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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. 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.

  6. 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.

  7. Multibeam Mapping of the West Andaman Fault, NW Sumatra Fault, Andaman Volcanic Arc and Their Tectonic and Magmatic Implications

    NASA Astrophysics Data System (ADS)

    Kattoju, K. A.; Mudholkar, A. V.; Murty, G.; Vadakkeyakath, Y.; Singh, S. C.; Kiranmai, S.; Moeremans, R.

    2012-12-01

    West Andaman Fault (WAF) is a major structural feature in the Andaman Offshore region that plays an important role in modulating the strain partitioning within the Andaman Sea, well known for its complex tectonics and seismic hazard potential. However, detailed configuration of the WAF and its interaction with the Sumatra fault system in the Andaman sector are not well understood. Here we present near complete coverage of about 800 km long section of the WAF with special emphasis on the zone of confluence of the WAF and the Sumatra Fault systems, and the adjacent volcanic arc in the offshore region of the Great Nicobar Island. We have examined the fault system, and the volcanic arc feature by combining the newly acquired multibeam bathymetry data with the available data northwest of Sumatra. New multibeam map revealed a pattern of faults that are formed in the region of joining of the Seulimeum (SEU) and Aceh strands (AS) of the Sumatra fault with the WAF off Great Nicobar Island. Sandwiched between these faults, at this location, is a 50 km long and 7 km wide conspicuous NS elongated block that rises to 500 m from an adjacent seafloor of about 2000 m. The surface of the block has a westward dipping topographic fabric. Serpentinites were recovered from the eastern cliff of this block, suggestive of mantle origin. A deformed zone with corrugated surface is documented southeast of this elongated block at water depth ranging from 1000 to 1500 m. The mantle block and the deformed zone are bifurcated by a fault, which might be a branch of the WAF. Further south the expression of the Sumatra platform, northern boundary of the Aceh basin pinching out to WAF, extension of the SEU, AS strands towards south, and the northern limit of Weh basin are observed. The other prominent feature that is documented for the first time is the expression of the Andaman volcanic arc. Twenty-three submarine volcanoes of varying sizes have been mapped between 6°30‧N to 8°15‧N. Magnetic

  8. 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.

  9. Marapi an active West-Central Sumatra Volcano: a geological and petrological study

    NASA Astrophysics Data System (ADS)

    Del Marmol, M.; Budianto, A.; Fournelle, J.; Jacobs, P.; Elburg, M. A.

    2010-12-01

    Marapi volcano (West - Central Sumatra), Sumatra’s most active volcano (not to be confused with Merapi on Java), located in a densely populated area and where more than 50 explosive eruptions have been recorded in the last 200 years has been studied in detail in the field to gain fundamental understanding of the volcano's activity in terms of its basic geology, petrology and geochemistry. Marapi is one of a few active volcanoes among many dormant volcanoes of this island. Large deposits of the nearby Maninjau caldera, dated 50 ka (n=3), associated with very silica-rich volcanic products is another reason for concern, since caldera formation is linked with severe explosive activity. Those deposits are found at the base of the volcano and largely in the deeply incised valley which follows the Sumatra fault extending parallel to the Sumatra volcanic front. A possible landslide parallel to the Sumatra fault is recognized on the LANDSAT image. Landslides on the external old external side have allowed the collection of the oldest part of the volcano as most of it is covered with a thick primary forest. These landslides occurring on old volcanic terrain are a threat to the surrounding population living nearby the rivers especially during the heavy rainy seasons. A 20 m high stratigraphic column has been studied, with the volcano’s explosive nature seen in the collected samples (i.e. bombs and pumices). A new sketch map of the area of the craters (6 over 2km) replaces the one made in 1921 at the Dutch colonial time. A geological and hazard map have been created showing the extension of the various deposits.

  10. Study of Genetic Diversity among Simmental Cross Cattle in West Sumatra Based on Microsatellite Markers

    PubMed Central

    Agung, Paskah Partogi; Saputra, Ferdy; Septian, Wike Andre; Lusiana; Zein, Moch. Syamsul Arifin; Sulandari, Sri; Anwar, Saiful; Wulandari, Ari Sulistyo; Said, Syahruddin; Tappa, Baharuddin

    2016-01-01

    A study was conducted to assess the genetic diversity among Simmental Cross cattle in West Sumatra using microsatellite DNA markers. A total of 176 individual cattle blood samples was used for obtaining DNA samples. Twelve primers of microsatellite loci as recommended by FAO were used to identify the genetic diversity of the Simmental Cross cattle population. Multiplex DNA fragment analysis method was used for allele identification. All the microsatellite loci in this study were highly polymorphic and all of the identified alleles were able to classify the cattle population into several groups based on their genetic distance. The heterozygosity values of microsatellite loci in this study ranged from 0.556 to 0.782. The polymorphism information content (PIC) value of the 12 observed loci is high (PIC>0.5). The highest PIC value in the Simmental cattle population was 0.893 (locus TGLA53), while the lowest value was 0.529 (locus BM1818). Based on the genetic distance value, the subpopulation of the Simmental Cross-Agam and the Simmental Cross-Limapuluh Kota was exceptionally close to the Simmental Purebred thus indicating that a grading-up process has taken place with the Simmental Purebred. In view of the advantages possessed by the Simmental Cross cattle and the evaluation of the genetic diversity results, a number of subpopulations in this study can be considered as the initial (base) population for the Simmental Cross cattle breeding programs in West Sumatra, Indonesia. PMID:26732442

  11. Study of Genetic Diversity among Simmental Cross Cattle in West Sumatra Based on Microsatellite Markers.

    PubMed

    Agung, Paskah Partogi; Saputra, Ferdy; Septian, Wike Andre; Lusiana; Zein, Moch Syamsul Arifin; Sulandari, Sri; Anwar, Saiful; Wulandari, Ari Sulistyo; Said, Syahruddin; Tappa, Baharuddin

    2016-02-01

    A study was conducted to assess the genetic diversity among Simmental Cross cattle in West Sumatra using microsatellite DNA markers. A total of 176 individual cattle blood samples was used for obtaining DNA samples. Twelve primers of microsatellite loci as recommended by FAO were used to identify the genetic diversity of the Simmental Cross cattle population. Multiplex DNA fragment analysis method was used for allele identification. All the microsatellite loci in this study were highly polymorphic and all of the identified alleles were able to classify the cattle population into several groups based on their genetic distance. The heterozygosity values of microsatellite loci in this study ranged from 0.556 to 0.782. The polymorphism information content (PIC) value of the 12 observed loci is high (PIC>0.5). The highest PIC value in the Simmental cattle population was 0.893 (locus TGLA53), while the lowest value was 0.529 (locus BM1818). Based on the genetic distance value, the subpopulation of the Simmental Cross-Agam and the Simmental Cross-Limapuluh Kota was exceptionally close to the Simmental Purebred thus indicating that a grading-up process has taken place with the Simmental Purebred. In view of the advantages possessed by the Simmental Cross cattle and the evaluation of the genetic diversity results, a number of subpopulations in this study can be considered as the initial (base) population for the Simmental Cross cattle breeding programs in West Sumatra, Indonesia. PMID:26732442

  12. 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.

  13. 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

  14. Intermediate water radiocarbon off west Sumatra during the last 45,000 years

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    Radiocarbon content of intermediate waters originating from the Southern Ocean is held as the likely smoking gun of the events that triggered the atmospheric CO2 rise and its radiocarbon content decline during the last glacial-interglacial transition. Extremely depleted radiocarbon has been found off the coast of Baja California, the Galapagos and the Arabian Sea, but not unequivocally elsewhere. Knowing the route of the old water is therefore central for the mechanistic linkage of Southern Ocean processes and the atmospheric response. Here, we present high-resolution radiocarbon content of intermediate depth waters off west Sumatra in the attempt to trace the hypothetical route of old water emanating near Antarctica. Sediment core SO189-39KL (0°47'S, 99°55'E, 517 m) resulted in a 1350 cm hemipelagic sedimentary sequence that spans the last 45,000 years and it was sampled for planktonic and benthic foraminifera radiocarbon determinations at a centennial time resolution. Besides the planktonic radiocarbon age control points, we attempted an independent stratigraphy based on the Mg/Ca sea surface temperature evolution and its apparent similarity with Antarctic Ice core records. This allowed us to infer surface reservoir ages as well as the D14C of the intermediate waters. Our results show that throughout the LGM and the entire deglaciation, radiocarbon content at 500 m depth off west Sumatra remained in equilibrium with the contemporaneous atmosphere, discarding this area as a probable route for the spreading of the old water along its way to northern latitudes. These results add up to increasing evidence that the radiocarbon content of intermediate waters originating from the Southern Ocean was not influenced by the upwelling of a large abyssal old water reservoir, as it has been hypothesized in order to explain the atmospheric deglacial records.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  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. 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.

  3. 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

  4. 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

  5. 41. West end of McHugh Basin, looking west toward Dingle ...

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

    41. West end of McHugh Basin, looking west toward Dingle Basin. Photo by Brian C. Morris, PUget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  6. Shallow shear-wave reflection seismics in the tsunami struck Krueng Aceh River Basin, Sumatra

    NASA Astrophysics Data System (ADS)

    Polom, U.; Arsyad, I.; Kümpel, H.-J.

    2008-01-01

    As part of the project "Management of Georisk" (MANGEONAD) of the Federal Institute for Geosciences and Natural Resources (BGR), Hanover, high resolution shallow shear-wave reflection seismics was applied in the Indonesian province Nanggroe Aceh Darussalam, North Sumatra in cooperation with the Government of Indonesia, local counterparts, and the Leibniz Institute for Applied Geosciences, Hanover. The investigations were expected to support classification of earthquake site effects for the reconstruction of buildings and infrastructure as well as for groundwater exploration. The study focussed on the city of Banda Aceh and the surroundings of Aceh Besar. The shear-wave seismic surveys were done parallel to standard geoengineering investigations like cone penetrometer tests to support subsequent site specific statistical calibration. They were also partly supplemented by shallow p-wave seismics for the identification of (a) elastic subsurface parameters and (b) zones with abundance of groundwater. Evaluation of seismic site effects based on shallow reflection seismics has in fact been found to be a highly useful method in Aceh province. In particular, use of a vibratory seismic source was essential for successful application of shear-wave seismics in the city of Banda Aceh and in areas with compacted ground like on farm tracks in the surroundings, presenting mostly agricultural land use areas. We thus were able to explore the mechanical stiffness of the subsurface down to 100 m depth, occasionally even deeper, with remarkably high resolution. The results were transferred into geotechnical site classification in terms of the International Building Code (IBC, 2003). The seismic images give also insights into the history of the basin sedimentation processes of the Krueng Aceh River delta, which is relevant for the exploration of new areas for construction of safe foundations of buildings and for identification of fresh water aquifers in the tsunami flooded region.

  7. Bicentennial Earthquake Supercycles Inferred from Relative Sealevel Changes in Corals off West Sumatra

    NASA Astrophysics Data System (ADS)

    Sieh, K.; Natawidjaja, D. H.; Meltzner, A. J.; Shen, C.; Suwargadi, B. W.; Galetzka, J.; Li, K.; Cheng, H.; Edwards, R.

    2008-12-01

    Records of strain accumulation and relief extracted from corals of the Mentawai islands, Sumatra, imply that this 700-km-long section of the Sunda megathrust has generated sequences of great earthquakes about every two centuries for at least the past 700 years. Episodes in the 14th and 16th/17th centuries resemble broadly the great rupture pair of 1797-1833. The MW8.4 earthquake of September 2007 represents the first in a series of large partial failures of the Mentawai section that will likely occur within the next several decades.

  8. Hydrocarbon habitat of the west Netherlands basin

    SciTech Connect

    De Jager, J. ); Doyle, M. ); Grantham, P. ); Mabillard, J. )

    1993-09-01

    The complex West Netherlands Basin contains oil and gas in Triassic and Upper Jurassic to Cretaceous clastic reservoir sequences. The understanding has always been that the Carboniferous coal measures have generated only gas and the Jurassic marine Posidonia Shale only oil. However, detailed geochemical analyses show that both source rocks have generated oil and gas. Geochemical fingerprinting established a correlation of the hydrocarbons with the main source rocks. The occurrence of these different hydrocarbons is consistent with migration routes. Map-based charge modeling shows that the main phase of hydrocarbon generation occurred prior to the Late Cretaceous inversion of the West Netherlands Basin. However, along the southwest flank of the basin and in lows between the inversion highs, significant charge continued during the Tertiary. Biodegradation of oils in Jurassic and Cretaceous reservoirs occurred during the earliest Tertiary, but only in reservoirs that were at that time at temperatures of less then 70 to 80[degrees]C, where bacteria could survive. This study shows that also in a mature hydrocarbon province an integrated hydrocarbon habitat study with modern analyses and state-of-the-art technology can lead to a much improved understanding of the distribution of oil and gas in the subsurface. The results of this study will allow a better risk assessment for remaining prospects, and an improved prediction of the type of trapped hydrocarbons in terms of gas, oil, and biodegraded oil.

  9. 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

  10. Analysis of K west basin canister gas

    SciTech Connect

    Trimble, D.J., Fluor Daniel Hanford

    1997-03-06

    Gas and Liquid samples have been collected 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 providing 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 for gas and liquid in 1995, and 50 canisters were sampled in a second campaign in 1996. The analysis results from the first campaign have been reported (Trimble 1995a, 1995b, 1996a, 1996b). The analysis results from the second campaign liquid samples have been documented (Trimble and Welsh 1997; Trimble 1997). This report documents the results for the gas samples from the second campaign and evaluates all gas data in terms of expected releases when opening the canisters for SNFP activities. The fuel storage canisters consist of two closed and sealed barrels, each with a gas trap. The barrels are attached at a trunion to make a canister, but are otherwise independent (Figure 1). Each barrel contains up to seven N Reactor fuel element assemblies. A gas space of nitrogen was established in the top 2.2 to 2.5 inches (5.6 to 6.4 cm) of each barrel. Many of the fuel elements were damaged allowing the metallic uranium fuel to be corroded by the canister water. The corrosion releases fission products and generates hydrogen gas. The released gas mixes with the gas-space gas and excess gas passes through the gas trap into the basin water. The canister design does not allow canister water to be exchanged with basin water.

  11. 74. (Credit CBF) Partition between east and west settling basins ...

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

    74. (Credit CBF) Partition between east and west settling basins c1912 with Adolphous Custodis stack (installed 1901) in background. The aerator in the west and the baffles in the east settling basin are visible. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

  12. 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.

  13. Paleozoic basins in West Africa and the Mauritanide thrust belt

    NASA Astrophysics Data System (ADS)

    Villeneuve, Michel

    2005-10-01

    The evolution of the Paleozoic basins of West Africa is strongly depending on the structuration of the different belts which are surrounding the West African Craton. We distinguish the "Taoudeni Basin" located in the center of the craton from the basins located on the West African Craton margin (Tindouf, Tamale and several troughs limiting the western side of the Taoudeni Basin). Other basins are located on top of the Pan-African or Hercynian belts (Bové, Kandi, Ouallen in Semmen and Diourbel basins) or on top of the Proterozoic shields (The Ghana basins). Some are evidenced underneath the Mesozoic-Cenozoic coastal basins (Bové and Ghana basins). The sedimentation started with the Marinoan glacial event (620-580 Ma) and ended with the carbonates of the Early Carboniferous. The main tectonic or climatic events that occurred during this period are registered by the sediments. Among them are, the "Série pourprée glaciogenic deposits, the Pan-African II tectonic event (550-500 Ma) which affects the southwestern part of the Taoudeni Basin, the Late Ordovician glaciogenic event, the Early Silurian marine transgression, the Early Devonian marine regression and the Hercynian tectonic event (330-270 Ma) which affects the Paleozoic basins located on the western and northern parts of the West African Craton. The second part of this paper is devoted to a synthetic review of the Mauritanides Belt which is extending from Southern Senegal to the Moroccan High Atlas. This belt includes both old Pan-African belts and Paleozoic sediments (belonging to the western part of the Bové, Taoudeni and Tindouf basins) tectonised and metamorphosed during the Hercynian orogen. The third part points out the close relationships between the Paleozoic basins and the main tectonic event for the main periods of the West African Craton evolution.

  14. 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

  15. Drainage areas of the Guyandotte River basin, West Virginia

    USGS Publications Warehouse

    Mathes, M.V.

    1977-01-01

    This report, prepared in cooperation with the West Virginia Office of Federal-State Relations (now the Office of Economic and Community Development), lists in tabular form 435 drainage areas for basins within the Guyandotte River basin of West Virginia. Drainage areas are compiled for sites at the mouths of all streams having drainage areas of approximately five square miles or greater, for sites at U.S. Geological Survey gaging stations (past and present), and for other miscellaneous sites. (Woodard-USGS)

  16. 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

  17. Drainage areas of the Kanawha River basin, West Virginia

    USGS Publications Warehouse

    Mathes, M.V.; Payne, D.D., Jr.; Shultz, R.A.; Kirby, J.R.

    1982-01-01

    Drainage areas for 1,493 drainage area divisions for the Kanawha River basin, West Virginia, are listed in the report. Also tabulated for each site are river miles, plus location identifiers: County, latitude and longitude, and the West Virginia District map number. (USGS)

  18. 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.

  19. 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.

  20. 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.

  1. 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

  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. 40. View west of Wickersham Basin in vicinity of McHugh ...

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

    40. View west of Wickersham Basin in vicinity of McHugh Basin, looking west. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  5. 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).

  6. 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

  7. Cesium-137 in K west basin canister water

    SciTech Connect

    Trimble, D.J.

    1997-01-24

    Liquid and gas samples were taken from 50 K West Basin fuel storage canisters in 1996. The cesium-137 data from the liquid samples and an analysis of the data are presented. The analysis indicated that the cesium-137 data follow a lognormal distribution. Assuming that the total distribution of the K West canister water was predicted, the total K West Basin canister water was estimated to contain about 8,150 curies. The mean canister contains about 2.14 curies with as many as 5% or 190 of the canisters exceeding 19 curies. Opening ten canisters per shift could include a hot canister (cesium-137 > 25 curies) in one out of eight shifts.

  8. 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).

  9. 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.

  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. 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.

  12. 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.

  13. Livelihood change and livelihood sustainability in the uplands of Lembang subwatershed, West Sumatra, Indonesia, in a changing natural resource management context.

    PubMed

    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. PMID:18506516

  14. 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.

  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. 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.

  17. Drainage areas of the Potomac River basin, West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Hunt, Michelle L.; Stewart, Donald K.

    1996-01-01

    This report contains data for 776 drainage-area divisions of the Potomac River Basin, from the headwaters to the confluence of the Potomac River and the Shenandoah River. Data, compiled in downstream order, are listed for streams with a drainage area of approximately 2 square miles or larger within West Virginia and for U.S. Geological Survey streamflow-gaging stations. The data presented are the stream name, the geographical limits in river miles, the latitude and longitude of the point, the name of the county, and the 7 1/2-minute quadrangle in which the point lies, and the drainage area of that site. The total drainage area of the Potomac River Basin downstream of the confluence of the Shenandoah River at the State boundary is 9,367.29 square miles.

  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. 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.

  1. Eclogitisation as the cause of the West Siberian Basin subsidence

    NASA Astrophysics Data System (ADS)

    Artemieva, I. M.; Cherepanova, Y. V.; Herceg, M.; Thybo, H.; Arndt, N.

