence of numerous reservoir levels (clastics, carbonates, and also sills) and many regional and local seal intervals (shales and evaporates) within the sedimentary pile, combined with a diverse structural style, allowed the oil and gas trapping. Hydrocarbons were generated in various kitchens working at different times, as result of the subsidence regime and geothermal gradient that diversely affected different regions of the Neuquen Basin.

  20. How Robust are Science-Based Disaster Preparedness Strategies? Lessons from Western Sumatra (Invited)

    NASA Astrophysics Data System (ADS)

    Shannon, R.; McCloskey, J.; McDowell, S.

    2009-12-01

    Forecasts of the next likely megathrust earthquake which will occur off the western coast of Sumatra, possibly in the near future, indicate that it will likely be tsunamigenic and could be more devastating than the 2004 event. Hundreds of simulations of potential earthquakes and their tsunamis show that, while the earthquake is fundamentally unpredictable, many scenarios would see dangerous inundation of low-lying areas along the west coast of Sumatra; the cities of Padang and Bengkulu broadside-on to the areas of highest seismic potential have a combined population of over one million. Understanding how the science of unpredictable, high probability events is absorbed by society is essential for the development of effective mitigation and preparedness campaigns. A five month field investigation conducted in Padang and Bengkulu aimed to conceptualise the main issues driving risk perception of tsunami hazard, and explore its influence upon preparedness. Of specific interest was the role of scientifically quantified hazard information upon risk perception and hazard preparedness. Target populations were adult community members (n=270) and senior high school students (n=90). Preliminary findings indicate that scientific knowledge of earthquake and tsunami threat amongst respondents in both cities is good. However the relationship between respondent’s hazard knowledge, desired risk perception, and the adoption of preparedness measures was often non-linear and is susceptible to the negative effects of unscientific forecasts disseminated by government and mass media. Evidence suggests that ‘mystic’ predictions often portrayed in the media as being scientific, have been readily absorbed by the public; when these fail to materialise the credibility of authentic science and scientists plummets. As a result levels of sustainable earthquake and tsunami preparedness measures adopted by those living in tsunami threatened areas can be detrimentally impacted. It is

  1. Seafloor Changes Offshore Northern Sumatra from 1997-2009 Bathymetric Data

    NASA Astrophysics Data System (ADS)

    Frederik, M. C. G.; Gulick, S. P. S.; Austin, J. A., Jr.; Bangs, N. L.; Udrekh, U.; Duncan, D.

    2015-12-01

    Following the 2004 Sumatra-Andaman giant earthquake (Mw 9.1), multiple geology and geophysical surveys were conducted to gain better understanding of the behavior and mechanism of the tsunamigenic event. We present the first regional study of seafloor depth changes offshore of northern Sumatra, covering from the northwest of Northern Sumatra to west of the Simeulue Island, 1-6.5°N and 93-96.5°E. The oldest bathymetric dataset was from Dec 1997-Jan 1998 and the newer datasets were from the multiple surveys between Jan-Feb 2005 and Jan-Mar 2009. Using a re-sampled cell size of 115 m and sample interval of 100 m, we focused our observation on five 30-50 km long, SW-NE transects comparing the 1997/8 data with later surveys of the toe of the accretionary prism. The depth errors are the standard deviation for each dataset. For the five regions discussed, from N to S, we observe for crossing: (1) an average shoaling of ~120 ±31 m between 1997 and 2005 adjacent to and on the seaward flank of a fold closest to the Sunda Trench; (2) a landward shift of the fold closest to the Trench with an average shoaling of ~29 ±9 m between 1997 and 2005 on the landward flank of this fold; (3) the second fold landward of the Trench shows an average deepening of ~43 ±16 m between 1997 and 2005 proximal to a mass-wasting feature and a consequent shoaling of ~44 ±3 m on landward flank of the next fold seaward; (4) a seaward shift and a shoaling of ~38 ±14 m between 1997 and 2005 on the fold closest to the Trench; and (5) a slight landward shift between 1997 and 2005. While uncertainties remain, the 10s of m vertical and 100s of m horizontal changes likely reflect co-seismic motion on the décollement (e.g. crossing 4), post-seismic motion on landward vergent thrusts (e.g. 2), and/or slumping (e.g. 1,3).

  2. Stratigraphy and depositional history of the West Franklin Limestone (Pennsylvanian) in the southernmost part of the Illinois Basin, western Kentucky

    SciTech Connect

    King, N.R. . Dept. of Geosciences)

    1994-04-01

    The West Franklin Limestone in the subsurface of Webster and Union Counties, Kentucky includes 7.5--18m of strata deposited during portions of four depositional cycles in the latest Desmoinesian and earliest Missourian (Pennsylvanian). These cycles began with marine flooding and deposition of limestone, followed by progradation of siliciclastics in three of the four cycles, and ended with emergence. The basal West Franklin is micritic limestone (0.5--3m) that rests on rooted mudstone. Overlying the limestone are siliciclastics (1.5--7m) dominated by red and green claystone that is rooted at the top. Next is a middle limestone zone that includes either a paleokarsted micritic limestone, or a thin bioclastic micritic limestone bed associated with phosphatic shale and locally a second bioclastic micritic limestone. Above that is another siliciclastic interval (4--9m) capped by rooted mudstone and locally a thin coal. The overlying micritic limestone (1.5--2.5m) marks the top of the West Franklin. Depositional events included: (1) marine flooding of an emergent shelf producing the basal limestone; (2) progradation of siliciclastics followed by emergence and paleosol development; (3) marine flooding producing a second limestone; (4) emergence and karstification of erosional remnants of the second limestone; (5) renewed marine flooding depositing shell hash'' limestones and phosphatic shale; (6) progradation of siliciclastics culminating in emergency; and (7) marine flooding producing the upper limestone. Thus, two flooding-emergence cycles are represented by the middle limestone zone. The second, locally-developed shell-hash'' limestone in the middle zone was deposited during the regressive phase of a depositional cycle. All of the other limestones were deposited during transgression.

  3. Geologic Controls of Hydrocarbon Occurrence in the Southern Appalachian Basin in Eastern Tennessee, Southwestern Virginia, Eastern Kentucky, and Southern West Virginia

    SciTech Connect

    Robert D. Hatcher

    2004-05-31

    This report summarizes the second-year accomplishments of a three-year program to investigate the geologic controls of hydrocarbon occurrence in the southern Appalachian basin in eastern Tennessee, southwestern Virginia, eastern Kentucky, and southern West Virginia. The project: (1) employs the petroleum system approach to understand the geologic controls of hydrocarbons; (2) attempts to characterize the T-P parameters driving petroleum evolution; (3) attempts to obtain more quantitative definitions of reservoir architecture and identify new traps; (4) is working with USGS and industry partners to develop new play concepts and geophysical log standards for subsurface correlation; and (5) is geochemically characterizing the hydrocarbons (cooperatively with USGS). Second-year results include: All current milestones have been met and other components of the project have been functioning in parallel toward satisfaction of year-3 milestones. We also have been effecting the ultimate goal of the project in the dissemination of information through presentations at professional meetings, convening a major workshop in August 2003, and the publication of results. Our work in geophysical log correlation in the Middle Ordovician units is bearing fruit in recognition that the criteria developed locally in Tennessee and southern Kentucky have much greater extensibility than anticipated earlier. We have identified a major 60 mi-long structure in the western part of the Valley and Ridge thrust belt that is generating considerable exploration interest. If this structure is productive, it will be one of the largest structures in the Appalachians. We are completing a more quantitative structural reconstruction of the Valley and Ridge than has been made before. This should yield major dividends in future exploration in the southern Appalachian basin. Our work in mapping, retrodeformation, and modeling of the Sevier basin is a major component of the understanding of the Ordovician

  4. Intraplate compressional deformation in West-Congo and the Congo basin: related to ridge-puch from the South Atlantic spreading ridge?

    NASA Astrophysics Data System (ADS)

    Delvaux, Damien; Everaerts, Michel; Kongota Isasi, Elvis; Ganza Bamulezi, Gloire

    2016-04-01

    After the break-up and separation of South America from Africa and the initiation of the South-Atlantic mid-oceanic ridge in the Albian, at about 120 Ma, ridge-push forces started to build-up in the oceanic lithosphere and were transmitted to the adjacent continental plates. This is particularly well expressed in the passive margin and continental interior of Central Africa. According to the relations of Wiens and Stein (1985) between ridge-push forces and basal drag in function of the lithospheric age of oceanic plates, the deviatoric stress reaches a compressional maximum between 50 and 100, Ma after the initiation of the spreading ridge, so broadly corresponding to the Paleocene in this case (~70-20 Ma). Earthquake focal mechanism data show that the West-Congo margin and a large part of the Congo basin are still currently under compressional stresses with an horizontal compression parallel to the direction of the active transform fracture zones. We studied the fracture network along the Congo River in Kinshasa and Brazzaville which affect Cambrian sandstones and probably also the late Cretaceous-Paleocene sediments. Their brittle tectonic evolution is compatible with the buildup of ridge-push forces related to the South-Atlantic opening. Further inland, low-angle reverse faults are found affecting Jurassic to Middle Cretaceous cores from the Samba borehole in the Congo basin and strike-slip movements are recorded as a second brittle phase in the Permian cores of the Dekese well, at the southern margin of the Congo basin. An analysis of the topography and river network of the Congo basin show the development of low-amplitude (50-100 m) long wavelengths (100-300 km) undulations that can be interpreted as lithospheric buckling in response to the compressional intraplate stress field generated by the Mid-Atlantic ridge-push. Wiens, D.A., Stein, S., 1985. Implications of oceanic intraplate seismicity for plate stresses, driving forces and theology. Tectonophysics

  5. Assessment of the health status of wild fish inhabiting a cotton basin heavily impacted by pesticides in Benin (West Africa).

    PubMed

    Agbohessi, Prudencio T; Imorou Toko, Ibrahim; Ouédraogo, Alfred; Jauniaux, Thierry; Mandiki, S N M; Kestemont, Patrick

    2015-02-15

    To determine the impact of agricultural pesticides used in cotton cultivation on the health status of fish living in a Beninese cotton basin, we compared the reproductive and hepatic systems of fish sampled from rivers located in both contaminated and pristine conditions. Different types of biomarkers, including biometric indices (a condition factor K, a gonadosomatic index GSI, and a hepatosomatic index HSI), plasma levels of sex steroids (11-ketotestosterone 11-KT, testosterone T and estradiol-17β E2) and the histopathology of the gonads and liver, were investigated for two different trophic levels of the following two fish species: the Guinean tilapia Tilapia guineensis and the African catfish Clarias gariepinus. The fish were captured during both the rainy season (when there is heavy use of pesticides on cotton fields) and the dry season from one site, in Pendjari River (reference site), which is located outside the cotton-producing basin, and from three other sites on the Alibori River within the cotton-producing basin. Comparing fish that were sampled from contaminated (high levels of endosulfan, heptachlor and DDT and metabolites) and reference sites, the results clearly indicated that agricultural pesticides significantly decreased K and GSI while they increased HSI, regardless of the season, species and sex of the fish. These pesticides also induced a decrease in the plasma levels of 11-KT and T and increased those of E2. The histopathology of the testes revealed, in both species, a high rate of testicular oocytes, up to 50% in the African catfish, downstream of the Alibori River, which indicated estrogenic effects from the pesticides. The disruption of male spermatogenesis primarily included necrosis, fibrosis and the presence of foam cells in the lobular lumen. The histopathology of the ovaries revealed high levels of pre-ovulatory follicular atresia, impaired oogenesis, a decrease in the oocyte vitellogenic diameter and other lesions, such as fibrosis

  6. Water quality in the Allegheny and Monongahela River basins, Pennsylvania, West Virginia, New York, and Maryland, 1996-98

    USGS Publications Warehouse

    Anderson, Robert M.; Beer, Kevin M.; Buckwalter, Theodore F.; Clark, Mary E.; McAuley, Steven D.; Sams, James I.; Williams, Donald R.

    2000-01-01

    Major influences and findings for ground water quality, surface water quality, and biology in the Allegheny and Monongahela River basins are described and illustrated. Samples were collected in a variety of media to determine trace elements, sulfate, pesticides, nitrate, volatile organic compounds, organochlorine compounds, and radon-222. This report discusses the influences of several land-use practices, such as coal mining, urbanization, agriculture, and forestry. The report also includes a summary of a regional investigation of water quality and quality invertebrates in the Northern and Central Appalachian coal regions.

  7. Paleoecological studies at Lake Patzcuaro on the west-central Mexican Plateau and at Chalco in the basin of Mexico

    USGS Publications Warehouse

    Watts, W.A.; Bradbury, J.P.

    1982-01-01

    A 1520-cm sediment core from Lake Patzcuaro, Michoacan, Mexico, is 44,000 yr old at the base. All parts of the core have abundant pollen of Pinus (pine), Alnus (alder), and Quercus (oak) with frequent Abies (fir). The interval dated from 44,000 to 11,000 yr ago has a homogeneous flora characterized by abundant Juniperus (juniper) pollen and frequent Artemisia (sagebrush). It is believed to represent an appreciably drier and colder climate than at present. The Holocene at Lake Patzcuaro is characterized by a moderate increase in Pinus pollen and the loss of Juniperus pollen, as the modern type of climate succeeded. Alnus was abundant until about 5000 yr ago; its abrupt decrease with the first appearance of herbaceous weed pollen may reflect the cutting of lake-shore and stream-course alder communities for agricultural purposes, or it may simply reflect a drying tendency in the climate. Pollen of Zea (corn) appears at Lake Patzcuaro along with low peaks of chenopod and grass pollen at 3500 yr B.P. apparently recording a human population large enough to modify the natural environment, as well as the beginning of agriculture. A rich aquatic flora in this phase suggests eutrophication of the lake by slope erosion. In the most recent period corn is absent from the sediments, perhaps reflecting a change in agricultural practices. The environment changes at Lake Patzcuaro are similar to and correlate with those in the Cuenca de Mexico, where diatom stratigraphy from the Chalco basin indicates fluctuations in lake levels and lake chemistry in response to variations in available moisture. Before 10,000 yr ago climates there were cool and dry, and the Chalco basin was occupied by a shallow freshwater marsh that drained north to Lake Texcoco, where saline water accumulated by evaporation. Increases in effective moisture and possible melting of glaciers during the Holocene caused lake levels to rise throughout the Cuenca de Mexico, and Lake Texcoco flooded the Chalco basin with

  8. Magnitudes, nature, and effects of point and nonpoint discharges in the Chattahoochee River basin, Atlanta to West Point Dam, Georgia

    USGS Publications Warehouse

    Stamer, J.K.; Cherry, R.N.; Faye, R.E.; Kleckner, R.L.

    1978-01-01

    On an average annual basis and during the storm period of March 12-15, 1976, nonpoint-source loads for most constituents were larger than point-source loads at the Whitesburg station, located on the Chattahoochee River about 40 miles downstream from Atlanta, GA. Most of the nonpoint-source constituent loads in the Atlanta to Whitesburg reach were from urban areas. Average annual point-source discharges accounted for about 50 percent of the dissolved nitrogen, total nitrogen, and total phosphorus loads and about 70 percent of the dissolved phosphorus loads at Whitesburg. During a low-flow period, June 1-2, 1977, five municipal point-sources contributed 63 percent of the ultimate biochemical oxygen demand, and 97 percent of the ammonium nitrogen loads at the Franklin station, at the upstream end of West Point Lake. Dissolved-oxygen concentrations of 4.1 to 5.0 milligrams per liter occurred in a 22-mile reach of the river downstream from Atlanta due about equally to nitrogenous and carbonaceous oxygen demands. The heat load from two thermoelectric powerplants caused a decrease in dissolved-oxygen concentration of about 0.2 milligrams per liter. Phytoplankton concentrations in West Point Lake, about 70 miles downstream from Atlanta, could exceed three million cells per millimeter during extended low-flow periods in the summer with present point-source phosphorus loads. (Woodard-USGS)

  9. Sedimentary characteristics of carbonate intra-platform shoals and their formation in Ordovician Tarim Basin, West China

    NASA Astrophysics Data System (ADS)

    Meng, M.

    2015-12-01

    The widely distributed carbonate intra-platform shoals has become a new important exploration target within the Tarim Basin, where reservoirs of Yubei oil-field (discovered in 2011) and the Shunnan oil-field (discovered in 2013) occur. Better understanding of the sedimentary characteristics and formation of intra-platform shoals is significant for predicting the distribution of Ordovician shoal reservoirs. The sedimentary characteristics, distribution patterns and formation mechanisms of carbonate intra-platform shoals in Ordovician Tarim Basin were studied based on outcrop analogue, core data, thin section observation, seismic, and well log data. Those shoals include oolitic shoal, intraclast shoal and bioclastic shoal. The intra-platform shoal consists of three sedimentary units: shoal base, shoal core and shoal cover, which are adjacent to intershoal sea faces. Laterally, the intra-platform shoals occurred as a more continuous sheet-like body.The intra-platform shoals deposited mainly in the lowstand systems tract and late stage of highstand systems tract. Several factors were probably responsible for the occurrence of intra-platform shoals, including: (i) a relatively shallow-water condition with a strong hydrodynamic environment, (ii) high-frequency oscillations of the sea level, and (iii) Subtle paleo-highs and relatively weak structural activities, which are important for the spatial distribution of reservoir facies.

  10. A Remote Sensing-Based Land Surface Phenology Application for Cropland Monitoring in the Volta River Basin of West Africa

    NASA Astrophysics Data System (ADS)

    Abd Salam El Vilaly, Mohamed; El Vilaly, Audra; Badiane, Ousmane

    2015-04-01

    Understanding the complex feedbacks between climate, environmental change, and human activities is essential to the development of sustainable agricultural systems. A key aspect of crop production that shows immediate response to climate change is crop phenology, which defines the shape and progress of the growing season and is an integrator of all environmental factors controlling crop production. This research aims to characterize remote sensing-based land surface phenology of cropped areas and compare them to the actual crop growing seasons recorded by farmers: planting, emergences, flowering, fruiting, and harvest date. We use the 2000-2013 MODIS Terra 16-day record of vegetation index to extract 4 phenometrics (Start and Length of Growing Season, Date of Growing Season Peak, and the Growing Season Cumulative Signal). Most of these metrics are simple time-related phenometrics. A spatiotemporal phenological characterization of cropped/managed lands in the basin already shows distinct response patterns and trajectories along climate gradients. This permits us to monitor cropped lands and their responses to disturbances, such as drought, fire, flooding, and human activities. In turn, interviewing farmers in the basin and consulting their phenological records. This study will allow for robust validation of remote sensing LSP algorithms, and more crucially, will help characterize any remote sensing-based metrics that contrast with the actual biological phenophases of monitored crops. In terms of its larger significance, this study demonstrates the fundamental role that remote sensing plays in global agriculture in informing conservation and management practices.

  11. The 2004 Sumatra Earthquake and Tsunami: Lessons Learned in Subduction Zone Science and Emergency Management for the Cascadia Subduction Zone

    NASA Astrophysics Data System (ADS)

    Cassidy, John F.

    2015-03-01

    The 26 December 2004, Mw 9.3 Sumatra earthquake and tsunami was a pivotal turning point in our awareness of the dangers posed by subduction zone earthquakes and tsunamis. This earthquake was the world's largest in 40 years, and it produced the world's deadliest tsunami. This earthquake ruptured a subduction zone that has many similarities to the Cascadia Subduction Zone. In this article, I summarize lessons learned from this tragedy, and make comparisons with potential rupture characteristics, slip distribution, deformation patterns, and aftershock patterns for Cascadia using theoretical modeling and interseismic observations. Both subduction zones are approximately 1,100-1,300 km in length. Both have similar convergence rates and represent oblique subduction. Slip along the subduction fault during the 26 December earthquake is estimated at 15-25 m, similar to values estimated for Cascadia. The width of the rupture, ~80-150 km estimated from modeling seismic and geodetic data, is similar to the width of the "locked and transition zone" estimated for Cascadia. Coseismic subsidence of up to 2 m along the Sumatra coast is also similar to that predicted for parts of northern Cascadia, based on paleoseismic evidence. In addition to scientific lessons learned, the 2004 tsunami provided many critical lessons for emergency management and preparedness. As a result of that tragedy, a number of preparedness initiatives are now underway to promote awareness of earthquake and tsunami hazards along the west coast of North America, and plans are underway to develop prototype tsunami and earthquake warning systems along Cascadia. Lessons learned from the great Sumatra earthquake and tsunami tragedy, both through scientific studies and through public education initiatives, will help to reduce losses during future earthquakes in Cascadia and other subduction zones of the world.

  12. Using a spatio-temporal dynamic state-space model with the EM algorithm to patch gaps in daily riverflow series, with examples from the Volta Basin, West Africa

    NASA Astrophysics Data System (ADS)

    Amisigo, B. A.; van de Giesen, N. C.

    2005-04-01

    A spatio-temporal linear dynamic model has been developed for patching short gaps in daily river runoff series. The model was cast in a state-space form in which the state variable was estimated using the Kalman smoother (RTS smoother). The EM algorithm was used to concurrently estimate both parameter and missing runoff values. Application of the model to daily runoff series in the Volta Basin of West Africa showed that the model was capable of providing good estimates of missing runoff values at a gauging station from the remaining series at the station and at spatially correlated stations in the same sub-basin.

  13. A Reconnaissance for Emerging Contaminants in the South Branch Potomac River, Cacapon River, and Williams River Basins, West Virginia, April-October 2004

    USGS Publications Warehouse

    Chambers, Douglas B.; Leiker, Thomas J.

    2006-01-01

    In 2003 a team of scientists from West Virginia Division of Natural Resources and the U. S. Geological Survey found a high incidence of an intersex condition, oocytes in the testes, among smallmouth bass (Micropterus dolomieu) in the South Branch Potomac River and the Cacapon River of West Virginia, indicating the possible presence of endocrine-disrupting compounds (EDCs). Possible sources of EDCs include municipal and domestic wastewater, and agricultural and industrial activities. Several sampling strategies were used to identify emerging contaminants, including potential EDCs, and their possible sources in these river basins and at an out-of-basin reference site. Passive water-sampling devices, which accumulate in-stream organic chemical compounds, were deployed for 40-41 days at 8 sampling sites. Sampler extracts were analyzed for a broad range of polar and non-polar organic compounds including pesticides, flame retardants, pharmaceuticals, and personal-care products. Analysis of passive-sampler extracts found 4 compounds; hexachloro-benzene; pentachloroanisole; 2,2',4,4',5-penta-bromo-diphenyl ether (BDE 47); and 2,2',4,4',6-penta-bromo-diphenyl ether (BDE 99) to be present at every sampled site, including the reference site, and several sites had detectable quantities of other compounds. No detectable quantity of any antibiotics was found in any passive-sampler extract. Effluent samples were analyzed for 39 antibiotics as tracers of human and agricultural waste. Additionally, poultry-processing plant effluent was sampled for roxarsone, an organoarsenic compound used as a poultry-feed additive, and other arsenic species as tracers of poultry waste. Antibiotics were detected in municipal wastewater, aquaculture, and poultry-processing effluent, with the highest number of antibiotics and the greatest concentrations found in municipal effluent. Arsenate was the only arsenic species detected in the poultry-processing plant effluent, at a concentration of 1.0 ?g

  14. Permian paleogeography of west-central Pangea: Reconstruction using sabkha-type gypsum-bearing deposits of Parnaíba Basin, Northern Brazil

    NASA Astrophysics Data System (ADS)

    Abrantes, Francisco R.; Nogueira, Afonso C. R.; Soares, Joelson L.

    2016-07-01

    Extreme aridity during Late Permian - Early Triassic period was the main factor for resetting the entire paleoclimate of the planet. Permian evaporite basins and lacustrine red beds were widely distributed along the supercontinent of Pangea. Sulphate deposits in Western Pangea, particularly in Northern Brazil, accumulated in an extensive playa lake system. Outcrop-based facies and stratigraphic analysis of up to 20 m thick evaporite-siliciclastic deposits reveal the predominance of laminated reddish mudstone with subordinate limestone, marl and lenses of gypsum. The succession was deposited in shallow lacustrine and inland sabkha environments associated with saline pans and mudflats. Gypsum deposits comprise six lithofacies: 1) bottom-growth gypsum, 2) nodular/micronodular gypsum, 3) mosaic gypsum, 4) fibrous/prismatic gypsum, 5) alabastrine gypsum, and 6) rosettes of gypsum. Gypsum types 1 and 2 are interpreted as primary deposition in saline pans. Bottom-growth gypsum forms grass-like crusts while nodular/micronodular gypsum indicates displacive precipitation of the crust in shallow water and the groundwater capillary zone. Types 3 and 4 are early diagenetic precipitates. Abundant inclusions of tiny lath-like anhydrite crystals suggest a primary origin of anhydrite. Alabastrine gypsum, fibrous gypsum (satinspar) and rosettes of gypsum probably derived from near-surface hydration of anhydrite. The gypsum-bearing deposits in the Parnaíba Basin contribute towards understanding paleogeographic changes in Western Pangea. A progressive uplift of East Pangea, culminated in the forced regression and retreat of epicontinental seas to the West. Restricted seas or large lakes were formed before the definitive onset of desert conditions in Pangea, leading to the development of extensive ergs.

  15. Karst development in the Tobosa basin (Ordovician-Devonian) strata in the El Paso border region of west Texas

    SciTech Connect

    Lemone, D.V. . Dept. of Geological Sciences)

    1993-02-01

    Karst development within the Tobosa basin strata in the El Paso border region is best displayed during two time intervals: Middle Ordovician (27 Ma) developed on the Lower Ordovician El Paso Group and Middle Silurian to Middle Devonian (40 Ma) karst developed on the Lower-Middle Fusselman Formation. These major exposure intervals are recognized in regional outcrops as well as in the subsurface of the Permian Basin where they form major reservoirs. Minor local karsting is noted also within and upon the Upper Ordovician (Montoya Group) and within the shoaling upward members of overlying the Fusselman Formation. Middle Ordovician karsting with major cavern development extends down into McKellingon Canyon Formation approximately 1,000 feet below the top of the Lower Ordovician El Paso Group. The McKellingon is overlain by the cavern roof-forming early diagenetic dolomites, lower Scenic Drive Formation which in turn is overlain by the locally karsted upper Scenic Drive and Florida Mountains formations. Collapse of the overlying Montoya Group into El Paso Group rocks is observed. The Fusselman Formation rests disconformably on the Montoya Group. It is a massive, vuggy, fine- to coarsely-crystalline, whitish dolomite. Extensive karsting has developed on the top of the Fusselman. The middle Devonian Canutillo Formation with a basal flooding deposit overlies this karst surface. Minor karsting following fracture systems extends from the major karst of the El Paso Group up into the major karst in the Fusselman. The karst seems to be following and developing along the same linear fracture systems. If so, it is not unreasonable to interpret these fracture systems as being inherited from the earlier Precambrian structures underlying them.

  16. Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian Basin from Medina County, Ohio, through southwestern and south-central Pennsylvania to Hampshire County, West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.; Harris, Anita G.; Repetski, John E.; revised and digitized by Crangle, Robert D.

    2003-01-01

    A 275-mi-long restored stratigraphic cross section from Medina County, Ohio, through southwestern and south-central Pennsylvania to Hampshire County, W. Va., provides new details on Cambrian and Ordovician stratigraphy in the central Appalachian basin and the structure of underlying Precambrian basement rocks. From west to east, the major structural elements of the block-faulted basement in this section are (1) the relatively stable, slightly extended craton, which includes the Wooster arch, (2) the fault-controlled Ohio-West Virginia hinge zone, which separates the craton from the adjoining Rome trough, (3) the Rome trough, which consists of an east-facing asymmetric graben and an overlying sag basin, and (4) a positive fault block, named here the South-central Pennsylvania arch, which borders the eastern margin of the graben part of the Rome trough. Pre-Middle Ordovician structural relief on Precambrian basement rocks across the down-to-the-west normal fault that separates the Rome trough and the adjoining South-central Pennsylvania arch amounted to between 6,000 and 7,000 ft. The restored cross section shows eastward thickening of the Cambrian and Ordovician sequence from about 3,000 ft near the crest of the Wooster arch at the western end of the section to about 5,150 ft at the Ohio-West Virginia hinge zone adjoining the western margin of the Rome trough to about 19,800 ft near the depositional axis of the Rome trough. East of the Rome trough, at the adjoining western edge of the South-central Pennsylvania arch, the Cambrian and Ordovician sequence thins abruptly to about 13,500 ft and then thins gradually eastward across the arch to about 12,700 ft near the Allegheny structural front and to about 10,150 ft at the eastern end of the restored section. In general, the Cambrian and Ordovician sequence along this section consists of four major lithofacies that are predominantly shallow marine to peritidal in origin. In ascending stratigraphic order, the lithofacies

  17. Simulation of storm peaks and storm volumes for selected subbasins in the West Fork Trinity River Basin, Texas, water years 1993-94

    USGS Publications Warehouse

    Raines, T.H.

    1996-01-01

    A model parameter set for use with the Hydrologic Simulation Program FORTRAN watershed model was developed to simulate storm peaks and storm volumes for the 28 subbasins of the West Fork Trinity River Basin upstream from Lake Worth, northwest of Fort Worth, Texas, from the calibration and testing of 5 gaged subbasins. These parameters can be transferred to the 23 ungaged subbasins. The model simulates storm runoff for a channel-routing model that can be used to improve reservoir operation during floods in the basin. Rainfall and runoff data were collected from October 1, 1992, to September 30, 1994. A total of 55 storms were recorded at the 5 streamgage stations during the 24 months. Twelve different pervious land segments were defined based on types of soil, land cover, and watershed slope. A total of 20 process-related parameters were defined for each land segment, and 6 basin-related parameters were defined for each stream reach. The mean absolute errors for the 5 subbasins for simulation of storm peaks range from 48.0 to 470 percent and for simulation of storm volumes range from 34.4 to 416 percent. A sensitivity analysis was done to determine what a change in a parameter value has on the largest storm peak and on the total storm volume. The model then was recalibrated and tested on the basis of the analysis of the sensitivity of parameters and on the analysis of the errors from the initial model calibration and testing. The mean absolute errors for the 5 subbasins using the recalibrated parameters for simulation of storm peaks range from 47.1 to 297 percent, and for simulation of storm volumes range from 27.6 to 193 percent. The model produced better results for simulation of the larger storm peaks and storm volumes than for simulation of the smaller storm peaks and storm volumes, especially after an extended period of no runoff. The same range in errors can be expected when transferring the parameters to the 23 ungaged subbasins. Additional data collection

  18. Lateglacial and Early Holocene vegetation history of the northern Wetterau and the Amöneburger Basin (Hessen), central-west Germany.

    PubMed

    Bos, J A.A.

    2001-06-01

    The Lateglacial and Early Holocene vegetation history of the northern Wetterau and Amöneburger Basin, two intra-montane basins in Hessen, central-west Germany, is reconstructed by means of pollen and macrofossil analyses. Regional pollen assemblage zones are defined for the Lateglacial and Early Holocene. After calibration of the radiocarbon dates and establishment of age/depth relationships, the ages of the pollen zone boundaries are calculated. The regional vegetation changes correlate closely with the major fluctuations in the delta18O curve of the Greenland ice cores spanning the same time period. During the early Lateglacial, the open herbaceous vegetation with dwarf shrubs in the northern Wetterau was replaced by woodlands. Initially these woodlands consisted of birch, but after the immigration of pine, mixed forests of pine and birch developed. Soon after its immigration pine became dominant and pine woodlands largely replaced the birch forests. Only on the locally wetter substrates of the river floodplain did Betula stands persist. Gradually the importance of herbaceous communities declined and the pine woodlands lost their open character. During the Lateglacial two regressive phases in the vegetation succession are reflected in the data which are equated with the Older- and Younger Dryas biozones. At the beginning of the Younger Dryas, the forest-limit was lowered and the importance of herbaceous communities increased. Later, pine woodlands thinned and Ericales became part of the vegetation, indicating the development of more acid, nutrient-poor soils. A subdivision of the Younger Dryas biozone into a wetter, colder first part and a drier, warmer second part is suggested. At the beginning of the Early Holocene, pine woodlands became more closed and soils more stabilised. The transition between the Younger Dryas and Preboreal biozones is indicated by a lithological change to organic (-rich) deposits. Betula stands persisted on the locally wetter substrates

  19. Eocene Total Petroleum System -- North and East of the Eocene West Side Fold Belt Assessment Unit of the San Joaquin Basin Province: Chapter 19 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Gautier, Donald L.; Hosford Scheirer, Allegra

    2009-01-01

    The North and East of Eocene West Side Fold Belt Assessment Unit (AU) of the Eocene Total Petroleum System of the San Joaquin Basin Province comprises all hydrocarbon accumulations within the geographic and stratigraphic limits of this confirmed AU. Oil and associated gas accumulations occur in Paleocene through early middle Miocene marine to nonmarine sandstones found on the comparatively stable northeast shelf of the basin. The assessment unit is located north and east of the thickest accumulation of Neogene sediments and the west side fold belt. The area enclosed by the AU has been affected by only mild deformation since Eocene time. Traps containing known accumulations are mostly low-relief domes, anticlines, and up-dip basin margin traps with faulting and stratigraphic components. Map boundaries of the assessment unit are shown in figures 19.1 and 19.2; this assessment unit replaces the Northeast Shelf of Neogene Basin play 1006, the East Central Basin and Slope North of Bakersfield Arch play 1010, and part of the West Side Fold Belt Sourced by Pre-middle Miocene Rocks play 1005 considered by the U.S. Geological Survey (USGS) in their 1995 National Assessment (Beyer, 1996). Stratigraphically, the AU includes rocks from the uppermost crystalline basement to the topographic surface. In the region of overlap with the Central Basin Monterey Diagenetic Traps Assessment Unit, the North and East of Eocene West Side Fold Belt AU extends from basement rocks to the top of the Temblor Formation (figs. 19.3 and 19.4). In map view, the northern boundary of the assessment unit corresponds to the northernmost extent of Eocene-age Kreyenhagen Formation. The northeast boundary is the eastern limit of possible oil reservoir rocks near the eastern edge of the basin. The southeast boundary corresponds to the pinch-out of Stevens sand of Eckis (1940) to the south, which approximately coincides with the northern flank of the Bakersfield Arch (fig. 19.1). The AU is bounded on the

  20. Joint development and tectonic stress field evolution in the southeastern Mesozoic Ordos Basin, west part of North China

    NASA Astrophysics Data System (ADS)

    Jiang, Lin; Qiu, Zhen; Wang, Qingchen; Guo, Yusen; Wu, Chaofan; Wu, Zhijie; Xue, Zhenhua

    2016-09-01

    Major joint sets trending E-W (J1), ENE-WSW (J2), NE-SW (J3), N-S (J4), NNW-SSE (J5), NNE-SSW (J6), NW-SE (J7), and WNW-ESE (J8) respectively are recognized in Mesozoic strata within the southeast of Ordos Basin. Among them, the J1, J2 and J3 joint sets are systematic joints, while the other five joint sets (J4, J5, J6, J7, J8) are nonsystematic joints. There are three groups of orthogonal joint systems (i.e. J1 and J4 sets, J2 and J5 sets, and J6 and J8 sets) and two groups of conjugate shear fractures (ENE-WSW and NNE-SSW, ENE-WSW and ESE-WNW) in the study area. Joint spacing analysis indicates that: (1) layer thickness has an effect on the joint spacing, but the correlation of joint spacing and layer thickness is low; (2) joint density of systematic joints is greater than nonsystematic joints, and the joint density of a thin layer is also greater than that of a thick layer; and (3) the joints of Mesozoic strata in the basin are the result of tectonic events affected by multiple stress fields. All these joints in the Mesozoic strata are formed in the two main tectonic events since Late Mesozoic times. One is the westward subduction of the Pacific Plate beneath the Eurasia Plate, which formed the approximately E-W-trending compressive stress field in the China continent. The trends of the J1 joint set (E-W) and the bisector of conjugate shear fractures composed of ENE-WSW and ESE-WNW fractures are all parallel to the trend of maximum compressive stress (E-W). The other stress field is related to the collision of the Indian and Eurasian Plates, which formed the NE-SW-trending compressive stress field in the China continent. The trends of the J3 joint set and bisector of conjugate shear fractures composed of ENE-WSW and NNE-SSW fractures are all parallel to the trend of maximum compressive stress (NE-SW). Finally, we conclude that the J1 and J4 sets are formed in the E-W-trending compressive stress field, and the J2, J3, J5, J6, J7 and J8 sets are formed in the NE

  1. Potential for pollution of the Upper Floridan aquifer from five sinkholes and an internally drained basin in west-central Florida

    USGS Publications Warehouse

    Trommer, J.T.

    1987-01-01

    Sinkholes are natural and common geologic features in west-central Florida, which is underlain by water soluble limestone deposits. Dissolution of these deposits is the fundamental cause of sinkhole development. Sinkholes and other karst features are more pronounced in the northern part of the study area, but sinkhole activity has occurred throughout the area. Fifty-eight sinkholes with known or suspected connection to the Upper Floridan aquifer are located in the study area. An internally drained basin near the city of Brandon and five sinkholes in Hillsborough, Pasco, and Hernando Counties were selected for detailed investigation. At all sites, chemical or biological constituents were detected that indicate pollutants had entered the aquifer. A generalized classification, based on the potential to pollute, was applied to the selected sites. Four of the sites have high potential and two have moderate potential to pollute the Upper Floridan aquifer. All of the sites investigated are capable of recharging large volumes of water to the Upper Floridan aquifer in short periods of time. Continued monitoring of the quality of water entering the sinkholes and of wells downgradient to the sinks is needed to assess the future impacts on the aquifer. (Author 's abstract)

  2. Geologic, hydrologic, and water-quality data from multiple-well monitoring sites in the Central and West Coast basins, Los Angeles County, California, 1995-2000

    USGS Publications Warehouse

    Land, Michael; Everett, R.R.; Crawford, S.M.

    2002-01-01

    In 1995, the U.S. Geological Survey (USGS), in cooperation with the HYPERLINK 'http://wrd.org' Water Replenishment District of Southern California (WRDSC), began a study to examine ground-water resources in the Central and West Coast Basins in Los Angeles County, California. The study characterizes the geohydrology and geochemistry of the regional ground-water flow system and provides extensive data for evaluating ground-water management issues. This report is a compilation of geologic, hydrologic, and water-quality data collected from 24 recently constructed multiple-well monitoring sites for the period 1995?2000. Descriptions of the collected drill cuttings were compiled into lithologic logs, which are summarized along with geophysical logs?including gamma-ray, spontaneous potential, resistivity, electromagnetic induction, and temperature tool logs?for each monitoring site. At selected sites, cores were analyzed for magnetic orientation, physical and thermal properties, and mineralogy. Field and laboratory estimates of hydraulic conductivity are presented for most multiple-well monitoring sites. Periodic water-level measurements are also reported. Water-quality information for major ions, nutrients, trace elements, deuterium and oxygen-18, and tritium is presented for the multiple-well monitoring locations, and for selected existing production and observation wells. In addition, boron-11, carbon-13, carbon-14, sulfur-34, and strontium-87/86 data are presented for selected wells.

  3. Depositional dynamics in a river diversion receiving basin: The case of the West Bay Mississippi River Diversion

    NASA Astrophysics Data System (ADS)

    Kolker, Alexander S.; Miner, Michael D.; Weathers, H. Dallon

    2012-06-01

    River deltas are a globally distributed class of sedimentary environment that are highly productive, ecologically diverse and serve as centers for population and commerce. Many deltas are also in a state of environmental degradation, and the Mississippi River Delta (MRD) stands out as a particularly iconic example. Plans to restore the MRD call for partially diverting the Mississippi River, which should reinitiate natural deltaic land-building processes. While the basic physical underpinnings of river diversions are relatively straightforward, there exists a considerable controversy over whether diversions can and do deliver enough sediment to the coastal zone to build sub-aerial land on restoration-dependent time scales. This controversy was addressed through a study of crevasse-splay dynamics at the West Bay Mississippi River Diversion, the largest diversion in the MRD that was specifically constructed for coastal restoration. We found that most sediments were distributed over a 13.5 km area, with the maximum deposition occurring at the seaward end of this field. These results indicate substantial sediment deposition downstream of project boundaries and run counter to simple sedimentary models, which predict that maximum sediment deposition should occur closest to the riverbank. Despite this, most sediments appear to be retained in the nearshore zone, suggesting that the sediment retention efficiency was at the higher end of the 30-70% range suggested by some sediment budgets.

  4. Geochemical evolution of groundwater in southern Bengal Basin: The example of Rajarhat and adjoining areas, West Bengal, India

    NASA Astrophysics Data System (ADS)

    Sahu, Paulami; Sikdar, P. K.; Chakraborty, Surajit

    2016-02-01

    Detailed geochemical analysis of groundwater beneath 1223 km2 area in southern Bengal Basin along with statistical analysis on the chemical data was attempted, to develop a better understanding of the geochemical processes that control the groundwater evolution in the deltaic aquifer of the region. Groundwater is categorized into three types: `excellent', `good' and `poor' and seven hydrochemical facies are assigned to three broad types: `fresh', `mixed' and `brackish' waters. The `fresh' water type dominated with sodium indicates active flushing of the aquifer, whereas chloride-rich `brackish' groundwater represents freshening of modified connate water. The `mixed' type groundwater has possibly evolved due to hydraulic mixing of `fresh' and `brackish' waters. Enrichment of major ions in groundwater is due to weathering of feldspathic and ferro-magnesian minerals by percolating water. The groundwater of Rajarhat New Town (RNT) and adjacent areas in the north and southeast is contaminated with arsenic. Current-pumping may induce more arsenic to flow into the aquifers of RNT and Kolkata cities. Future large-scale pumping of groundwater beneath RNT can modify the hydrological system, which may transport arsenic and low quality water from adjacent aquifers to presently unpolluted aquifer.

  5. Geologic Controls of Hydrocarbon Occurrence in the Southern Appalachian Basin in Eastern Tennessee, Southwestern Virginia, Eastern Kentucky, and Southern West Virginia

    SciTech Connect

    Robert D. Hatcher

    2003-05-31

    This report summarizes the first-year accomplishments of a three-year program to investigate the geologic controls of hydrocarbon occurrence in the southern Appalachian basin in eastern Tennessee, southwestern Virginia, eastern Kentucky, and southern West Virginia. The project: (1) employs the petroleum system approach to understand the geologic controls of hydrocarbons; (2) attempts to characterize the T-P parameters driving petroleum evolution; (3) attempts to obtain more quantitative definitions of reservoir architecture and identify new traps; (4) is working with USGS and industry partners to develop new play concepts and geophysical log standards for subsurface correlation; and (5) is geochemically characterizing the hydrocarbons (cooperatively with USGS). First-year results include: (1) meeting specific milestones (determination of thrust movement vectors, fracture analysis, and communicating results at professional meetings and through publication). All milestones were met. Movement vectors for Valley and Ridge thrusts were confirmed to be west-directed and derived from pushing by the Blue Ridge thrust sheet, and fan about the Tennessee salient. Fracture systems developed during Paleozoic, Mesozoic, and Cenozoic to Holocene compressional and extensional tectonic events, and are more intense near faults. Presentations of first-year results were made at the Tennessee Oil and Gas Association meeting (invited) in June, 2003, at a workshop in August 2003 on geophysical logs in Ordovician rocks, and at the Eastern Section AAPG meeting in September 2003. Papers on thrust tectonics and a major prospect discovered during the first year are in press in an AAPG Memoir and published in the July 28, 2003, issue of the Oil and Gas Journal. (2) collaboration with industry and USGS partners. Several Middle Ordovician black shale samples were sent to USGS for organic carbon analysis. Mississippian and Middle Ordovician rock samples were collected by John Repetski (USGS) and

  6. Late Quaternary Uplift Rates and Geomorphology of the Santa Fe Springs and West Coyote Folds, Los Angeles Basin, California

    NASA Astrophysics Data System (ADS)

    Sundermann, S. T.; Mueller, K. J.

    2001-12-01

    We mapped Quaternary aquifers with water wells and 5 m DEM's from IFSAR to define rates of folding along the Puente Hills blind thrust system. A cross section across Santa Fe Springs along Carfax Ave suggests 100 and 165 m of uplift of the 330 ka Gage and 650 ka Lynwood aquifers, yielding uplift rates of 0.2 mm/yr between 330-650 ka and 0.27 mm/yr beween 0-330 ka. For a 27° thrust, this yields a slip rate of 0.44 - 0.59 mm/yr. Surface folding is discernable across the Santa Fe Springs segment in the DEM, to a point 4 km west of the San Gabriel River. Aquifers correlated with reflectors in a USGS seismic profile along Carfax suggests lower relief for the Lynwood (85 m) and the Gage (59 m). We suggest the 1 km-long USGS profile images only part of the fold limb and that additional structural relief is accommodated further north, as defined by our subsurface mapping. Correlation of a shallow reflector in the seismic profile with the 15-20 ka Gaspur aquifer suggests Holocene uplift of 1.0 mm/yr. A similar analysis undertaken for the Coyote fold near Trojan Ave. suggests 85 and 229 m of uplift for the Gage and Lynwood, yielding uplift rates of 0.26 mm/yr between 0-330 ka and 0.45 mm/yr between 330-650 ka. Correlation of the Gage with a reflector on another USGS seismic profile along Trojan suggests equivalent uplift (86 m), indicating the profile images the entire width of the Coyote forelimb at this site.

  7. Calcitization and silicification of evaporites in Guadalupian back-reef carbonates of the Delaware basin, west Texas and New Mexico

    SciTech Connect

    Ulmer, D.S.; Scholle, P.A. )

    1991-03-01

    Outcrop of the Seven Rivers, Yates, and Tansill formations contain numerous examples of evaporites that have been replaced by both quartz and calcite. The original evaporites consisted of discrete horizons, scattered nodules, enterolithic layers, and individual crystal laths of gypsum and/or anhydrite within a predominantly dolomitic matrix. Based on field and petrographic observations, evaporite replacement proceeded from the exterior to the interior of the nodules. The earliest replacement was by euhedral, black megaquartz containing abundant hydrocarbon inclusions. Calcite replacement followed silicification and consists of coarse, equant, blocky spar. Isotopic analyses of these calcites form two distinct groups: the first group ranges from -10.9 to -20.1{per thousand} (average -16.4{per thousand}) {delta}{sup 13}C and -6.4 to -13.8{per thousand} (average -10.9{per thousand}) {delta}{sup 18}O; the second group ranges from +1.4 to 5.8{per thousand} (average -2.4{per thousand}) {delta}{sup 13}C and -6.2 to 14.1{per thousand} (average -9.2{per thousand}) {delta}{sup 18}O. Evaporite silicification was coeval with hydrocarbon migration as indicated by the inclusion data. Calcitization, however, was associated with mid-Tertiary block faulting that uplifted the area causing deep groundwater circulation. The isotopically very light calcites resulted from the mixing of meteoric fluids and hydrocarbon-rich pore fluids, probably during early uplift while these strata were still at significant depth. The calcites with heavier isotopic values were produced somewhat later by meteoric fluids that had little or no contact with hydrocarbons. Evaporite diagenesis in the Delaware basin is an ongoing process that started during hydrocarbon migration, continued over millions of years, and has the potential to significantly change the porosity of these units.

  8. Analysis of afterslip and viscoelastic relaxation following the 2004 Sumatra-Andaman earthquake from GPS observations in northern Sumatra

    NASA Astrophysics Data System (ADS)

    Gunawan, E.; Sagiya, T.; Ito, T.; Kimata, F.; Tabei, T.; Ohta, Y.; Meilano, I.; Abidin, H. Z.; Agustan, A.; Nurdin, I.; Sugiyanto, D.