    2013-12-01

    The West Siberian Basin (WSB) is one of the largest in the world intracontinental basins (compared in size with Western Europe) located between the Urals mountains and the Siberian craton. Its basement formed by a mosaics of micro-continents, relict ocean basins, and island arcs ranging in age from Proterozoic to Paleozoic has been significantly reworked during the Permian-early Triassic rifting, followed by emplacement of the Siberian traps, which cover much of the basin. Despite a vast amount of drilling and exploration geophysical data for the sedimentary cover, little is known about the deep lithosphere structure of the WSB, which hampers understanding of its geodynamic evolution. Recent regional crustal model constrained by crustal-scale seismic profiles indicates significant variations in the depth to Moho (ranging from 32-35 km to ca. 45 km), thickness of sediments (from near-zero to ca. 15 km), and average crustal Vp velocity (from ca. 6.0 to ca. 6.7 km/s) (Cherepanova et al., 2013). However, near-zero free-air gravity indicates that the basin is close to isostatic equilibrium. Here we use two independent methods to calculate density variations in the mantle beneath the WSB, taking advantage of the new regional crustal model. The first approach is based on free-board modeling, while the second one is based on GOCE satellite gravity data. Both density calculations show the presence of a high-density material beneath the axial part of the major rift system. Recalculation of density anomalies to room P-T conditions, based on a regional thermal model (Artemieva and Mooney, 2001) and assuming different models for the lithosphere thickness, yields mantle density of 3.43-3.50 g/cc over half of the basin with local peak values up to ca. 3.55 g/cc. We interpret this density anomaly as the evidence for the presence of eclogites and speculate that eclogitisation may be the primary cause of basin subsidence. This conclusion is supported by high seismic velocities in

  2. A revised spreading model of the West Philippine Basin

    NASA Astrophysics Data System (ADS)

    Sasaki, Tomohiro; Yamazaki, Toshitsugu; Ishizuka, Osamu

    2014-12-01

    The West Philippine Basin (WPB) occupies the western part of the Philippine Sea (PHS) plate. The WPB is generally considered to have opened from approximately 50 to 30 Ma at the CBF rift; however, the detailed spreading history of the WPB is not yet clear. In particular, the origin and age of the southern subbasin, the Palau Basin, are unknown. To better understand the initiation and early evolution of the Izu-Bonin (Ogasawara)-Mariana arc, knowing the configuration of the PHS plate at that time is necessary. In this study, we examine the spreading history of the WPB using newly acquired three-component magnetic anomaly and swath bathymetry data, as well as existing datasets. In the WPB south of the CBF rift, the observed magnetic anomalies correspond to Chron C16r to C21n (approximately 36 to 46 Ma). Prevailing models of the WPB reconstruction show a decrease in the spreading rate from 4.4 to 1.8 cm/year since C18n.2n (approximately 39.5 Ma). Our research, however, indicates that the change in the spreading rate is not required to correlate the observed magnetic anomalies to the geomagnetic polarity reversal timescale. The age of the spreading cessation in our interpretation, approximately 36 Ma, is several million years older than in previous estimates, and the spreading ceased progressively from southeast to northwest along the CBF rift. In the Palau Basin, seafloor fabrics and magnetic lineations trend N-S, which indicates E-W seafloor-spreading. Based on 40Ar/39Ar age, we suggest that the magnetic lineations correspond to polarity reversals from C18n.1n to C15r (approximately 38.5 to 35 Ma). The spreading of the Palau Basin may have been coeval with that of the WPB near the CBF rift, although their spreading directions are different.

  3. 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.

  4. 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

  5. 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

  6. Detailed fault structure of the Tarutung Pull-Apart Basin in Sumatra, Indonesia, derived from local earthquake data

    NASA Astrophysics Data System (ADS)

    Muksin, Umar; Haberland, Christian; Nukman, Mochamad; Bauer, Klaus; Weber, Michael

    2014-12-01

    The Tarutung Basin is located at a right step-over in the northern central segment of the dextral strike-slip Sumatran Fault System (SFS). Details of the fault structure along the Tarutung Basin are derived from the relocations of seismicity as well as from focal mechanism and structural geology. The seismicity distribution derived by a 3D inversion for hypocenter relocation is clustered according to a fault-like seismicity distribution. The seismicity is relocated with a double-difference technique (HYPODD) involving the waveform cross-correlations. We used 46,904 and 3191 arrival differences obtained from catalogue data and cross-correlation analysis, respectively. Focal mechanisms of events were analyzed by applying a grid search method (HASH code). Although there is no significant shift of the hypocenters (10.8 m in average) and centroids (167 m in average), the application of the double difference relocation sharpens the earthquake distribution. The earthquake lineation reflects the fault system, the extensional duplex fault system, and the negative flower structure within the Tarutung Basin. The focal mechanisms of events at the edge of the basin are dominantly of strike-slip type representing the dextral strike-slip Sumatran Fault System. The almost north-south striking normal fault events along extensional zones beneath the basin correlate with the maximum principal stress direction which is the direction of the Indo-Australian plate motion. The extensional zones form an en-echelon pattern indicated by the presence of strike-slip faults striking NE-SW to NW-SE events. The detailed characteristics of the fault system derived from the seismological study are also corroborated by structural geology at the surface.

  7. Normal-mode frequency band view of the Off-the-West-Coast of Northern Sumatra Earthquake of April 11, 2012

    NASA Astrophysics Data System (ADS)

    Igarashi, M.; Tanimoto, T.

    2012-12-01

    Many studies with body-wave and long-period surface wave analyses on the Off-the-West-coast of Northern Sumatra Earthquake of April 11, 2012, have already pointed out complexities of this event (e.g., Meng et al., 2012). A sequence of events with fairly wide spatial and temporal extent are clearly needed to explain many facets of seismic data. In this study, we attempt to summarize a few distinct features from the normal-mode frequency band (0.3-2.0 mHz) which are obviously much simpler by their long wavelength and long periods. We analyzed long-period seismic data from STS1 and KS54000 sensors for the first 12 hours of the main event using the time-domain waveform fitting technique (Tanimoto, et al., 2012). Adoption of this short time series is partly to avoid uncertain Q parameters on amplitudes but also to avoid the effects from two earthquakes in Oregon (Mw6.0) and Mexico (Mw6.7) that occurred about 23rd hour on the same day. These events are much smaller but their effects cannot be ignored in seismic stations in North America. Two major events reported by the Global CMT project, the Mw8.6 main shock and the Mw8.2 aftershock that occurred two hours later, are clearly not sufficient to explain the amplitude data at about 1 mHz (0.6-1.5 mHz). Synthetic seismograms for the two events under-predicts data by about 30 percent. Amplitudes also show two-theta azimuthal variation that indicates a necessity of at least one hidden event (if not rupture propagation). This necessity has already been pointed out by various groups (e.g., Duputel et al., 2012, Shao et al., 2012). Duputel et al. (2012), for example, reports that the Mw8.6 main event by GCMT should be split up by two large events, the Mw8.5 main event and Mw8.3 event that occurred 70 seconds later. Our analysis shows that their three-source solution, including the Mw8.2 event two hours later, satisfies overall amplitude data in the normal-mode frequency band. However, their solution still shows two

  8. 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.

  9. K West Basin sludge volume estimates for integrated water treatment system

    SciTech Connect

    Pitner, A.L.

    1998-08-19

    This document provides estimates of the volume of sludge (1) expected from Integrated Process Strategy (IPS) processing of the fuel elements and (2) in the fuel storage canisters in K West Basin. The original estimates were based on visual observations of fuel element condition in the basin and laboratory measurements of KE canister sludge density. Revision 1 revised the volume estimates of sludge based on additional data from evaluations of material from the KW Basin fuel subsurface examinations and KW canister sludge characterization data. A nominal Working Estimate and an upper level Working Bound is developed for the canister sludge and the fuel wash sludge components in the KW Basin.

  10. Structure of the Basin and Ridge System West of New Caledonia (Southwest Pacific): A Synthesis

    NASA Astrophysics Data System (ADS)

    Lafoy, Y.; Brodien, I.; Vially, R.; Exon, N. F.

    2005-03-01

    Complementary to previous work mainly based on seismic interpretation, our compilation of geophysical data (multibeam bathymetry, gravity, magnetic and seismic) acquired within the framework of the ZoNéCo (ongoing since 1993) and FAUST (1998 2001) programs enables us to improve the knowledge of the New Caledonia Basin, Fairway Basin and Fairway Ridge, located within the Southwest Pacific region. The structural synthesis map obtained from geophysical data interpretation allows definition of the deep structure, nature and formation of the Fairway and New Caledonia Basins. Development of the Fairway Basin took place during the Late Cretaceous (95 65 Ma) by continental stretching. This perched basin forms the western margin of the New Caledonia Basin. A newly identified major SW NE boundary fault zone separates northern NW SE trending segments of the two basins from southern N S trending segments. This crustal-scale fault lineament, that we interpret to be related to Cretaceous-early Cainozoic Tasman Sea spreading, separates the NW SE thinned-continental and N S oceanic segments of the New Caledonia Basin. We can thus propose the following pattern for the formation of the study area. The end of continental stretching within the Fairway and West Caledonia Basins ( 65 62 Ma) is interpreted as contemporaneous with the onset of emplacement of oceanic crust within the New Caledonia Basin’s central segment. Spreading occurred during the Paleocene (62 56 Ma), and isolated the Gondwanaland block to the west from the Norfolk block to the east. Finally, our geophysical synthesis enables us to extend the structural Fairway Basin down to the structural Taranaki Basin, with the structural New Caledonia Basin lying east of the Fairway Basin and ending further north than previously thought, within the Reinga Basin northwest of New Zealand.

  11. Geology of the Douala basin, offshore Cameroon, West Africa

    SciTech Connect

    Pauken, R.J.; Thompson, J.M.; Schumann, J.R. ); Cooke, J.C. )

    1991-03-01

    The Douala basin is predominantly an offshore basin extending from the Cameroon volcanic line in the north to the Corisco arch in the south near the Equatorial Guinea-Gabon border. The basin lies wholly within the territorial borders of Cameroon and Equatorial Guinea. The Douala basin is one of a series of divergent margin basins occurring along the southwest African coastline resulting from the rifting of Africa from South America. Continental rifting in the Doula basin was initiated at least by Aptian-Albian time and possibly as early as Jurassic. The rift stage persisted until Albian time when the onset of drifting occurred. The sedimentary section in the basin has a maximum thickness of 8-10 km, based on exploration drilling and gravity and magnetics modeling. The synrift section consists of Aptian-Albian sands and shales, deposited primarily as submarine fans, fan-deltas, and turbidite deposits. These are overlain by salt, thought to be equivalent to the Ezagna salt of Aptian age in the Gabon basin to the south. The synrift section is separated from the overlying postrift shale sequence of Late Cretaceous and Tertiary age by a major late Albian unconformity. The Douala basin has been explored for hydrocarbons intermittently over the last 25 years. Results show a distinct tendency for gas-proneness. The largest field recorded to date is the Sanaga Sud gas field, discovered in 1979, offshore, near the coastal city of Kribi.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. Exploration of drought evolution using numerical simulations over the Xijiang (West River) basin in South China

    NASA Astrophysics Data System (ADS)

    Niu, Jun; Chen, Ji; Sun, Liqun

    2015-07-01

    The knowledge of drought evolution characteristics may aid the decision making process in mitigating drought impacts. This study uses a macro-scale hydrological model, Variable Infiltration Capacity (VIC) model, to simulate terrestrial hydrological processes over the Xijiang (West River) basin in South China. Three drought indices, namely standardized precipitation index (SPI), standardized runoff index (SRI), and soil moisture anomaly index (SMAI), are employed to examine the spatio-temporal and evolution features of drought events. SPI, SRI and SMAI represent meteorological drought, hydrological drought and agricultural drought, respectively. The results reveal that the drought severity depicted by SPI and SRI is similar with increasing timescales; SRI is close to that of SPI in the wet season for the Liu River basin as the high-frequency precipitation is conserved more by runoff; the time lags appear between SPI and SRI due to the delay response of runoff to precipitation variability for the You River basin. The case study in 2010 spring drought further shows that the spatio-temporal evolutions are modulated by the basin-scale topography. There is more consistency between meteorological and hydrological droughts for the fan-like basin with a converged river network. For the west area of the Xijiang basin with the high elevation, the hydrological drought severity is less than meteorological drought during the developing stage. The recovery of hydrological and agricultural droughts is slower than that of meteorological drought for basins with a longer mainstream.

  19. Aluminum hydroxide coating thickness measurements and brushing tests on K West Basin fuel elements

    SciTech Connect

    Pitner, A.L.

    1998-09-11

    Aluminum hydroxide coating thicknesses were measured on fuel elements stored in aluminum canisters in K West Basin using specially developed eddy current probes . The results were used to estimate coating inventories for MCO fuel,loading. Brushing tests successfully demonstrated the ability to remove the coating if deemed necessary prior to MCO loading.

  20. 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)

  1. 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.

  2. Data compliation report: K West Basin fuel storage canister liquid samples

    SciTech Connect

    Trimble, D.J.

    1995-12-21

    Sample analysis data from the 222-S Laboratory are reported. The data are for liquid samples taken from spent fuel storage canisters in the 105 K West Basin during March 1995. An analysis and data report from the Special Analytical Studies group of Westinghouse Hanford Company regarding these samples is also included. Data analysis is not included herein.

  3. 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.

  4. 33 CFR 165.777 - Security Zone; West Basin, Port Canaveral Harbor, Cape Canaveral, Florida.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  5. 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...

  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. 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.

  8. Organic matter in the Paleogene west European rift: Bresse and Valence salt basins (France)

    SciTech Connect

    Curial, A.; Dumas, D.; Moretto, R.

    1988-08-01

    The Bresse and Valence basins are two adjacent segments of the West European rift. They contain thick Paleogene halite sequences including intercalated and interfingering siliciclastic material and carbonate and sulfate deposits. Source rock samples in this study were mainly taken from the depocenters because of maximum sampling coverage. Organic matter (OM) is generally immature and occurs primarily within intercalated nonhalitic beds. The Bresse basin seems to contain more OM in (1) the Intermediate Salt Formation (Priabonian), composed of alternating laminated carbonate and halite beds; (2) the upper part of the Upper Salt Formation (clayey carbonate beds; Rupelian), affected by synsedimentary halite solution; and (3) the solution breccia which immediate overlies the salt sequence. In the Valence basin, the organic-rich layers are concentrated in the Subsalt Formation (carbonate beds; Priabonian), and the upper part of the Lower Salt Formation (laminates; Rupelian). In both basins, type III organic matter is associated with terrigenous facies. Type I is abundant in the Valence basin (laminites), and type II seems to be more abundant in the Bresse basin. The amount of OM varies considerably, and we suppose it is higher toward the basin margins. From studies made in evaporite basins in other region, which are also known to have significant amounts of organic matter, we find a similar range of organic composition. Such studies are of interest because of their petroleum potential and for understanding precise depositional environments and waste disposal problems (gas generation with local heat source).

  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. Seismicity of the Earth 1900-2012 Sumatra and vicinity

    USGS Publications Warehouse

    Hayes, Gavin P., (compiler); 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.

  11. Tectonic Setting of the Lyra Basin, west of the Ontong Java Plateau

    NASA Astrophysics Data System (ADS)

    Nakanishi, M.; Sano, T.; Shimizu, K.

    2007-12-01

    We present the preliminary results of the geophysical investigation and rock sampling in the Lyra Basin, the deep ocean basin west of the Ontong Java Plateau. The Ontong Java Plateau (OJP) is one of the most voluminous large igneous provinces. The evidences from drilling samples indicate that most of the OJP formed rapidly about 120 Ma at mid-southern latitude in the Pacific Basin. Deep ocean basins are contiguous with the OJP. For settlement of the argument about the origin of the OJP, the tectonic setting of the deep ocean basins around the OJP must be revealed. Tectonic histories of the Nauru, East Mariana, and Pigafetta basins, were revealed using the Mesozoic magnetic anomaly lineations. That of Lyra basin is, however, still unknown because of lack of magnetic anomaly lineations. The depth of the seafloor in the Lyra Basin deepens west, from 4000 to 5000 m. The Lyra Trough, crossing the Lyra Basin, is a broad and deep graben. In December 2006, we conducted the geophysical investigation and rock sampling in the Lyra Basin using R/V KAIREI, Japan Agency for Marine-Earth Science and Technology. Our bathymetric measurement revealed the topographic expression of the Lyra Trough. The depth of the trough is around 5500 m. The bottom of the trench as a whole is very smooth except for several lineated ridges. The height of the lineated ridges is about 500 m. The length of the lineated ridges is around 20 km. The strike of some ridges is N35°W and parallel to the trough strike. That of others is N50°W and oblique to the trough strike. Seamounts are located in the eastern rim of the Lyra Trough south of 1°30'N. The height of the seamounts is more than 2500 m. We obtained volcanic samples from the lineated ridge in the Lyra Trough and the seamount in the eastern rim of the trough. Most of igneous rocks are volcanic breccia, being coated by thick Mn crust. Although many volcanoclastic rocks are highly altered, some fresh samples were recovered. They are olivine

  12. 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.

  13. 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

  14. 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).

  15. 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.

  16. 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.

  17. Genesis of the West Siberian basin and its petroleum geology: A recent interpretation

    SciTech Connect

    Clarke, J.W.

    1994-11-01

    A prominent Western specialist on the geology of the oil and gas deposits of Russian provides an interpretation of the genesis of the West Siberian basin, relying, in part, on most recent Russian studies as well as information made available in 1994 evaluating the reserves of Russia`s most important producing province. From Late Carboniferous through Middle Jurassic time, the region of West Siberia passed through orogenic, rift, and early platform stages. A domal high was present in the region during the orogenic stage, arising from crationization of the Ural-Mongolian fold belt. Early Triassic rifting was part of a global rifting event and was a precursor to the subsequent crustal sagging that produced the West Siberian basin. The Early-Middle Jurassic was a time of cyclical marine and continental deposition, the sea moving back and forth from the north. The Talinskoye oil field occurs in Lower-Middle Jurassic sandstones that have the form of a river channel that extends more than 200 km. The Priobskoye field is associated with a Lower Cretaceous clinoform that has been traced N-S for more than 300 km. 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. 14 refs., 8 figs.

  18. 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.

  19. 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.

  20. 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).

  1. 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

  2. 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.

  3. 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.

  4. Predictive Modeling of West Nile Virus Transmission Risk in the Mediterranean Basin: How Far from Landing?

    PubMed Central

    Chevalier, Véronique; Tran, Annelise; Durand, Benoit

    2013-01-01

    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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Epidemiology of West Nile Disease in Europe and in the Mediterranean Basin from 2009 to 2013

    PubMed Central

    Di Sabatino, Daria; Bruno, Rossana; Danzetta, Maria Luisa; Cito, Francesca; Iannetti, Simona; Narcisi, Valeria; De Massis, Fabrizio; Calistri, Paolo

    2014-01-01

    West Nile virus (WNV) transmission has been confirmed in the last four years in Europe and in the Mediterranean Basin. An increasing concern towards West Nile disease (WND) has been observed due to the high number of human and animal cases reported in these areas confirming the importance of this zoonosis. A new epidemiological scenario is currently emerging: although new introductions of the virus from abroad are always possible, confirming the epidemiological role played by migratory birds, the infection endemisation in some European territories today is a reality supported by the constant reoccurrence of the same strains across years in the same geographical areas. Despite the WND reoccurrence in the Old World, the overwintering mechanisms are not well known, and the role of local resident birds or mosquitoes in this context is poorly understood. A recent new epidemiological scenario is the spread of lineage 2 strain across European and Mediterranean countries in regions where lineage 1 strain is still circulating creating favourable conditions for genetic reassortments and emergence of new strains. This paper summarizes the main epidemiological findings on WNV occurrence in Europe and in the Mediterranean Basin from 2009 to 2013, considering potential future spread patterns. PMID:25302311

  12. 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

  13. 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)

  14. 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).

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Surface deformation on the west portion of the Chapala lake basin: uncertainties and facts

    NASA Astrophysics Data System (ADS)

    Hernandez-Marin, M.; Pacheco-Martinez, J.; Ortiz-Lozano, J. A.; Araiza-Garaygordobil, G.; Ramirez-Cortes, A.

    2015-11-01

    In this study we investigate different aspects of land subsidence and ground failures occurring in the west portion of Chapala lake basin. Currently, surface discontinuities seem to be associated with subsiding bowls. In an effort to understand some of the conditioning factors to surface deformation, two sounding cores from the upper sequence (11 m depth) were extracted for analyzing physical and mechanical properties. The upper subsoil showed a predominant silty composition and several lenses of pumice pyroclastic sand. Despite the relative predominance of fine soil, the subsoil shows mechanical properties with low clay content, variable water content, low plasticity and variable compressibility index, amongst some others. Some of these properties seem to be influenced by the sandy pyroclastic lenses, therefore, a potential source of the ground failure could be heterogeneities in the upper soil.

  10. 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. PMID:25099955

  11. Structural subprovinces of the Central Basin Platform, west Texas: Strike-slip bounded crustal blocks

    SciTech Connect

    Gardiner, W.B. )

    1990-05-01

    The Central Basin platform (CBP) of west Texas is composed of six structural blocks, which moved independently during the Ouachita orogeny. As the South American plate collided with North America the Wasson uplift on the northwestern shelf of the Permian basin acted as a buttress against which the CBP was compressed. Shear forces transmitted through the crust resulted in buckling, uplifting, and faulting of the greater CBP. Although the platform is dominated by vertical movement, it did not however, uplift as a single tectonic unit. Rather, it splintered into six megablocks, which moved simultaneously along oblique-slip fault systems. A tectonic model for formation of the CBP is useful for predicting the orientation and spacing of fault systems. The three structurally highest blocks on the CBP, the Eunice high, the Sand Hills high, and the Fort Stockton uplift, show three distinct positive gravity and magnetic anomalies. These county-sized blocks (35 x 80 km) share similar characteristics: (1) they are bounded by strike-slip faults that involve basement uplift; (2) they have maximum structural deformation along their margins where bends in the strike-slip fault system enhance compressions; and (3) their oil is trapped in high-angle fault structures (R-shears ) along the clock boundaries, but toward the center of the blocks, oil tends to accumulate at unconformity and fold traps. Strike-slip fault systems in west Texas are subtle, with only about 3-7 km of offset and commonly may be overlooked. However, detailed regional mapping indicates that these individual fault segments are parts of through-going systems, which are distributed in logical patterns based upon models for strike-slip tectonics.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 300-Myr-old magmatic CO2 in natural gas reservoirs of the west Texas Permian basin.

    PubMed

    Ballentine, C J; Schoell, M; Coleman, D; Cain, B A

    2001-01-18

    Except in regions of recent crustal extension, the dominant origin of carbon dioxide in fluids in sedimentary basins has been assumed to be from crustal organic matter or mineral reactions. Here we show, by contrast, that Rayleigh fractionation caused by partial degassing of a magma body can explain the CO2/3He ratios and delta13C(CO2) values observed in CO2-rich natural gases in the west Texas Val Verde basin and also the mantle 3He/22Ne ratios observed in other basin systems. Regional changes in CO2/3He and CO2/CH4 ratios can be explained if the CO2 input pre-dates methane generation in the basin, which occurred about 280 Myr ago. Uplift to the north of the Val Verde basin between 310 and 280 Myr ago appears to be the only tectonic event with appropriate timing and location to be the source of the magmatic CO2. Our identification of magmatic CO2 in a foreland basin indicates that the origin of CO2 in other mid-continent basin systems should be re-evaluated. Also, the inferred closed-system preservation of natural gas in a trapping structure for approximately 300 Myr is far longer than the residence time predicted by diffusion models. PMID:11201738

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  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. 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

  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. 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.

  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. 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.

  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. 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

  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. 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.

  18. 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.

  19. 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.

  20. Conditions for Land Subsidence and Ground Failure in Lacustrine Sediments, the Case of West Chapala Basin.

    NASA Astrophysics Data System (ADS)

    Hernandez-Marin, M.; Pacheco, J.; Ortiz-Lozano, J. A.; Ramirez-Cortes, A.; Araiza, G.

    2014-12-01

    Surface deformation in the form of land subsidence and ground failure in the Chapala Basin has caused serious damage to structures, mostly homes. In this work, the conditions for the occurrence of deformation particularly regarding the physical and mechanical properties of the soil are discussed. In 2012 a maximum land subsidence of 7.16 cm in a short period of 8 months was recorded with maximum velocities of deformation close to 0.89 centimeters per month. Natural conditions of the zone of study include a lacustrine low land with the perennial Chapala Lake, surrounded by ranges formed by volcanic extrusive rocks, mostly basalts and andesites. Two soil cores of 11 meters depth show the predominance of fine soil but with the incrustation of several sandy lenses of volcanic ash. In the first core closer to the piedmont, the volcanic ash presents an accumulated thickness close to three meters, starting at 4.5 meters depth; on the contrary, this thickness in the second core closer to the lake is critically reduced to no more than 50 centimeters. Even though the predominance of fine soil is significant, water-content averages 100 % and the liquid limit is low, suggesting amongst other possibilities, low content of clay or at least low content of smectites or allophanes in the clayey portion. Other properties of the soil are being determined for analyses. The occurrence of three alignments of ground failures in the community of Jocotepec at the west, mostly faults, suggests highly heterogeneous subsoil. The high volumes of groundwater withdrawn from the local aquifers mainly for agriculture are directly contributing to the increase of the effective stress and surface deformation, however, the relationship between level descents and surficial deformation is still not clear.

  1. 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

  2. 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).

  3. 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

  4. 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

    1997-07-30

    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.

  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. Identification and evaluation of CCS sweet spots in the West Netherlands Basin

    NASA Astrophysics Data System (ADS)

    van Toorenenburg, Koen A.; Donselaar, Marinus E.; Vandeweijer, Vincent P.; Pluymaekers, Maarten P.; van de Weerd, Andrew A.; Groenenberg, Remco M.; Flores Colmenares, Jonatan S.

    2013-04-01

    Carbon capture and sequestration (CCS) is expected to become a serious CO2-emission reduction technology in the Netherlands. The industry- and government-supported national research programme CATO-2 is tasked to investigate the opportunities and feasibility of CCS projects, both onshore and offshore in the Dutch territory. An example of such opportunities are the deep aquifers and (soon-to-be) depleted gas reservoirs in the mature West Netherlands Basin (WNB), conveniently situated near CO2-emitting sources in the Rotterdam industrial area and a future >1,000MW coal-fired power station. This study aims to define, identify, evaluate and compare potential CO2-storage reservoirs within the WNB, focusing on Triassic and Lower Cretaceous intervals. The identification of sweet spots for CO2 storage is based on pre-defined geological boundary conditions, including trap type, geological and petrophysical reservoir architecture, top-seal and fault-seal quality, CO2-storage capacity and reservoir depth, contributing to a cost-efficient reservoir (re)development at low environmental impact. These criteria are applied to a basin-scale structural model, constructed from a representative selection of public well and seismic data, in combination with a literature study on the lithology and petrophysical properties of the targeted stratigraphic intervals. Next, high-resolution 3D static reservoir models are constructed for identified sweet spots. The models are based on the analysis and correlation of comprehensive subsurface datasets, which allow for an accurate time-to-depth conversion, and reconstruction of the structural architecture and reservoir facies distribution. The models are populated with known petrophysical properties from the targeted stratigraphic intervals in the same area. These serve as a basis for subsequent dynamic flow modelling, CO2-storage capacity recalculation and overburden studies. The various uncertainties in e.g. structural architecture, facies

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

    USGS Publications Warehouse

    Blake, B.M., Jr.; 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

  12. 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

  13. P-wave velocity structure offshore central Sumatra: implications for compressional and strike-slip faulting

    NASA Astrophysics Data System (ADS)

    Karplus, M.; Henstock, T.; McNeill, L. C.; Vermeesch, P. M. T.; Barton, P. J.

    2014-12-01

    The Sunda subduction zone features significant along-strike structural variability including changes in accretionary prism and forearc morphology. Some of these changes have been linked to changes in megathrust faulting styles, and some have been linked to other thrust and strike-slip fault systems across this obliquely convergent margin (~54-58 mm/yr convergence rate, 40-45 mm/yr subduction rate). We examine these structural changes in detail across central Sumatra, from Siberut to Nias Island, offshore Indonesia. In this area the Investigator Fracture Zone and the Wharton Fossil Ridge, features with significant topography, are being subducted, which may affect sediment thickness variation and margin morphology. We present new seismic refraction P-wave velocity models using marine seismic data collected during Sonne cruise SO198 in 2008. The experiment geometry consisted of 57 ocean bottom seismometers, 23 land seismometers, and over 10,000 air gun shots recorded along ~1750 km of profiles. About 130,000 P-wave first arrival refractions were picked, and the picks were inverted using FAST (First Arrivals Refraction Tomography) 3-D to give a velocity model, best-resolved in the top 25 km. Moho depths, crustal composition, prism geometry, slab dip, and upper and lower plate structures provide insight into the past and present tectonic processes at this plate boundary. We specifically examine the relationships between velocity structure and faulting locations/ styles. These observations have implications for strain-partitioning along the boundary. The Mentawai Fault, located west of the forearc basin in parts of Central Sumatra, has been interpreted variably as a backthrust, strike-slip, and normal fault. We integrate existing data to evaluate these hypotheses. Regional megathrust earthquake ruptures indicate plate boundary segmentation in our study area. The offshore forearc west of Siberut is almost aseismic, reflecting the locked state of the plate interface, which

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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.

  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. 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

  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

    Dutton, S.P.

    1997-10-30

    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{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, water flood, 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 present at ions, the knowledge gained in the comparative study of these two fields can then be applied to increase product ion

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

    SciTech Connect

    Dutton, S.P.

    1996-04-30

    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. One the reservoir-characterization study of both field 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 well will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and producibility problem characterization.

  3. 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, S.P.; Flanders, W.A.; Guzman, J.I.; Zirczy, H.

    1999-06-08

    The objective of this Class III 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 geologically based field development. This year the project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Orla Petco, Inc., as the East Ford unit; it contained an estimated 19.8 million barrels (MMbbl) of original oil in place. Petrophysical characterization of the East Ford unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. Most methods of petrophysical analysis that had been developed during an earlier study of the Ford Geraldine unit were successfully transferred to the East Ford unit. The approach that was used to interpret water saturation from resistivity logs, however, had to be modified because in some East Ford wells the log-calculated water saturation was too high and inconsistent with observations made during the actual production. Log-porosity to core-porosity transforms and core-porosity to core-permeability transforms were derived from the East Ford reservoir. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobil-oil saturation, and other reservoir properties.

  4. 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

  5. New Constraints on Amazonian Versus West African Cratonic Source Components of the Peri-Gondwanan Sedimentary Basins

    NASA Astrophysics Data System (ADS)

    Schofield, D. I.; Horstwood, M. S.

    2009-05-01

    Unravelling the Palaeogeography of the Peri-Gondwanan terranes during the Early Palaeozoic is in part predicated on the interpretation of detrital zircon analyses from the continental margin sedimentary basins compared to potential source regions. Recent reviews of available detrital zircon data (e.g. Nance et al., 2008) reflect the strong control of the source regions with Gander, Avalonia, Carolina and the cratonic Central American terranes strongly biased toward an Amazonia-Baltica-Laurentia provenance, shown by the relative abundance of Mesoproterozoic zircon populations. In contrast, Meguma, Florida, Cadomia, Iberia and Bohemia show a relative absence of Mesoproterozoic populations and a bias toward palaeoproterozoic populations characteristic of the Eburnean orogeny of the West African Craton. However, understanding of the age compositions of the source areas is often based on sparse, often quite old data. Here, the source regions of the West African Craton are reviewed in light of new U-Pb LA-MC-ICP-MS data from the Reguibat Shield and adjacent Mauritenide orogenic belt, and the implications for the relative dispersal of the peri-Gondwanan terranes considered. Present understanding of the West African source region is based largely on the, historically more economic and better studied, Man Shield of equatorial West Africa. In common with the Man Shield, the Reguibat comprises a western 'Archaean' domain and an eastern Palaeoproterozoic or 'Eburnean' domain. Published U-Pb zircon age data from the western domain show that the Mesoarchaean nuclei in the SW of the shield is relatively abundant in ca. 2.95 and 2.9 Ga magmatic rocks, but preserves a record of earlier ca. 3.5-3.4 Ma magmatism and metamorphism. However, new data from the eastern margin of this domain indicate the presence of previously unrecorded extensive Neoarchaean granite migmatite terrane, making up approximately 25% of the exposed area of the shield, yielding ages between ca. 2.7 and 2.45 Ga

  6. 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

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

    PubMed

    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

  8. 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

  9. 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

  10. 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.

  11. Assessing Climate Risks on the Investment Plans in the Niger River Basin, West Africa

    NASA Astrophysics Data System (ADS)

    Ghile, Y. B.; Brown, C. M.

    2010-12-01

    There is growing concern that the Niger River Basin (NRB) system is vulnerable to climate variability and climate change. The projected impacts of climate change, in particular, may induce some potential risks to an investment plan of $7.8 billion for building new water infrastructures in the basin. For this reason, water resource managers and policy makers seek the best possible sources of climate change projections and information to assist their decision making needs. In this presentation, we describe and demonstrate a bottom-up, risk-based framework for the analysis of climate impacts on water resources systems in the basin. The process focuses on characterizing the spatial and temporal hydrologic variability with a hydrologic model, modeling the NRB system using the Mike Basin model, identifying climate risks, and assessing those risks using climate information centered on 2030, 2050 and 2070 from multiple sources. Generally, the assessment indicates that some potential risks for hydro-electricity, navigation and environmental flows. The approach used in this study may help policy makers to understand the general pattern of climate change risks in the NRB, and it may assist them to address the multitude of future uncertainties that affect the investment plans in the NRB.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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; Chemia, Zurab

    2013-12-01

    We present a digital model SibCrust of the crustal structure of the Siberian craton (SC) and the West Siberian basin (WSB), based on all seismic profiles published since 1960 and sampled with a nominal interval of 50 km. Data quality is assessed and quantitatively assigned to each profile based on acquisition and interpretation method and completeness of crustal model. The database represents major improvement in coverage and resolution and 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. Maps and cross sections demonstrate strong crustal heterogeneity, which correlates weakly with tectono-thermal age and strongly with tectonic setting. Sedimentary thickness varies from 0-3 km in stable craton to 10-20 km in extended regions. Typical Moho depths are 44-48 km in Archean crust and up-to 54 km around the Anabar shield, 40-42 km in Proterozoic orogens, 35-38 km in extended cratonic crust, and 38-42 km in the West Siberian basin. Average crustal Vp velocity is similar for the SC and the WSB and shows a bimodal distribution with peaks at ca. 5.4 km/s in deep sedimentary basins and ~ 6.2-6.6 km/s in parts of the WSB and SC. Exceptionally high basement Vp velocities (6.8-7.0 km/s) at the northern border between the SC and the WSB indicate the presence of magmatic intrusions and are proposed to mark the source zone of the Siberian LIP. The cratonic crust generally consists of three layers and high-velocity lowermost crust (Vp ~ 7.4 km/s) is observed only locally. Pn velocities are generally ~ 8.2 km/s in the SC and WSB and abnormally high (8.6-8.9 km/s) around kimberlite fields. We discuss the origin of crustal heterogeneity and link it to regional crustal evolution.

  19. 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

  20. 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.

  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

    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.

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

    USGS Publications Warehouse

    Hobba, William A., Jr.

    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.

  3. 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.

  4. 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

  5. Sedimentary basin analysis constrained by 3d seismic and subsidence modelling: the case of the Phanerozoic evolution of the Dampier Sub-basin, North West Shelf of Australia.

    NASA Astrophysics Data System (ADS)

    Langhi, L.; Borel, G. D.

    2003-04-01

    The North West Shelf of Australia has been a long term passive margin, which underwent a polyphased tectonic history associated with the disintegration of Eastern Gondwana. Several Phanerozoic sedimentary basins like the Northern Carnarvon Basin developed during the rifting phases culminating in the opening of the NeoTethys during the Late Paleozoic and the abyssal plains during the Mesozoic. In order to accurately constrain the Phanerozoic evolution of the proximal part of the Dampier Sub-basin (Mermaid Nose), a thorough 3D structural and stratigraphic analysis was performed on the basis of 2D/3D seismic data. It has enabled to highlight about twenty depositional sequences from Early Permian (Late Carboniferous?) to Late Cretaceous. The cuttings description of the deepest well of the area (Roebuck-1, 2871 mRT) was (has been) interpreted on the basis of the lithological changes and 19 units were highlighted from the Kungurian Kennedy Group to the Campanian Withnell Formation. The association of the 2D/3D seismic data and the regional Late Palaeozoic units described in the literature allows to generate a pseudo-well below Roebuck-1 total depth reaching the (Late Carboniferous?) Early Permian Lyons Group sequences. The sediments of the glacially-related Lyons Group have been interpreted on the seismic data as representing the first syntectonic infilling a half-graben. This extensional episode is linked to the NeoTethys rifting that extended up to the eastern Mediterranean area removing slivers of continents from Gondwana, known as the Cimmerian terranes. Stratigraphic, sedimentary and paleontological data provided by well and seismic analysis from the Mermaid Nose have been combined to produce subsidence curves. The subsidence modelling for the Mermaid Nose clearly emphasises the predominance of the effects of the NeoTethys rifting that took place under an ice-sheet whereas the extension coeval with the opening of the abyssal plains that occurred later and closer to

  6. 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.

  7. Influence of Neoproterozoic tectonic fabric on the origin of the Potiguar Basin, northeastern Brazil and its links with West Africa based on gravity and magnetic data

    NASA Astrophysics Data System (ADS)

    de Castro, David Lopes; Bezerra, Francisco H. R.; Sousa, Maria O. L.; Fuck, Reinhardt A.

    2012-03-01

    The Potiguar Basin is a ˜6,000 m thick aborted NE-trending rift that was formed during the Cretaceous in the continental margin of northeastern Brazil. Its ˜E-W-trending offshore faults form part of the successful continental margin rift that evolved into the South Atlantic Ocean. The region represents one of the most significant pre-Pangea breakup piercing points between eastern South America and West Africa. We used gravity, aeromagnetic, and geological data to assess the role of reactivated Precambrian shear zones and major terrain boundaries in the development of the Potiguar Basin from the Cretaceous to the Cenozoic. We also looked for possible links between these structures in northeastern Brazil and their continuation in West Africa. Our results indicate that the major fault systems of the Potiguar Basin were superimposed on the Precambrian fabric. Both gravity and magnetic maps show lineaments related to the shear zones and major terrain boundaries in the Precambrian crystalline basement, which also characterize the architecture of the rift. For example, the Carnaubais fault, the master fault of the rift system, represents the reactivation of the Portalegre shear zone, the major tectonic boundary between Precambrian terrains in the crystalline basement. In addition, part of the Moho topography is controlled by these shear zones and developed during the period of main rift extension in the Neocomian. The shear zones bounding the Potiguar rift system continue in West Africa around and underneath the Benue Basin, where fault reactivation also took place.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Semi-Idealized COAMPS®* Simulations of Sumatra Squall Lines: the Role of Boundary Forcing

    NASA Astrophysics Data System (ADS)

    Yi, Lan; Lim, Hock

    Sumatra squall line is a fairly impactive convective storm that often forms along the Malacca Straits and sweeps across Singapore in the early mornings of April to November each year. To understand and better predict this phenomenon, cloud resolving simulations with COAMPS at 3 km horizontal resolution are performed in a 3-D semi-idealized framework starting from a horizontally uniform atmosphere initialized by observed radiosonde data. Realistic boundary forcing effects by land-sea distribution, radiative fluxes, topography, and sea surface temperature (SST) are evaluated. Five ellipsoidal warm bubbles are prescribed to line up along the Malacca Straits to spawn a squall line. The bubbles are excluded in some cases to see if the squall line can be triggered without the initial external perturbation. Results demonstrate that line convection can be initiated by SST heating under no initial thermal perturbation; warm SST is conducive to kicking off convection. The diurnal circulations driven by the land sea thermal contrast play an important role in the intensification of the Sumatra squall line and its eastward migration. The shallow convection is enhanced by the convergence resulting from colliding land breezes from the west and the east coast of the Malacca Straits. It is found that the high relieves along west Sumatra and northwest Malaysia act to veer the low to mid tropospheric westerly winds into northerly flows, which converge into the strait with the southwest monsoonal flows from the south. The low-level convergence may then trigger and sustain the squall line.