    2013-12-01

    Global Positioning System (GPS) data in northern Sumatra, Andaman Islands and Thailand provides an opportunity to understand the postseismic deformation associated with the 2004 Sumatra-Andaman earthquake. Previous study of postseismic deformation after the 2004 earthquake reached different conclusions, which attributed to different assumption on the postseismic deformation mechanisms. Also, previous studies use only a certain part (e.g. Andaman Islands only) of observations without investigating postseismic deformation data in northern Sumatra, which is close to the largest coseismic slip rupture of 2004 SAE. In this study, we tackle this problem by taking GPS data in northern Sumatra, Aceh GPS Network for Sumatran Fault System (AGNeSS), into account. AGNeSS data are important because of the following reasons: (1) The network is located in the near-field of the main slip patch of the 2004 SAE. (2) GPS measurements started a few months after the main shock, providing information of early postseismic deformation after the 2004 SAE. (3) Continuous GPS measurements provide a good control on both horizontal and vertical components. (4) GPS data have never been used in analyzing postseismic deformation. The continuous GPS data in northern Sumatra suggest that there are multiple physical mechanisms controls the postseismic deformation, that is afterslip and viscoelastic relaxation. In the first step, we search for the optimum rheology model by fitting vertical component with viscoelastic relaxation model, and consider residual is caused by an afterslip. Using the estimated rheology model, we calculate 'afterslip' displacements by subtracting predicted viscoelastic displacements from observed GPS data, and with these 'afterslip' displacements, we estimate afterslip distribution on the plate interface. Since in the first estimation of the rheology model analyzed displacement data contain afterslip effects, we then correct the afterslip contribution from the original

  9. An integrated geological and geophysical study of the Uinta Mountains, Utah, Colorado and a geophysical study on Tamarix in the Rio Grande River basin, West Texas

    NASA Astrophysics Data System (ADS)

    Khatun, Salma

    2008-07-01

    This research consists of two parts. One part deals with an integrated analysis of the structural anomaly associated with the Uinta Mountains, Utah. The other part deals with a study on the effect of Tamarix on soil and water quality. The Uinta Mountains are an anomalous east-west trending range of the Central Rocky Mountains and are located in northeastern Utah and northwestern Colorado. They have long been recognized as a structural anomaly that is surrounded by other Laramide structures that trend N-S or northwest. The study area extends from -112 to -108 degrees longitude and 41.5 to 39 degrees latitude and consists of three major geologic features: The Green River basin, Uinta Mountains, and the Uinta basin. This study investigates the tectonic evolution and the structural development of the Uinta aulacogen. There is a growing interest in exploration for petroleum and other hydrocarbons in the area of this study. Oil companies have been drilling wells in this area since the 1950's. The results of this study will enhance the existing knowledge of this region, and thus will help in the pursuit of hydrocarbons. A highly integrated approach was followed for this investigation. Gravity, magnetic, drill hole, seismic and receiver function data were used in the analysis. Gravity and magnetic data were analyzed using software tools available in the Department of Geological Sciences such as Oasis Montaj and GIS. Filtered gravity maps show that the Uinta Mountains and the surrounding basins and uplifts are deep seated features. These maps also reveal a correlation between the Uinta Mountains and the regional tectonic structures. This correlation helps in understanding how the different tectonic events that this region went through contributed to the different phases of development of the Uinta aulacogen. Four gravity models were generated along four north-south trending profile lines covering the target area from east to west. Interpretations of these models give a

  10. An integrated geological and geophysical study of the Uinta Mountains, Utah, Colorado and a geophysical study on Tamarix in the Rio Grande River basin, West Texas

    NASA Astrophysics Data System (ADS)

    Khatun, Salma

    2008-07-01

    This research consists of two parts. One part deals with an integrated analysis of the structural anomaly associated with the Uinta Mountains, Utah. The other part deals with a study on the effect of Tamarix on soil and water quality. The Uinta Mountains are an anomalous east-west trending range of the Central Rocky Mountains and are located in northeastern Utah and northwestern Colorado. They have long been recognized as a structural anomaly that is surrounded by other Laramide structures that trend N-S or northwest. The study area extends from -112 to -108 degrees longitude and 41.5 to 39 degrees latitude and consists of three major geologic features: The Green River basin, Uinta Mountains, and the Uinta basin. This study investigates the tectonic evolution and the structural development of the Uinta aulacogen. There is a growing interest in exploration for petroleum and other hydrocarbons in the area of this study. Oil companies have been drilling wells in this area since the 1950's. The results of this study will enhance the existing knowledge of this region, and thus will help in the pursuit of hydrocarbons. A highly integrated approach was followed for this investigation. Gravity, magnetic, drill hole, seismic and receiver function data were used in the analysis. Gravity and magnetic data were analyzed using software tools available in the Department of Geological Sciences such as Oasis Montaj and GIS. Filtered gravity maps show that the Uinta Mountains and the surrounding basins and uplifts are deep seated features. These maps also reveal a correlation between the Uinta Mountains and the regional tectonic structures. This correlation helps in understanding how the different tectonic events that this region went through contributed to the different phases of development of the Uinta aulacogen. Four gravity models were generated along four north-south trending profile lines covering the target area from east to west. Interpretations of these models give a

  11. Mathematical Understanding and Representation Ability of Public Junior High School in North Sumatra

    ERIC Educational Resources Information Center

    Minarni, Ani; Napitupulu, E. Elvis; Husein, Rahmad

    2016-01-01

    This paper is the result of first phase of the research about the development of students' mathematical understanding and representation ability through Joyful Problem-Based Learning (JPBL) at Public Junior High School in North Sumatra, Indonesia. The population is all of the students of public junior high school (PJHS) in North Sumatra. Samples…

  12. Demonstration optimization analyses of pumping from selected Arapahoe aquifer municipal wells in the west-central Denver Basin, Colorado, 2010–2109

    USGS Publications Warehouse

    Banta, Edward R.; Paschke, Suzanne S.

    2012-01-01

    Declining water levels caused by withdrawals of water from wells in the west-central part of the Denver Basin bedrock-aquifer system have raised concerns with respect to the ability of the aquifer system to sustain production. The Arapahoe aquifer in particular is heavily used in this area. Two optimization analyses were conducted to demonstrate approaches that could be used to evaluate possible future pumping scenarios intended to prolong the productivity of the aquifer and to delay excessive loss of saturated thickness. These analyses were designed as demonstrations only, and were not intended as a comprehensive optimization study. Optimization analyses were based on a groundwater-flow model of the Denver Basin developed as part of a recently published U.S. Geological Survey groundwater-availability study. For each analysis an optimization problem was set up to maximize total withdrawal rate, subject to withdrawal-rate and hydraulic-head constraints, for 119 selected municipal water-supply wells located in 96 model cells. The optimization analyses were based on 50- and 100-year simulations of groundwater withdrawals. The optimized total withdrawal rate for all selected wells for a 50-year simulation time was about 58.8 cubic feet per second. For an analysis in which the simulation time and head-constraint time were extended to 100 years, the optimized total withdrawal rate for all selected wells was about 53.0 cubic feet per second, demonstrating that a reduction in withdrawal rate of about 10 percent may extend the time before the hydraulic-head constraints are violated by 50 years, provided that pumping rates are optimally distributed. Analysis of simulation results showed that initially, the pumping produces water primarily by release of water from storage in the Arapahoe aquifer. However, because confining layers between the Denver and Arapahoe aquifers are thin, in less than 5 years, most of the water removed by managed-flows pumping likely would be supplied

  13. Products of Submarine Fountains and Bubble-burst Eruptive Activity at 1200 m on West Mata Volcano, Lau Basin

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Rubin, K. H.; Keller, N. S.

    2009-12-01

    An eruption was observed and sampled at West Mata Volcano using ROV JASON II for 5 days in May 2009 during the NSF-NOAA eruption response cruise to this region of suspected volcanic activity. Activity was focused near the summit at the Prometheus and Hades vents. Prometheus erupted almost exclusively as low-level fountains. Activity at Hades cycled between vigorous degassing, low fountains, and bubble-bursts, building up and partially collapsing a small spatter/scoria cone and feeding short sheet-like and pillow flows. Fire fountains at Prometheus produced mostly small primary pyroclasts that include Pele's hair and fluidal fragments of highly vesicular volcanic glass. These fragments have mostly shattered and broken surfaces, although smooth spatter-like surfaces also occur. As activity wanes, glow in the vent fades, and denser, sometimes altered volcanic clasts are incorporated into the eruption. The latter are likely from the conduit walls and/or vent-rim ejecta, drawn back into the vent by inrushing seawater that replaces water entrained in the rising volcanic plume. Repeated recycling of previously erupted materials eventually produces rounded clasts resembling beach cobbles and pitted surfaces on broken phenocrysts of pyroxene and olivine. We estimate that roughly 33% of near vent ejecta are recycled. Our best sample of this ejecta type was deposited in the drawer of the JASON II ROV during a particularly large explosion that occurred during plume sampling immediately above the vent. Elemental sulfur spherules up to 5 mm in diameter are common in ejecta from both vents and occur inside some of the lava fragments Hades activity included dramatic bubble-bursts unlike anything previously observed under water. The lava bubbles, sometimes occurring in rapid-fire sequence, collapsed in the water-column, producing fragments that are quenched in less than a second to form Pele's hair, limu o Pele, spatter-like lava blobs, and scoria. All are highly vesicular

  14. Contrasting décollement and prism properties over the Sumatra 2004-2005 earthquake rupture boundary.

    PubMed

    Dean, Simon M; McNeill, Lisa C; Henstock, Timothy J; Bull, Jonathan M; Gulick, Sean P S; Austin, James A; Bangs, Nathan L B; Djajadihardja, Yusuf S; Permana, Haryadi

    2010-07-01

    Styles of subduction zone deformation and earthquake rupture dynamics are strongly linked, jointly influencing hazard potential. Seismic reflection profiles across the trench west of Sumatra, Indonesia, show differences across the boundary between the major 2004 and 2005 plate interface earthquakes, which exhibited contrasting earthquake rupture and tsunami generation. In the southern part of the 2004 rupture, we interpret a negative-polarity sedimentary reflector approximately 500 meters above the subducting oceanic basement as the seaward extension of the plate interface. This predécollement reflector corresponds to unusual prism structure, morphology, and seismogenic behavior that are absent along the 2005 rupture zone. Although margins like the 2004 rupture zone are globally rare, our results suggest that sediment properties influence earthquake rupture, tsunami hazard, and prism development at subducting plate boundaries.

  15. Isolation of an arsenate-respiring bacterium from a redox front in an arsenic-polluted aquifer in West Bengal, Bengal Basin.

    PubMed

    Osborne, Thomas H; McArthur, John M; Sikdar, Pradip K; Santini, Joanne M

    2015-04-01

    Natural pollution of groundwater by arsenic adversely affects the health of tens of millions of people worldwide, with the deltaic aquifers of SE Asia being particularly polluted. The pollution is caused primarily by, or as a side reaction of, the microbial reduction of sedimentary Fe(III)-oxyhydroxides, but the organism(s) responsible for As release have not been isolated. Here we report the first isolation of a dissimilatory arsenate reducer from sediments of the Bengal Basin in West Bengal. The bacterium, here designated WB3, respires soluble arsenate and couples its reduction to the oxidation of acetate; WB3 is therefore implicated in the process of arsenic pollution of groundwater, which is largely by arsenite. The bacterium WB3 is also capable of reducing dissolved Fe(III) citrate, solid Fe(III)-oxyhydroxide, and elemental sulfur, using acetate as the electron donor. It is a member of the Desulfuromonas genus and possesses a dissimilatory arsenate reductase that was identified using degenerate polymerase chain reaction primers. The sediment from which WB3 was isolated was brown, Pleistocene sand at a depth of 35.2 m below ground level (mbgl). This level was some 3 cm below the boundary between the brown sands and overlying reduced, gray, Holocene aquifer sands. The color boundary is interpreted to be a reduction front that releases As for resorption downflow, yielding a high load of labile As sorbed to the sediment at a depth of 35.8 mbgl and concentrations of As in groundwater that reach >1000 μg/L.

  16. Hydrologic conditions in the Jacobs Creek, Stony Brook, and Beden Brook drainage basins, west-central New Jersey, 1986-88

    USGS Publications Warehouse

    Jacobsen, Eric; Hardy, M.A.; Kurtz, B.A.

    1993-01-01

    Data on the quantity and quality of groundwater and surface water in the drainage basins of Jacobs Creek, Stony Brook, and Beden Brook upstream from U.S. Route 206 in west-central New Jersey were collected from October 1, 1986, through September 30, 1988. Water levels measured in 74 wells ranged from 49 to 453 ft above sea level. The water-table surface generally mimicked topography; however, the water-level altitude in one well indicates the possibility of local interbasin groundwater flow. Calcium and bicarbonate were the most abundant cation and anion in most of the 25 groundwater samples. With one exception, concentrations of nutrients, trace elements, organic carbon, and volatile organic compounds in groundwater samples were less than U.S. Environmental Protection Agency primary drinking-water regulations. Stream low-flow measurements made twice at each of 63 sites indicate that both discharge and runoff increased downstream for most reaches of Jacobs Creek, Stony Brook, and Beden Brook. For main-stem sites, the highest base-flow runoff occurred at site 01462733 on Jacobs Creek; the greatest discharge was measured at site 01401100 on Stony Brook. The flow-duration curve for Stony Brook for 1987-88 indicates a wetter- than-normal period for the area. Results of surface-water-quality analyses indicate that calcium and sodium plus potassium were the dominant or codominant cations, and bicarbonate and chloride were the dominant or codominant anions in most samples. Concentrations of nutrients typically exceeded those needed to support surplus algal growth. Concentrations of trace elements generally were less than U.S. Environmental Protection Agency primary drinking-water regulations. Bottom-sediment samples contained several persistent organic compounds. Significant downstream variations were found in concentrations of copper and lead in Jacobs Creek and Stony Brook. Results of macroinvertebrate community sampling indicate an input of nutrients to several stream

  17. On the surging potential of polar ice streams: Part 2, Ice streams and physical characteristics of the Ross Sea drainage basin, West Antarctica

    SciTech Connect

    Jenssen, D.; Budd, W.F.; Smith, I.N.; Radok, U.

    1985-01-01

    The West Antarctic region from which ice drains into the Ross Sea is described and analyzed on a twenty km grid with the assumption that the ice is in a steady state of zero overall mass balance. The most striking features of the basin are five major ice streams moving in their lower reaches with velocities two orders of magnitude larger than the ice in which they are embedded. These high velocities are produced by driving stresses which markedly decrease downstream; this suggests that basal sliding takes over from internal deformation as dominant mode of flow. Algebraic expressions for both velocity components are given in terms of the downslope driving (or basal shear) stress, the ice thickness excess above the maximum thickness that can float on rock below mean sea level (''thickness above buoyancy''), and the basal temperature. Thus computed the velocities agree broadly with those derived directly from the condition of steady-state mass conservation (''balance velocities'') but there remain large local discrepancies. The latter fully define the three-dimensional strain rate fields and permit the residence times and ages of the ice to be estimated. They also enter into solutions of thermodynamic energy balance equations which give the temperatures in the ice and define regions where basal melting can be expected to occur for different values of the geothermal heat flux. The associated melt water layer is the key feature for a deeper understanding of the sliding and surging processes in ice streams and for improving the agreement between modeled and observed ice velocities.

  18. Status of peatland degradation and development in Sumatra and Kalimantan.

    PubMed

    Miettinen, Jukka; Liew, Soo Chin

    2010-01-01

    Peatlands cover around 13 Mha in Sumatra and Kalimantan, Indonesia. Human activities have rapidly increased in the peatland ecosystems during the last two decades, invariably degrading them and making them vulnerable to fires. This causes high carbon emissions that contribute to global climate change. For this article, we used 94 high resolution (10-20 m) satellite images to map the status of peatland degradation and development in Sumatra and Kalimantan using visual image interpretation. The results reveal that less than 4% of the peatland areas remain covered by pristine peatswamp forests (PSFs), while 37% are covered by PSFs with varying degree of degradation. Furthermore, over 20% is considered to be unmanaged degraded landscape, occupied by ferns, shrubs and secondary growth. This alarming extent of degradation makes peatlands vulnerable to accelerated peat decomposition and catastrophic fire episodes that will have global consequences. With on-going degradation and development the existence of the entire tropical peatland ecosystem in this region is in great danger. PMID:21053723

  19. Thermal maturity patterns in Pennsylvanian coal-bearing rocks in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania: Chapter F.2 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    USGS Publications Warehouse

    Ruppert, Leslie F.; Trippi, Michael H.; Hower, James C.; Grady, William C.; Levine, Jeffrey R.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Thermal maturation patterns of Pennsylvanian strata in the Appalachian basin and part of the Black Warrior basin were determined by compiling previously published and unpublished percent-vitrinite-reflectance (%R0) measurements and preparing isograd maps on the basis of the measurements. The isograd values range from 0.6 %R0 in Ohio and the western side of the Eastern Kentucky coal field to 5.5 %R0 in the Southern field in the Pennsylvania Anthracite region, Schuylkill County, Pa. The vitrinite-reflectance values correspond to the American Society of Testing Materials (ASTM) coal-rank classes of high-volatile C bituminous to meta-anthracite, respectively. In general, the isograds show that thermal maturity patterns of Pennsylvanian coals within the Appalachian basin generally decrease from east to west. In the Black Warrior basin of Alabama, the isograds show a circular pattern with the highest values (greater than 1.6 %R0) centered in Jefferson County, Ala. Most of the observed patterns can be explained by variations in the depth of burial, variations in geothermal gradient, or a combination of both; however, there are at least four areas of higher ranking coal in the Appalachian basin that are difficult to explain by these two processes alone: (1) a set of west- to northwest-trending salients centered in Somerset, Cambria, and Fayette Counties, Pa.; (2) an elliptically shaped, northeast-trending area centered in southern West Virginia and western Virginia; (3) the Pennsylvania Anthracite region in eastern Pennsylvania; and (4) the eastern part of the Black Warrior coal field in Alabama. The areas of high-ranking coal in southwestern Pennsylvania, the Black Warrior coal field, and the Pennsylvania Anthracite region are interpreted here to represent areas of higher paleo-heat flow related to syntectonic movement of hot fluids towards the foreland associated with Alleghanian deformation. In addition to the higher heat flow from these fluids, the Pennsylvania

  20. Sumatra-Andaman Megathrust Earthquake Slip: Insights From Mechanical Modeling of ICESat Surface Deformation Measurements

    NASA Astrophysics Data System (ADS)

    Harding, D. J.; Miuller, J. R.

    2005-12-01

    Modeling the kinematics of the 2004 Great Sumatra-Andaman earthquake is limited in the northern two-thirds of the rupture zone by a scarcity of near-rupture geodetic deformation measurements. Precisely repeated Ice, Cloud, and Land Elevation Satellite (ICESat) profiles across the Andaman and Nicobar Islands provide a means to more fully document the spatial pattern of surface vertical displacements and thus better constrain geomechanical modeling of the slip distribution. ICESat profiles that total ~45 km in length cross Car Nicobar, Kamorta, and Katchall in the Nicobar chain. Within the Andamans, the coverage includes ~350 km on North, Central, and South Andaman Islands along two NNE and NNW-trending profiles that provide elevations on both the east and west coasts of the island chain. Two profiles totaling ~80 km in length cross South Sentinel Island, and one profile ~10 km long crosses North Sentinel Island. With an average laser footprint spacing of 175 m, the total coverage provides over 2700 georeferenced surface elevations measurements for each operations period. Laser backscatter waveforms recorded for each footprint enable detection of forest canopy top and underlying ground elevations with decimeter vertical precision. Surface elevation change is determined from elevation profiles, acquired before and after the earthquake, that are repeated with a cross-track separation of less than 100 m by precision pointing of the ICESat spacecraft. Apparent elevation changes associated with cross-track offsets are corrected according to local slopes calculated from multiple post-earthquake repeated profiles. The surface deformation measurements recorded by ICESat are generally consistent with the spatial distribution of uplift predicted by a preliminary slip distribution model. To predict co-seismic surface deformation, we apply a slip distribution, derived from the released energy distribution computed by Ishii et al. (2005), as the displacement discontinuity

  1. Geochemistry of Selected Coal Samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia

    USGS Publications Warehouse

    Belkin, Harvey E.; Tewalt, Susan J.

    2007-01-01

    Introduction Indonesia is an archipelago of more than 17,000 islands that stretches astride the equator for about 5,200 km in southeast Asia (figure 1) and includes major Cenozoic volcano-plutonic arcs, active volcanoes, and various related onshore and offshore basins. These magmatic arcs have extensive Cu and Au mineralization that has generated much exploration and mining in the last 50 years. Although Au and Ag have been mined in Indonesia for over 1000 years (van Leeuwen, 1994), it was not until the middle of the nineteenth century that the Dutch explored and developed major Sn and minor Au, Ag, Ni, bauxite, and coal resources. The metallogeny of Indonesia includes Au-rich porphyry Cu, porphyry Mo, skarn Cu-Au, sedimentary-rock hosted Au, epithermal Au, laterite Ni, and diamond deposits. For example, the Grasberg deposit in Papua has the world's largest gold reserves and the third-largest copper reserves (Sillitoe, 1994). Coal mining in Indonesia also has had a long history beginning with the initial production in 1849 in the Mahakam coal field near Pengaron, East Kalimantan; in 1891 in the Ombilin area, Sumatra, (van Leeuwen, 1994); and in South Sumatra in 1919 at the Bukit Asam mine (Soehandojo, 1989). Total production from deposits in Sumatra and Kalimantan, from the 19thth century to World War II, amounted to 40 million metric tons (Mt). After World War II, production declined due to various factors including politics and a boom in the world-wide oil economy. Active exploration and increased mining began again in the 1980's mainly through a change in Indonesian government policy of collaboration with foreign companies and the global oil crises (Prijono, 1989). This recent coal revival (van Leeuwen, 1994) has lead Indonesia to become the largest exporter of thermal (steam) coal and the second largest combined thermal and metallurgical (coking) coal exporter in the world market (Fairhead and others, 2006). The exported coal is desirable as it is low sulfur

  2. Sensitivity of a lumped and semi-distributed hydrological model to several methods of rainfall interpolation on a large basin in West Africa

    NASA Astrophysics Data System (ADS)

    Ruelland, D.; Ardoin-Bardin, S.; Billen, G.; Servat, E.

    2008-10-01

    SummaryThis paper examines the sensitivity of a hydrological model to several methods of spatial interpolation of rainfall data. The question is investigated in a context of scarcity of data over a large West African catchment (100,000 km 2) subject to a drastic trend of rain deficit since the 1970s. Thirteen widely scattered rainfall stations and their daily time series were used to interpolate gridded rainfall surfaces over the 1950-1992 period via various methods: Thiessen polygons, inverse distance weighted (IDW) method, thin smooth plate splines (spline), and ordinary kriging. The accuracy of these interpolated datasets was evaluated using two complementary approaches. First, a point-by-point assessment was conducted, involving comparison of the interpolated values by reference to observed point data. Second, a conceptual rainfall-runoff model (Hydrostrahler) was used in order to assess whether and to what extent the alternative sets of interpolated rainfall impacted on the hydrological simulations. A lumped modelling exercise over a long period (1952-1992) and a semi-distributed exercise over a short period (1971-1976) were performed, using calibrations aimed at optimizing a Nash-Sutcliffe criterion. The results were evaluated for each interpolated forcing dataset using statistical analysis and visual inspection of the simulated and observed hydrographs and the parameters obtained from calibration. Assessment of the interpolation methods by reference to point data indicates that interpolations using the IDW and kriging methods are more efficient than the simple Thiessen technique, and, to a lesser extent, than spline. The use of these data in a daily lumped modelling application shows a different ranking of the various interpolation methods with regard to various hydrological assessments. The model is particularly sensitive to the differences in the rainfall input volume produced by each interpolation method: the IDW dataset yields the highest hydrological

  3. Precipitation and runoff simulations of select perennial and ephemeral watersheds in the middle Carson River basin, Eagle, Dayton, and Churchill Valleys, west-central Nevada

    USGS Publications Warehouse

    Jeton, Anne E.; Maurer, Douglas K.