  20. 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.

  1. Visualizing petroleum systems with a combination of GIS and multimedia technologies: An example from the West Siberia Basin

    SciTech Connect

    Walsh, D.B.; Grace, J.D.

    1996-12-31

    Petroleum system studies provide an ideal application for the combination of Geographic Information System (GIS) and multimedia technologies. GIS technology is used to build and maintain the spatial and tabular data within the study region. Spatial data may comprise the zones of active source rocks and potential reservoir facies. Similarly, tabular data include the attendant source rock parameters (e.g. pyroloysis results, organic carbon content) and field-level exploration and production histories for the basin. Once the spatial and tabular data base has been constructed, GIS technology is useful in finding favorable exploration trends, such as zones of high organic content, mature source rocks in positions adjacent to sealed, high porosity reservoir facies. Multimedia technology provides powerful visualization tools for petroleum system studies. The components of petroleum system development, most importantly generation, migration and trap development typically span periods of tens to hundreds of millions of years. The ability to animate spatial data over time provides an insightful alternative for studying the development of processes which are only captured in {open_quotes}snapshots{close_quotes} by static maps. New multimedia-authoring software provides this temporal dimension. The ability to record this data on CD-ROMs and allow user- interactivity further leverages the combination of spatial data bases, tabular data bases and time-based animations. The example used for this study was the Bazhenov-Neocomian petroleum system of West Siberia.

  2. Reef to basin sediment transport using Halimeda as a sediment tracer, Grand Cayman Island, West Indies

    NASA Astrophysics Data System (ADS)

    Johns, Hilary D.; Moore, Clyde H.

    1988-03-01

    Fragments of the calcareous green alga Halimeda form a large part of the sediment in the fringing reef system and adjacent deep marine environments of Grand Cayman Island, West Indies. Nine species combine to form three depth-related assemblages that are characteristic of the major reef-related environments (lagoonpatch reef, reef terraces, and deep reef). These modern plant assemblages form the basis of the use of Halimeda as a sediment tracer. Halimeda-based tracer studies of Holocene sediments indicate that only sediments containing deep reef species of Halimeda are presently being transported through the reef system by sediment creep and being deposited at the juncture of the upper and lower island slope. Sediments containing shallow reef Halimeda are retained within the reef and lithified by marine carbonate cements. Tracer studies of Pleistocene sediment indicate large amounts of reef-derived carbonate sand containing deep water Halimeda were produced during interglacial high stands of sea level. Much of this material was removed by turbidity currents moving out of the reef system to the island slope down submarine channels perpendicular to the reef trend. These channels may still be identified on bathymetric profiles, but are no longer receiving coarse reef debris and are veneered with a blanket of pelagic carbonate mud.

  3. 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

  4. 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.

  5. Geological structure of the offshore Sumatra forearc region estimated from high-resolution MCS reflection survey

    NASA Astrophysics Data System (ADS)

    Misawa, Ayanori; Hirata, Kenji; Seeber, Leonard; Arai, Kohsaku; Nakamura, Yasuyuki; Rahardiawan, Riza; Udrekh; Fujiwara, Toshiya; Kinoshita, Masataka; Baba, Hisatoshi; Kameo, Katsura; Adachi, Keita; Sarukawa, Hiroshi; Tokuyama, Hidekazu; Permana, Haryadi; Djajadihardja, Yusuf S.; Ashi, Juichiro

    2014-01-01

    To investigate detailed fault distributions and shallow geological structure offshore northwestern Sumatra, we obtained high-resolution Multi-Channel Seismic (MCS) reflection data around the Sunda Trench, trench slope, and forearc high regions offshore northwestern Sumatra. In general, trench-parallel anticlinal ridges are distributed from trench slope region to forearc high region. Two kinds of different vergence systems are characterized in the Sumatra forearc region; landward vergence is dominant in the lower trench slope region, and seaward vergence is dominant in the forearc high region. Moreover, piggyback or slope basins are recognized between anticlinal ridges. Deformation in the uppermost part of these basins, that is referred to ‘recent’ deformation in this paper, can be identified not only along major thrusts but also between major thrusts and the lower trench slope, suggesting these are related to recently active faulting. Several but the largest number of such deformation are distributed along a major thrust located in the middle of the forearc high region, whereas few are done along other major thrusts.

  6. 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

  7. 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.

  8. 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

  9. 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

  10. Tertiary Tectonics of the West Qinling Fault Zone : evidence from deformation, sedimentation, and magneto-stratigraphy in associated basins in the NE Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Brian, H.; Lease, R. O.; Garzione, C. N.; Zhang, P.

    2012-12-01

    The West Qinling fault zone (WQFZ) is one of the important NWW-trending faults in the northeastern margin of the Tibetan plateau. Field work in Longxi and Wushan region of the east Gansu province indicates that thrust faulting predominated the history of the fault belt in Cenozoic time, while strike-slip movement probably did not appear until the middle Miocene. We argue here that WQFZ has been so sensitive a structure that its Cenozoic activities may be related to the collision between India and Eurasia and the rising of the Tibetan plateau. Reverse faulting and associated mountain uplift along WQFZ at ˜45-50 Ma has been inferred with thermo-chronological dating in its west segment. According to our research, about 30% shortening occurred during the late Paleogene deformation in the Tange basin south of the WQFZ, while significant shortening for regions north of the WQFZ occurred no earlier than the middle Miocene. This shows that the WQFZ became the early northern boundary of the Tibetan Plateau during the late Paleogene. Basin geometry, magnetostratigraphy, sedimentation characteristics and the early syn-depositional deformation indicates that the Wushan basin with ~1700 m of sedimentary rocks generated in association with transpressional deformation along the WQFZ since ~16 Ma when another pulse of uplift and/or deformation began across the north and east margin of the Tibetan plateau. Furthermore, the WQFZ may have played an important role in the process of basin segmentation initiated since ~22 Ma in the region from the Qinghai lake to the east part of Gansu province. We suggest that the middle Miocene (~16 Ma) may represent a change in kinematics and deformation style in the region along and to the south of the WQFZ. At this time, there was a transition from NNE-SSW compressional deformation that dominated the region since the late Paleogene to the development of WNW-ESE and/or E-W trending strike-slip movement and associated transpressional and

  11. Southern extension of the Sumatra Fault and its tectonic significance

    NASA Astrophysics Data System (ADS)

    Soh, W.; Gaedicke, C.; Djajadihardja, Y. S.; Saito, S.

    2003-12-01

    Mode of slip partitioning in a fore arc of Sunda Arc between near trench normal thrusting and trench-parallel strike-slip faulting has been postulated mainly from the study of earthquake slip vectors and slip rate of the strike slip Sumatra Fault. However, there is no dependable geomorphic data, despite great attention for the area off the Sunda Strait which represent the junction between normal subduction off Java and oblique subduction off Sumatra. New single channel and bathymetric data were obtained by R/V Yokosuka, YK01-02/YK02-07 cruises and they provide a quite different geomorphologic view to the previously knowledge. New discovery of the southern extension of the Sumatra Fault is an example. In the southern extension, Shinkai 6500 dives allow us to identify more or less a meter of vertical topographic displacement along the SSE-trending active fault. Several amount of mud diapir mounds and a few sink hole are first recognized in the area where corresponds to a significant negative Bouguer anomaly zone. A methan content anomaly is detected in the summit of the mounds and bottom floor of the sink hole, together with Calyptogena colony. On the other hand, geomorphologic feature in the junction area is quite different to those of forearc setting; the area is covered by a bundle of tectonic blocks including the Genteng Bank, that well demarcated by the SSE- and east-trending conjugate lineaments. The junction area extending toward SSE occupies between the fore arc basin and the outer arc high and is demarcated by faults. The boundary fault cuts the preexisting geomorphology including trench-parallel strike slip fault in the outer arc high; e.g. Mentaiwai Faults. Consequently these geomorphic feature, as an accumulation of crustal deformation (plastic strain), is most likely to be caused by stretching of the fore arc crust. This study suggests that strain (plastic) partitioning in a fore arc occurs within the localized (or concentrated) area such as the junction

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 26th December 2004 Great Sumatra Earthquake: first insights from the summer 2005 Marion Dufresne cruise

    NASA Astrophysics Data System (ADS)

    Sibuet, J.

    2005-12-01

    The 26th December 2004 Great Sumatra Earthquake is the second biggest earthquake (Mw=9.3) recorded during the past century. It initiated at a depth of 20-30 km, close to an indentation of the Indonesian fore-arc. The rupture propagated about 1200 km northward and terminated north of Andaman Islands. The "Sumatra Aftershocks" cruise performed on the French R/V Marion Dufresne started July 15 in Jakarta and ended August 9, 2005 in Colombo. We carried out a complete swath-bathymetric survey in a 370*75 km stripe located between northern Sumatra and the Indonesia/India boundary and from the trench to northeast of the Sumatra fault. 20 OBSs were deployed in the area and recorded about 2000 earthquakes during that period. Coring, heat-flow and piezometer measurements were also carried out. Offshore northern Sumatra, the Australia/Sundaland motion is 5 cm/yr in the N008° direction (Bock et al., J. Geophys. Res., 2003), which means that both strike-slip and normal components might occur along features parallel to the trench direction. However, focal mechanisms of the 26th December 2004 earthquake as well as co-seismic motions and 5-days post-seismic displacement field determined from GPS sites are essentially perpendicular to the trench direction (Vigny et al., Nature, 2005). There is consequently an apparent mismatch between deformations derived from plate motions and from co-seismic and immediate after-slip motions. This might suggest that long-term post-seismic motions might have also a significant component of strike-slip motion along features parallel to the trench direction. Between the trench and the backstop located southwest of the Aceh forearc basin, numerous trench parallel piggy back basins were mapped, suggesting the existence of numerous thrust faults. On the basis of morphology, coring and heat flow measurements, a major active thrust fault, which might correspond to an active splay fault, was identified southwest of the Aceh forearc basin. The

  1. 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.

  2. 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.

  3. 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.

  4. Deep Seismic Reflection Images of the Sumatra Seismic and Aseismic Gaps

    NASA Astrophysics Data System (ADS)

    Singh, S. C.; Hananto, N. D.; Chauhan, A.; Carton, H. D.; Midenet, S.; Djajadihardja, Y.

    2009-12-01

    The Sumatra subduction zone is seismically most active region on the Earth, and has been the site of three great earthquakes only in the last four years. The first of the series, the 2004 Boxing Day earthquake, broke 1300 km of the plate boundary and produced the devastating tsunami around the Indian Ocean. The second great earthquake occurred three months later in March 2005, about 150 km SE of the 2004 event. The Earth waited for three years, and then broke again in September 2007 at 1300 km SE of the 2004 event producing a twin earthquake of magnitudes of 8.5 and 7.9 at an interval of 12 hours, leaving a seismic gap of about 600 km between the second and third earthquake, the Sumatra Seismic Gap. Seismological and geodetic studies suggest that this gap is fully locked and may break any time. In order to study the seismic and tsunami risk in this locked region, a deep seismic reflection survey (Tsunami Investigation Deep Evaluation Seismic -TIDES) was carried out in May 2009 using the CGGVeritas vessel Geowave Champion towing a 15 long streamer, the longest ever used during a seismic survey, to image the nature of the subducting plate and associated features, including the seismogenic zone, from seafloor down to 50 km depth. A total of 1700 km of deep seismic reflection data were acquired. Three dip lines traverse the Sumatra subduction zone; one going through the Sumatra Seismic Gap, one crossing the region that broke during the 2007 great earthquake, and one going through the aseismic zone. These three dip profiles should provide insight about the locking mechanism and help us to understand why an earthquake occurs in one zone and not in aseismic zone. A strike-line was shot in the forearc basin connecting the locked zone with broken zone profiles, which should provide insight about barriers that might have stopped propagation of 2007 earthquake rupture further northward.

  5. 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.

    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).

  6. 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.

    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.

  7. Effects of the West Desert Pumping Project on Near-Surface Brine Resources in the Newfoundland Basin, Tooele and Box Elder Counties, Utah

    NASA Astrophysics Data System (ADS)

    White, W. W.; Jones, B. F.; Kohler, J. F.

    2006-12-01

    The Bureau of Land Management and U.S. Geological Survey have identified changes in Newfoundland Basin shallow-brine aquifer chemistry that resulted from pumping Great Salt Lake brine into the Newfoundland Evaporation Basin during the West Desert pumping project. The pumping project was operated by the State of Utah from April 1987, to June 1989 in an attempt to lower the historically high level of Great Salt Lake (pond elevation was 4,211.85 feet in 1986). Effects of the pumping on the Newfoundland Basin included altering the chemical character of the shallow brine aquifer by mixing two chemically different brines, and depositing a halite salt crust where none was previously reported on the lacustrine sediments of the Newfoundland Basin playa. The halite salt crust resulted from evaporation of the brine pond generated by the pumping project. Changes in the shallow-brine aquifer chemistry were determined by comparing pre-pumping brine chemistry with that of post pumping brine, and examining variation with borehole depth and location (i.e., playa periphery vs central basin topographic low) of specific analyte concentration profiles and solid-phase mineral assemblages obtained from analyses of core sample pore water and mineralogy. Brine sample analyses from 72 exploratory boreholes drilled in the Newfoundland Basin by Reynolds Metals Company during the mid 1960's provided pre-pumping brine chemistry. Post pumping chemistry was obtained from analyses of brine samples from 24 boreholes hand-augured between 1998 and 2001 in the central and peripheral portions of the Newfoundland Basin. TEQUIL, a brine equilibrium model, was used to better understand how the Great Salt Lake brines introduced into the Newfoundland Basin may have interacted with fluids contained within the Basin's shallow-brine aquifer. TEQUIL identified the sequence of mineral precipitation from evaporation of pre and post-pumping Newfoundland Basin shallow-aquifer fluids and Great Salt Lake brine. The

  8. 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

  9. Landslides and mass wasting offshore Sumatra - results from the Sumatra Earthquake HMS Scott survey January-February 2005

    NASA Astrophysics Data System (ADS)

    Tappin, D. R.; Henstock, T.; McNeill, L.; Grilli, S.; Biscontin, G.; Watts, P.

    2005-12-01

    Earthquakes are a commonly cited mechanism for triggering submarine landslides that have the potential to generate damaging tsunamis (e.g. Papua New Guinea 1998). Notwithstanding, the Indian Ocean earthquake of December 26th 2005 has been cited as the cause of both far field and local tsunami runups that have been measured at over 35 metres on the west coast of Sumatra. On the basis of present modelling this seems to be the case. However, if earthquakes are such a common trigger for landslides then the magnitude 9.3 earthquake of December 26th might be expected to have caused numerous seabed failures within the area of rupture that may have contributed to local tsunami runup. This contribution discusses the seabed morphology offshore of Sumatra acquired during the survey carried out by HMS Scott in January and February 2005. Utilising a unique high resolution 12 kHz, 361-beam hull-mounted Sass IV sonar, over 40,000 square kilometres of seabed were mapped. The objective was to identify seabed movements that were the result of the earthquake and to identify submarine slope failures that may have contributed to the tsunami. This paper reports on the results of the survey using Fledermaus imaging software. The area mapped is an accretionary complex formed as the two plates have converged over the past 40 million years. From the data several seabed failure mechanisms of different ages have been identified. Along the plate margin in the west of the survey area the deformation front comprises a series of young thrust folds up to 1000m in elevation and tens of kilometres in length. In places the seaward faces of these folds have failed cohesively and slumped blocks 100's of metres high and up to several kilometres long have been displaced up to 13 kilometres onto the inner trench floor. At other locations older episodes of failure are identified by the presence of displaced slumped blocks located on the crests of the folds; the slumps thus predating uplift. Where young

  10. A Model For The Development Of The Porcupine Basin West Of Ireland: Evidence For Regional Syn-rift Tectonic Linkages?

    NASA Astrophysics Data System (ADS)

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

    The Porcupine Basin developed during the Mesozoic Era and is sited between the highly stretched crust of the Rockall Basin (where beta = 5 to 6) and the Protero- zoic crust of the Irish mainland, where the crust thickens to 30 km. Marine gravity sur- veys around Ireland together with satellite gravity data from the deeper ocean are used to investigate the larger-scale crustal structure of these two basins. Crustal structure derived from wide-angle and vertical incidence seismic data controls the interpretation and modeling of gravity data. An axial NE-trending gravity low caused by seismically defined crustal thickening towards the centre of the Rockall Basin is also present in the South Porcupine Basin where the crust has been extended by similar amounts. In contrast the amount of extension is less across the narrower North Porcupine Basin, where a N-trending axial gravity high is present due to poorly understood anoma- lous density variations in the crust/upper mantle. The change in crustal geometry and gravity properties occurs across a distinctive set of NW trending gravity lineaments. These are interpreted as a set of cross-basin syn-rift faults which control large-scale segmentation of extensional deformation at mid to upper crustal levels. Lithospheric stretching in the South Porcupine Basin involved a large anticlockwise rotation of the South Porcupine High, while to the north the stretching involved a smaller antipathetic clockwise rotation of the North Porcupine High. Restoration of the pre-rift crustal ge- ometry requires that a large amount (10's of km) of cumulative sinistral motion on NW-trending cross-basin faults accompanied these rotations, causing the southward broadening of the Rockall Basin. A tectonic linkage between the syn-rift development of the two basins and the smaller more numerous inboard basins in the Celtic area to the east is also required in this model. The NW-trending fault systems may have been important in focusing fluid flow in

  11. The particulate fraction of nutrients transported in river loads in the South West River Basin District (SWRBD), Ireland

    NASA Astrophysics Data System (ADS)

    Harrington, S.; Harrington, J.