    2011-01-01

    The effect that land use may have on streamflow in the Carson River, and ultimately its impact on downstream users can be evaluated by simulating precipitation-runoff processes and estimating groundwater inflow in the middle Carson River in west-central Nevada. To address these concerns, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, began a study in 2008 to evaluate groundwater flow in the Carson River basin extending from Eagle Valley to Churchill Valley, called the middle Carson River basin in this report. This report documents the development and calibration of 12 watershed models and presents model results and the estimated mean annual water budgets for the modeled watersheds. This part of the larger middle Carson River study will provide estimates of runoff tributary to the Carson River and the potential for groundwater inflow (defined here as that component of recharge derived from percolation of excess water from the soil zone to the groundwater reservoir). The model used for the study was the U.S. Geological Survey's Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Models were developed for 2 perennial watersheds in Eagle Valley having gaged daily mean runoff, Ash Canyon Creek and Clear Creek, and for 10 ephemeral watersheds in the Dayton Valley and Churchill Valley hydrologic areas. Model calibration was constrained by daily mean runoff for the 2 perennial watersheds and for the 10 ephemeral watersheds by limited indirect runoff estimates and by mean annual runoff estimates derived from empirical methods. The models were further constrained by limited climate data adjusted for altitude differences using annual precipitation volumes estimated in a previous study. The calibration periods were water years 1980-2007 for Ash Canyon Creek, and water years 1991-2007 for Clear Creek. To

  4. Nutrient, sediment, and pesticide data collected at four small agricultural basins in the Beaver Creek watershed, West Tennessee, 1990-1995

    USGS Publications Warehouse

    Williams, Shannon D.; Harris, Robin M.

    1996-01-01

    In 1989, the U.S. Geological Survey began a cooperative study with the Tennessee Department of Agriculture to assess the impact of agricultural activities on water quality in the Beaver Creek watershed in West Tennessee. Quantification of the transport of nutrients, sediment, and pesticides from agricultural fields was one of the objectives of the study. This report presents nutrient, sediment, and pesticide data collected during selected storm events from 1990 through 1995 at four relatively small, agricultural basins (28 to 422 acres) in the Beaver Creek watershed. Approximately 3,000 water samples (500 to 1,000 at each site) were analyzed for nitrogen and phosphorus species. Total nitrogen (N) concentrations ranged from 0.2 to 41.2 milligrams per liter (mg/L). Median concentrations for samples from each site ranged from 2.0 to 2.7 mg/L for total nitrogen, 1.2 to 1.9 mg/L for organic nitrogen, 0.05 to 0.14 mg/L for ammonia (measured as N), and 0.2 to 0.8 mg/L for nitrate plus nitrite (measured as N). Total phosphorus (P) concentrations ranged from 0.03 to 16.0 mg/L. Median concentrations for samples from each site ranged from 0.80 to 1.2 mg/L for total phosphorus and 0.15 to 0.72 for orthophosphate (measured as P). Approximately 6,000 water samples (1,300 to 1,800 at each site) were analyzed for suspended sediment. Suspended-sediment concentrations ranged from 8.0 to 98,353 mg/L. Concentrations exceeded 1,000 mg/L in 33 percent of the samples collected and exceeded 10,000 mg/L in 6 percent of the samples. Median concentrations ranged from 347 to 713 mg/L at the four sites. Several herbicides and insecticides were detected in water samples. Maximum concentrations detected were 37 micrograms per liter for metolachlor, 3.2 for trifluralin, 150 for fluometuron, and 430 for aldicarb. Aldicarb metabolites were also detected in several samples. The maximum aldicarb sulfoxide and aldicarb sulfone concentrations detected were 68.4 and 14.3 micrograms per liter

  5. Mantle volatiles in spring gases in the Basin and Range Province on the west of Beijing, China: Constraints from helium and carbon isotopes

    NASA Astrophysics Data System (ADS)

    Zhang, Weibin; Du, Jianguo; Zhou, Xiaocheng; Wang, Fei

    2016-01-01

    The mantle degassing observed at the Earth surface demonstrates both a provenance of fluids in the mantle and a pathway to the surface. Quantities of this process are discovered on the plate boundaries, where there are plenty of active volcanoes and active faults, releasing plenty of mantle volatiles. However, in intraplate tectonic settings without obvious mantle plume, the work for mantle degassing observed in spring gasses seems comparatively limited. We selected the Basin and Range Province on the west of Beijing, an area in the inner part of North China Craton, to discuss the mantle degassing based on the helium and carbon isotopes of spring gasses, and the previous works on seismic tomography and fault slip rate. The spring gas helium and carbon (CO2) isotopes indicate the mixture of crustal and mantle materials. The helium ratios (reported as RC/RA, air-corrected 3He/4He ratio, RA = 1.4 × 10- 6; RA is the air ratio) vary in the range of 0.33-2.08. The calculated mantle helium contributes 4% ~ 26% of helium in spring gasses, and the remaining is generated in the crust by radiogenic decay of U-Th series with tiny air mixture. CO2 acquires analytical δ13CV-PDB values in the range from - 20.3‰ to - 10.2‰, affected by carbonate precipitation. The unaffected values are calculated to be - 8.5 ~ 5.1 ‰ by temperature-dependent isotope fractionation, indicating the mixture of mantle and crustal (limestone) materials. The mantle volatiles are possibly generated in the upwelling asthenosphere, in that, the 3He/4He ratio corresponds well with the negative anomaly of P-wave velocity at the depth of 70 km imaged by seismic tomography. The 3He/4He ratio also correlates with time-averaged fault slip rate, suggesting higher slip rate renders more permeable mantle vent. These consequences help to construct a conceptual model for intraplate mantle degassing, that the mantle volatiles generate in the upwelling asthenosphere and uprise through faults and fractures whose

  6. Hydrologic Impacts Associated with the Increased Role of Wildland Fire Across the Rangeland-Xeric Forest Continuum of the Great Basin and Intermountain West, USA

    NASA Astrophysics Data System (ADS)

    Williams, C. J.; Pierson, F. B.; Robichaud, P. R.; Boll, J.; Al-Hamdan, O. Z.

    2011-12-01

    The increased role of wildland fire across the rangeland-xeric forest continuum in the western United States (US) presents landscape-scale consequences relative runoff and erosion. Concomitant climate conditions and altered plant community transitions in recent decades along grassland-shrubland-woodland-xeric forest transitions have promoted frequent and large wildland fires, and the continuance of the trend appears likely if current or warming climate conditions prevail. Much of the Great Basin and Intermountain West in the US now exists in a state in which rangeland and woodland wildfires stimulated by invasive cheatgrass and dense, horizontal and vertical fuel layers have a greater likelihood of progressing upslope into xeric forests. Drier moisture conditions and warmer seasonal air temperatures, along with dense fuel loads, have lengthened fire seasons and facilitated an increase in the frequency, severity and area burned in mid-elevation western US forests. These changes potentially increase the overall hydrologic vulnerability across the rangeland-xeric forest continuum by spatially and temporally increasing soil surface exposure to runoff and erosion processes. Plot-to-hillslope scale studies demonstrate burning may increase event runoff and/or erosion by factors of 2-40 over small-plots scales and more than 100-fold over large-plot to hillslope scales. Anecdotal reports of large-scale flooding and debris-flow events from rangelands and xeric forests following burning document the potential risk to resources (soil loss, water quality, degraded aquatic habitat, etc.), property and infrastructure, and human life. Such risks are particularly concerning for urban centers near the urban-wildland interface. We do not yet know the long-term ramifications of frequent soil loss associated with commonly occurring runoff events on repeatedly burned sites. However, plot to landscape-scale post-fire erosion rate estimates suggest potential losses of biologically

  7. West Virginia baseline

    NASA Astrophysics Data System (ADS)

    Cardi, V. P.; Baer, C.; Graham, A.; Hall, T.; Rankin, D.; Sweet, T. J.

    1981-04-01

    Baseline information on West Virginia is provided. The topics covered are terrestrial ecology, aquatic ecology, geology and climatology, socioeconomics, and a legal analysis of institutional accountability. The hydrology, water quality, endangered species, and clean streams of five river basins are described.

  8. Seismology: speed and size of the Sumatra earthquake.

    PubMed

    Stein, Seth; Okal, Emile A

    2005-03-31

    Our seismological results reveal that Indonesia's devastating Sumatra-Andaman earthquake on 26 December 2004 was 2.5 times larger than initial reports suggested--second only to the 1960 Chilean earthquake in recorded magnitude. They indicate that it slowly released its energy by slip along a 1,200-km fault, generating a long rupture that contributed to the subsequent tsunami. Now that the entire rupture zone has slipped, the strain accumulated from the subduction of the Indian plate beneath the Burma microplate has been released, and there is no immediate danger of a similar tsunami being generated on this part of the plate boundary, although large earthquakes on segments to the south still present a threat.

  9. Interpretation of Geoelectric Structure at Hululais Prospect Area, South Sumatra

    SciTech Connect

    Mulyadi

    1995-01-01

    Schlumberger resistivity surveys were conducted in 1993 as part of a combined geological, geophysical and geological program to investigate a geothermal prospect in the Hululais area, Southern Sumatra. These resistivity data resolved the upper conductive layer and were interpreted to define the shallow extent of a possible geothermal system. A follow-up magnetotelluric (MT) survey was carried out to probe deeper than the dc resistivity survey results achieved. However, the resistive sub-stratum below the conductive layer was still poorly resolved. Possible reasons for this include a preferential channeling of the telluric current within the thick shallow very conductive layer, thus limiting the penetration depth of the magnetotelluric signals and poor resolution due to high noise levels caused by significant rain and sferics.

  10. Groundwater Eruption in China Triggered By the 2004 Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Shi, Z.; Wang, D.; Manga, M.; Wang, C. Y.; Wang, G.

    2014-12-01

    The 2004 Mw9.3 Sumatra earthquake initiated a large, sustained groundwater eruption in Guangdong, China, 3200 km away from the epicenter. The erupted water column reached a height of ~60 m above the ground surface when it was first sighted and the eruption lasted about 10 days. Estimated seismic energy density at the eruption site is only 0.046 J.m-3; thus it is surprising that the earthquake caused such an intense response. A field survey showed that a large amount of gaseous CO2 was released from groundwater during the eruption and suggested that the eruption was caused by the exsolution of CO2 from groundwater. In this study, we use numerical simulation to explore the mechanism of the well eruption. We apply tidal analysis to water level data from 2003 to 2006 to estimate the aquifer parameters before and after the earthquake; the hydraulic diffusivity inferred this way is 0.423 m2/s and 1.371 m2/s before and after the earthquake, respectively. Based on these parameters, we use TOUGH2, a widely used numerical program for simulating two-phase hydrothermal processes, to simulate the evolution of CO2 saturation, the velocity of erupted groundwater and pressure in the well-aquifer system after Sumatra earthquake. The simulations show that the earthquake may have triggered bubbles to nucleate from the CO2-rich groundwater and enhanced the aquifer permeability, leading to increased groundwater discharge to the well. Decreased pore-pressure in the aquifer caused greater exsolution of CO2 and greater discharge, leading to groundwater eruption. Exsolution of CO2 extends radially away from the wellbore as a function of time and the continued exsolution of CO2 sustained the eruption until pressure in the aquifer drops below hydrostatic, which is marked by a ~9 m drop in groundwater level from that before the earthquake. That earthquake trigger eruption and CO2 exsolution has implications for CO2 sequestration.

  11. Paleoenvironmental conditions in the late Paleogene, Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    O'shea, Natalie; Arthur Bettis, E.; Zaim, Yahdi; Rizal, Yan; Aswan, Aswan; Gunnell, Gregg F.; Zonneveld, John-Paul; Ciochon, Russell L.

    2015-11-01

    A stratified paleosol sequence exposed in an open pit mine in central Sumatra provides a record of the paleoenvironmental conditions in the lower reaches of a large river system in the late Paleogene (latest Eocene or Oligocene). Morphological, geochemical, and stable isotope data suggest that the sequence represents a mosaic of local environmental conditions changing from estuarine to riverine up section. Weakly expressed soils formed on low-lying estuary surfaces, while more well expressed soils formed on higher, better drained surfaces. Peatlands (coal) with clayey subsoils were along the estuary margins. Well-expressed soils with evidence of clay translocation and chemical weathering become more common higher in the section where alluvial deposits associated with a meandering river are dominant. Stable carbon isotope ratios support a paleolandscape dominated by C3 plants with input by C4 vegetation limited to a few intervals. Finally, whole-rock geochemistry suggests moderate chemical weathering consistent with a tropical locality. This multi-proxy paleoenvironmental reconstruction suggests a highly productive lowland forest environment at this locality in the late Paleogene and provides the first direct examination of the terrestrial environment in Sumatra at this time. The limited fossil record in Island Southeast Asia during this time period is likely a result of poor bone and shell preservation in tropical forest environments combined with a general lack of systematic prospecting. However, our continuing work in this area has produced a relatively diverse assemblage of fossil vertebrates, now including fishes, amphibians, turtles, crocodiles, and mammals, as well as a growing diversity of fossil plants.

  12. Apes in Space: Saving an Imperilled Orangutan Population in Sumatra

    PubMed Central

    Campbell-Smith, Gail; Campbell-Smith, Miran; Singleton, Ian; Linkie, Matthew

    2011-01-01

    Deforestation rates in Sumatra are amongst the highest in the tropics. Lowland forests, which support the highest densities of orangutans, are particularly vulnerable to clearance and fragmentation because they are highly accessible. Consequently, many orangutans will, in the future, live in strictly or partially isolated populations. Whilst orangutans have been extensively studied in primary forests, their response to living in human-dominated landscapes remains poorly known, despite it being essential for their future management. Here, we focus on an isolated group of critically endangered Sumatran orangutans (Pongo abelii) that co-exist with farmers in a mixed agroforest system consisting of degraded natural forest, smallholder (predominantly rubber) farms and oil palm plantations. Over 24 months we conducted the first ever spatial assessment of orangutan habitat use in the human-transformed landscape of Batang Serangan, North Sumatra. From 1,204 independent crop-raiding incidents recorded, orangutans showed strong foraging preference for mixed farmland/degraded forest habitat over oil palm patches. The core home range areas of the eight adult orangutans encompassed only 14% of the available study area. Monthly home range sizes averaged 423 ha (±139, SD) for males, and 131±46 ha for females, and were positively influenced by wild and cultivated fruit presence, and by crop consumption. The average daily distance travelled was similar for both adult males (868 m±350, SD) and females (866 m±195), but increased when orangutans raided crops. These findings show that orangutans can survive, demographically, in certain types of degraded landscapes, foraging on a mixture of crops and wild fruits. However, the poor quality habitat offered to orangutans by oil palm plantations, in terms of low food availability and as a barrier to female movements, is cause for concern since this is the land use type that is most rapidly replacing the preferred forest habitat across

  13. Apes in space: saving an imperilled orangutan population in Sumatra.

    PubMed

    Campbell-Smith, Gail; Campbell-Smith, Miran; Singleton, Ian; Linkie, Matthew

    2011-01-01

    Deforestation rates in Sumatra are amongst the highest in the tropics. Lowland forests, which support the highest densities of orangutans, are particularly vulnerable to clearance and fragmentation because they are highly accessible. Consequently, many orangutans will, in the future, live in strictly or partially isolated populations. Whilst orangutans have been extensively studied in primary forests, their response to living in human-dominated landscapes remains poorly known, despite it being essential for their future management. Here, we focus on an isolated group of critically endangered Sumatran orangutans (Pongo abelii) that co-exist with farmers in a mixed agroforest system consisting of degraded natural forest, smallholder (predominantly rubber) farms and oil palm plantations. Over 24 months we conducted the first ever spatial assessment of orangutan habitat use in the human-transformed landscape of Batang Serangan, North Sumatra. From 1,204 independent crop-raiding incidents recorded, orangutans showed strong foraging preference for mixed farmland/degraded forest habitat over oil palm patches. The core home range areas of the eight adult orangutans encompassed only 14% of the available study area. Monthly home range sizes averaged 423 ha (±139, SD) for males, and 131 ± 46 ha for females, and were positively influenced by wild and cultivated fruit presence, and by crop consumption. The average daily distance travelled was similar for both adult males (868 m ± 350, SD) and females (866 m ± 195), but increased when orangutans raided crops. These findings show that orangutans can survive, demographically, in certain types of degraded landscapes, foraging on a mixture of crops and wild fruits. However, the poor quality habitat offered to orangutans by oil palm plantations, in terms of low food availability and as a barrier to female movements, is cause for concern since this is the land use type that is most rapidly replacing the preferred forest habitat

  14. Coral Radiocarbon Record of Interannual Variability in Wind-induced Upwelling Along the Coast of Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Grumet, N. S.; Abram, N. J.; Beck, J. W.; Dunbar, R. B.; Gagan, M. K.

    2002-12-01

    Radiocarbon measurements from annually banded corals have been shown to track radiocarbon levels of dissolved inorganic carbon (DIC) in the surrounding surface water. As a result of nuclear weapons testing in the 1950s, production of excess radiocarbon has increased the contrast between surface and deep ocean carbon-14 concentrations. The temporal evolution of this gradient in radiocarbon is preserved in a coral record from the Mentawai Islands, Sumatra (0S, 98E), in the eastern Indian Ocean. During the southeast monsoon, alongshore winds generate Ekman upwelling along the Java-Sumatra coasts, which transports 14C-depleted thermocline water toward the surface-dwelling Mentawai corals. The strength of upwelling in the Mentawai Islands, which is characterized by lower sea surface temperatures, a shallower thermocline and lower sea surface height, reflects variability in the monsoon winds and is modulated by interannual atmosphere-ocean teleconnections. Bimonthly AMS-14C measurements on the Mentawai coral show that the seasonal radiocarbon signal is relatively weak, while the interannual signal is clearly marked by episodic depletions in radiocarbon levels. These events are most likely responding to a relaxation of the westerly trades and subsequent strengthening of the easterlies. Easterly anomalies are linked to a large scale adjustment of the sea surface height along the equator and a shallower eastern thermocline. Our results suggest that interannual climate variability is the dominant forcing mechanism with seasonal variability secondary. Together, bimonthly coral oxygen isotope and radiocarbon records capture variability in upwelling, and hence the strength of the southeast monsoon. Comparison with a coral radiocarbon record from the western Indian Ocean provides insights into oceanic processes across the Indian Ocean basin and the question of the existence of an Indian Ocean Dipole.

  15. Hydrologic analysis of two headwater lake basins of differing lake pH in the west-central Adirondack Mountains of New York

    USGS Publications Warehouse

    Murdoch, Peter S.; Peters, N.E.; Newton, R.M.

    1987-01-01

    Hydrologic analysis of two headwater lake basins in the Adirondack Mountains, New York, during 1980-81 indicates that the degree of neutralization of acid precipitation is controlled by the groundwater contribution to the lake. According to flow-duration analyses, daily mean outflow/unit area from the neutral lake (Panther Lake, pH 5-7) was more sustained and contained a higher percentage of groundwater than that of the acidic lake (Woods Lake, pH 4-5). Outflow recession rates and maximum base-flow rates, derived from individual recession curves, were 3.9 times and 1.5 times greater, respectively, in the neutral-lake basin than in the acidic-lake basin. Groundwater contribution to lake outflow was also calculated from a lake-water budget; the groundwater contribution to the neutral lake was about 10 times greater than that to the acidic lake. Thick sandy till forms the groundwater reservoir and the major recharge area in both basins but covers 8.5 times more area in the neutral-lake basin than in the acidic-lake basin. More groundwater storage within the neutral basin provides longer contact time with neutralizing minerals and more groundwater discharge. As a result, the neutral lake has relatively high pH and alkalinity, and more net cation transport. (USGS)

  16. Effects of groundwater levels and headwater wetlands on streamflow in the Charlie Creek basin, Peace River watershed, west-central Florida

    USGS Publications Warehouse

    Lee, T.M.; Sacks, L.A.; Hughes, J.D.

    2010-01-01

    The Charlie Creek basin was studied from April 2004 to December 2005 to better understand how groundwater levels in the underlying aquifers and storage and overflow of water from headwater wetlands preserve the streamflows exiting this least-developed tributary basin of the Peace River watershed. The hydrogeologic framework, physical characteristics, and streamflow were described and quantified for five subbasins of the 330-square mile Charlie Creek basin, allowing the contribution of its headwaters area and tributary subbasins to be separately quantified. A MIKE SHE model simulation of the integrated surface-water and groundwater flow processes in the basin was used to simulate daily streamflow observed over 21 months in 2004 and 2005 at five streamflow stations, and to quantify the monthly and annual water budgets for the five subbasins including the changing amount of water stored in wetlands. Groundwater heads were mapped in Zone 2 of the intermediate aquifer system and in the Upper Floridan aquifer, and were used to interpret the location of artesian head conditions in the Charlie Creek basin and its relation to streamflow. Artesian conditions in the intermediate aquifer system induce upward groundwater flow into the surficial aquifer and help sustain base flow which supplies about two-thirds of the streamflow from the Charlie Creek basin. Seepage measurements confirmed seepage inflow to Charlie Creek during the study period. The upper half of the basin, comprised largely of the Upper Charlie Creek subbasin, has lower runoff potential than the lower basin, more storage of runoff in wetlands, and periodically generates no streamflow. Artesian head conditions in the intermediate aquifer system were widespread in the upper half of the Charlie Creek basin, preventing downward leakage from expansive areas of wetlands and enabling them to act as headwaters to Charlie Creek once their storage requirements were met. Currently, the dynamic balance between wetland

  17. Factors influencing the use of antenatal care in rural West Sumatra, Indonesia

    PubMed Central

    2012-01-01

    Background Every year, nearly half a million women and girls needlessly die as a result of complications during pregnancy, childbirth or the 6 weeks following delivery. Almost all (99%) of these deaths occur in developing countries. The study aim was to describe the factors related to low visits for antenatal care (ANC) services among pregnant women in Indonesia. Method A total of 145 of 200 married women of reproductive age who were pregnant or had experienced birth responded to the questionnaire about their ANC visits. We developed a questionnaire containing 35 items and four sections. Section one and two included the women's socio demographics, section three about basic knowledge of pregnancy and section four contained two subsections about preferences about midwives and preferences about Traditional Birth Attendant (TBA) and the second subsections were traditional beliefs. Data were collected using a convenience sampling strategy during July and August 2010, from 10 villages in the Tanjung Emas. Multiple regression analysis was used for preference for types of providers. Results Three-quarter of respondents (77.9%) received ANC more than four times. The other 22.1% received ANC less than four times. 59.4% received ANC visits during pregnancy, which was statistically significant compared to multiparous (p = 0.001). Women who were encouraged by their family to receive ANC had statistically significant higher traditional belief scores compared to those who encouraged themselves (p = 0.003). Preference for TBAs was most strongly affected by traditional beliefs (p < 0.001). On the contrary, preference for midwives was negatively correlated with traditional beliefs (p < 0.001). Conclusions Parity was the factor influencing women's receiving less than the recommended four ANC visits during pregnancy. Women who were encouraged by their family to get ANC services had higher traditional beliefs score than women who encouraged themselves. Moreover, traditional beliefs followed by lower income families had the greater influence over preferring TBAs, with the opposite trend for preferring midwives. Increased attention needs to be given to the women; it also very important for exploring women's perceptions about health services that they received. PMID:22353252

  18. Four new bioactive polybrominated diphenyl ethers of the sponge Dysidea herbacea from West Sumatra, Indonesia.

    PubMed

    Handayani, D; Edrada, R A; Proksch, P; Wray, V; Witte, L; Van Soest, R W; Kunzmann, A; Soedarsono

    1997-12-01

    The marine sponge Dysidea herbacea collected from Indonesia yielded four new polybrominated diphenyl ether congeners 2-5 and the known derivatives 1, 6, and 7. The structures of the new compounds were unambiguously established on the basis of NMR spectroscopic (1H, 13C, COSY, 1H-detected direct and long-range 13C-1H correlations) and mass spectrometric (EIMS) data. All of the compounds were active against the Gram-positive bacteria Bacillus subtilis and the phytopathogenic fungus Cladosporium cucumerinum. The isolated polybrominated compounds were also active in the brine shrimp lethality test. In the latter bioassay, compounds 1 and 6 were the most active with LC50's of 0.96 [SE +/- 0.19] and 0.94 [SE +/- 0.70] microg/mL, respectively.