    2009-04-01

    Nutrient and sediment budgets help river basin managers devise and implement appropriate strategies and methods to manage river basins. The enriching effects of nutrients are well documented, and quantifying nutrient loads can help predict algal blooms and thus minimise their occurrence. Many studies concentrate on the dissolved fraction of nutrients whilst ignoring the particulate proportion. Other studies fail to differentiate between particulate and dissolved forms. This paper reports on the results of the first investigation on Irish rivers concerning the fraction of nutrients that are found in particulate form, as well as nutrient riverine loads. Seven rivers in three different catchments in the South West River Basin District (SWRBD), as defined under the Water Frameworks Directive (200/60/EC, WFD), in the Republic of Ireland were investigated. The rivers investigated were the Lee, Shournagh, Glashaboy and Owenabue which discharge to Cork Estuary; the Bandon River which discharges to Kinsale Estuary; and the Blackwater and Bride rivers which discharge to Youghal Estuary. Thirty five water samples (five on each river) were collected for nutrient analysis between January and September 2008. Nutrients tested included; total dissolved P (TDP), total particulate P (TPP), dissolved orthophosphate, particulate orthophosphate, total dissolved N (TDN), total particulate N (TPN), dissolved nitrate and particulate nitrate. Results show that phosphorus transport in all catchments is largely dependent on suspended sediment concentration and flow rate. The fraction of total load for nitrogen and phosphorus that was found to be particulate varied largely between catchments. Nutrient loads were calculated for each river. Annual TN loads ranged approximately between 655 tonnes and 17,000 tonnes. TP loads ranged from as little as 12 tonnes to almost 1,400 tonnes. The fraction of TP found to be particulate varied from 16% to 81%, with an average of 50%. TPN had a range of 20

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Seismic structure of uppermost mantle and crust beneath West Philippine Basin and Kyusyu-Palau ridge by seafloor borehole seismometer, OBS and airgun experiment

    NASA Astrophysics Data System (ADS)

    Arisaka, M.; Shinohara, M.; Yamada, T.; Mochizuki, K.; Kaiho, Y.; Araki, E.; Nakahigashi, K.; Ito, M.; Shiobara, H.; Suehiro, K.; Kanazawa, T.

    2003-12-01

    The western Pacific area including the Philippine Sea plate is characterized by many island-arc and trench systems and back-arc basins, which are estimated to correspond to subduction of oceanic plates. The Philippine Sea plate is divided into two regions by the Kyushu-Palau Ridge running from north to south. There are the Shikoku basin and the Parece-Vela basin in the eastern part, and the West Philippine basin exists in the western part. It is important to study an uppermost mantle and crustal seismic structure of the Philippine Sea plate to consider the formation process and to estimate the development process of an island-arc and trench system. In addition, the borehole broadband seismic station (WP-1) was installed in the easternmost part of the West Philippine basin in 2001 and is in operation. To obtain the seismic structure is also important for analyses of the data retrieved from the WP-1. We conducted seismic surveys with ocean bottom seismometers (OBS), the WP-1 and controlled sources to obtain the seismic crustal structure around the WP-1 observatory March 2002, October 2002 and May 2003 using the R/V KAIREI, JAMSTEC. The total length of the profile parallel to the ridge (NS line) is about 100 km. The profile perpendicular to the ridge (EW line) has approximately 120 km long in total and crosses the ridge and the WP-1 borehole seismometer. As the controlled sources, we used a GI gun (3 liters) and Bolt 1500LL type (1500cu.in.) airguns. Number and kind of airguns differed in each experiment. Total 12 OBSs were deployed at an average interval of 10km(NS line) and 15km (EW line) for the experiments. A seismic velocity model for shallow structure is derived from using a tau-p inversion of individual OBS records. A deep structure beneath the profile is estimated by using a two-dimensional ray tracing method. The preliminary results for the NS line are obtained. P-wave velocity of the sedimentary layer is 2.7 km/s and the thickness is about 500 m. These

  18. Application of mineral-solution equilibria to geochemical exploration for sandstone-hosted uranium deposits in two basins in west central Utah.

    USGS Publications Warehouse

    Miller, W.R.; Wanty, R.B.; McHugh, J.B.

    1984-01-01

    This study applies mineral-solution equilibrium methods to the interpretation of ground-water chemistry in evaluating the uranium potential of the Beaver and Milford basins in west central Utah. Waters were collected mainly from wells and springs at 100 sites in limited areas in the basins, and in part from mixed sources. The waters were analysed for T, pH, alkalinity, specific conductance, SO4, Cl, F, NO3, Ca, Mg, Na, K, SiO2, Zn, Cu, Mo, As, U, V, Se, Li, Fe, Mn, and Al on different fractions. A computer model (WATEQ3) was used to calculate the redox potential and the state of saturation of the waters with respect to uraninite, coffinite, realgar and arsenopyrite. Mineral saturation studies have reliably predicted the location of known (none given here) U deposits and are more diagnostic of these deposits than are concentrations of indicator elements (U, Mo, As, Se). Several areas in the basins have ground-water environments of reducing redox potential, favourable for precipitation of reduced U minerals, and some of these areas are saturated or near-saturated with respect to uraninite and coffinite. The approach shows only that the environment is favourable locally for precipitation of reduced U minerals, but thereby locates exploration targets for (modern?) sandstone-hosted U deposits.-G.J.N.

  19. 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

  20. 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. PMID:15800612

  1. 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.

  2. 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

  3. 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

  4. 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., Jr.; 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.

  5. Surface-water quality in the West Branch Susquehanna River Basin, Pennsylvania: An appraisal of areal and temporal variability from 1962 to 1982 in Hydrologic Accounting Unit 020502

    SciTech Connect

    Hainly, R.A.; Truhlar, J.F.; Wetzel, K.L.

    1989-01-01

    A National Stream Quality Accounting Network (NASQAN) water quality data collection site, maintained by the US Geological Survey, is located on the river near its mouth at Lewisburg, Pennsylvania. Data collected were used to evaluate water quality variability in the basin. The following objectives were addressed: (1) describe the surface water quality upstream of the NASQAN site on an areal and temporal basis; (2) relate the water quality variability on both an areal and temporal basis, to general basin characteristics; and (3) assess the ability of the water quality data collected at the NASQAN site to represent, on both an areal and temporal basis the water quality upstream from the site. Generally the river was found to have moderately good water quality in the upper reaches, poor water quality in its middle reach, and good water quality near the mouth. Of the constitutents analyzed, those which exhibited increasing or decreasing trends most frequently were pH, alkalinity, dissolved sulfate, total ammonia, and total nitrite plus nitrate. The largest trends were in the concentrations of total-recoverable aluminum, manganese, and zinc. Causes of areal variation were attributed to land use and geologic variations throughout the basin. Trends which indicate an improvement in water quality are believed to be caused by improvements in the treatment of acid mine drainage and wastewater. Trends which indicated degradation of water quality were generally found in areas where these types of treatment are not yet effective. The NASQAN site at Lewisburg was shown not to represent the water quality of the entire basin, either areally or temporally. It does, however, represent the water quality of the West Branch Susquehanna River at its mouth.

  6. 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)

  7. 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

  8. Analyse sismo-stratigraphique du bassin d'Abda (Maroc occidental), exemple de structures inverses pendant le rifting atlantiqueSeismo-stratigraphic analysis of the Abda Basin (West Morocco): a case of reverse structures during the Atlantic rifting

    NASA Astrophysics Data System (ADS)

    Echarfaoui, Hassan; Hafid, Mohamed; Salem, Abdallah Aı̈t; Abderrahmane, Aı̈t Fora

    The review of the seismic reflection and well data from the coastal Abda Basin (western Morocco) shows that its Triassic and Jurassic sequences were deposited in a submeridean sag basin, whose eastern margin is characterised by progressive truncations and pinching out of these sequences against a prominent Palaeozoic high. The uplift of this latter is interpreted as a response to an Upper Triassic-Middle Jurassic local compressional event that controlled Triassic-Jurassic sedimentation within the Abda Basin. The present day 'West Meseta Flexure' is a surface expression of this uplift. To cite this article: H. Echarfaoui et al., C. R. Geoscience 334 (2002) 371-377.

  9. 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).

  10. Lower Triassic sequence stratigraphy of the western part of the Germanic Basin (west of Black Forest): Fluvial system evolution through time and space

    NASA Astrophysics Data System (ADS)

    Bourquin, Sylvie; Peron, Samuel; Durand, Marc

    2006-05-01

    .y. During the period of the stratigraphic base-level fall of the major cycle, a maximum of 65 m of sediment would have accumulated over 2.5 m.y. On the western edge of the Germanic Basin, the top of the Scythian is marked by a major sedimentary break characterised by a planation surface, with preservation of the first paleosols, followed by the Hardegsen unconformity. This unconformity is tectonically deformed, leading to the development of a new sedimentation area in the west of the basin. The fluvial sedimentation above this discontinuity shows a trend towards enhanced development of floodplain or lacustrine-type environments at its western margin, with the formation of paleosols. The fluvial systems are linked with sabkhas, and then with a shallow sea connected to the Tethys Ocean. In this context, the stratigraphic cycles are caused by variations in relative sea level and/or sediment supply. The fluvial deposits are preserved in an exoreic basin.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Hydrologic characteristics and possible effects of surface mining in the northwestern part of West Branch Antelope Creek basin, Mercer County, North Dakota

    USGS Publications Warehouse

    Crawley, Mark E.; Emerson, Douglas G.

    1981-01-01

    Lignite beds and abundant discontinuous sandstone beds of the Paleocene Sentinel Butte Member of the Fort Union Formation and sand and gravel beds in the Quarternary glaciofluvial deposits (Antelope Creek aquifer) are the most important aquifers for domestic and livestock water supplies in the West Branch Antelope Creek basin. In the Beulah-Zap lignite, ground water moves from highland area in the west toward the Antelope Creek aquifer. Water levels in the basal Sentinel Butte sandstone appear to be controlled by the level of Lake Sakakawea. In the glaciofluvial deposits of the Antelope Creek aquifer water moves from a ground-water divide northwestward to Lake Sakakawea and southeastward toward the Knife River. Large water-level declines in wells completed in the lignite and shallower aquifers could be expected with mining. The effects probably would be limited to within 1 to 2 miles of an active mine. Surface-runoff duration could be altered by increased infiltration and retention in the reclaimed are and possible temporal extension of base flow could occur. Shallow ground water beneath mine sites would be expected to increase in dissolved solids and locally to contain large sodium and sulfate concentrations. In some locations movement of poor quality water toward the Antelope Creek aquifer would be expected. (USGS)

  16. 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.

  17. 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.

  18. 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.

  19. 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., Jr.; 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

  20. 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.

  1. 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.

  2. An approach for reconstructing past streamflows using a water balance model and tree-ring records in the upper West Walker River basin, California

    NASA Astrophysics Data System (ADS)

    Vittori, J. C.; Saito, L.; Biondi, F.

    2010-12-01

    Historical streamflows in a given river basin can be useful for determining regional patterns of drought and climate, yet such measured data are typically available for the last 100 years at most. To extend the measured record, observed streamflows can be regressed against tree-ring data that serve as proxies for streamflow. This empirical approach, however, cannot account for or test factors that do not directly affect tree-ring growth but may influence streamflow. To reconstruct past streamflows in a more mechanistic way, a seasonal water balance model has been developed for the upper West Walker River basin that uses proxy precipitation and air temperature data derived from tree-ring records as input. The model incorporates simplistic relationships between precipitation and other components of the hydrologic cycle, as well as a component for modeling snow, and operates at a seasonal time scale. The model allows for flexibility in manipulating various hydrologic and land use characteristics, and can be applied to other watersheds. The intent is for the model to investigate sources of uncertainty in streamflow reconstructions, and how factors such as wildfire or changes in vegetation cover could impact estimates of past flows, something regression-based models are not able to do. In addition, the use of a mechanistic water balance model calibrated against proxy climate records can provide information on changes in various components of the water cycle, including the interaction between evapotranspiration, snowmelt, and runoff under warmer climatic regimes.

  3. Influence of the Neotethys rifting on the development of the Dampier Sub-basin (North West Shelf of Australia), highlighted by subsidence modelling

    NASA Astrophysics Data System (ADS)

    Langhi, Laurent; Borel, Gilles D.

    2005-03-01

    During the Late Palaeozoic and the Mesozoic, the development and evolution of the North West Shelf of Australia have been mostly driven by rifting phases associated with the break-up of Gondwana. These extensional episodes, which culminated in the opening of the Neotethys Ocean during the Permo-Carboniferous and a series of abyssal plains during the Jurassic-Cretaceous, are characterised by different stress regimes and modes of extension, and therefore had distinctive effects on the margin, and particularly on the Northern Carnarvon Basin. Interpretation of 3D and 2D seismic data enables a structural and stratigraphic analysis of the Late Palaeozoic sediments deposited in the proximal part of the Dampier Sub-basin (Mermaid Nose). Based on their seismic characters, stratigraphic relationship, internal patterns, lateral continuity, and architecture, these units are associated here with the Pennsylvanian?-Early Sakmarian glaciogenic Lyons Group and the Sakmarian-Artinskian Callytharra Formation. The former were deposited in a half-graben whose development is associated with the onset of the Neotethys rifting, and the latter is characterised by restricted deposition, inversion of prograding patterns, and uplift. The integration of seismo-stratigraphic characterisation of the Late Palaeozoic sequences and Mesozoic data from one exploration well (Roebuck-1) enables the construction of subsidence curves for the Mermaid Nose and the interpretation of its geohistory. The tectonic subsidence curves show a striking Permo-Carboniferous rifting phase related to the Neotethys rifting and a discrete Late Jurassic-Early Cretaceous event coeval with the opening and the spreading of the Argo Abyssal Plain. This result points out the predominance of the effects of the Permo-Carboniferous Neotethys episode, whereas the extension related to the Argo Abyssal Plain rifting that occurred later and closer to the studied area, had only limited effects on the subsidence of the proximal

  4. 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.

  5. 3D Visualization of Recent Sumatra Earthquake

    NASA Astrophysics Data System (ADS)

    Nayak, Atul; Kilb, Debi

    2005-04-01

    Scientists and visualization experts at the Scripps Institution of Oceanography have created an interactive three-dimensional visualization of the 28 March 2005 magnitude 8.7 earthquake in Sumatra. The visualization shows the earthquake's hypocenter and aftershocks recorded until 29 March 2005, and compares it with the location of the 26 December 2004 magnitude 9 event and the consequent seismicity in that region. The 3D visualization was created using the Fledermaus software developed by Interactive Visualization Systems (http://www.ivs.unb.ca/) and stored as a ``scene'' file. To view this visualization, viewers need to download and install the free viewer program iView3D (http://www.ivs3d.com/products/iview3d).

  6. Coseismic deformation induced by the Sumatra earthquake

    NASA Astrophysics Data System (ADS)

    Boschi, E.; Casarotti, E.; Devoti, R.; Melini, D.; Piersanti, A.; Pietrantonio, G.; Riguzzi, F.

    2006-08-01

    The giant Sumatra-Andaman earthquake of December 26, 2004 caused permanent deformations effects in a region of previously never observed extension. The GPS data from the worldwide network of permanent IGS sites show significant coseismic displacements in an area exceeding 10 7 km 2, reaching most of South-East Asia, besides Indonesia and India. We have analyzed long GPS time series histories in order to characterize the noise type of each site and, consequently, to precisely assess the formal errors of the coseismic offset estimates. The synthetic simulations of the coseismic displacement field obtained by means of a spherical model using different rupture histories indicate that a major part of the energy release took place in a fault plane similar to that obtained by Ammon et al. (2005) and Vigny et al. (2005) but with a larger amount of compressional slip on the northern segment of the fault area.

  7. 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.

  8. 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.

  9. The 2005 volcano-tectonic earthquake swarm in the Andaman Sea: Triggered by the 2004 great Sumatra-Andaman earthquake

    NASA Astrophysics Data System (ADS)

    Kundu, Bhaskar; Legrand, Denis; Gahalaut, Kalpna; Gahalaut, Vineet K.; Mahesh, P.; Kamesh Raju, K. A.; Catherine, J. K.; Ambikapthy, A.; Chadha, R. K.

    2012-10-01

    A 6 day duration earthquakes swarm occurred in the Andaman Sea, 31 days after the giant 2004 Sumatra-Andaman earthquake (Mw 9.2). The swarm occurred less than 100 km from the eastern edge of the 2004 earthquake rupture and is the most energetic ever recorded in the world. The earthquakes swarm appear to have occurred on en echelon fault system bounded by the two main right-lateral strike-slip faults, namely, the Seulimeum Strand of Sumatra Fault system (SEU) and the West Andaman Fault (WAF). At the beginning of the swarm, earthquakes with predominantly strike-slip focal mechanisms occurred which were followed by earthquakes with predominantly normal faulting focal mechanisms having significant deviatoric component. Highbvalue, presence of double slope in the Gutenberg-Richter relation, presence of monogenetic submarine volcanoes in the region of the swarm and the earthquake focal mechanisms suggest that the swarm was of volcano-tectonic origin and fluid flow played an important role in its occurrence. Indeed, our modeling suggests that it was triggered by the 2004 Sumatra-Andaman earthquake through poroelastic relaxation of the coseismic stresses.

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

    PubMed Central

    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. PMID:25419471

  11. 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

  12. 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

  13. Acceptance for Beneficial Use for the Canister Cleaning System for the K West basin Project A-2A

    SciTech Connect

    FARWICK, C.C.

    2000-04-04

    This documents the documentation that is required to be turned over to Operations with the Canister Cleaning System (CCS). The Acceptance for Beneficial Use will be updated as required prior to turnover. This document is prepared for the purposes of documenting an agreement among the various disciplines and organizations within the Spent Nuclear Fuel (SNF) Project as to what is required in terms of installed components of the CCS. This documentation will be used to achieve project closeout and turnover of ownership of the CCS to K Basins Operations.

  14. 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., III; 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.

  15. 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)

  16. 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.

  17. 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.

  18. 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.

  19. Seismicity in Andaman - Nicobar - Java - Sumatra Region and its Bearing on the Volcanism in the Region, With Special Reference to the Barren Island.

    NASA Astrophysics Data System (ADS)

    Alam, M.; Chandrasekharam, D.

    2005-12-01

    Barren Island volcano in the Andaman Sea (Indian Ocean) is the lone active volcano in the Indian Subcontinent. The island showed renewed activity (commenced from May 28, 2005) after the great earthquake of Sumatra (December 26, 2004) along with increased mud volcanism in Bartang (south of Barren Island) and first ever reported mud volcanism on Narcondum (north of Barren Island) in the Andaman-Nicobar Archipelago. These islands lie on a volcanic arc that extends from the extinct volcanoes like Mt. Popa, Mt. Wuntho of Myanmar in the north to the active volcanoes of Sumatra and Java in the south. Regional tectonism of this region is largely driven by the subduction of the Indo-Australian plate beneath the Asian (Burmese) plate. Regional seismicity pattern reflects different tectonic regimes, namely, thrust dominated subduction front, strike-slip faulting (west Andaman fault) and the extensional processes in the Andaman spreading center. Earthquakes of magnitude more than 4.5 on Richter Scale are quite frequent in the region and are related to the subduction-related processes. Continuous seismic activities in the Andaman-Nicobar-Java-Sumatra region cannot be dealt with separately as evident from the increased volcanic activities following the great earthquake of Sumatra. More recently increased seismic activity in the vicinity of the dormant volcano of Mt. Toba is very much likely to culminate in a catastrophic eruption of this volcano in near future.

  20. 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

  1. Subsurface geology of the Warfield structures in southwestern West Virginia: Implications for tectonic deformation and hydrocarbon exploration in the Central Appalachian basin

    SciTech Connect

    Gao, D.; Shumaker, R.C.

    1996-08-01

    Data from over 6000 wells and five multichannel reflection seismic lines were used to constrain the subsurface geometry of the Warfield structures in southwestern West Virginia within the central Appalachian basin. Based on their vertical differences in geometry and structural styles, we divided the Warfield structures into shallow (above the Devonian Onondaga Limestone), intermediate (between the Devonian Onondaga Limestone and the Silurian Tuscarora Sandstone), and deep (below the Ordovician Trenton horizon) structural levels. Shallow structures are related to the Alleghanian deformation above the major detachment horizon of the Devonian shales and consist of the Warfield anticline with a 91.5-m closure and southeast-dipping monoclines, which aided the northwest migration and entrapment of oil and gas. At the intermediate level, the closure of the Warfield anticline is lost because the Alleghanian deformation is obscured below the major detachment of the Devonian shales, which explains the reduced production from the Devonian and Silurian reservoirs. Deep structures are characterized by an asymmetric half graben within a continental rift system known as the Rome trough, in which a thick sequence of sedimentary rocks exists to provide sources for overlying reservoirs. Although stratigraphic traps may be associated with thickness and facies changes, the deep level is structurally unfavorable for trapping hydrocarbons. Based on changes we found in map trend, we divided the Warfield structures into a middle segment and southern and northern bends. The middle segment is parallel to the New York-Alabama lineament (a northeast-trending magnetic gradient); the southern and the northern bends are linked to the 38th parallel lineament (a west-trending fault system) and the Burning Springs-Mann Mountain lineament (a north-trending magnetic gradient), respectively.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. Subsurface plumbing and fluid expulsion from sedimentary basins: evidence from the sedimentary record offshore West Africa (Invited)

    NASA Astrophysics Data System (ADS)

    Huuse, M.

    2010-12-01

    Many petroliferous basins around the world show evidence for fluid expulsion and seepage on the land surface or seafloor. However, not all fluid expulsion features are evidence of a working hydrocarbon systems and one needs to carefully evaluate fluid expulsion features and their associated geology and in particular their plumbing systems before inferring the nature of the expelled fluids. Geochemical fingerprinting of the migrating fluids may be sampled directly or via carbonate cements secreted in association with focus fluid conduits and may help determine the nature of the expelled fluids including their stratigraphic origin. When such evidence is unavailable, one may have to rely on remote sensing, including 3D seismic characterization in order to assess the nature of expelled fluids and links with hydrocarbon migration and/or ‘normal’ diagenetic fluid expulsion. This paper presents 3D seismic case studies of pockmarks, fluid flow pipes and polygonal fault systems which show evidence of both deep and shallow sources of expelled fluids and discuss the different controls on their occurrence and significance. Importantly, there is evidence of both conducting and sealing behaviours of polygonal fault sytems. Bottom-Simulating Reflections from interfaces between free gas and overlying gas hydrate occur in a variety of manifestations and may be linked with both deep and shallow sources of methane. Their depth of occurrence relative to seafloor depth may be used to infer local geothermal gradients and it is shown that underlying salt causes BSRs to shallow, indicative of a doubling of the geothermal gradient above salt structures compared to the adjacent salt mini basins. It is further suggested that salt structures on the middle slope serve a dual purpose as trap and leak-forming features, with traps focused on the down-dip side of overhanging diapirs and leaks located on the updip side and flanks. Associated leakage phenomena include gas and gas hydrate

  9. 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)

  10. Anisotropy Modelling of the Fissure-Karstic Aquifer of the Opole-Zawadzkie Major Groundwater Basin (South-West Poland)

    NASA Astrophysics Data System (ADS)

    Wcisło, Marek; Olichwer, Tomasz; Staśko, Stanisław

    2014-12-01

    The problem of the anisotropy and heterogeneity of karstic aquifers has been previously described. The Opole-Zawadzkie Major Groundwater Body (south-west Poland) was chosen for this investigation. The parameters for anisotropy were analysed on the basis of well yield and observation of macro-fractures (field scale) compared with micro-fractures. Sta-tistical tools were used to assess the directions and values of anisotropy. The estimated parameters were tested on two different models realized in Visual Modflow code. The anisotropy of hydraulic conductivity was recognized as an es-sential factor for groundwater flow direction and water table depletion prognosis as well as for water budget modification. The second model (M2), representing anisotropy flow conditions, gave an 11% lower value of safe yield in com-parison with the first model (M1-isotropic). Additionally, anisotropy conditions caused water table lowering and limitation of aquifer recharge. The results of these studies indicate the need for more attention to be paid to the anisotropy problem in the area, where fracture-karstic aquifers are the main source of groundwater supply.

  11. 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.

  12. 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.

  13. Fractures, convection and underpressure: hydrogeology on the southern margin of the Piceance basin, west-central Colorado, USA

    NASA Astrophysics Data System (ADS)

    Lazear, Gregory D.

    2009-05-01

    Grand Mesa is an erosional remnant on the southern margin of the Piceance basin (Colorado, USA) that appears to host topographically driven groundwater flow in low permeability strata via a pervasive network of vertical extensional fractures. The vertical fractures cut more than 1 km of clay-rich lithology ranging in age from Upper Cretaceous through Eocene, and likely formed from horizontal dilation, cooling, and erosional unloading associated with 2.8 km of regional uplift and 1.5 km of incision by the Gunnison and Colorado rivers. The vertical fractures create anisotropy in which vertical permeability exceeds horizontal permeability. This enhances vertical flow and depth of penetration of groundwater, favors local flow regimes over regional flow, and results in groundwater temperatures that are elevated by up to 10°C over mean surface temperatures at the location of springs. The uplift and cooling that formed the fractures may also have produced domains of abnormally underpressured pore fluids and natural gas within blocks of low permeability bedrock bounded by the fractures. Pore pressures inside these blocks may be in disequilibrium with the groundwater flow system due to ongoing stress release, and the long time scales required for pressure equilibration in the low permeability strata.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. The global reach of the 26 December 2004 Sumatra tsunami.

    PubMed

    Titov, Vasily; Rabinovich, Alexander B; Mofjeld, Harold O; Thomson, Richard E; González, Frank I

    2005-09-23

    Numerical model simulations, combined with tide-gauge and satellite altimetry data, reveal that wave amplitudes, directionality, and global propagation patterns of the 26 December 2004 Sumatra tsunami were primarily determined by the orientation and intensity of the offshore seismic line source and subsequently by the trapping effect of mid-ocean ridge topographic waveguides. PMID:16123264

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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

  8. The June 2000 Enggano earthquake, South Sumatra, and the role of the Mentawai Fault

    NASA Astrophysics Data System (ADS)

    Milsom, J.; Abercrombie, R. E.

    2003-04-01

    Sumatra is widely regarded as a type example of strain-partitioning during oblique subduction. In the simplest view, arc-orthogonal motion is accomodated at the trench and arc-parallel motion is accomodated at the strike-slip Sumatra Fault System along the volcanic line. There is, however, a third, more enigmatic, feature that runs the length of the oceanward side of the forearc basin and defines, in many cases, steep eastern margins to the forearc islands. This 'Mentawai Fault' has been variously interpreted as a fold and as a fault with strike-slip, normal or high-angle reverse motion. Seismic reflection images vary considerably from place to place, and the role of the feature in the subduction process remains controversial. It is, however, significant that repeat GPS measurements in the vicinity of Enggano, the southernmost of the forearc islands, indicated that much of the convergence between the Indian Ocean and Southeast Asian plates was being absorbed within the forearc basin during the period of observation. The Mentawai Fault is the only feature observed on the seismic sections that appears capable of accomodating this convergence. The subduction zone beneath Sumatra has been the site of repeated large earthquakes, most recently in June 2000 when a Magnitude 7.9 earthquake occurred near Enggano followed by a strong aftershock sequence. Analysis of the main shock, using body and surface waves, indicates that there were two distinct sub-events occurring a few seconds apart. The first, involving strike-slip within the subducting Indian Ocean Plate, evidently triggered reverse slip on the subduction interface. Both sub-events were too deep, and in the wrong locations, to be due to failure on the Mentawai Fault. They do, however, provide important insights into its likely role. The GPS results indicate that in areas such as Enggano, and possibly only for short periods, the forearc wedge moves with the subducting plate. It must therefore compress against the

  9. 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)

  10. 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. PMID:20616276

  11. 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

  12. Geothermal investigations in West Virginia

    SciTech Connect

    Hendry, R.; Hilfiker, K.; Hodge, D.; Morgan, P.; Swanberg, C.; Shannon, S.S. Jr.

    1982-11-01

    Deep sedimentary basins and warm-spring systems in West Virginia are potential geothermal resources. A temperature gradient map based on 800 bottom-hole temperatures for West Virginia shows that variations of temperature gradient trend northeasterly, parallel to regional structure. Highest temperature gradient values of about 28/sup 0/C/km occur in east-central West Virginia, and the lowest gradients (18/sup 0/C/km) are found over the Rome Trough. Results from ground-water geochemistry indicate that the warm waters circulate in very shallow aquifers and are subject to seasonal temperature fluctuations. Silica heat-flow data in West Virginia vary from about 0.89 to 1.4 HFU and generally increase towards the west. Bouguer, magnetic, and temperature gradient profiles suggest that an ancient rift transects the state and is the site of several deep sedimentary basins.

  13. 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…

  14. 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).

  15. 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.

  16. Anomalous variation in GPS TEC prior to the 11 April 2012 Sumatra earthquake

    NASA Astrophysics Data System (ADS)

    Zhu, Fuying; Zhou, Yiyan; Wu, Yun

    2013-06-01

    On 11 April 2012, a strong earthquake of magnitude Ms8.6 occurred near the west coast of Northern Sumatra, Indonesia. In this paper, we investigated the morphological characteristics of anomalous variations in Global Positioning System Total Electron Content (GPS TEC) prior to the earthquake by the method of the statistical analysis. It was found the TEC anomaly was firstly decreased, then, it became more enhanced, finally, it decreased, the peak of anomaly enhancement arose from 13:00-17:00 LT on April 5 lasted for ˜4 hours and the anomalous ionospheric regions extended to ˜40∘ in longitude and ˜20∘ in latitude, its location did not coincide with the vertical projection of the epicenter, but lies at the north and south of the geomagnetic equator, meanwhile, corresponding ionospheric anomalies are also observed in the magneto conjugate region. Potential causes of these results are discussed,eliminating the ionospheric anomalies that may be caused by solar activities and magnetic storms, it can be concluded that the observed obvious anomalous variation in GPS TEC on April 5 were possibly related to the earthquake.

  17. 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

  18. An Overview of SEATOS: Sumatra Earthquake and Tsunami Offshore Survey

    NASA Astrophysics Data System (ADS)

    Moran, K.; Grilli, S.; Tappin, D.

    2005-12-01

    In May 2005, an international, interdisciplinary team of scientists conducted a detailed survey of the seafloor in the vicinity of the epicenter of the Great Sumatra earthquake of December 26, 2004-dubbed Sumatra Earthquake and Tsunami Offshore Survey (SEATOS 2005). The overall goal of the survey was to gather data to improve models of seafloor displacement and the resulting tsunami waves. To accomplish this goal, SEATOS conducted detailed investigations at seven sites: a large underwater landslide, initially thought to be the result of the December 26th earthquake: a ~20km long trench feature at the deformation front that was interpreted to represent recent seafloor displacement; seafloor locations at three sites on the forearc high; and a steep mound north of Sumatra, interpreted as volcanic. High resolution seismic lines were run across the margin and between detailed study sites to characterize the overall style of the subduction zone (see abstract by Mosher et al., this session). At each site, detailed surveys including seismic, and remotely operated vehicles (ROV) were conducted. ROV surveys included high definition television-quality video imaging of the seafloor, as well as core sampling for biological and geotechnical analyses. During SEATOS, tsunami simulations were also conducted using a wave model based on fully nonlinear Boussinesq equations (see Grilli et al. abstract, this session). Such a model better represents the oscillatory wave trains that were typically observed during the event. Early results suggest seafloor disturbances (from the Dec. 26th 2004 earthquake) and the formation of new seafloor features occurred at the deformation front and stable seafloor conditions prevailed at the forearc high. These data are currently being analyzed, along with recently published seismic inversion analyses, to develop a seafloor displacement model that best represents the Dec. 26th event. Also, the comparison of wave model results with observations at tide

  19. Numerical Modeling and Forecasting of Strong Sumatra Earthquakes

    NASA Astrophysics Data System (ADS)

    Xing, H. L.; Yin, C.

    2007-12-01

    ESyS-Crustal, a finite element based computational model and software has been developed and applied to simulate the complex nonlinear interacting fault systems with the goal to accurately predict earthquakes and tsunami generation. With the available tectonic setting and GPS data around the Sumatra region, the simulation results using the developed software have clearly indicated that the shallow part of the subduction zone in the Sumatra region between latitude 6S and 2N has been locked for a long time, and remained locked even after the Northern part of the zone underwent a major slip event resulting into the infamous Boxing Day tsunami. Two strong earthquakes that occurred in the distant past in this region (between 6S and 1S) in 1797 (M8.2) and 1833 (M9.0) respectively are indicative of the high potential for very large destructive earthquakes to occur in this region with relatively long periods of quiescence in between. The results have been presented in the 5th ACES International Workshop in 2006 before the recent 2007 Sumatra earthquakes occurred which exactly fell into the predicted zone (see the following web site for ACES2006 and detailed presentation file through workshop agenda). The preliminary simulation results obtained so far have shown that there seem to be a few obvious events around the previously locked zone before it is totally ruptured, but apparently no indication of a giant earthquake similar to the 2004 M9 event in the near future which is believed to happen by several earthquake scientists. Further detailed simulations will be carried out and presented in the meeting.

  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. 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.

  2. 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.

  3. Planning status report: water resources appraisal for hydroelectric licensing, Potomac River basin, Pennsylvania, Maryland, West Virginia, Virginia, and District of Columbia

    SciTech Connect

    Not Available

    1980-01-01

    Updated information on water resources in the Potomac River Basin is presented for use by the FERC and its staff when considering hydroelectric licensing and other work. The report presents data on water resource developments, existing and potential, and on water use by existing and projected steam-electric generating facilities. Past and present planning studies are summarized.

  4. Recurrence of great earthquakes and tsunamis, Aceh Province, Sumatra

    NASA Astrophysics Data System (ADS)

    Rubin, C. M.; Horton, B.; Sieh, K.; Pilarczyk, J.; Hawkes, A. D.; Daly, P.; Kelsey, H. M.; McKinnon, E.; Ismail, N.; Daryono, M. R.

    2013-12-01

    The timing and characterization of ancient earthquakes and tsunamis inferred from a variety of geologic studies in Aceh Province, Sumatra, are helping to understand predecessors of the 2004 event in the Indian Ocean region. We report results from three different depositional environments along the western and northern coast of Aceh Province, Sumatra, that illuminate the history of tsunamis through the past several millennia. Within a coastal cave along the western coast is an extraordinary sedimentary deposit that contains a 7,000-year long sequence of tsunami sands separated by bat guano. In two sea cliff exposures along the northern coast of Aceh is evidence for two closely timed predecessors of the giant 2004 tsunami that destroyed communities along the coast about 500 years ago. In addition, coastal wetlands along the western coast document land-level changes and tsunamis associated with the earthquake cycle in the early- to mid-Holocene. Together these records show a marked variability in recurrence of large tsunamis along the Acehnese coast. Time between inundations averages close to 500 years but range from a few centuries to a millennium.

  5. 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

  6. 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.

  7. Tracing Mantle and Slab Contributions to the Proto Izu-Bonin-Mariana Arc Magmatism: Mineralogical and Geochemical Studies of a Volcaniclastic Sequence From the Palau-Kyushu Ridge, West Philippine Basin

    NASA Astrophysics Data System (ADS)

    D'Antonio, M.; Savov, I. P.; Hickey-Vargas, R.; Spadea, P.; Lockwood, J.

    2005-05-01

    The submerged Palau-Kyushu Ridge (PKP) is the remnant of a proto-Izu-Bonin-Mariana (IBM) island arc, which was active since about 48 to 35 Ma ago, contemporaneously to subduction of the Pacific plate beneath the spreading West Philippine basin. Volcanic activity along the PKR stopped in response to plate reorganization, and renewed subduction which initiated with an E-W rifting, separating the PKR from the Iwo Jima ridge in the north and the West Mariana Ridge in the south. A 400 m- thick sequence of turbidites containing volcaniclastic sediments, underlain by basin basalt with a magnetic age of 49 Ma, was drilled during ODP Leg 195 at Site 1201, located about 200 km off the western slope of the PKR. These volcaniclastics represent a unique opportunity to sample the past activity of the PKR. Therefore, the mineralogical and geochemical features of these volcaniclastics are used to investigate the petrogenesis of the proto-IBM arc magmas, and the temporal evolution of the currently active intra-oceanic IBM island arc and related back-arc basins. From the recovered turbidite sequence, many volcaniclasts (mm- to cm- sized) and fresh pyroxene and plagioclase grains (xenocrysts) were collected and investigated from a petrological point of view. Most of the clasts are angular (breccias), and no rounded grains occur in the xenocrysts population, suggesting that these materials were incorporated in the turbidites fairly quickly after removal from the slopes of the PKR. The analyzed clasts range in composition from basalt (one sample) to basaltic andesite (the majority); a few samples showing a high total alkalis content like mugearite, are classified as altered basalts enriched in alkalis by hydrothermal alteration. Trace element abundance and distribution are indicative of a calk-alkaline affinity, also evidenced by high LILE/HFSE and LREE/HREE ratios. Initial Sr and Nd isotope ratios indicate derivation of the parental magmas from an arc-like mantle source, suggesting

  8. 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.

  9. Statistical Analysis of Seismicity in the Sumatra Region

    NASA Astrophysics Data System (ADS)

    Bansal, A.; Main, I.

    2007-12-01

    We examine the effect of the great M=9.0 Boxing day 2004 earthquake on the statistics of seismicity in the Sumatra region by dividing data from the NEIC catalogue into two time windows before and after the earthquake. First we determine a completeness threshold of magnitude 4.5 for the whole dataset from the stability of the maximum likelihood b-value with respect to changes in the threshold. The split data sets have similar statistical sampling, with 2563 events before and 3701 after the event. Temporal clustering is first quantified broadly by the fractal dimension of the time series to be respectively 0.137, 0.259 and 0.222 before, after and for the whole dataset, compared to a Poisson null hypothesis of 0, indicating a significant increase in temporal clustering after the event associated with aftershocks. To quantify this further we apply the Epidemic Type Aftershock Sequence (ETAS) model. The background random seismicity rate £g and the coefficient Ñ, a measure of an efficiency of a magnitude of an earthquake in generating its aftershocks, do not change significantly when averaged over the two time periods. In contrast the amplitude A of aftershock generation changes by a factor 4 or so, and there is a small but statistically significant increase in the Omori decay exponent p, indicating a faster decay rate of the aftershocks after the Sumatra earthquake. The ETAS model parameters are calculated for different magnitude threshold (i.e. 4.5, 5.0, 5.5) with similar results for the different magnitude thresholds. The Ñ values increases from near 1 to near 1.5, possibly reflecting known changes in the scaling exponent between scalar moment and magnitude with increasing magnitude. A simple relation of magnitude and span of aftershock activity indicates that detectable aftershock activity of the Sumatra earthquake may last up to 8.7 years. Earthquakes are predominantly in the depth range 30-40 km before 20-30 km after the mainshock, compared to a CMT centroid

  10. 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.

  11. 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.

  12. Seismicity of west Texas

    SciTech Connect

    Dumas, D.B.