  19. University-NGO connections for earthquake and tsunami risk reduction: lessons learned in West Sumatra

    NASA Astrophysics Data System (ADS)

    McCaughey, J.; Dewi, P. R.

    2013-12-01

    Scientists have information that is critical to policy and public education, yet lack field staff of their own to put this into practice. NGOs have field staff as well as connections with policymakers and the community, yet lack a direct connection to the latest scientific research. Scientists face pressure to obtain grants and publish; NGOs face pressure to deliver programs to as many people as possible. Lacking institutional incentives that recognize efforts to bridge the science-practice gap, it is often out of personal convictions that scientists seek to share their results with NGOs, and NGO practitioners seek to deepen their own scientific knowledge. Such individual efforts are impactful; however, more can be achieved with institutional commitments to closer collaboration. Science communication is dialogue, not a one-way transfer of knowledge from science to practice. On the university side, listening to our NGO partners has inspired faculty, staff, and students, identified new areas of fundamental scientific research inspired by practical use, and helped prioritize and clarify the scientific information that is most useful for disaster-risk-reduction practice. On the NGO side, connections to scientists have informed the content of public education and policy advocacy programs and clarified technical information; this new understanding has been incorporated in advocacy and community engagement programs.

  20. An Evaluation of Infrastructure for Tsunami Evacuation in Padang, West Sumatra, Indonesia (Invited)

    NASA Astrophysics Data System (ADS)

    Cedillos, V.; Canney, N.; Deierlein, G.; Diposaptono, S.; Geist, E. L.; Henderson, S.; Ismail, F.; Jachowski, N.; McAdoo, B. G.; Muhari, A.; Natawidjaja, D. H.; Sieh, K. E.; Toth, J.; Tucker, B. E.; Wood, K.

    2009-12-01

    Padang has one of the world’s highest tsunami risks due to its high hazard, vulnerable terrain and population density. The current strategy to prepare for tsunamis in Padang is focused on developing early warning systems, planning evacuation routes, conducting evacuation drills, and raising local awareness. Although these are all necessary, they are insufficient. Padang’s proximity to the Sunda Trench and flat terrain make reaching safe ground impossible for much of the population. The natural warning in Padang - a strong earthquake that lasts over a minute - will be the first indicator of a potential tsunami. People will have about 30 minutes after the earthquake to reach safe ground. It is estimated that roughly 50,000 people in Padang will be unable to evacuate in that time. Given these conditions, other means to prepare for the expected tsunami must be developed. With this motivation, GeoHazards International and Stanford University’s Chapter of Engineers for a Sustainable World partnered with Indonesian organizations - Andalas University and Tsunami Alert Community in Padang, Laboratory for Earth Hazards, and the Ministry of Marine Affairs and Fisheries - in an effort to evaluate the need for and feasibility of tsunami evacuation infrastructure in Padang. Tsunami evacuation infrastructure can include earthquake-resistant bridges and evacuation structures that rise above the maximum tsunami water level, and can withstand the expected earthquake and tsunami forces. The choices for evacuation structures vary widely - new and existing buildings, evacuation towers, soil berms, elevated highways and pedestrian overpasses. This interdisciplinary project conducted a course at Stanford University, undertook several field investigations, and concluded that: (1) tsunami evacuation structures and bridges are essential to protect the people in Padang, (2) there is a need for a more thorough engineering-based evaluation than conducted to-date of the suitability of existing buildings to serve as evacuation structures, and of existing bridges to serve as elements of evacuation routes, and (3) additions to Padang’s tsunami evacuation infrastructure must carefully take into account technical matters (e.g. expected wave height, debris impact forces), social considerations (e.g. cultural acceptability, public’s confidence in the structure’s integrity), and political issues (e.g. land availability, cost, maintenance). Future plans include collaboration between U.S. and Indonesian engineers in developing designs for new tsunami evacuation structures, as well as providing training for Indonesian authorities on: (1) siting, designing, and constructing tsunami evacuation structures, and (2) evaluating the suitability of existing buildings to serve as tsunami evacuation shelters.

  1. Time Reversal of Seismic Waves and the Great Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Montagner, J.; Larmat, C.; Fink, M.; Capdeville, Y.; Clevede, E.; Tourin, A.

    2005-12-01

    The occurrence of the disastrous Sumatra-Andaman earthquake on dec. 26, 2004 makes it necessary to develop innovative techniques for studying the complex spatio-temporal rupture mechanism of this giant earthquake. We present here the first application of time-reversal to seismic data. This concept was previously successfully applied for acoustic waves in many fields such as medical imaging, oceanography and non destructive testing. Time-reversal experiments are using the time reversal invariance and the spatial reciprocity of the wave equation. Their primary goal is the refocusing of energy at the location and the time of an acoustic source by time-reversing the recorded signals. As in acoustics, seismic waves are also potentially reversible. In order to achieve a time reversal experiment within the three-dimensional Earth, we take advantage of the increasing power of numerical methods (such as spectral elements methods), which enable to simulate more and more accurately the propagation of seismic waves in heterogeneous media. In addition, at very long period (longer than 200s), the available earth models are sufficiently good to enable the backpropagation of 3-component seismic waves of real data. For the first time, we have performed several synthetic and real data time-reversal experiments for seismic waves by a purely numerical technique. The seismograms of the FDSN Global network used as an active network, seismic waves are backpropagated by numerical calculation in reversed time. The time reversal technique is applied to real data at very long period (T>200s). For a point source,the coordinates of the earthquake and the strike of the fault plane are correctly retrieved, and the focusing in space and time is sharp. When time-reversing seismic data of the recent Great Sumatra- Andaman earthquake (Dec 26, 2004, Magnitude 9.3), in spite of the large extension of the source in space and time, it is shown that we still refocus at the location and time of the

  2. Malaria prevalence in Nias District, North Sumatra Province, Indonesia

    PubMed Central

    Syafruddin, Din; Asih, Puji BS; Wahid, Isra; Dewi, Rita M; Tuti, Sekar; Laowo, Idaman; Hulu, Waozidohu; Zendrato, Pardamean; Laihad, Ferdinand; Shankar, Anuraj H

    2007-01-01

    Background The Nias district of the North Sumatra Province of Indonesia has long been known to be endemic for malaria. Following the economic crisis at the end of 1998 and the subsequent tsunami and earthquake, in December 2004 and March 2005, respectively, the malaria control programme in the area deteriorated. The present study aims to provide baseline data for the establishment of a suitable malaria control programme in the area and to analyse the frequency distribution of drug resistance alleles associated with resistance to chloroquine and sulphadoxine-pyrimethamine. Methods Malariometric and entomology surveys were performed in three subdistricts. Thin and thick blood smears were stained with Giemsa and examined under binocular light microscopy. Blood blots on filter paper were also prepared for isolation of parasite and host DNA to be used for molecular analysis of band 3 (SAO), pfcrt, pfmdr1, dhfr, and dhps. In addition, haemoglobin measurement was performed in the second and third surveys for the subjects less than 10 years old. Results Results of the three surveys revealed an average slide positivity rate of 8.13%, with a relatively higher rate in certain foci. Host genetic analysis, to identify the Band 3 deletion associated with Southeast Asian Ovalocytosis (SAO), revealed an overall frequency of 1.0% among the 1,484 samples examined. One hundred six Plasmodium falciparum isolates from three sub-districts were successfully analysed. Alleles of the dhfr and dhps genes associated with resistance to sulphadoxine-pyrimethamine, dhfr C59R and S108N, and dhps A437G and K540E, were present at frequencies of 52.2%, 82.5%, 1.18% and 1.18%, respectively. The pfmdr1 alleles N86Y and N1042D, putatively associated with mefloquine resistance, were present at 31.4% and 2%, respectively. All but one sample carried the pfcrt 76T allele associated with chloroquine resistance. Entomologic surveys identified three potential anopheline vectors in the area, Anopheles

  3. Parana basin

    SciTech Connect

    Zalan, P.V.; Wolff, S.; Conceicao, J.C.J.; Vieira, I.S.; Astolfi, M.A.; Appi, V.T.; Zanotto, O.; Neto, E.V.S.; Cerqueira, J.R.

    1987-05-01

    The Parana basin is a large intracratonic basin in South America, developed entirely on continental crust and filled with sedimentary and volcanic rocks ranging in age from Silurian to Cretaceous. It occupies the southern portion of Brazil (1,100,000 km/sup 2/ or 425,000 mi/sup 2/) and the eastern half of Paraguay (100,000 km/sup 2/ or 39,000 mi/sup 2/); its extension into Argentina and Uruguay is known as the Chaco-Parana basin. Five major depositional sequences (Silurian, Devonian, Permo-Carboniferous, Triassic, Juro-Cretaceous) constitute the stratigraphic framework of the basin. The first four are predominantly siliciclastic in nature, and the fifth contains the most voluminous basaltic lava flows of the planet. Maximum thicknesses are in the order of 6000 m (19,646 ft). The sequences are separated by basin wide unconformities related in the Paleozoic to Andean orogenic events and in the Mesozoic to the continental breakup and sea floor spreading between South America and Africa. The structural framework of the Parana basin consists of a remarkable pattern of criss-crossing linear features (faults, fault zones, arches) clustered into three major groups (N45/sup 0/-65/sup 0/W, N50/sup 0/-70/sup 0/E, E-W). The northwest- and northeast-trending faults are long-lived tectonic elements inherited from the Precambrian basement whose recurrent activity throughout the Phanerozoic strongly influenced sedimentation, facies distribution, and development of structures in the basin. Thermomechanical analyses indicate three main phases of subsidence (Silurian-Devonian, late Carboniferous-Permian, Late Jurassic-Early Cretaceous) and low geothermal gradients until the beginning of the Late Jurassic Permian oil-prone source rocks attained maturation due to extra heat originated from Juro-Cretaceous igneous intrusions. The third phase of subsidence also coincided with strong tectonic reactivation and creation of a third structural trend (east-west).

  4. Mercury'S Dark Plains West Of Caloris Basin--high Ca Clinopyroxene, Na-rich Plagioclase, Mg-rich Olivine, Tio2: Caloris Basin--k-spar, High Ca Clinopyroxene, Tio2, Na-rich Plagioclase, Hornblende And Mg- And Ca-rich Garnets

    NASA Astrophysics Data System (ADS)

    Sprague, Ann L.; Donaldson Hanna, K. L.; Kozlowski, R. W. H.; Helbert, J.; Maturilli, A.

    2008-09-01

    We identify mineral phases and approximate abundances on Mercury's surface for spectral measurements made over Caloris Basin and the dark plains to the west. Our results are obtained by fitting spectra obtained with the Mid-Infrared Spectrometer and Imager (MIRSI) at the Infrared Telescope Facility (IRTF) using an established spectral deconvolution algorithm (Ramsey 1996, Ph.D. Dissertation, ASU; Ramsey and Christiansen 1998, JGR). We have assembled several laboratory mineral spectral libraries (JHU, Salisbury et al. 1987, Open-File Report 87-263, USGS; JPL, http://speclib.jpl.nasa.gov; RELAB, http://www.planetary.brown.edu/relab; ASU, Christensen et al. 2000, JGR; BED, Helbert et al. 2007, Adv. Space Res.; USGS, Clark et al. 2007, USGS digital spectral library) with a wide range of known mineral compositions with grain sizes ranging from the finest separates, 0 - 45 µm, incrementally increasing to 250 - 400 µm. Head et al. and Murchie et al. (Science, 2008) show ample evidence for one or more episodes of extrusive volcanism in around Caloris Basin. Our spectral fitting suggests similarities and differences between Caloris infill and the dark plains to the west. Both contain high-Ca clinopyroxene, Mg-rich orthopyroxene (Sprague et al. 1998, Icarus), Na-rich to intermediate plagioclase (Sprague et al. 1994, Icarus), and TiO2 likely in the form of rutile. Sanidine appears to be the dominate K-spar in Caloris Basin, but not in the dark plains (Donaldson Hanna et al. 2008, EGU Abs). A slight improvement in spectral fitting was made to one spectrum from Caloris by including a Na- and K-rich hornblende. In addition small abundances of pyrope and grossular (Ca- and Mg-rich garnets) are apparently present in Caloris Basin infill. This indicates extrusive volcanic episodes moved lava to the surface quickly before entrained garnets from the upper mantle could dissolve and equilibrate with the source magma. This work was funded by NSF AST0406796.

  5. First images of the crustal structure across the central Algerian margin, off Tipaza (West Algiers) from deep penetrating seismic data: new information to constrain the opening of the Algerian basin

    NASA Astrophysics Data System (ADS)

    Leprêtre, A.; Deverchere, J.; Klingelhoefer, F.; Graindorge, D.; Schnurle, P.; Yelles, K.; Bracene, R.

    2011-12-01

    The origin of the Algerian margin remains one of the key questions still unresolved in the Western Mediterranean sea. This is related to the unknown nature and kinematics of this Neogene basin. Whereas the westernmost margin is generally assumed to have been shaped as a STEP-fault (Subduction-Transform Edge Propagator, transcurrent) margin by the westward displacement of the Alboran block, the central Algerian margin is believed to have involved a NW-SE basin opening related to a southward slab rollback. This work sheds insight on this issue, using data acquired in the context of the Algerian-French program SPIRAL (Sismique Profonde et Investigation Régionale en Algérie): a cruise conducted on the 'R/V L'Atalante' in October-November 2009. It has provided 5 new combined onshore-offshore wide-angle seismic profiles and an extensive multi-channel seismic dataset spread along the margin, from Oran to Annaba. In this work, the available structural information on the ~N-S wide-angle transect of Tipaza is presented, where the margin broadens due to the presence of a bathymetric high (the Khayr-Al-Din bank) which is assumed to represent a remaining titled block of the passive margin. Along the transect, 39 OBS and 13 landstations recorded 751 low frequency airgun shots. Travel-time tomography and forward modelling were computed using the software developed by Zelt and Barton (1998) and Zelt and Smith (1992), to obtain the velocity structure in the region. A set of multi-channel seismic reflection profiles including two coincident profiles with the wide-angle data allows a combined interpretation and extend the deep structure in the Bou Ismail Bay. MCS data outline the sedimentary sequence filling the Algerian basin depicting an intensive salt tectonic associated with the Messinan Salinity Crisis and allowing to image locally below the salt layer. The deep penetrating data SPIRAL allow to image the sedimentary sequence in the Algerian basin off Tipaza (West Algiers) and

  6. Sumatran tiger (Panthera tigris sumatrae): a review of conservation status.

    PubMed

    Wibisono, Hariyo T; Pusparini, Wulan

    2010-12-01

    The majority of wild Sumatran tigers are believed to live in 12 Tiger Conservation Landscapes covering approximately 88,000 km(2) . However, the actual distribution of tigers across Sumatra has never been accurately mapped. Over the past 20 years, conservation efforts focused on the Sumatran tigers have increased, but the population continues to decline as a result of several key threats. To identify the status of the Sumatran tiger distribution across the island, an island-wide questionnaire survey comprised of 35 respondents from various backgrounds was conducted between May and June 2010. The survey found that Sumatran tigers are positively present in 27 habitat patches larger than 250 km(2) and possibly present in another 2. In addition, a review on major published studies on the Sumatran tiger was conducted to identify the current conservation status of the Sumatran tiger. Collectively, these studies have identified several key factors that have contributed to the decline of Sumatran tiger populations, including: forest habitat fragmentation and loss, direct killing of tigers and their prey, and the retaliatory killing of tigers due to conflict with villagers. The present paper provides management authorities and the international community with a recent assessment and a base map of the actual distribution of Sumatran tigers as well as a general overview on the current status and possible future conservation challenges of Sumatran tiger management.

  7. Sumatran tiger (Panthera tigris sumatrae): a review of conservation status.

    PubMed

    Wibisono, Hariyo T; Pusparini, Wulan

    2010-12-01

    The majority of wild Sumatran tigers are believed to live in 12 Tiger Conservation Landscapes covering approximately 88,000 km(2) . However, the actual distribution of tigers across Sumatra has never been accurately mapped. Over the past 20 years, conservation efforts focused on the Sumatran tigers have increased, but the population continues to decline as a result of several key threats. To identify the status of the Sumatran tiger distribution across the island, an island-wide questionnaire survey comprised of 35 respondents from various backgrounds was conducted between May and June 2010. The survey found that Sumatran tigers are positively present in 27 habitat patches larger than 250 km(2) and possibly present in another 2. In addition, a review on major published studies on the Sumatran tiger was conducted to identify the current conservation status of the Sumatran tiger. Collectively, these studies have identified several key factors that have contributed to the decline of Sumatran tiger populations, including: forest habitat fragmentation and loss, direct killing of tigers and their prey, and the retaliatory killing of tigers due to conflict with villagers. The present paper provides management authorities and the international community with a recent assessment and a base map of the actual distribution of Sumatran tigers as well as a general overview on the current status and possible future conservation challenges of Sumatran tiger management. PMID:21392349

  8. Evidence of Fluid/Gas Along the Backthrust Offshore Central Sumatra from Seismic Full Waveform Inversion

    NASA Astrophysics Data System (ADS)

    Singh, S. C.; Huot, G.

    2014-12-01

    The Sumatra subduction zone is one of the most seismically active zones on the earth and has experienced great earthquakes in the last decade, including one of the largest earthquakes of the 21st century on December 26, 2004 (M 9.3) producing a devastating tsunami. Geodetic and seismological studies suggest that a part of the subduction is still fully locked and may produce a great earthquake up to Mw=9 in the coming future. In order to understand the earthquake and subduction zone processes, we applied elastic full waveform inversion (FWI) on 50km deep seismic reflection data from Benkulu forearc basin. Data were acquired in partnership with CGG in 2009 using a 15 km ultra-long offset streamer, with shots every 50m and receivers every 12.5m. Unlike usual exploration data, the streamer was dived at 22.5m and the source was triggered at 15m. These characteristics provided wide aperture and low frequencies to the data which are required for FWI. To match our modelling with the observed data before applying FWI, we first estimated the source wavelet from simulated far-offset signature. Then, the same pass-band filter was applied to both the source and the observed data from 1 to 15 Hz frequency bandwidth. Additionally, an f-k filter was applied to the real data to remove the remaining swell noise up to 4 Hz, without losing any useful signal. Our starting 2D Vp model was found by applying traveltime tomography to a smooth 1D model. Our Vs model was linked by empirical relationship to our Vp model. By inverting first for far-offset refraction to recover the background velocity model and using a multi-scale strategy by going from 1Hz to 15Hz, we image the forearc basin down to 10km depth. We highlight the presence of a 10km wide low velocity structure at 3km depth. The sharp velocity change from 4km/s to 2km/s indicates the presence of gaz or fluid which could come from the mantle through the backthrust fault. The complexity of the sea floor makes the reflection

  9. Correlation of Plio-Pleistocene deposits of the Lower Rhine Basin (North-West Germany) and the Valle Ricca pits (Central Italy)

    NASA Astrophysics Data System (ADS)

    Arias, Claudio; Bigazzi, Giulio; Bonadonna, Francescopaolo; Brunnacker, Karl; Urban, Brigitte

    Biostratigraphic and palaeomagnetic research has been carried out on selected profiles in North-Western Germany and Central Italy in order to correlate Plio-Pleistocene sections. Around the Réunion subchronozone, vegetation in the Valle Ricca was dominated by a mountain forest type pointing to cool climatic conditions. In the Lower Rhine Basin vegetation had a slightly warmer character, but was also dominated strongly by a mountain type of forest vegetation, characteristic of cooler summers and higher precipitation than at present. Two warmer periods have been determined in the Central Italian profiles; the youngest around the Olduvai reversal, should correspond to the youngest Tiglian beds of the Lower Rhine Basin. Deposits older than the Réunion subzone have not been found in the Valle Ricca. In the Lower Rhine Basin, on the other hand, the Gauss-Matuyama boundary is located between the uppermost Pliocene, the Reuverian C and the Praetiglian.

  10. Interpretation of magnetic anomalies over the Grenada Basin

    NASA Astrophysics Data System (ADS)

    Bird, Dale E.; Hall, Stuart A.; Casey, John F.; Millegan, Patrick S.

    1993-10-01

    The Grenada Basin is a back arc basin located near the eastern border of the Caribbean Plate. The basin is bounded on the west by the north-south trending Aves Ridge (a remnant island arc) and on the east by the active Lesser Antilles island arc. Although this physiography suggests that east-west extension formed the basin, magnetic anomalies over the basin exhibit predominantly east-west trends. If the observed magnetic anomalies over the basin are produced by seafloor spreading, then the orientation of extension is complex. Extension in back arc basins is roughly normal to the trench, although some basins exhibit oblique extension. Present models for the formation of the Grenada Basin vary from north-south extension through northeast-southwest extension to east-west extension. An interpretation of magnetic anomalies over the Grenada Basin supports basin development by nearly east-west extension. Low amplitude magnetic anomaly trends subparallel to the island arc magnetic anomaly trends over the southern part of the basin and the results of forward three-dimensional (3-D) magnetic modeling are consistent with this conclusion. Late Cenozoic tectonic movements may have been responsible for disrupting the magnetic signature over the northern part of the basin. On the basis of our 3-D analysis, we attribute the prominent east-west trending anomalies of the Grenada Basin to fracture zones formed during seafloor spreading at low latitude. This east-west trend is not interpreted as indicating north-south extension of the basin.

  11. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  12. Precipitation microstructure in different Madden-Julian Oscillation phases over Sumatra

    NASA Astrophysics Data System (ADS)

    Marzuki; Hashiguchi, Hiroyuki; Kozu, Toshiaki; Shimomai, Toyoshi; Shibagaki, Yoshiaki; Takahashi, Yukihiro

    2016-02-01

    Intraseasonal variations of precipitation and its microstructure are investigated using measurements of the Equatorial Atmospheric Radar (EAR) facilities at Kototabang, west Sumatra, Indonesia (0.20°S, 100.32°E, 864 m above sea level). Raindrop size distribution (DSD) observations are obtained from a 2D-Video Disdrometer (2DVD) with a near continuous record of operation over eight consecutive years (2003-2010). Precipitation types are classified using 1.3-GHz wind profiler observation, and are partitioned according to active and inactive convective phases of Madden-Julian Oscillation (MJO). It is found that precipitation systems during the inactive phase are more continental in nature than those during the active phase. Cloud propagation from brightness temperature data indicates that Sumatra receives the rainfall mainly from maritime clouds during the active phase, while it is mainly from the continental clouds (land-based convection) during the inactive phase. Other remarkable differences between active and inactive phase precipitation systems are also observed from the vertical structure of precipitation. The precipitation during the inactive phase has deeper storms, a higher reflectivity aloft, more lightning activity and less stratiform characteristics, as compared to the active phase. Assessment of cloud effective radius of the Moderate Resolution Imaging Spectroradiometer (MODIS) data also shows a slight difference in the cloud droplet between the active and the inactive MJO phases. Different convective storms in different MJO phases lead to different DSD characteristics and Z-R relationships. The DSD during the inactive phase tends to have a higher concentration of medium and large-size drops than the active counterpart, consistent with the previous study during the first campaign of Coupling Processes in the Equatorial Atmosphere project. Although the DSD parameters and coefficient of Z-R relationships fall within the range of tropical maritime

  13. Long Continuous Deformation during 2008-2012 Sumatra Earthquakes Using DINSAR and GPS

    NASA Astrophysics Data System (ADS)

    Nur Cahyadi, C. N.

    2015-12-01

    Indonesia located in three tectonic plates. This situation caused many earthquakes and long continuous movement of plate tectonics. The island which has big tectonic movement phenomena was Sumatra Island. We monitored long deformation process during interseismic and coseismic of three earthquakes in this Island. The three earthquakes were Mentawai 2008, Padang 2009 and North Sumatra 2012 earthquakes. We used Differential Interferometric Synthetic Aperture Radar (DINSAR) and Global Positioning System (GPS) satellite in order to monitor the displacement. We used GAMIT software for GPS and open source software ROYPAC for DINSAR. Sumatra GPS Array (SUGAR) Networks were used to analyze the displacement rate. The result of displacement was very different year to year, Mw 7.6 Padang earthquake had 15.8 cm up and caused subduction zone of trench Sumatra movement about 1.8 cm to 7 cm up. The displacements was continued by Mw 7.7 Mentawai earthquake 2008. We monitored intersesismic, coseismic and postseismic phase. Coseismic phase was 0.222m in horizontal direction and 0.1415 m in vertical direction (SLBU station). The interseismic phase was smaller about 0.118 m in BSAT stations (south east direction). The biggest deformation was detected during interseismic and postseismic North Sumatra 2012 earthquakes with deformation 0.300-3.00 meter.

  14. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico - petrophysical characterization of the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Lucia, F.J.

    1997-06-01

    Reservoir performance of the South Cowden Grayburg field suggests that only 21 percent of the original oil in place has been recovered. The purpose of this study is to construct a realistic reservoir model to be used to predict the location of the remaining mobile oil. Construction of reservoir models for fluid-flow simulation of carbonate reservoirs is difficult because they typically have complicated and unpredictable permeability patterns. Much of the difficulty results from the degree to which diagenetic overprinting masks depositional textures and patterns. For example, the task of constructing a reservoir model of a limestone reservoir that has undergone only cementation and compaction is easier than constructing a model of a karsted reservoir that has undergone cavern formation and collapse as well as cementation and compaction. The Permian-age carbonate-ramp reservoirs in the Permian Basin, West Texas and New Mexico, are typically anhydritic dolomitized limestone. Because the dolomitization occurred soon after deposition, depositional fabrics and patterns are often retained, and a reservoir model can be constructed using depositional concepts. Recent studies of the San Andres outcrop in the Guadalupe Mountains and the Seminole San Andres reservoir in the Permian Basin illustrate how depositional fabrics and patterns can be used to construct a reservoir model when depositional features are retained.

  15. [Genetic Differentiation of Sockeye Salmon Oncorhynchus nerka from Kamchatka River Basin and the Lake-River Systems of the West Coast of the Bering Sea as Inferred from Data on Single Nucleotide Polymorphism].

    PubMed

    Khrustaleva, A M; Klovach, N V; Vedischeva, E V; Seeb, J E

    2015-10-01

    The variability of 45 single nucleotide polymorphism loci (SNP) was studied in sockeye salmon from the Kamchatka River basin and four lake-river systems of the west coast of the Bering Sea. Based on the genetic differentiation estimates for the largest sockeye salmon populations of Eastern Kamchatka and Chukotka, the examined samples were combined into two regional groups represented by the population of the Kamchatka River drainage, which included numerous local subpopulations and seasonal races, and the northern population grouping from the rivers of Olutorsko-Navarinsky raion, wherein the sockeye salmon from Maynypilginskaya Lake-River system was relatively isolated. Considerable divergence was observed between the island (Sarannoe Lake, Bering Island) and continental populations. Genetic heterogeneity was revealed and groups of early- and late-maturing individuals were isolated in the sample of late-run sockeye salmon from Kamchatka River. In Apuka River, subdivision of the spawning run into two genetically distinct spatial and temporal groupings was also observed. The results suggest that the differentiation of sockeye salmon samples by single nucleotide substitution frequencies was largely due to differences in the direction and strength of local selection at some loci in the population complexes and intrapopulation groupings from the examined river basins of Eastern Kamchatka, Chukotka, and Commander Islands. PMID:27169229

  16. Future fire emissions associated with projected land use change in Sumatra.

    PubMed

    Marlier, Miriam E; DeFries, Ruth; Pennington, Derric; Nelson, Erik; Ordway, Elsa M; Lewis, Jeremy; Koplitz, Shannon N; Mickley, Loretta J

    2015-01-01

    Indonesia has experienced rapid land use change over the last few decades as forests and peatswamps have been cleared for more intensively managed land uses, including oil palm and timber plantations. Fires are the predominant method of clearing and managing land for more intensive uses, and the related emissions affect public health by contributing to regional particulate matter and ozone concentrations and adding to global atmospheric carbon dioxide concentrations. Here, we examine emissions from fires associated with land use clearing and land management on the Indonesian island of Sumatra and the sensitivity of this fire activity to interannual meteorological variability. We find ~80% of 2005-2009 Sumatra emissions are associated with degradation or land use maintenance instead of immediate land use conversion, especially in dry years. We estimate Sumatra fire emissions from land use change and maintenance for the next two decades with five scenarios of land use change, the Global Fire Emissions Database Version 3, detailed 1-km2 land use change maps, and MODIS fire radiative power observations. Despite comprising only 16% of the original study area, we predict that 37-48% of future Sumatra emissions from land use change will occur in fuel-rich peatswamps unless this land cover type is protected effectively. This result means that the impact of fires on future air quality and climate in Equatorial Asia will be decided in part by the conservation status given to the remaining peatswamps on Sumatra. Results from this article will be implemented in an atmospheric transport model to quantify the public health impacts from the transport of fire emissions associated with future land use scenarios in Sumatra. PMID:25044917

  17. Future fire emissions associated with projected land use change in Sumatra.

    PubMed

    Marlier, Miriam E; DeFries, Ruth; Pennington, Derric; Nelson, Erik; Ordway, Elsa M; Lewis, Jeremy; Koplitz, Shannon N; Mickley, Loretta J

    2015-01-01

    Indonesia has experienced rapid land use change over the last few decades as forests and peatswamps have been cleared for more intensively managed land uses, including oil palm and timber plantations. Fires are the predominant method of clearing and managing land for more intensive uses, and the related emissions affect public health by contributing to regional particulate matter and ozone concentrations and adding to global atmospheric carbon dioxide concentrations. Here, we examine emissions from fires associated with land use clearing and land management on the Indonesian island of Sumatra and the sensitivity of this fire activity to interannual meteorological variability. We find ~80% of 2005-2009 Sumatra emissions are associated with degradation or land use maintenance instead of immediate land use conversion, especially in dry years. We estimate Sumatra fire emissions from land use change and maintenance for the next two decades with five scenarios of land use change, the Global Fire Emissions Database Version 3, detailed 1-km2 land use change maps, and MODIS fire radiative power observations. Despite comprising only 16% of the original study area, we predict that 37-48% of future Sumatra emissions from land use change will occur in fuel-rich peatswamps unless this land cover type is protected effectively. This result means that the impact of fires on future air quality and climate in Equatorial Asia will be decided in part by the conservation status given to the remaining peatswamps on Sumatra. Results from this article will be implemented in an atmospheric transport model to quantify the public health impacts from the transport of fire emissions associated with future land use scenarios in Sumatra.

  18. Determining Deep Basin Structure of the Hueco and southern Mesilla Bolsons, West Texas, Southern New Mexico and Northern Chihuahua Using Nonseismic Geophysical Techniques

    NASA Astrophysics Data System (ADS)

    Doser, D. I.; Avila, V.; Budhathoki, P.; Marrufo, S.; Montana, C. J.; Kaip, G.; Moncada, M.; Dena Ornelas, O.

    2012-12-01

    The Hueco and southern Mesilla bolsons are the primary groundwater source for much of the El Paso/Ciudad Juarez metropolitan region of over 1 million residents. The bolsons lie at the point where the strike of the southern Rio Grande rift changes from north-south to northwest-southeast, likely due to its interaction with pre-existing Mesozoic and Paleozoic structures. Tectonic activity continues with recent (< 750,000 years) movement along basin bounding and low level (M<4) seismicity. Over the past 4 years we have been using a conjunction of microgravity, magnetic, water well logs and electrical resistivity studies to image the complex structure of these basins within a heavily urbanized environment. These studies suggest the presence of several northwest-southeast striking cross faults within the southern Mesilla Bolson as well as an extensive subsurface andesite body related to the Cristo Rey laccolith. Intrabasin faults in the Hueco Bolson appear to cut the basin into at least 3 smaller subbasins and to control the boundary between fresh and saline water within the aquifer system beneath El Paso. We are also able to trace the East Franklins Mountain fault (last movement < 15,000 ya) at least 15 km south of the U.S.-Mexico border.

  19. Storm-runoff generation in the Permanente Creek drainage basin, west central California - An example of flood-wave effects on runoff composition

    USGS Publications Warehouse

    Nolan, K.M.; Hill, B.R.

    1990-01-01

    Variations in the isotopic and chemical composition of storm runoff in the 10.6-km2 Permanente Creek basin, Santa Clara County, California, indicate that changes in water composition lag behind changes in streamflow. This lag occurs even though field observations and rainfall-runoff modeling indicate that much of the storm runoff must be composed of "new" water running off impervious surfaces. The apparent incompatibility posed by the presence of "old" water and the direct and indirect evidence that surface runoff contributes substantially to storm runoff can be explained if initial rises in streamflow result from effects of flood waves. Flood waves composed of old channel water reach downstream locations ahead of the new water derived from impervious areas. By this mechanism, streamflow can rise rapidly in response to surface runoff and still be composed of large amounts of old water. Data collected in Permanente Creek indicate that flood waves can occur even in small basins, at least when those basins contain impervious surfaces. ?? 1990.

  20. Deterioration of soil fertility by land use changes in South Sumatra, Indonesia: from 1970 to 1990

    NASA Astrophysics Data System (ADS)

    Lumbanraja, Jamalam; Syam, Tamaluddin; Nishide, Hiroyo; Kabul Mahi, Ali; Utomo, Muhajir; Sarno; Kimura, Makoto

    1998-10-01

    We monitored the land use changes in a hilly area of West Lampung, South Sumatra, Indonesia, from 1970 to 1990. The main data sources were the land use maps produced in 1970, 1978, 1984 and 1990 covering the area of 27 km×27 km. Transmigration and the resultant effect of increased population were the major driving forces in land use changes. Fifty-seven per cent of the study area was covered with primary forests in 1970, but only 13% in 1990. Areas under plantations, which were absent in 1970, increased to 60% in 1990. In addition, the change from monoculture plantations (mostly coffee plantation) to mixed plantations was noticeable from 1984 to 1990. Total upland areas including upland areas under shifting cultivation and upland fields with crops and vegetables decreased from 21% in 1970 to 0·1% in 1990. Soil chemical properties (total organic C, total N, available P, total P, exchangeable cations, cation exchangeable capacity (CEC), etc.) were analysed for lands under different land use forms after deforestation in the study area. Soil samples (surface layers, 0-20 cm, and subsurface layers, 20-40 cm) were collected from three different locations, each comprised of four different land use systems: i.e. primary forests, secondary forests, coffee plantations and cultivated lands. The contents of total organic C, total N, available P, total P, exchangeable cations and CEC decreased significantly with land use change from primary forests to the other land use forms. Cultivated lands exhibited the lowest values. Although less remarkable than in the surface layers, the amounts of total organic C, total N, total P, exchangeable cations and CEC were also decreased by forest clearing in the subsurface layers.Based on the land use changes from 1978 in the study area and the deterioration of soil chemical properties by forest clearing, total decreases in the amounts of nutrients in the surface and subsurface layers were estimated. The land use changes were estimated to

  1. Shallow subsurface temperature surveys in the basin and range province-II. Ground temperatures in the upsal hogback geothermal area, West-Central Nevada, U.S.A.

    USGS Publications Warehouse

    Olmsted, F.H.; Ingebritsen, S.E.

    1986-01-01

    Numerous temperature surveys at a depth of 1 m were made in 1973-1985 in the Upsal Hogback and Soda Lakes geothermal areas in west-central Nevada. Whereas the surveys effectively delineated temperature at depth and heat flow within the relatively intense Soda Lakes thermal anomaly, they were not effective at the diffuse Upsal Hogback anomaly, where several perturbing factors that affect shallow subsurface temperatures are exceedingly variable. Albedo is the most important factor in the Upsal Hogback area, even at a depth of 30 m. All possible perturbing factors should be considered when designing a shallow temperature-based prospecting scheme. ?? 1986.

  2. Performance of Buildings in the 2009 Western Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Deierlein, G.; Hart, T.; Alexander, N.; Hausler, E.; Henderson, S.; Wood, K.; Cedillos, V.; Wijanto, S.; Cabrera, C.; Rudianto, S.

    2009-12-01

    The M7.6 earthquake of 30 September 2009 in Western Sumatra, Indonesia caused significant damage and collapse to hundreds of buildings and the deaths of 1,117 people. In Padang City, with a population of about 900,000 people, building collapse was the primary cause of deaths and serious injuries (313 deaths and 431 serious injuries). The predominant building construction types in Padang are concrete moment frames with brick infill and masonry bearing wall systems. Concrete frames are common in multistory commercial retail buildings, offices, schools, and hotels; and masonry bearing wall systems are primarily used in low-rise (usually single story) residential and school buildings. In general, buildings that collapsed did not conform to modern seismic engineering practices that are required by the current Indonesian building code and would be expected in regions of moderate to high seismicity. While collapse of multi-story concrete buildings was more prevalent in older buildings (more than 10 years old), there were several newer buildings that collapsed. Primary deficiencies identified in collapsed or severely damaged buildings included: (a) soft or weak stories that failed in either by sidesway mechanisms or shear failures followed by loss of axial capacity of columns, (b) lack of ductile reinforcing bar detailing in concrete beams, columns, and beam-column joints, (c) poor quality concrete and mortar materials and workmanship, (d) vulnerable building configurations and designs with incomplete or deficient load paths, and (e) out-of-plane wall failures in unreinforced (or marginally reinforced) masonry. While these deficiencies may be expected in older buildings, damage and collapse to some modern (or recently rennovated buildings) indicates a lack of enforcement of building code provisions for design and construction quality assurance. Many new buildings whose structural systems were undamaged were closed due to extensive earthquake damage to brick infill walls

  3. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, F.J.; Kerans, C.

    1996-12-31

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study.

  4. Availability and chemical quality of ground water in the Crystal River and Cattle Creek Drainage Basins near Glenwood Springs, west-central Colorado

    USGS Publications Warehouse

    Brogden, Robert E.; Giles, T.F.

    1976-01-01

    Parts of the Crystal River and cattle Creek drainage basins near Glenwood Springs, Colo., have undergone rapid population growth in recent years. This growth has resulted in an increased demand for information for additional domestic, industrial, and municipal water supplies. A knowledge of the occurrence of ground water will permit a more efficient allocation of the resource. Aquifers in the two drainage basins include: alluvium, basalts, the Mesa Verde Formation, Mancos Shale, Dakota Sandstone, Morrison Formation, Entrada Sandstone, Maroon Formation, Eagle Valley Evaporite, and undifferentiated formations. Except for aquifers in the alluvium, and basalt, well yields are generally low and are less than 25 gallons per minute. Well yields form aquifers in the alluvium and basalt can be as much as several hundred gallons per minute. Water quality is dependent of rock type. Calcium bicarbonate is the predominant type of water in the study area. However, calcium sulfate type water may be found in aquifers in the Eagle Valley Evaporite and in the alluvium where the alluvial material has been derived from the Eagle Valley Evaporite. Concentrations of selenium in excess of U.S. Public Health Service standards for drinking water can be found locally in aquifers in the Eagle Valley Evaporite. (Woodard-USGS)

  5. Deformations Associated With Large Interplate Earthquakes Along the Sumatra-Andaman Subduction Zone

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Fukushima, Y.; Katagi, T.; Hashizume, M.; Satomura, M.; Wu, P.; Kato, T.

    2008-12-01

    Since the occurrence of the 2004 Sumatra-Andaman earthquake (Mw9.2), the Sumatra-Andaman Subduction zone has attracted geophysicists' attention. We have been carrying on CGPS observation in Thailand and Myanmar to detect postseismic deformation following this gigantic event. Since CGPS on land is not enough to clarify the detailed image of postseismic deformation, we also make InSAR analyses in Andaman and Phuket Islands. On September 12, 2007, another Mw8.4 event occurred SW off Sumatra. We report deformations observed with GPS and SAR including co- and postseismic deformation following this event. We have analyzed CGPS data up to the end of 2007 and detected postseismic displacements all over the Indochina peninsula. Phuket, which suffered from about 26cm coseismic displacement, has shifted by 26cm southwestward till July, 2007. Postseismic transient is clearly recognized and already exceeds coseismic movements at remote sites such as Bangkok and Chiang Mai in Thailand. We processed ALOS/PALSAR data in Andaman and Phuket islands. No remarkable deformation is found in Andaman and Phuket Islands, since the operation period of ALOS/PALSAR is not long enough and the wavelength of postseismic deformation may be much longer than the swath. We try to synthesize the postseismic displacement using a 3-D viscoelastic FEM model. Its results imply that viscoelastic relaxation in mantle with a typical mantle viscosity may play an important role for the observed postseismic transients except during the first six month. An extremely low viscosity is not required beneath the Andaman Sea, though this back arc is now actively opening. Coseismic motion following the 2007 Sumatra event is detected north of Benkgulu on the coast of southern Sumatra with InSAR. The largest LOS displacement of about 35cm is observed 100km NW of Bengkulu. Coseismic westward displacements of 3.5cm from the 2007 Sumatra event are also observed at Singapore, whose epicentral distance is about 700km, with

  6. Water-power resources in upper Carson River basin, California-Nevada, A discussion of potential development of power and reservoir sites on east and west forks, Carson River

    USGS Publications Warehouse

    Pumphrey, Harold L.

    1955-01-01

    West Fork Carson River offers the best opportunity for power development in the Carson River basin. The Hope Valley reservoir site could be developed to provide adequate storage regulation and concentration of fall would permit utilization of 1,400 feet of head in 51h miles below the clam site, or 1,900 feet of head in about 972 miles below the dam site; however, the average annual runoff susceptible of development is only about 70,000 acre-feet which limits the power that could be developed continuously in an average year with regulation to about 8,700 kilowatts utilizing 1,400 feet of head, or 12,000 kilowatts utilizing 1,900 feet of head. The method and degree of development will be determined to large extent by the method devised to supplement regulated flows from the Hope Valley reservoir to supply the water already appropriated for irrigation. If the Hope Valley site and the Watasheamu site on East Fork Carson River were developed coordinately water could be transferred to the West Fork for distribution through canals leading from that stream thus satisfying the deficiency due to regulation at Hope Valley and release of stored water on a power schedule. This would permit utilization of the entire 1,900 feet of fall. Independent development of the West Fork for optimum power production would require re-regulation of releases from Hope Valley reservoir and storage of a considerable part of the fall and winter flow for use during the irrigation season. Adequate storage capacity is apparently not available on the West Fork below Hope Valley; but offstream storage may be available in Diamond Valley which could be utilized by diversion from the West Fork near Woodfords. This would limit the utilization of the stream for power purposes to the development of the 1,400 feet of head between the Hope Valley dam site and Wood fords. In a year of average discharge East Fork Carson River and three of its principal tributaries could be developed to produce about 13

  7. Supplementary information on K-Basin sludges

    SciTech Connect

    MAKENAS, B.J.

    1999-03-15

    Three previous documents in this series have been published covering the analysis of: K East Basin Floor and Pit Sludge, K East Basin Canister Sludge, and K West Basin Canister Sludge. Since their publication, additional data have been acquired and analyses performed. It is the purpose of this volume to summarize the additional insights gained in the interim time period.

  8. Characteristics and properties of the basin-fill aquifer determined from three test wells west of Albuquerque, Bernalillo County, New Mexico

    USGS Publications Warehouse

    Wilkins, D.W.

    1987-01-01

    Three test wells were drilled west of Albuquerque; two are on the mesa west of the city, the third well is near the Rio Grande flood plain, west of the river. Test well 1, was drilled to a depth of 1,204 ft. Transmissivity of perforated intervals in the alluvial zone (980-1121 ft) ranged from 3.1 to 3.9 ft sq/day, and horizontal hydraulic conductivity from .02 to .03 ft/day. Vertical hydraulic conductivity of the semiconfining layer between the alluvial and volcanic zones is estimated to range from .00031 to .0031 ft/day. Transmissivity of the volcanic zone (1139-1179 ft) is about 81 ft sq/day, and horizontal hydraulic conductivity is about 2.0 ft/day. Dissolved-iron and manganese concentrations exceed recommended constituent limits for a public water supply. Vertical flow is upward; the potentiometric surface in the volcanic zone is about 2 ft higher than in the alluvial zone. Water levels are about 883 ft below land surface. Test well 2 was drilled to a depth of 1,828 ft below land surface with seven intervals open to the aquifer. During development, fine sand and silt entered the casing, filling it to a depth of 1,500 ft. The dissolved-cadmium concentration exceeds the maximum contaminant level and the dissolved-manganese concentration exceeds the recommended constituent limit for a public water supply. The vertical flow gradient is downward; the potentiometric surface in the middle and lower zones is about 17 ft lower than in the upper zones. Depth to water in the upper zone is about 767 below land surface and in the lower two zones the depth to water is about 784 ft below land surface. Test well 3 was drilled to a depth of 1,050 ft. Only the interval from 490 to 590 ft below land surface could be used to calculate transmissivity which was about 1,300 ft sq/day; horizontal hydraulic conductivity is about 13 ft/day. Quality of water is acceptable for a public water supply. Vertical flow is downward; the potentiometric surface in the deepest interval is about 7

  9. Origins of streamflow in a crystalline basement catchment in a sub-humid Sudanian zone: The Donga basin (Benin, West Africa): Inter-annual variability of water budget

    NASA Astrophysics Data System (ADS)

    Séguis, L.; Kamagaté, B.; Favreau, G.; Descloitres, M.; Seidel, J.-L.; Galle, S.; Peugeot, C.; Gosset, M.; Le Barbé, L.; Malinur, F.; Van Exter, S.; Arjounin, M.; Boubkraoui, S.; Wubda, M.

    2011-05-01

    SummaryDuring the last quarter of the 20th century, West Africa underwent a particularly intense and generalized drought. During this period, the biggest drops in streamflow were observed in the Sudanian zone rather than in the Sahelian zone, but the reasons are still poorly understood. In 2000, a meso-scale hydrological observatory was set up in the sub-humid Sudanian zone of the Upper Ouémé Valley (Benin). Three embedded catchments of 12-586 km 2 located on a crystalline bedrock were intensively instrumented to document the different terms of the water budget and to identify the main streamflow generating processes and base-flow mechanisms at different scales. Geophysical, hydrological and geochemical data were collected throughout the catchments from 2002 to 2006. Crossing these data helped define their hydrological functioning. The region has seasonal streamflow, and the permanent groundwater in the weathered mantle does not drain to rivers, instead, seasonal perched groundwaters are the major contributor to annual streamflow. The perched groundwaters are mainly located in seasonally waterlogged sandy layers in the headwater bottom-lands called bas-fonds in French-speaking West Africa of 1st order streams. During the period 2003-2006, regolith groundwater recharge ranged between 10% and 15% of the annual rainfall depth. Depletion of permanent groundwater during the dry season is probably explained by local evapotranspiration which was seen not to be limited to gallery forests. During the 4-year study period, a reduction of 20% in annual rainfall led to a 50% reduction in streamflow. This reduction was observed in the two components of the flow: direct runoff and drainage of perched groundwater. Thanks to the comprehensive dataset obtained, the results obtained for the Donga experimental catchment are now being extrapolated to the whole upper Ouémé valley, which can be considered as representative of sub-humid Sudanian rivers flowing on a crystalline

  10. 77 FR 12281 - Williston Basin Interstate Pipeline Company; Notice of Request Under Blanket Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Energy Regulatory Commission Williston Basin Interstate Pipeline Company; Notice of Request Under Blanket Authorization Take notice that on February 15, 2012, Williston Basin Interstate Pipeline Company (Williston Basin), 1250 West Century Avenue, Bismarck, North Dakota 58503, pursuant to its blanket...

  11. How well do land surface models reproduce the water and energy cycles in the West African monsoon system ? Evaluation over the Upper Ouémé basin, Benin (ALMIP2 project)

    NASA Astrophysics Data System (ADS)

    Peugeot, C.; Boone, A. A.; Demarty, J.; manuela, G.; Laurent, K.; Cappelaere, B.; Awessou, B.; Cohard, J.; Galle, S.; Gascon, T.; Getirana, A.; Hector, B.; Mamadou, O.; Richard, A.; Seghieri, J.; Séguis, L.