    1981-01-01

    A four year seismic study has found the Basin and Range province of west Texas and the adjacent area of Mexico to be more seismically active then than heretofore known. A University of Texas five station seismic array around the Marfa Basin has located or detected approximately 800 local and regional earthquakes with S-P times of less than 30 sec. A crustal model for the Basin and Range is derived from natural and artificial sources and contains four layers having velocities of 3.60, 4.93, 6.11, and 6.60 km/sec, respectively, overlying a mantle of 8.37 km/sec. A moderate level of seismic activity has been detected near Van Horn, in the Marfa Basin, and along the Texas-Mexico border between latitudes 30 and 31/sup 0/N. Five earthquake sequences were recorded, two near the Texas-Mexico border and three in the Marfa Basin. Four of these sequences showed quiescent periods in foreshock activity preceding the main shock. On the eastern side of the Marfa Basin a diffuse linear seismic zone may represent an unmapped fault, striking N 50/sup 0/W that coincides with Muehlberger's proposed eastern boundary of Basin and Range faulting. A new epicenter for the Valentine, Texas earthquake of August 16, 1931 has been relocated instrumentally at the northern end of this diffuse zone. Regional and local teleseismic P-wave arrival time anomalies observed for the nearby Gnome underground nuclear explosion of 1961 are used to determine station corrections and thus to locate the new 1931 epicenter at 3.69/sup 0/N, 104.57/sup 0/W. Several estimates of magnitude (m/sub b/) based on intensity data range from 5.6 to 6.4. Fault-plane and composite fault-plane solutions support Muehlberger's hypothesis that the Basin and Range is undergoing extension in a SW-NE direction.

  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, 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.

  14. 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

  15. 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.

  16. 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)

  17. 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

  18. 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.

  19. 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. PMID:9463111

  20. 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.

  1. Geothermal exploration using audio-magnetotelluric in Pariangan Tanah Datar, West Sumatra

    NASA Astrophysics Data System (ADS)

    Saputra, Andriyan; Widodo, Kholid, Muhammad

    2015-04-01

    The existence of Mt. Marapi in Pariangan Tanah Datar has a big potential of geothermal energy resource. The study area is located in southeastern Mt. Marapi. The geological elements correspond to lava granitic, sandstone quartz, quartzite and conglomerate. The aim of this research is to investigate the geothermal system in this area. Measurements of audio-magnetotelluric (AMT) long line are 10 km with two profiles. The audio-magnetotelluric (AMT) data carried out during July 2014. The models result were done by using 1-D inversion technique. The 1-D inversion was done with Occam and Marquadt algoritm. We assumed that for the first layer indicates as the conductive zone (±10 Ωm), the second layer as the reservoir geothermal system (±100 Ωm) that contains with sandstone quartz, and the third layer can be interpreted as volcanic rock (±1000 - 10000 Ωm) which is the basement of geothermal system.

  2. 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

  3. 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

  4. 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.

  5. Fault interactions and triggering during the 10 January 2012 Mw 7.2 Sumatra earthquake

    NASA Astrophysics Data System (ADS)

    Fan, Wenyuan; Shearer, Peter M.

    2016-03-01

    The 10 January 2012 Mw 7.2 Sumatra earthquake in the Wharton basin occurred 3 months before the great Mw 8.6 and Mw 8.2 earthquakes in the same region, which had complex ruptures and are the largest strike-slip earthquakes ever recorded. Teleseismic P wave back projection of the Mw 7.2 earthquake images a unilateral rupture lasting ˜40 s without observable frequency dependency (low frequency, 0.05-0.3 Hz, high frequency, 0.3-1 Hz). In addition to radiation bursts during the Mw 7.2 main shock, coherent energy releases from 50 to 75 s and from 100 to 125 s are observed about 143 km northeast of the main shock rupture and landward of the trench. Analysis of globally recorded P waves, in both 0.02-0.05 Hz velocity records and 1-5 Hz stacked envelope functions, confirms the presence of coherent sources during the time windows. The observed energy bursts are likely to be large early aftershocks occurring on or near the subduction interface. Both dynamic and static triggering could have induced these early aftershocks, as they initiated after the surface wave passed by, and the Coulomb stress perturbations from the Mw 7.2 main shock promote earthquakes in the observed locations. The earthquake sequence is a clear example of a seaward-intraplate strike-slip earthquake triggering landward-intraplate earthquakes in the same region, in contrast to previously reported normal-reverse or reverse-normal interactions at subduction zones.

  6. The 2012 Mw 8.6 Sumatra earthquake: Evidence of westward sequential seismic ruptures associated to the reactivation of a N-S ocean fabric

    NASA Astrophysics Data System (ADS)

    Satriano, Claudio; Kiraly, Eszter; Bernard, Pascal; Vilotte, Jean-Pierre

    2012-08-01

    The 11 April 2012 Mw 8.6 earthquake offshore Sumatra is the largest of the rare great intraplate earthquakes of the instrumental era. This major strike-slip event occurred in the diffuse zone of deformation that accommodates differential rotation between Indian and Australian plates. We perform a back projection analysis - calibrated with well-located aftershocks - of short-period teleseismic P-waves recorded by the European array to image the rupture process during the mainshock. In complement, a Love wave analysis is conducted for tracking azimuthal change in the apparent global source duration due to the source spatio-temporal extent. The combined analysis reveals a complex rupture pattern, characterized by three main episodes of energy release, the latest being located 370 km west of the epicenter, on the Ninety East Ridge, with a delay of 120 s. We interpret the 11 April 2012 Mw 8.6 offshore Sumatra earthquake as a complex westward-propagating sequence of dynamically triggered strike-slip fault ruptures, associated to the reactivation of the inherited NNE-striking sea floor fabric. The dynamic triggering mechanism could result from the interaction between transient surface wave stress perturbations and fluids.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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)

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. Regional GPS data confirm high strain accumulation prior to the 2000 June 4 Mw = 7.8 earthquake at southeast Sumatra

    NASA Astrophysics Data System (ADS)

    Michel, G. W.; Becker, M.; Reigber, Ch.; Tibi, R.; Yu, Y. Q.; Zhu, S. Y.

    2001-09-01

    Site velocities derived from repeated measurements in a regional GPS network in Southeast Asia help to constrain the motion of tectonic blocks as well as slip rates along major faults in the area. Using 3-D forward dislocation modelling, the influence of seismic elastic loading and unloading on the measured site motions are approximated. Results suggest that the northwestern Sunda arc is fully coupled seismogenically, whereas its eastern part along Java shows localized deformation. Higher horizontal velocity gradients than expected from the modelling of a fully coupled plate interface west of Manila in the Philippines suggest that deformation may be localized there. Assuming that geodetically derived convergence represents long-term rates, accumulated geodetic moments are compared to those derived using seismic data from 1977 to 2000 (Harvard CMT catalogue). If areas displaying localized deformation are dominated by creep processes, the largest difference between accumulated and seismically released deformation is located where the 2000 June 4 Mw=7.8 Sumatra earthquake occurred.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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

  2. Rock-physics-based carbonate pore type characterization and reservoir permeability heterogeneity evaluation, Upper San Andres reservoir, Permian Basin, west Texas

    NASA Astrophysics Data System (ADS)

    Dou, Qifeng; Sun, Yuefeng; Sullivan, Charlotte

    2011-05-01

    In addition to mineral composition and pore fluid, pore type variations play an important role in affecting the complexity of velocity-porosity relationship and permeability heterogeneity of carbonate reservoirs. Without consideration of pore type diversity, most rock physics models applicable to clastic rocks for explaining the rock acoustic properties and reservoir parameters relationship may not work well for carbonate reservoirs. A frame flexibility factor ( γ) defined in a new carbonate rock physics model can quantify the effect of pore structure changes on seismic wave velocity and permeability heterogeneity in carbonate reservoirs. Our study of an Upper San Andres carbonate reservoir, Permian Basin, shows that for core samples of given porosity, the lower the frame flexibility factor ( γ), the higher the sonic wave velocity. For the studied reservoir, samples with frame flexibility factor ( γ) < 3.85 represent either visible vuggy pore space in a dolopackstone or intercrystalline pore space in dolowackstone. On the other hand, samples with frame flexibility factor ( γ) > 3.85 indicate either dominant interparticle pore space in dolopackstone or microcrack pore space in dolowackstone or dolomudstone. Using the frame flexibility factor ( γ), different porosity-impedance and porosity-permeability trends can be classified with clear geologic interpretation such as pore type and rock texture variations to improve porosity and permeability prediction accuracy. New porosity-permeability relations with γ classification help delineate permeability heterogeneity in the Upper San Andres reservoir, and could be useful for other similar carbonate reservoir studies. In addition, results from analysis of amplitude variation with offset (AVO) and impedance modeling indicate that by combining rock physics model and pre-stack seismic inversion, simultaneous estimation of porosity and frame flexibility factor ( γ) is quite feasible because of the strong influence of

  3. GPS measurements of postseismic deformation in the Andaman-Nicobar region following the giant 2004 Sumatra-Andaman earthquake

    NASA Astrophysics Data System (ADS)

    Gahalaut, V. K.; Jade, S.; Catherine, J. K.; Gireesh, R.; Ananda, M. B.; Kumar, P.; Narsaiah, M.; Jafri, S. S. H.; Ambikapathy, A.; Bansal, A.; Chadha, R. K.; Gupta, D. C.; Nagarajan, B.; Kumar, S.

    2008-08-01

    We report GPS measurements of postseismic deformation from 22 campaign-mode and one continuous GPS sites in the Andaman-Nicobar region following the great Sumatra-Andaman earthquake of 26 December 2004. Large horizontal displacements toward west to southwest, varying in magnitude from 10 to 40 cm, and with uplift reaching 16 cm, occurred in the region in the first year after the earthquake. The observed motion decreased logarithmically in the subsequent year. We suggest that in the Andaman region, frictional afterslip occurred farther downdip of the coseismic rupture, while in the Little Andaman and Nicobar regions, the coseismic rupture and afterslip patch partly overlapped. The afterslip was mostly aseismic and did not contribute to the aftershocks. The aftershocks and postseismic displacements appear to follow a similar relationship, although with different decay times. The temporal dependence of the two differs only by a term linear in time. Thus the temporal evolution of the afterslip seems to be consistent with a mechanism governed by frictional afterslip. Available rates of interseismic and postseismic deformation and coseismic static offsets allow us to approximately estimate a return period of about 400 years for great earthquakes in the Andaman region.

  4. Co-seismic and post-seismic gravity change due to the 2004 Sumatra-Andaman earthquake: EOF study

    NASA Astrophysics Data System (ADS)

    Li, Y.; Chao, B. F.

    2009-12-01

    The magnitude 9.3 earthquake in Sumatra-Andaman on December 26, 2004, was the second largest earthquake in the past century. We examine the before-and-after time-variable gravity (TVG) associated with the earthquake using the monthly data from the GRACE satellite mission (launched in 2002). We calculate the EOF (Empirical Orthogonal Function) to analyze the space-time variation of the co-seismic and post-seismic behavior of the epicentral region. In addition to the conspicuous co-seismic, dipolar jump of TVG in the region, we found: (1) no evidence of pre-seismic TVG behavior; (2) a gradual post-seismic appearance of a third decreasing TVG pattern to the southwest of the co-seismic dipole; (3) that the west side of the Sunda Trench sees a post-seismic TVG growth on top of the co-seismic jump; (4) that the east side of the Sunda Trench sees a post-seismic TVG recovery from the co-seismic jump. One can thus infer the post-seismic mass flow across the fault zone. We also analyzed by EOF the sea level change as a proxy for the regional geoid change using radar altimetry data. We could only find a weak signal that appears to be related to the co-seismic dipolar TVG in the form of geoid change, obscured by the presence of various meteorological and oceanographic signals.

  5. 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.

  6. 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

  7. Structure and Evolution of the Accretionary Margin of Java-Sumatra. Seismic Data and Numerical Modeling Comparisons.

    NASA Astrophysics Data System (ADS)

    Kopp, H.; Hindle, D.

    2007-12-01

    We present a numerical model for the evolution of an accretionary prism along a subduction margin. We find the mechanical partitioning of the growing prism into active region, abutting against a deformable backstop, and a relatively undeformed forearc basin is a function of the double tapered basal geometry, where the dip of the detachment is assumed to be opposite above oceanic or continental lithopshere. Varying properties of both materials and detachment can be used to adjust the surface slope and hence geometry of the system, but mechanical partitioning remains essentially the same with the regions becoming broader or narrower. The model appears to closely reproduce the geometry of the Sumatra-Java prism, where a high accretion margin has produced the same distinct mechanical units. Newly prestack depth-migrated marine seismic data reveal the extent and geometry of the active deformation of the deformable backstop, and give indications of some material passing into a subduction channel below the accretionary complex. The deformable backstop appears to be composed of multiple duplex structures, but present day tectonic activity is mostly in the form of transtensive or transpressive deformation, possibly reactivating older dip-slip, accretionary structures. The numerical approach used in the simulation (distinct elements) shows great promise in modelling large deformation in situations such as accretionary prisms, and has also been adapted to incorporate the role of fluid pressure and migration in tandem with large deformation (shortening of the order of 100's of kilometres).

  8. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico--waterflood performance analysis for the South Cowden Grayburg Reservoir, Ector County, Texas. Final report

    SciTech Connect

    Jennings, J.W. Jr.

    1997-05-01

    A reservoir engineering study was conducted of waterflood performance in the South Cowden field, an Upper Permian Grayburg reservoir on the Central Basin Platform in West Texas. The study was undertaken to understand the historically poor waterflood performance, evaluate three techniques for incorporating petrophysical measurements and geological interpretation into heterogeneous reservoir models, and identify issues in heterogeneity modeling and fluid-flow scaleup that require further research. The approach included analysis of relative permeability data, analysis of injection and production data, heterogeneity modeling, and waterflood simulation. The poor South Cowden waterflood recovery is due, in part, to completion of wells in only the top half of the formation. Recompletion of wells through the entire formation is estimated to improve recovery in ten years by 6 percent of the original oil in place in some areas of the field. A direct three-dimensional stochastic approach to heterogeneity modeling produced the best fit to waterflood performance and injectivity, but a more conventional model based on smooth mapping of layer-averaged properties was almost as good. The results reaffirm the importance of large-scale heterogeneities in waterflood modeling but demonstrate only a slight advantage for stochastic modeling at this scale. All the flow simulations required a reduction to the measured whole-core k{sub v}/k{sub h} to explain waterflood behavior, suggesting the presence of barriers to vertical flow not explicitly accounted for in any of the heterogeneity models. They also required modifications to the measured steady-state relative permeabilities, suggesting the importance of small-scale heterogeneities and scaleup. Vertical flow barriers, small-scale heterogeneity modeling, and relative permeability scaleup require additional research for waterflood performance prediction in reservoirs like South Cowden.

  9. Reconstruction of the slip distributions in historical earthquakes on the Sunda megathrust, W. Sumatra

    NASA Astrophysics Data System (ADS)

    Nic Bhloscaidh, Mairéad; McCloskey, John; Naylor, Mark; Murphy, Shane; Lindsay, Anthony

    2015-08-01

    Spatially heterogeneous inversions for the slip in major earthquakes are typically only available for modern, instrumentally recorded events. Stress reconstructions on active faults, which are potentially vital elements of earthquake hazard assessment, are usually based on one or two instrumental inversions and some semi-quantitative information concerning historical seismic activity. Here we develop a new Bayesian Monte Carlo inversion method for sparse, large uncertainty data, such as is available for many historical earthquakes. We use it to reconstruct the slip in two great historical earthquakes on the Sunda megathrust, from 200 yr of paleogeodetic data recorded in the stratigraphy of coral microatolls on the forearc islands. The technique is based on the stochastic forward modelling of many slip distributions, which are constrained by the observed fractal scaling in the slip field. A set of static elastic Green's functions is used to estimate the vertical displacement at the coral locations resulting from each trial slip distribution. The posterior expected value of the slip and its variance are obtained from the average of the trial slips, weighted by their ability to reproduce the coral displacements. We successfully test the method on a synthetic slip distribution, before applying it to reconstruct the slip in a recent, instrumentally recorded event. We then invert for the great 1797 and 1833 megathrust events under the Mentawai Islands west of Sumatra. When compared with the slip distributions in recent earthquakes, our results unambiguously indicate that the sequence is not consistent with the classic characteristic earthquake model; earthquakes tend to incrementally tessellate the active fault plane rather than repeatedly breaking a segment of it. The results indicate that homogeneous loading of a fault with heterogeneous initial stress is enough to explain the observations on the Mentawai segment of the Sunda megathrust; no time dependence of material

  10. 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

  11. 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

  12. West Coast Tsunami: Cascadia's Fault?

    NASA Astrophysics Data System (ADS)

    Wei, Y.; Bernard, E. N.; Titov, V.

    2013-12-01

    The tragedies of 2004 Sumatra and 2011 Japan tsunamis exposed the limits of our knowledge in preparing for devastating tsunamis. The 1,100-km coastline of the Pacific coast of North America has tectonic and geological settings similar to Sumatra and Japan. The geological records unambiguously show that the Cascadia fault had caused devastating tsunamis in the past and this geological process will cause tsunamis in the future. Hypotheses of the rupture process of Cascadia fault include a long rupture (M9.1) along the entire fault line, short ruptures (M8.8 - M9.1) nucleating only a segment of the coastline, or a series of lesser events of M8+. Recent studies also indicate an increasing probability of small rupture occurring at the south end of the Cascadia fault. Some of these hypotheses were implemented in the development of tsunami evacuation maps in Washington and Oregon. However, the developed maps do not reflect the tsunami impact caused by the most recent updates regarding the Cascadia fault rupture process. The most recent study by Wang et al. (2013) suggests a rupture pattern of high- slip patches separated by low-slip areas constrained by estimates of coseismic subsidence based on microfossil analyses. Since this study infers that a Tokohu-type of earthquake could strike in the Cascadia subduction zone, how would such an tsunami affect the tsunami hazard assessment and planning along the Pacific Coast of North America? The rapid development of computing technology allowed us to look into the tsunami impact caused by above hypotheses using high-resolution models with large coverage of Pacific Northwest. With the slab model of MaCrory et al. (2012) (as part of the USGS slab 1.0 model) for the Cascadia earthquake, we tested the above hypotheses to assess the tsunami hazards along the entire U.S. West Coast. The modeled results indicate these hypothetical scenarios may cause runup heights very similar to those observed along Japan's coastline during the 2011

  13. 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.

  14. 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 may differ from the water table, especially in areas where wells are completed in a semi-confined zone or have long open intervals that reflect the composite hydraulic head of multiple water-yielding fractures. A composite

  15. Rupture characteristics of 28 March 2005 Sumatra earthquake from GPS measurements and its implication for tsunami generation

    NASA Astrophysics Data System (ADS)

    Gahalaut, V. K.; Catherine, J. K.

    2006-09-01

    The great earthquake of 28 March 2005 (Mw 8.6) that occurred off the western coast of Sumatra did not cause a much-anticipated major tsunami, despite its large magnitude and its similarities with the giant 2004 Sumatra-Andaman earthquake. The later earthquake caused a deadly tsunami. Here, we analyse the coseismic displacements estimated from Global Positioning System (GPS) measurements in the Sumatra region, which provide constraints on the rupture characteristics. We suggest that since majority of the slip on rupture of this earthquake occurred under the island belt and under shallow water east of it, it could only cause a minor tsunami.

  16. 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

  17. 6. GENERAL WIDE VIEW SHOWING EAST (SOUTHEAST) SIDE, LOOKING WEST ...

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

    6. GENERAL WIDE VIEW SHOWING EAST (SOUTHEAST) SIDE, LOOKING WEST ACROSS TURNING BASIN; FREIGHTER LOADING IN FOREGROUND - Oakland Army Base, Transit Shed, East of Dunkirk Street & South of Burma Road, Oakland, Alameda County, CA

  18. View of upstream face of Grand Coulee Dam, looking west. ...

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

    View of upstream face of Grand Coulee Dam, looking west. - Columbia Basin Project, Grand Coulee Dam & Franklin D. Roosevelt Lake, Across Columbia River, Southeast of Town of Grand Coulee, Grand Coulee, Grant County, WA

  19. 5. DECK VIEW, LOOKING WEST, SHOWING RESERVOIR AT RIGHT AND ...