    2013-12-01

    Land surface models (LSMs) are widely used in environmental and climate sciences to simulate matter (water, carbon) and energy exchanges between the continental surface and the atmosphere. They are also increasingly used in a wide range of applications such as impact studies on land use management or climate change. The AMMA project and the associated observation campaigns provided unique data-sets to drive land surface models and to evaluate their results over the West African region, where such high added-value information has been lacking. In the framework of the ALMIP2 project (AMMA Land surface Model Inter-comparison Project - phase 2), simulations from about 20 LSMs were done on three contrasted meso-scale domains in Mali, Niger and Benin, over the period 2005-2008 using the same forcing data sets at 0.05 degree and 30 minutes space-time resolution. This talk analyses the simulated water and energy budget components on the sub-humid upper Ouémé basin (10,000 km2, Benin site), where the high-quality rainfall and runoff datasets allow a detailed and original hydrological evaluation of these meso-scale simulations. As expected, the model inter-comparison shows large differences in the water and energy partitioning, either at the annual (see figure) or intra-seasonal time scale. Most of them do not reproduce the observed runoff, with annual biases ranging from -100% to 200 %. The multi-model mean Evapotranspiration (ET) correctly matches the observations, specially in the rainy season, with contrasted simulations of evaporation vs. transpiration from one model to the other. The identification of the more realistic water and energy partitioning is a key issue addressed by the ALMIP2 project. Previous studies performed in the AMMA framework on the Oueme basin highlighted the key role of below-ground water dynamics in the hydrological cycle (lateral transfer to rivers, groundwater seasonal recharge-discharge, ...). Moreover, field evidences suggested that

  12. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-29

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  13. Geoscience/Engineering Characterization of the Interwell Environment in Carbonate Reservoirs Based on Outcrop Analogs, Permian Basin, West Texas and New Mexico.

    SciTech Connect

    Lucia, Jerry F.; Kerans, Charles

    1997-05-19

    The objective of this project is to investigate styles of reservoir heterogeneity found in low permeability pelleted wackestone/packstone facies and mixed carbonate/clastic facies found in Permian Basin reservoirs by studying similar facies exposed in the Guadalupe Mountains. Specific objectives for the outcrop study include construction of a stratigraphic framework, petrophysical quantification of the framework, and testing the outcrop reservoir model for effects of reservoir heterogeneity on production performance. Specific objectives for the subsurface study parallel objectives for the outcrop study. Subsurface Activities - We continue to prepare two final reports that summarize research results of the South Cowden Field study. One report summarizes results of the petrophysical characterization research, and one summarizes results of the fluid-flow modeling research. Outcrop Activities - We also continue to prepare the final report, which summarizes the research results of the Grayburg outcrop reservoir study.

  14. Results from SCS Profiling of the Sumatra accretionary prism: insights into tsnamigenesis

    NASA Astrophysics Data System (ADS)

    Fisher, D.; Mosher, D.; Austin, J.; Gulick, S.; Moran, K.; Masterlark, T.

    2007-12-01

    The SEATOS high resolution single-channel seismic reflection survey of the Sumatran accretionary prism depicts a landward-vergent thrust front, with active folding characterizing part of the December 2004 Mw9.2 earthquake rupture zone. Structure and bathymetry co-vary at distinct wavelengths along a 220-km-long profile crossing the prism and the Aceh (forearc) Basin. At the largest wavelength (tens of kms), the prism surface is defined by a steep (8-12 degrees), 55-km-wide outer slope, a 110-km-wide upper slope forming a broad depression between two forearc highs, and a 25 km-wide, steep inner slope between the landward high and the forearc basin. Anticlinal ridges spaced ~13 km apart display landward- and seaward-vergent folds along the inner and outer slopes, respectively; symmetric folding occurs across the upper slope. We suggest that the long-wavelength variations are consistent with the existence of a strong inner wedge beneath the upper slope. The ~13 km anticline spacing implies deformation of a slope apron deforming independently of this stronger wedge interior. Seismic profiles crossing the toe of the prism image a series of landward vergent, fault-related folds, suggesting that the shallow fill of the Sunda Trench is delaminated from the predominantly seaward-vergent plate boundary system and is uptilted along a triangle zone. Profiles crossing the seaward flank of the Aceh Basin reveal a near- vertical, undulatory deformation front that appears to mark the location of the West Andaman-Mentawai right- lateral strike-slip fault zone. Our model for prism architecture based on these geophysical results involves advance of the strong inner wedge during great earthquakes like the 2004 event, which then peels up shallower and less competent trench fill, deforming the toe and the upper slope of the forearc, producing massive uplift that is likely tsunamigenic. Seismic rupture was limited to the megathrust westward of the West Andaman fault and ROV observations

  15. Heterogeneity of fluvial-deltaic reservoirs in the Appalachian basin: A case study from a Lower Mississippian oil field in central West Virginia

    SciTech Connect

    Hohn, M.E.; McDowell, R.R.; Matchen, D.L.

    1997-06-01

    Since discovery in 1924, Granny Creek field in central West Virginia has experienced several periods of renewed drilling for oil in a fluvial-deltaic sandstone in the Lower Mississippian Price Formation. Depositional and diagenetic features leading to reservoir heterogeneity include highly variable grain size, thin shale and siltstone beds, and zones containing large quantities of calcite, siderite, or quartz cement. Electrofacies defined through cluster analysis of wireline log responses corresponded approximately to facies observed in core. Three-dimensional models of porosity computed from density logs showed that zones of relatively high porosity were discontinuous across the field. The regression of core permeability on core porosity is statistically significant, and differs for each electrofacies. Zones of high permeability estimated from porosity and electrofacies tend to be discontinuous and aligned roughly north-south. Cumulative oil production varies considerably between adjacent wells, and corresponds very poorly with trends in porosity and permeability. Original oil in place, estimated for each well from reservoir thickness, porosity, water saturation, and an assumed value for drainage radius, is highly variable in the southern part of the field, which is characterized by relatively complex interfingering of electrofacies and similar variability in porosity and permeability.

  16. Stratigraphy, sedimentology, and ichnology of the Late Pennsylvanian Glenshaw Formation (Lower Conemaugh Group), southern Dunkard basin, Ohio-Kentucky-West Virginia

    SciTech Connect

    Martino, R.L. . Dept. of Geology)

    1994-03-01

    Facies analysis of outcrops of the Glenshaw Formation was carried out at 45 localities over a 761 sq. km area. The glenshaw Formation is 61--76 m thick in the study area. Four marine units (Lower Brush Creek, Upper Brush Creek, Cambridge , and Ames) occur which contain invertebrate body fossils and/or trace fossils including Teichichnus, Rhizocorallium, Aulichnites, Paleophycus, Lockeia, and Curvolithus. Alluvial channel-fills contain internal features that reflect deposition in high sinuosity suspended or mixed load rivers. Paleocurrent data (N = 77) are broadly dispersed with a mean azimuth of 335 degrees. Overbank facies have yielded trackways from giant arthropods and Eryopoid amphibians (Limnopus). There are fewer marine units in the glenshaw than toward the north and west which has made direct detailed correlation of much of the formation problematic. The coal beds and marine units used previous stratigraphic studies may be extended through the recognition of non-coal-bearing paleosols and marine-influenced intervals distinguished by facies relations, and sedimentary and biogenic structures. Nine laterally persistent, paleosol-bounded packages occur which are comparable to allocyclic T-R units reported by Busch and Rollins (1984) from Pennsylvania and Ohio. Alternating episodes of soil formation and alluvial aggradation may reflect updip coastal plain responses to low stand incision of drainage lines and sediment bypassing followed by aggradation of alluvial systems in response to rising sea level. Climate changes may also have played a role in sediment flux.

  17. Monitoring the UPS and Downs of Sumatra and Java with D-Insar Time-Series

    NASA Astrophysics Data System (ADS)

    Chaussard, E.; Amelung, F.

    2010-12-01

    We performed, for the first time, a global D-InSAR survey of the Indonesian islands of Sumatra and Java to define locations where deformation is occurring. The goals of this study are 1) to create an inventory of actively deforming volcanic centers and 2) monitor all types of ground motion. This work provides ground deformation data for previously unmonitored areas and can assist the Indonesian authorities to improve hazards assessment. The D-InSAR survey covers an area of about 500 000 km2 and 3000 km long on the islands of Sumatra, Java and Bali. We used ALOS data from 45 tracks and more than 1500 granules obtained from the Alaska Satellite Facility (ASF) through the US Government Research Consortium (USGRC). We completed more than 1000 interferograms spanning a period from the end of 2006 to the beginning of 2009. L-band SAR images enable deformation mapping at global scales even in highly vegetated areas where C-band signal experiences loss of coherence. To identify locations where ground deformations are occurring, we used multiple SAR acquisitions of the same area and performed time series analysis using the Small BAseline Subset (SBAS) method. Interferograms with a maximum spatial baseline of 3000 m were phase-unwrapped and subsequently inverted for the phase with respect to the first acquisition. Temporal coherence of each pixel is computed on the set of interferograms in order to select only pixels with high temporal coherence. The compiled InSAR velocity map reveals the background level of activity of the 84 volcanic centers constituting the Sumatra, Java and Bali volcanic arcs. We identified possible uplift at 6 volcanic centers: Agung (Bali), Lamongan (Java), Lawu (Java), Slamet (Java), Kerinci (Sumatra) and Sinabung (Sumatra). Moreover, we identified subsidence in 5 major cities and 1 coastal area. Subsidence rates range from 6 cm/yr in Medan, the largest city of Sumatra, to more than 15 cm/yr in Jakarta. These major subsidence areas are probably due

  18. Tectonic events, sequence stratigraphy and prediction of petroleum play elements in the Cretaceous and Tertiary of the northern Carnarvon Basin, north west shelf, Australia

    SciTech Connect

    Romine, K.K.; Durrant, J.D.

    1996-12-31

    The Carnarvon Basin is one of Australia`s most prolific oil and gas provinces. A recent Paleocene discovery has initiated a shift in exploration interest from traditional Jurassic/Triassic plays to the younger Cretaceous and Tertiary section. To improve play element prediction, a sequence stratigraphic study has been completed, utilizing newly acquired, regional high-resolution seismic data and 80 wells. The occurrence and distribution of the key play elements, reservoir, source and seal, is controlled by the interaction of tectonic subsidence, eustasy and paleogeography, with traps and migration pathways set up and modified by regional tectonic events. For example, a major rifting event commenced in the latest Kimmeridgian-Tithonian that resulted in structuring of older Jurassic sediments and initiation of seafloor spreading in the adjacent Cuvier-Gascoyne Abyssal Plain in the Valanginian. This event was accompanied by a dramatic fall in eustasy that initiated the deposition of high-quality reservoir sandstones of the Tithonian-Valanginian age Barrow Delta. The post-rift phase of thermal cooling and rapid subsidence resulted in transgression, accompanied by deposition of backstepping parasequences of the Mardie Greensand, a potential thief zone and reservoir, and culminated in maximum transgression and deposition of seal and source facies of the Muclerong Shale. The improved sequence stratigraphic framework established in this study provides a predictive tool for the development and assessment of new plays.

  19. Tectonic events, sequence stratigraphy and prediction of petroleum play elements in the Cretaceous and Tertiary of the northern Carnarvon Basin, north west shelf, Australia

    SciTech Connect

    Romine, K.K. ); Durrant, J.D. )

    1996-01-01

    The Carnarvon Basin is one of Australia's most prolific oil and gas provinces. A recent Paleocene discovery has initiated a shift in exploration interest from traditional Jurassic/Triassic plays to the younger Cretaceous and Tertiary section. To improve play element prediction, a sequence stratigraphic study has been completed, utilizing newly acquired, regional high-resolution seismic data and 80 wells. The occurrence and distribution of the key play elements, reservoir, source and seal, is controlled by the interaction of tectonic subsidence, eustasy and paleogeography, with traps and migration pathways set up and modified by regional tectonic events. For example, a major rifting event commenced in the latest Kimmeridgian-Tithonian that resulted in structuring of older Jurassic sediments and initiation of seafloor spreading in the adjacent Cuvier-Gascoyne Abyssal Plain in the Valanginian. This event was accompanied by a dramatic fall in eustasy that initiated the deposition of high-quality reservoir sandstones of the Tithonian-Valanginian age Barrow Delta. The post-rift phase of thermal cooling and rapid subsidence resulted in transgression, accompanied by deposition of backstepping parasequences of the Mardie Greensand, a potential thief zone and reservoir, and culminated in maximum transgression and deposition of seal and source facies of the Muclerong Shale. The improved sequence stratigraphic framework established in this study provides a predictive tool for the development and assessment of new plays.

  20. Stratigraphic Framework of Cambrian and Ordovician Rocks in the Appalachian Basin from Sequatchie County, Tennessee, through Eastern Kentucky, to Mingo County, West Virginia

    USGS Publications Warehouse

    Ryder, Robert T.; Crangle, Robert D.; Repetski, John E.; Harris, Anita G.

    2008-01-01

    Cross section H-H' is the seventh in a series of restored cross sections constructed by the lead author to show the stratigraphic framework of Cambrian and Ordovician rocks in the Appalachian basin from Pennsylvania to Tennessee. The sections show complexly intertongued carbonate and siliciclastic lithofacies, marked thickness variations, key marker horizons, unconformities, stratigraphic nomenclature of the Cambrian and Ordovician sequence, and major faults that offset Proterozoic basement and overlying lower Paleozoic rocks. Several of the drill holes along the cross section have yielded a variety of whole and (or) fragmented conodont elements. The identifiable conodonts are used to differentiate strata of Late Cambrian, Early Ordovician, and Middle Ordovician age, and their conodont color alteration index (CAI) values are used to establish the thermal maturity of the sequence. Previous cross sections in this series are G-G', F-F', E-E', D-D', C-C', and B-B'. Many of these cross sections (B-B', C-C', D-D', and G-G') have been improved with the addition of gamma-ray log traces, converted to digital images, and made accessible on the Web.

  1. Improvement and Comparative Assessment of a New Hydrological Modelling Approach for the Ouémé River Basin (Bénin), West Africa

    NASA Astrophysics Data System (ADS)

    GABA, C. O. U.

    2015-12-01

    Assessing water resources is still an important issue especially in the context of climatic changes. Although numerous hydrological models exist, new approaches are still under investigation. In this context, we propose a new modelling approach based on the Physics Principle of Least Action. A first version of a Least Action based model, in its deterministic version has already given very good results on simulating the Bétérou catchment in the Ouémé basin, Benin. The paper presents new hypotheses to go further in the model development with a view of widening its application. The improved version of the model MODYPMA was applied on 22 subcatchments in Africa, in Bénin, Côte d'Ivoire, Ethiopia; in Europe, and in the USA. Its performance was compared to two well known lumped conceptual models, the GR4J and HBV models. The model could be successfully calibrated and validated; it shows a good performance for a range of scales but a limited applicability to catchments smaller than 500 km2 . The analysis revealed that the three models have similar performance and timing errors. The parameter uncertainty was analysed using the GLUE methodology. It is concluded that model uncertainty is higher during high flows and that uncertainty analysis should include the uncertainty of the discharge data. Finally, some aspects that further research must address are brought out.

  2. Ground water withdrawn for municipal, industrial, and irrigation use in the Upper Peace and Alafia River basins, west-central Florida, 1970-74

    USGS Publications Warehouse

    Robertson, Alton F.; Mills, L.R.; Parsons, D.C.

    1978-01-01

    Data are presented for ground-water withdrawals for municipal, industrial and irrigation use in the upper Peace and Alafia River basins during 1970-71. Within the 1,160-square-mile study area, the principal source of ground water is the Floridan aquifer. Methods used to determine ground-water withdrawal include: metering water use; relating measured well discharge to power consumption of pumping time; and relating water use to phosphate production, citrus irrigation or processing. About 90 percent of municipal pumpage is metered, and annual pumpage increased from 11,165 million gallons in 1970 to 13,455 in 1974. Water use per ton of phosphate produced is estimated to be 3,320 gallons per ton prior to 1971 and 2,460 gallons per ton from 1971 through 1974. Estimated ground-eater use by the phosphate industry has declined from 93.3 billion gallons in 1970 to 78.7 in 1974. Citrus irrigation pumpage is obtained by extrapolating pumpage obtained from pilot areas of unmeasured areas and has declined from 33.4 billion gallons in 1970 to 31.3 in 1974. The citrus processing industry used about 4.9 billion gallons in 1970 and about 5.9 in 1974. (Woodard-USGS)

  3. Sedimentary profile from oxbow lake as an archive for past productivity and vegetation changes: a case study from Ganges basin, West Bengal, India

    NASA Astrophysics Data System (ADS)

    Rakshit, Subhadeep; Ghosh, Sambit; Sanyal, Prasanta; Ambili, Anoop

    2015-04-01

    Isotope (δ13CSOM) and biomarker (lipid n-alkane) investigations has been carried out on three sedimentary profiles (ca. 1.8 m depth) collected from Mohanpur, West Bengal, India with the aim of reconstructing paleovegetational and paleoproductivity changes. Satellite images reveal that the investigated sediments has been deposited in an oxbow lake setting of the river Ganges. The correlation of the three sedimentary profiles has been achieved using lithological and isotopic (δ13CSOM) marker layers. The total organic carbon (TOC) content of the profile ranges from 0.9% to 0.1%. The isotopic analysis (δ13CSOM) shows values mostly fluctuating between -19.2o to -22o with a rapid excursions (~5) showing enriched δ13CSOMvalue (-14.2) observed at ca. 1.5 m depth. The biomarker studies of the profile reveals dominant preferences in short carbon chain (C14, C16, C18, C20) with a little preferences for higher chain (C29, C31, C33). Interestingly, n-alkanes at 1.5 m depth shows very high concentration in short chain n-alkanes. Since the lower chain n-alkane represents aquatic vegetation/productivity and higher chain indicates the terrestrial contribution, the data from the investigated sedimentary profile shows contribution mostly from aquatic vegetation with a little contribution from terrestrial plants. This inference has been further corroborated by δ13CSOMvalues (-19.2o to -22) of the sedimentary profile typical of mixed aquatic and terrestrial vegetation. Additionally, the enriched δ13CSOMvalue (-14.2) coupled with very high concentration of short chain n-alkanes at 1.5 m depth reveals intense lake eutrophication. The development of rigorous chronology and high resolution data set of additional analytical parameters (e.g., C/N, δ15N) will provide crucial paleoclimate data set from this unexplored setting of Indian summer monsoon domain.

  4. Streamflow and water-quality properties in the West Fork San Jacinto River Basin and regression models to estimate real-time suspended-sediment and total suspended-solids concentrations and loads in the West Fork San Jacinto River in the vicinity of Conroe, Texas, July 2008-August 2009

    USGS Publications Warehouse

    Bodkin, Lee J.; Oden, Jeannette H.

    2010-01-01

    To better understand the hydrology (streamflow and water quality) of the West Fork San Jacinto River Basin downstream from Lake Conroe near Conroe, Texas, including spatial and temporal variation in suspended-sediment (SS) and total suspended-solids (TSS) concentrations and loads, the U.S. Geological Survey, in cooperation with the Houston-Galveston Area Council and the Texas Commission on Environmental Quality, measured streamflow and collected continuous and discrete water-quality data during July 2008-August 2009 in the West Fork San Jacinto River Basin downstream from Lake Conroe. During July 2008-August 2009, discrete samples were collected and streamflow measurements were made over the range of flow conditions at two streamflow-gaging stations on the West Fork San Jacinto River: West Fork San Jacinto River below Lake Conroe near Conroe, Texas (station 08067650) and West Fork San Jacinto River near Conroe, Texas (station 08068000). In addition to samples collected at these two main monitoring sites, discrete sediment samples were also collected at five additional monitoring sites to help characterize water quality in the West Fork San Jacinto River Basin. Discrete samples were collected semimonthly, regardless of flow conditions, and during periods of high flow resulting from storms or releases from Lake Conroe. Because the period of data collection was relatively short (14 months) and low flow was prevalent during much of the study, relatively few samples collected were representative of the middle and upper ranges of historical daily mean streamflows. The largest streamflows tended to occur in response to large rainfall events and generally were associated with the largest SS and TSS concentrations. The maximum SS and TSS concentrations at station 08067650 (180 and 133 milligrams per liter [mg/L], respectively) were on April 19, 2009, when the instantaneous streamflow was the third largest associated with a discrete sample at the station. SS concentrations

  5. Case Studies of Massive Gravity Slides Imaged in 3D Seismic Volumes: Passive Margin and Basinal Settings (West Africa and Northwest Europe)

    NASA Astrophysics Data System (ADS)

    Benjamin, U. K.; Le, A. N.; Oluboyo, A. P.; Irving, D. H.; Huuse, M.

    2010-12-01

    Regionally extensive scour surfaces on continental margins and in epeiric basins develop due to two major processes: submarine landslides, mainly affecting slopes in excess of 1 degree and subglacial scour beneath ice streams draining alpine or continental ice sheets. Both types of surfaces can extend for tens to hundreds of kilometres in the dip and strike directions, with tens of metres relief across tens of kilometres long scours and ridges. Correct interpretation within a sediment system tract enlightens models of synchronous glacial, marine and climatic conditions. We present four megaslides imaged in, and interpreted from 3D seismic volumes acquired in diverse settings: 1: On the passive margin shelf of Cameroon, large-scale, downslope-oriented striations extend 40 km from the upper slope to the deep basin area. Individual striations are 20-50 m wide, 8 km long, 5-10 ms TWT deep, and broadly arcuate. The striations present in two sets and mark the base of a chaotic-to-discontinuous, high-amplitude package with chaotic, low amplitude reflections in the unstriated area. The facies is interpreted as a zone of repeated gravity sliding during the early Pleistocene in response to tectono-climatic forcing. 2: A basal surface from the Moray Firth, UK Central North Sea, tentatively dated as Paleocene in age. It is 20 km in width, over 40 km long and displays parallel grooves measuring typically 100-1000 m wide, 10-20 km long, of sinuous form along the section imaged in the dataset and with evidence of post-slump failure along the margins of the slide zone. It is interpreted as scour caused by a single sliding event. 3: An areally extensive scoured surface measuring 45x45 km that is part of a larger Pliocene system on the Angolan margin. The basal shear surface is marked by divergent scours. The geometry and spatial location of this flow are confined by listric faults and salt-cored folds with compressional thrusts within the distal toe of deposits on the flanks of

  6. Paleontological analysis of a lacustrine carbonaceous uranium deposit at the Anderson mine, Date Creek basin, west-central Arizona (U.S.A.)

    USGS Publications Warehouse

    Otton, J.K.; Bradbury, J.P.; Forester, R.M.; Hanley, J.H.

    1990-01-01

    The Tertiary sedimentary sequence of the Date Creek basin area of Arizona is composed principally of intertonguing alluvial-fan and lacustrine deposits. The lacustrine rocks contain large intermediate- to, locally, high-grade uranium deposits that form one of the largest uranium resources in the United States (an estimated 670,000 tons of U3O8 at an average grade of 0.023% is indicated by drilling to date). At the Anderson mine, about 50,000 tons of U3O8 occurs in lacustrine carbonaceous siltstones and mudstones (using a cutoff grade of 0.01%). The Anderson mine constitutes a new class of ore deposit, a lacustrine carbonaceous uranium deposit. Floral and faunal remains at the Anderson mine played a critical role in creating and documenting conditions necessary for uranium mineralization. Organic-rich, uraniferous rocks at the Anderson mine contain plant remains and ostracodes having remarkably detailed preservation of internal features because of infilling by opaline silica. This preservation suggests that the alkaline lake waters in the mine area contained high concentrations of dissolved silica and that silicification occurred rapidly, before compaction or cementation of the enclosing sediment. Uranium coprecipitated with the silica. Thinly laminated, dark-colored, siliceous beds contain centric diatoms preserved with carbonaceous material suggesting that lake waters at the mine were locally deep and anoxic. These alkaline, silica-charged waters and a stagnant, anoxic environment in parts of the lake were necessary conditions for the precipitation of large amounts of uranium in the lake-bottom sediments. Sediments at the Anderson mine contain plant remains and pollen that were derived from diverse vegetative zones suggesting about 1500 m of relief in the area at the time of deposition. The pollen suggests that the valley floor was semiarid and subtropical, whereas nearby mountains supported temperate deciduous forests. ?? 1990.

  7. Agricultural crop mapping and classification by Landsat images to evaluate water use in the Lake Urmia basin, North-west Iran

    NASA Astrophysics Data System (ADS)

    Fazel, Nasim; Norouzi, Hamid; Madani, Kaveh; Kløve, Bjørn

    2016-04-01

    Lake Urmia, once one of the largest hypersaline lakes in the world has lost more than 90% of its surface body mainly due to the intensive expansion of agriculture, using more than 90% of all water in the region. Access to accurate and up-to-date information on the extent and distribution of individual crop types, associated with land use changes and practices, has significant value in intensively agricultural regions. Explicit information of croplands can be useful for sustainable water resources, land and agriculture planning and management. Remote sensing, has been proven to be a more cost-effective alternative to the traditional statistically-based ground surveys for crop coverage areas that are costly and provide insufficient information. Satellite images along with ground surveys can provide the necessary information of spatial coverage and spectral responses of croplands for sustainable agricultural management. This study strives to differentiate different crop types and agricultural practices to achieve a higher detailed crop map of the Lake Urmia basin. The mapping approach consists of a two-stage supervised classification of multi-temporal multi-spectral high resolution images obtained from Landsat imagery archive. Irrigated and non-irrigated croplands and orchards were separated from other major land covers (urban, ranges, bare-lands, and water) in the region by means of maximum Likelihood supervised classification method. The field data collected during 2015 and land use maps generated in 2007 and Google Earth comparisons were used to form a training data set to perform the supervised classification. In the second stage, non-agricultural lands were masked and the supervised classification was applied on the Landsat images stack to identify seven major croplands in the region (wheat and barley, beetroot, corn, sunflower, alfalfa, vineyards, and apple orchards). The obtained results can be of significant value to the Urmia Lake restoration efforts which

  8. Rupture and frequency-dependent seismic radiation of the 2012 Mw 8.6 Sumatra strike-slip earthquake

    NASA Astrophysics Data System (ADS)

    Yin, Jiuxun; Yao, Huajian

    2016-06-01

    On 2012 April 11, a great strike-slip earthquake (moment magnitude of Mw 8.6) occurred off the west coast of northern Sumatra area followed by an Mw 8.2 aftershock 2 hr later. Different geophysical data and methods have been used to investigate the mechanism, faulting, seismic radiation and slip propagation of this event, but frequency-dependent features of its rupture process have not been discussed much. In this study, we use a compressive sensing method based on sparsity inversion in the frequency domain to study the frequency-dependent seismic radiation and rupture process of this event. Our results indicate a very complex rupture process concerning at least three different rupture stages on multiple subfaults with nearly conjugate geometries. The main shock has triggered seismicity on a series of ridge-perpendicular or ridge-parallel conjugate strike-slip faults around the Nighty East Ridge. Obvious frequency-dependent rupture process has been presented and discussed. Combining results from slip inversion based on the finite-fault model, we observe that in the beginning stage of the rupture lower frequency radiation appears to originate from the areas with large slip, while the high-frequency radiation is located at the boundary of large-slip region or rupture front. Some radiation probably originates from the repeating slip on the main faults or triggered events on some nearby faults in the rupture area. The complex frequency-dependent seismic radiation patterns observed in this study provide important information for future investigation of rupture physics of this complex strike-slip event.

  9. Ischnura foylei sp. nov. (Odonata, Coenagrionidae) from the highlands of Sumatra.

    PubMed

    Kosterin, Oleg E

    2015-01-01

    Ischnura foylei sp. nov. is described from Indonesia, Sumatra, Jambi Province, Danau Gunung Tujuh (or Danau Sakti), a lake situated in an extinct volcanic crater, 1°41'15"S, 101°25'28"S, 1995 m a.s.l. Structurally it is close to I. senegalensis but larger and with differently shaped cerci in males and a more trilobate posterior lobe of the prothorax; males and androchromatic females have a unique colour pattern. PMID:26624348

  10. Postseismic deformations following the Sumatra-Andaman earthquake in SE Asia during three and half years

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Fukushima, Y.; Katagi, T.; Hashizume, M.; Satomura, M.; Wu, P.; Ishii, M.; Kato, T.; Fukuda, Y.

    2009-04-01

    Since the occurrence of the 2004 Sumatra-Andaman earthquake (Mw9.2), the Sumatra-Andaman Subduction zone has attracted geophysicists' attention. We have been carrying on CGPS observation in Thailand and Myanmar to detect postseismic deformation following this gigantic event. Since CGPS on land is not enough to clarify the detailed image of postseismic deformation, we also make InSAR analyses in Andaman and Phuket Islands. On September 12, 2007, another Mw8.4 event occurred SW off Sumatra. We report deformations observed with GPS and SAR including co- and postseismic deformation following this event. We have analyzed CGPS data up to the end of 2007 and detected postseismic displacements all over the Indochina peninsula. Phuket, which suffered from about 26cm coseismic displacement, has shifted by ~26cm southwestward till July, 2007. Postseismic transient is clearly recognized and already exceeds coseismic movements at remote sites such as Bangkok and Chiang Mai in Thailand. We try to invert observed postseismic displacement and estimate distribution of afterslip using Yabuki and Matsu'ura's(1992) scheme. Afterslip may have rapidly decayed in and around the source region of the Nias earthquake and beneath the Andaman Islands, while it still continues beneath the northern tip of Sumatra and Nicobar Island. This result implies spatial variation in frictional property on the plate interface. Our GPS sites are located in far field and the afterslip distribution obtained above does not have enough resolution in the depth direction. In order to examine near-field displacement, we also process 3 ALOS/PALSAR images acquired during Jun.19, 2007 and May 6, 2008, in Andaman Islands in order detect postseismic transient. The result shows a negative line-of-sight displacement in the southern part, which is consistent with CGPS observation by Paul et al.(2007). This movement can be simulated by an afterslip on a shallow part of the plate interface.

  11. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    SciTech Connect

    Lestari, Titik; Nugraha, Andri Dian

    2015-04-24

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA’s) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 – April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity.

  12. Coseismic and post-seismic signatures of the Sumatra 2004 December and 2005 March earthquakes in GRACE satellite gravity

    USGS Publications Warehouse

    Panet, I.; Mikhailov, V.; Diament, M.; Pollitz, F.; King, G.; de Viron, O.; Holschneider, M.; Biancale, R.; Lemoine, J.-M.

    2007-01-01

    The GRACE satellite mission has been measuring the Earth's gravity field and its temporal variations since 2002 April. Although these variations are mainly due to mass transfer within the geofluid envelops, they also result from mass displacements associated with phenomena including glacial isostatic adjustment and earthquakes. However, these last contributions are difficult to isolate because of the presence of noise and of geofluid signals, and because of GRACE's coarse spatial resolution (>400 km half-wavelength). In this paper, we show that a wavelet analysis on the sphere helps to retrieve earthquake signatures from GRACE geoid products. Using a wavelet analysis of GRACE geoids products, we show that the geoid variations caused by the 2004 December (Mw = 9.2) and 2005 March (Mw = 8.7) Sumatra earthquakes can be detected. At GRACE resolution, the 2004 December earthquake produced a strong coseismic decrease of the gravity field in the Andaman Sea, followed by relaxation in the area affected by both the Andaman 2004 and the Nias 2005 earthquakes. We find two characteristic timescales for the relaxation, with a fast variation occurring in the vicinity of the Central Andaman ridge. We discuss our coseismic observations in terms of density changes of crustal and upper-mantle rocks, and of the vertical displacements in the Andaman Sea. We interpret the post-seismic signal in terms of the viscoelastic response of the Earth's mantle. The transient component of the relaxation may indicate the presence of hot, viscous material beneath the active Central Andaman Basin. ?? 2007 The Authors Journal compilation ?? 2007 RAS.

  13. Increasing potential of biomass burning over Sumatra, Indonesia induced by anthropogenic tropical warming

    NASA Astrophysics Data System (ADS)

    Kartika Lestari, R.; Watanabe, Masahiro; Imada, Yukiko; Shiogama, Hideo; Field, Robert D.; Takemura, Toshihiko; Kimoto, Masahide

    2014-10-01

    Uncontrolled biomass burning in Indonesia during drought periods damages the landscape, degrades regional air quality, and acts as a disproportionately large source of greenhouse gas emissions. The expansion of forest fires is mostly observed in October in Sumatra favored by persistent droughts during the dry season from June to November. The contribution of anthropogenic warming to the probability of severe droughts is not yet clear. Here, we show evidence that past events in Sumatra were exacerbated by anthropogenic warming and that they will become more frequent under a future emissions scenario. By conducting two sets of atmospheric general circulation model ensemble experiments driven by observed sea surface temperature for 1960-2011, one with and one without an anthropogenic warming component, we found that a recent weakening of the Walker circulation associated with tropical ocean warming increased the probability of severe droughts in Sumatra, despite increasing tropical-mean precipitation. A future increase in the frequency of droughts is then suggested from our analyses of the Coupled Model Intercomparison Project Phase 5 model ensembles. Increasing precipitation to the north of the equator accompanies drier conditions over Indonesia, amplified by enhanced ocean surface warming in the central equatorial Pacific. The resultant precipitation decrease leads to a ˜25% increase in severe drought events from 1951-2000 to 2001-2050. Our results therefore indicate the global warming impact to a potential of wide-spreading forest fires over Indonesia, which requires mitigation policy for disaster prevention.

  14. Viscoelastic relaxation in a heterogeneous Earth following the 2004 Sumatra-Andaman earthquake

    NASA Astrophysics Data System (ADS)

    Wiseman, Kelly; Bürgmann, Roland; Freed, Andrew M.; Banerjee, Paramesh

    2015-12-01

    Consideration of the three-dimensional heterogeneity of mantle rheology allows models of viscoelastic relaxation following the 2004 Sumatra-Andaman earthquake to simultaneously fit both the observed far-field and near-field postseismic deformation. We use horizontal and vertical campaign and continuous GPS observations from the Andaman, Nicobar, and Sumatran forearc islands, mainland Sumatra, Thailand, the Malay Peninsula, the Indian Ocean, and southern India, spanning the first five years of postseismic deformation. The postseismic relaxation models consider contributions from the 2004 Mw 9.2 Sumatra-Andaman, the 2005 Mw 8.7 Nias, and 2007 Mw 8.4 Bengkulu earthquakes. Far-field motions to the east of the ruptures are equally well fit by homogeneous or laterally variable earth models. However, only models with contrasting rheology across the subducting slab, a ten-times higher mantle viscosity under the Indian Ocean lithosphere than the backarc mantle, can also produce the observed enduring postseismic uplift along the forearc and lack of far-field transient displacements in southern India. While postseismic uplift of forearc stations can also be produced by rapid and enduring down-dip afterslip, the inferred rheology structure is consistent with the distribution of mantle temperature inferred from seismic tomography.

  15. Plate-boundary deformation associated with the great Sumatra-Andaman earthquake.

    PubMed

    Subarya, Cecep; Chlieh, Mohamed; Prawirodirdjo, Linette; Avouac, Jean-Philippe; Bock, Yehuda; Sieh, Kerry; Meltzner, Aron J; Natawidjaja, Danny H; McCaffrey, Robert

    2006-03-01

    The Sumatra-Andaman earthquake of 26 December 2004 is the first giant earthquake (moment magnitude M(w) > 9.0) to have occurred since the advent of modern space-based geodesy and broadband seismology. It therefore provides an unprecedented opportunity to investigate the characteristics of one of these enormous and rare events. Here we report estimates of the ground displacement associated with this event, using near-field Global Positioning System (GPS) surveys in northwestern Sumatra combined with in situ and remote observations of the vertical motion of coral reefs. These data show that the earthquake was generated by rupture of the Sunda subduction megathrust over a distance of >1,500 kilometres and a width of <150 kilometres. Megathrust slip exceeded 20 metres offshore northern Sumatra, mostly at depths shallower than 30 kilometres. Comparison of the geodetically and seismically inferred slip distribution indicates that approximately 30 per cent additional fault slip accrued in the 1.5 months following the 500-second-long seismic rupture. Both seismic and aseismic slip before our re-occupation of GPS sites occurred on the shallow portion of the megathrust, where the large Aceh tsunami originated. Slip tapers off abruptly along strike beneath Simeulue Island at the southeastern edge of the rupture, where the earthquake nucleated and where an M(w) = 7.2 earthquake occurred in late 2002. This edge also abuts the northern limit of slip in the 28 March 2005 M(w) = 8.7 Nias-Simeulue earthquake.

  16. Processes of inclusion and adverse incorporation: oil palm and agrarian change in Sumatra, Indonesia.

    PubMed

    McCarthy, John

    2010-01-01

    Changes in globalised agriculture raise critical questions as rapid agricultural development leads to widespread social and environmental transformation. With increased global demand for vegetable oils and biofuel, in Indonesia the area under oil palm has doubled over the last decade. This paper presents a case study of how micro-processes that are linked to wider dynamics shape oil palm related agrarian change in villages in Sumatra, Indonesia. It pursues related questions regarding the impact of agribusiness-driven agriculture, the fate of smallholders experiencing contemporary agrarian transition, and the impact of increased demand for vegetable oils and biofuels on agrarian structures in Sumatra. It argues that the paths of agrarian change are highly uneven and depend on how changing livelihood strategies are enabled or constrained by economic, social and political relations that vary over time and space. In contrast to simplifying narratives of inclusion/exclusion, it argues that outcomes depend on the terms under which smallholders engage with oil palm. Distinguishing between exogenous processes of agribusiness expansion and endogenous commodity market expansion, it finds each is associated with characteristic processes of change. It concludes that the way successive policy interventions have worked with the specific characteristics of oil palm have cumulatively shaped the space where agrarian change occurs in Sumatra.

  17. Tectonic framework of Turkish sedimentary basins

    SciTech Connect

    Yilmaz, P.O. )

    1988-08-01

    Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary. The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very little in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide. The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in mesozoic and Tertiary. The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.

  18. Atmospheric processes in reaction of Northern Sumatra Earthquake sequence Dec 2004-Apr 2005

    NASA Astrophysics Data System (ADS)

    Ouzounov, D.; Pulinets, S.; Cervone, G.; Singh, R.; Taylor, P.

    2005-05-01

    This work describes our first results in analyzing data from different and independent sources ûemitted long-wavelength radiation (OLR), surface latent heat flux (SHLF) and GPS Total Electron Content (TEC) collected from ground based (GPS) and satellite TIR (thermal infra-red) data sources (NOAA/AVHRR, MODIS). We found atmosphere and ionosphere anomalies one week prior to both the Sumatra-Andaman Islands earthquake (Dec 26, 2004) and M 8.7 - Northern Sumatra, March 28, 2005. We analyzed 118 days of data from December 1, 2004 through April 1, 2005 for the area (0°-10°,north latitude and 90°-100° east longitude) which included 125 earthquakes with M>5.5. Recent analysis of the continuous OLR from the Earth surface indicates anomalous variations (on top of the atmosphere) prior to a number of medium to large earthquakes. In the case of M 9.0 - Sumatra-Andaman Islands event, compared to the reference fields for the months of December between 2001 and 2004, we found strongly OLR anomalous +80 W/m2 signals (two sigma) along the epicentral area on Dec 21, 2004 five days before the event. In the case of M8.7 March 28, 2005 anomalues signatures over the epicenter appears on March 26 is much weaker (only +20W/m2) and have a different topology. Anomalous values of SHLF associated with M9.0 - Sumatra-Andaman Islands were found on Dec 22, 2005 (SLHF +280Wm2) and less intensity on Mar 23, 2005 (SLHF +180Wm2). Ionospheric variations (GPS/TEC) associated with the Northern Sumatra events were determine by five Regional GPS network stations (COCO, BAKO, NTUS, HYDE and BAST2). For every station time series of the vertical TEC (VTEC) were computed together with correlation with the Dst index. On December 22, four days prior to the M9.0 quake GPS/TEC data reach the monthly maximum for COCO with minor DST activity. For the M 8.7-March 28 event, the increased values of GPS/TEC were observed during four days (March 22-25) in quiet geomagnetic background. Our results need additional

  19. Quaternary faults of west Texas

    SciTech Connect

    Collins, E.W.; Raney, J.A. . Bureau of Economic Geology)

    1993-04-01

    North- and northwest-striking intermontane basins and associated normal faults in West Texas and adjacent Chihuahua, Mexico, formed in response to Basin and Range tectonism that began about 24 Ma ago. Data on the precise ages of faulted and unfaulted Quaternary deposits are sparse. However, age estimates made on the basis of field stratigraphic relationships and the degree of calcic soil development have helped determine that many of the faults that bound the basin margins ruptured since the middle Pleistocene and that some faults probably ruptured during the Holocene. Average recurrence intervals between surface ruptures since the middle Pleistocene appear to be relatively long, about 10,000 to 100,000 yr. Maximum throw during single rupture events have been between 1 and 3 m. Historic seismicity in West Texas is low compared to seismicity in many parts of the Basin and Range province. The largest historic earthquake, the 1931 Valentine earthquake in Ryan Flat/Lobo Valley, had a magnitude of 6.4 and no reported surface rupture. The most active Quaternary faults occur within the 120-km-long Hueco Bolson, the 70-km-long Red Light Bolson, and the > 200-km-long Salt Basins/Wild Horse Flat/Lobo Valley/Ryan Flat.

  20. Chronostratigraphy of the Fish Creek-Vallecito Basin, SW Salton Trough: A High-Fidelity Record of Slip on the West Salton Detachment Fault and Subsidence in its Upper Plate

    NASA Astrophysics Data System (ADS)

    Dorsey, R. J.; Housen, B. A.; Janecke, S. U.; McDougall, K.; Fanning, M.; Fluette, A.; Axen, G. J.; Shirvell, C. R.

    2006-12-01

    The Fish Creek-Vallecito basin contains a 5.1-km thick section of sedimentary rocks in the SW Salton Trough that range in age from 8.1 to 0.9 Ma. The section preserves a record of basin subsidence related to slip on the West Salton detachment fault (WSDF), which formed the main western rift-flank structure of the Salton Trough. We obtained a well-constrained chronology from compilation of existing (Johnson et al., 1983) and new paleomagnetic data, ages of two tuffs high in the section, and thicknesses calculated from the geologic map of Winker (1987) and our work in the lower 1.3 km. The tuffs yielded SHRIMP U-Pb ages of 2.56 ± 0.09 and 2.54 ± 0.09 Ma from single zircons. Geohistory analysis, corrected for paleobathymetry and global sea- level change, yields a decompacted subsidence curve with 5 segments bounded by abrupt changes in subsidence rate: (1) 0.46 mm/yr from 8.1 to 5.5 Ma; (2) 1.8 mm/yr from 5.5 to 5.2 Ma; (3) zero subsidence or slight uplift from 5.2 to 4.6 Ma; (4) 1.9 mm/yr from 4.6 to 3.2 Ma; and (5) 0.4 mm/yr from 3.2 to 0.9 Ma. The base of the Elephant Trees Fm, dated here at 8.1 Ma, provides the earliest well dated record of extension in the SW Salton Trough. Earliest marine incursion is dated at 6.3 Ma, and the first appearance of Colorado River sand coincides closely with the Miocene-Pliocene boundary (5.33 Ma). Because the base of the marine Imperial Group does not coincide with a change in subsidence rate, we suggest that initial marine incursion resulted from a latest Miocene global sea-level highstand superposed on steady subsidence. Thus, the inflections at 8.1 and 5.5 Ma are the two most likely ages for onset of slip on the WSDF, but 4.6 Ma is also possible. Variations in subsidence rate are not predicted by models for extensional detachment faults, and may reflect episodic pulsed fault slip and/or long-wavelength folding related to dextral-wrench tectonics. Rapid subsidence in segment 4 began during progradation of the Colorado River

  1. Cenozoic basin development in Hispaniola

    SciTech Connect

    Mann, P.; Burke, K.

    1984-04-01

    Four distinct generations of Cenozoic basins have developed in Hispaniola (Haiti and Dominican Republic) as a result of collisional or strike-slip interactions between the North America and Caribbean plates. First generation basins formed when the north-facing Hispaniola arc collided with the Bahama platform in the middle Eocene; because of large post-Eocene vertical movements, these basins are preserved locally in widely separated areas but contain several kilometers of arc and ophiolite-derived clastic marine sediments, probably deposited in thrust-loaded, flexure-type basins. Second generation basins, of which only one is exposed at the surface, formed during west-northwesterly strike-slip displacement of southern Cuba and northern Hispaniola relative to central Hispaniola during the middle to late Oligocene; deposition occurred along a 5-km (3-mi) wide fault-angle depression and consisted of about 2 km (1 mi) of submarine fan deposits. Third generation basins developed during post-Oligocene convergent strike-slip displacement across a restraining bend formed in central Hispaniola; the southern 2 basins are fairly symmetrical, thrust-bounded ramp valleys, and the third is an asymmetrical fault-angle basin. Fourth generation basins are pull-aparts formed during post-Miocene divergent strike-slip motion along a fault zone across southern Hispaniola. As in other Caribbean areas, good source rocks are present in all generations of basins, but suitable reservoir rocks are scarce. Proven reservoirs are late Neogene shallow marine and fluvial sandstones in third generation basins.

  2. Assessment of undiscovered carboniferous coal-bed gas resources of the Appalachian Basin and Black Warrior Basin Provinces, 2002

    SciTech Connect

    Milici, R.C.; Hatch, J.R.

    2004-09-15

    Coalbed methane (CBM) occurs in coal beds of Mississippian and Pennsylvanian (Carboniferous) age in the Appalachian basin, which extends almost continuously from New York to Alabama. In general, the basin includes three structural subbasins: the Dunkard basin in Pennsylvania, Ohio, and northern West Virginia; the Pocahontas basin in southern West Virginia, eastern Kentucky, and southwestern Virginia; and the Black Warrior basin in Alabama and Mississippi. For assessment purposes, the Appalachian basin was divided into two assessment provinces: the Appalachian Basin Province from New York to Alabama, and the Black Warrior Basin Province in Alabama and Mississippi. By far, most of the coalbed methane produced in the entire Appalachian basin has come from the Black Warrior Basin Province. 8 refs., 1 fig., 1 tab.

  3. Altitude and Configuration of the Potentiometric Surface in the Upper White Clay Creek and Lower West Branch Brandywine Creek Basins including Portions of Penn, London Grove, New Garden, Londonderry, West Marlborough, Highland, and East Fallowfield Townships and West Grove, Avondale, Modena, and South Coatesville boroughs, Chester County, Pennsylvania, May through July 2006

    USGS Publications Warehouse

    Hale, Lindsay B.

    2007-01-01

    INTRODUCTION Since 1984, the U.S. Geological Survey (USGS) has been mapping the altitude and configuration of the potentiometric surface in Chester County as part of an ongoing cooperative program to measure and describe the water resources of the county. These maps can be used to determine the general direction of ground-water flow and are frequently referenced by municipalities and developers to evaluate ground-water conditions for water supply and resource-protection requirements. For this study, the potentiometric surface was mapped for an area in south-central Chester County. The northern part of the map includes portions of Highland, East Fallowfield, Londonderry, and West Marlborough Townships and South Coatesville and Modena Boroughs. The southern part of the map includes portions of Londonderry, West Marlborough, Penn, London Grove, and New Garden Townships and West Grove and Avondale Boroughs. The study area is mostly underlain by metamorphic rocks of the Glenarm Supergroup including Peters Creek Schist, Octoraro Phyllite, Wissahickon Schist, Cockeysville Mrable, and Setters Quartzite; and by pegmatite, mafic gneiss, felsic gneiss, and diabase. Ground water is obtained from these bedrock formations by wells that intercept fractures. The altitude and configuration of the potentiometric surface was contoured from water levels measured on different dates in available wells during May through July 2006 and from the altitude of springs and perennial streams. Topography was used as a guide for contouring so that the altitude of the potentiometric surface was inferred nowhere to be higher than the land surface. The potentiometric surface shown on this map is an approximation of the water table. The altitude of the actual potentiometric surface