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

    5. DECK VIEW, LOOKING WEST, SHOWING RESERVOIR AT RIGHT AND LINCOLN MEMORIAL AT DISTANT CENTER. - Tidal Reservoir, Inlet Bridge, Ohio Drive, spanning Inlet of Tidal Basin, Washington, District of Columbia, DC

  20. 2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST ...

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

    2. VIEW OF POND B, LOOKING NORTHEAST FROM THE WEST SIDE OF THE SOURIS RIVER VALLEY, DUE SOUTH OF THE LOOKOUT TOWER - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  1. Horizons West.

    ERIC Educational Resources Information Center

    Kitses, Jim

    The western is the most popular and enduring of Hollywood forms. It is one embodiment of a traditional theme in American culture: the West as both Garden of natural dignity and innocence and also as treacherous Desert resisting the gradual sweep of agrarian progress and community values. Westerns have in common: a) history, America's past; b)…

  2. A melt inclusion study of the Toba Tuffs, Sumatra, Indonesia

    NASA Astrophysics Data System (ADS)

    Chesner, Craig A.; Luhr, James F.

    2010-11-01

    The Toba Caldera in Northern Sumatra, Indonesia is the site of Earth's largest Quaternary volcanic eruption. This eruption, dated at 74 ka, produced the 2800 km 3 Youngest Toba Tuff (YTT) and ash-fall. Quartz-bearing silicic pumices ranging from 68 to 77 wt.% SiO 2 indicate that the YTT magma was zoned compositionally and mineralogically. Prior to the YTT eruption, two other silicic quartz-bearing tuffs known as the Middle Toba Tuff (MTT) and the Oldest Toba Tuff (OTT) were erupted from Toba at 0.501 Ma and 0.840 Ma respectively. Although the volatile contents of the Toba magmas are poorly constrained, aerosols generated by the YTT eruption are generally thought to have caused a global volcanic winter. An evaluation of the pre-eruptive dissolved gas contents of the YTT magma is fundamental to understanding the global effects of this eruption. We used melt inclusions in quartz crystals to determine the dissolved H 2O, CO 2, S, Cl, and F contents of the YTT, MTT, and OTT magmas. Quartz crystals selected from pumice blocks and welded tuffs that spanned the compositional ranges of the three units were chosen for study. Major and trace element analyses of melt inclusions were also conducted to characterize melt evolution and provide context to the volatile data. Melt inclusions from the YTT, MTT, and OTT are rhyolitic in composition (73-77 wt.% SiO 2) and have overlapping, indistinguishable major element trends. Inclusions from the large eruptions (YTT and OTT) have similar geochemical relationships where the most evolved melt inclusions occur in the least silicic bulk rock samples and are more evolved than their matrix glasses. In contrast, the least evolved melt inclusions occur in the most silicic samples and either overlap with, or are less evolved than their matrix glasses. These patterns can be explained if quartz crystals in the least silicic magmas were inherited from more evolved melt, while those in the most silicic melt formed in-situ. Several lines of

  3. Mississippian facies relationships, eastern Anadarko basin, Oklahoma

    SciTech Connect

    Peace, H.W. ); Forgotson, J.M. )

    1991-08-01

    Mississippian strata in the eastern Anadarko basin record a gradual deepening of the basin. Late and post-Mississippian tectonism (Wichita and Arbuckle orogenies) fragmented the single large basin into the series of paired basins and uplifts recognized in the southern half of Oklahoma today. Lower Mississippian isopach and facies trends (Sycamore and Caney Formations) indicate that basinal strike in the study area (southeastern Anadarko basin) was predominantly east-west. Depositional environment interpretations made for Lower Mississippian strata suggest that the basin was partially sediment starved and exhibited a low shelf-to-basin gradient. Upper Mississippian isopach and facies trends suggest that basinal strike within the study area shifted from dominantly east-west to dominantly northwest-southeast due to Late Mississippian and Early Pennsylvanian uplift along the Nemaha ridge. Within the study area, the Chester Formation, composed of gray to dove-gray shales with interbedded limestones deposited on a carbonate shelf, thins depositionally into the basin and is thinnest at its facies boundary with the Springer Group and the upper portion of the Caney Formation. As basin subsidence rates accelerated, the southern edge of the Chester carbonate shelf was progressively drowned, causing a backstepping of the Chester Formation calcareous shale and carbonate facies. Springer Group sands and black shales transgressed northward over the drowned Chester Formation shelf.

  4. Numerical modelling of potential submarine landslides and generated tsunami in Sumatra

    NASA Astrophysics Data System (ADS)

    Fernandez-Nieto, E.; Mangeney, A.; Singh, S. C.; Chauhan, A.; Bouchut, F.; Castro Díaz, M.

    2010-12-01

    Recent studies suggests that tsunami risk along the SW coast of Sumatra could be due to co-seismic slip along a backthrust at the NE Margin of the Mentawai Island and associated landslides (Singh et al., 2010). Using a combination of high-resolution seismic reflection and bathymetry data, they observed deposits of large submarine landslides at the NE margin of Mentawai Island and suggest that the high wave that occurred in 1797 might have been enhanced by landslides, producing a large localised tsunami. Until now most of the work devoted to tsunami hazard assessment in the area of Sumatra Island focussed on megaearthquakes earthquakes generated tsunamis. Therefore, estimating the run up heights due to submarine landslides is essential for risk mitigation along the SW coast of Sumatra. A series of numerical scenarios are performed here to simulate potential submarine landslides and generated tsunamis in the area of Sumatra Island. The height and velocity of the water wave and the impact zones are calculated using a new numerical model solving the depth-averaged shallow water equations with high order finite volume methods. This model corresponds to the 2D extension of the model developed by Fernández-Nieto et al., 2008. The fluidized mass is modeled using a generalization of the Savage-Hutter model [Savage and Hutter, 1989] by including the role of buoyancy and fluid into the thin-layer equations with a Coulomb-type friction law. Our model takes into account the coupling between the fluid and the landslides and incorporates the rigorous description of topography effects that play a key role in the dynamics of landslides. We study the magnitude of variation of the wave expected depending on the location and volume released. These results shows that landslide generated tsunamis have to be taken into account for risk assessment in the area of Sumatra Island. E.D. Fernández-Nieto, F. Bouchut, D. Bresch, M.J. Castro, A. Mangeney, 2008. A new Savage-Hutter type model

  5. Description of fuel element brush assembly`s fabrication for 105-K west

    SciTech Connect

    Maassen, D. P.

    1997-10-15

    This report is a description of the process to redesign and fabricate, as well as, describe the features of the Fuel Element Brush Assembly used in the 105-K West Basin. This narrative description will identify problems that occurred during the redesigning and fabrication of the 105-K West Basin Fuel Element Brush Assembly and specifically address their solutions.

  6. 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.

  7. Multisatellite observations of an intensified equatorial ionization anomaly in relation to the northern Sumatra earthquake of March 2005

    NASA Astrophysics Data System (ADS)

    Ryu, K.; Lee, E.; Chae, J. S.; Parrot, M.; Oyama, K.-I.

    2014-06-01

    Here we report multisatellite observations of ionospheric disturbances in relation to the occurrence of the M8.7 northern Sumatra earthquake of 28 March 2005. The DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) and CHAMP (Challenging Minisatellite Payload) satellite data were investigated to find possible precursory and postevent phenomena. It was found that EIA (equatorial ionization anomaly) strength expressed in the apex height, derived from the CHAMP plasma density profile, was intensified along the orbits whose longitudes were close to the epicenter within about a week before and after occurrence of the earthquake. Increases in electron and O+ density along the orbits close to the epicenter were also observed in the DEMETER measurements. The normalized equatorial plasma density derived from the DEMETER measurements showed intensification about a week before and after the earthquake reaching maximum the day after the shock and afterward disappearing. In addition, similar behavior of the EIA enhancements related to the M8.0 Pisco earthquake of 15 August 2007 was observed. Surveys of space weather and geomagnetic activities excluded the possibility that these fluctuations were caused by changes in space weather or by a geomagnetic storm. Statistical analyses of the longitudinal variation revealed that the EIA was enhanced in the west of the epicenter and reduced in the east of the epicenter, and this fits the "increased conductivity" model. Based on these observations, we proposed a revised view of seismo-ionospheric coupling in the region of the geomagnetic equator, to explain the EIA features observed in this study.

  8. Global analysis of intraplate basins

    NASA Astrophysics Data System (ADS)

    Heine, C.; Mueller, D. R.; Dyksterhuis, S.

    2005-12-01

    Broad intraplate sedimentary basins often show a mismatch of lithospheric extension factors compared to those inferred from sediment thickness and subsidence modelling, not conforming to the current understanding of rift basin evolution. Mostly, these basins are underlain by a very heterogeneous and structurally complex basement which has been formed as a product of Phanerozoic continent-continent or terrane/arc-continent collision and is usually referred to as being accretionary. Most likely, the basin-underlying substrate is one of the key factors controlling the style of extension. In order to investigate and model the geodynamic framework and mechanics controlling formation and evolution of these long-term depositional regions, we have been analysing a global set of more than 200 basins using various remotely sensed geophysical data sets and relational geospatial databases. We have compared elevation, crustal and sediment thickness, heatflow, crustal structure, basin ages and -geometries with computed differential beta, anomalous tectonic subsidence, and differential extension factor grids for these basins. The crust/mantle interactions in the basin regions are investigated using plate tectonic reconstructions in a mantle convection framework for the last 160 Ma. Characteristic parameters and patterns derived from this global analysis are then used to generate a classification scheme, to estimate the misfit between models derived from either crustal thinning or sediment thickness, and as input for extension models using particle-in-cell finite element codes. Basins with high differential extension values include the ``classical'' intraplate-basins, like the Michigan Basin in North America, the Zaire Basin in Africa, basins of the Arabian Penisula, and the West Siberian Basin. According to our global analysis so far, these basins show, that with increasing basin age, the amount of crustal extension vs. the extension values estimated from sediment thickness

  9. Debris Removal Project K West Canister Cleaning System Performance Specification

    SciTech Connect

    FARWICK, C.C.

    1999-12-09

    Approximately 2,300 metric tons Spent Nuclear Fuel (SNF) are currently stored within two water filled pools, the 105 K East (KE) fuel storage basin and the 105 K West (KW) fuel storage basin, at the U.S. Department of Energy, Richland Operations Office (RL). The SNF Project is responsible for operation of the K Basins and for the materials within them. A subproject to the SNF Project is the Debris Removal Subproject, which is responsible for removal of empty canisters and lids from the basins. Design criteria for a Canister Cleaning System to be installed in the KW Basin. This documents the requirements for design and installation of the system.

  10. 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.

  11. Nam Con Son Basin

    SciTech Connect

    Tin, N.T.; Ty, N.D.; Hung, L.T.

    1994-07-01

    The Nam Con Son basin is the largest oil and gas bearing basin in Vietnam, and has a number of producing fields. The history of studies in the basin can be divided into four periods: Pre-1975, 1976-1980, 1981-1989, and 1990-present. A number of oil companies have carried out geological and geophysical studies and conducted drilling activities in the basin. These include ONGC, Enterprise Oil, BP, Shell, Petro-Canada, IPL, Lasmo, etc. Pre-Tertiary formations comprise quartz diorites, granodiorites, and metamorphic rocks of Mesozoic age. Cenozoic rocks include those of the Cau Formation (Oligocene and older), Dua Formation (lower Miocene), Thong-Mang Cau Formation (middle Miocene), Nam Con Son Formation (upper Miocene) and Bien Dong Formation (Pliocene-Quaternary). The basement is composed of pre-Cenozoic formations. Three fault systems are evident in the basin: north-south fault system, northeast-southwest fault system, and east-west fault system. Four tectonic zones can also be distinguished: western differentiated zone, northern differentiated zone, Dua-Natuna high zone, and eastern trough zone.

  12. Estimates of potential new production in the Java-Sumatra upwelling system

    NASA Astrophysics Data System (ADS)

    Wei, Xing; Liao, Xiaomei; Zhan, Haigang; Liu, Hailong

    2012-11-01

    The Java-Sumatra upwelling is one of the most important upwelling systems in the Indian Ocean, with maximum upwelling intensity in July through August. To estimate the nitrate supplied by upwelling, we developed a three-dimensional hydrodynamic model to calculate the mean vertical speed and determine the depth of upwelling. We used in-situ vertical nitrate profiles to assess nitrate concentration in the upwelled waters, and calculated the nitrate supply as the product of nitrate concentration and vertical transport obtained from the numerical model. The calculated result represents potential new production generated in the upwelling region. We found that on the event time scale (monthly) of Java-Sumatra upwelling, water brought to the surface originated from locations 100-m deep, giving a nitrate supply of 93.77×103 mol/s and potential new production of 1.02×1014 gC/a.

  13. 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.

  14. 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

  15. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    NASA Astrophysics Data System (ADS)

    Lestari, Titik; Nugraha, Andri Dian

    2015-04-01

    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.

  16. West Africa

    NASA Technical Reports Server (NTRS)

    2002-01-01

    With its vast expanses of sand, framed by mountain ranges and exposed rock, northwestern Africa makes a pretty picture when viewed from above. This image was acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. The Canary Islands can be seen on the left side of the image just off Africa's Atlantic shore. The light brown expanse running through the northern two thirds of the image is the Sahara Desert. The desert runs up against the dark brown Haut Atlas mountain range of Morocco in the northwest, the Atlantic Ocean to the west and the semi-arid (light brown pixels) Sahelian region in the South. The Sahara, however, isn't staying put. Since the 1960s, the desert has been expanding into the Sahelian region at a rate of up to 6 kilometers per year. In the 1980s this desert expansion, combined with over cultivation of the Sahel, caused a major famine across west Africa. Over the summer months, strong winds pick up sands from the Sahara and blow them across the Atlantic as far west as North America, causing air pollution in Miami and damaging coral reefs in the Bahamas and the Florida Keys. The white outlines on the map represent country borders. Starting at the top-most portion of the map and working clockwise, the countries shown are Morocco, Western Sahara, Mauritania, Senegal, Mali, Burkina Fasso, Nigeria, Mali (again), and Algeria. Image by Reto Stockli, Robert Simmon, and Brian Montgomery, NASA Earth Observatory, based on data from MODIS

  17. Rapid decision tool to predict earthquake destruction in Sumatra by using first motion study

    NASA Astrophysics Data System (ADS)

    Bhakta, Shardul Sanjay

    The main idea of this project is to build an interactive and smart Geographic Information system tool which can help predict intensity of real time earthquakes in Sumatra Island of Indonesia. The tool has an underlying intelligence to predict the intensity of an earthquake depending on analysis of similar earthquakes in the past in that specific region. Whenever an earthquake takes place in Sumatra, a First Motion Study is conducted; this decides its type, depth, latitude and longitude. When the user inputs this information into the input string, the tool will try to find similar earthquakes with a similar First Motion Survey and depth. It will do a survey of similar earthquakes and predict if this real time earthquake can be disastrous or not. This tool has been developed in JAVA. I have used MOJO (Map Objects JAVA Objects) to show map of Indonesia and earthquake locations in the form of points. ESRI has created MOJO which is a set of JAVA API's. The Indonesia map, earthquake location points and its co-relation was all designed using MOJO. MOJO is a powerful tool which made it easy to design the tool. This tool is easy to use and the user has to input only a few parameters for the end result. I hope this tool justifies its use in prediction of earthquakes and help save lives in Sumatra.

  18. 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. PMID:20873030

  19. 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.

  20. 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.

  1. Sedimentary basins in Ross Sea, Antarctica

    SciTech Connect

    Cooper, A.K.; Davey, F.J.

    1986-07-01

    The Ross Sea lies in the Pacific sector of the Antarctic continental margin. Three major sedimentary basins (from east to west, the Eastern, Central, and Victoria Land basins) lie beneath the broad, deep continental shelf of the Ross Sea. These north-south-trending basins occur in the extensionally deformed region between East and West Antarctica. Multichannel seismic reflection (MCS) surveys have been conducted over these basins since 1980 by West German, French, Japanese, and US expeditions. The MCS and previous geophysical surveys have shown that the three basins contain 5-6 km of sedimentary rock, possibly Late Cretaceous and younger. An additional 6-8 km of sedimentary and volcanic rock lies within the deeper parts of the Victoria Land basin. The basins are separated by uplifted and eroded basement ridges covered by thin sedimentary sections. Each basin has distinct characteristics, commonly related to its extensional origin. Petroleum hydrocarbons are unknown from the Ross Sea region, with the possible exception of ethane gas recovered by the Deep Sea Drilling Project. Previous model studies, based on estimated sediment thickness, assumed temperature gradients, and postulated seismostratigraphy, indicate that hydrocarbons could be generated at depths of 3.5-6km within the sedimentary section. However, this hypothesis cannot be verified without further geologic and geophysical data from the Ross Sea region.

  2. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    SciTech Connect

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

  3. Geology and K-Ar geochronology of the Paradise Peak Mine and the relationship of pre-Basin and Range extension to Early Miocene precious metal mineralization in west-central Nevada

    USGS Publications Warehouse

    John, D.A.; Thomason, R.E.; McKee, E.H.

    1989-01-01

    The Paradise Peak mine is a major gold-silver-mercury deposit located in the southwestern part of the Paradise Range near the eastern edge of the Walker Lane in the western Great Basin, Nevada. Regional stratigraphic relations and K-Ar ages indicate that volcanism changed from silicic ash-flow tuffs to intermediate lavas at about 20 to 19 Ma. Regionally extensive angular unconformities indicate that a period of "pre-Basin and Range' crustal extension occurred between about 22 to 19 Ma. This extension was penecontemporaneous with the shift in the style of volcanism and with gold-silver mineralization in the Paradise Peak mine and in the Goldfield and Tonopah districts of western Nevada. The close temporal and spatial relationships of precious metal mineralization with pre-Basin and Range extension suggest that extension was a major factor in the genesis of early Miocene precious metal deposits in the western Great Basin. -from Authors

  4. 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

  5. Petroleum system of the Gippsland Basin, Australia

    USGS Publications Warehouse

    Bishop, Michele G.

    2000-01-01

    The Gippsland Basin Province 3930, located on the southeastern coast of Australia, is formed from two successive failed rifts that developed into a passive margin during the Cretaceous. Formation of this basin is related to the break up of Gondwana, which resulted in the separation of Antarctica from Australia, and the separation of the New Zealand and Lord Howe Rise continental crust from Australia. Coals and coaly shales of Late Cretaceous through Eocene age are the source rocks for oil and gas that accumulated predominantly in anticlinal traps. The basin was Australia?s major producing basin until 1996 when daily oil/condensate production from the North West Shelf surpassed it.

  6. Hydrocarbon accumulations of Mississippian Berea sandstone in west-central West Virginia

    SciTech Connect

    Cox, D.L. )

    1988-08-01

    The Berea Sandstone is a widely recognized producer of oil and gas in the Appalachian basin. Subsurface mapping, core analysis, and production data from producing wells have been evaluated in west-central West Virginia, where the Berea Sandstone represents a wide range of nearshore and coastal environments. Fluvial system deposits are found in southern Jackson County as channel sands (Gay-Fink) and adjacent deltaic facies. Coastal sediments were deposited to the north as intertidal shoals, tidal flats, and coarse-grained tidal-creek point bars. Marine shelf sands are found to the west.

  7. Australia`s southeastern Bonaparte basin has plenty of potential

    SciTech Connect

    Miyazaki, S.

    1997-04-21

    Situated in the Timor Sea and Joseph Bonaparte Gulf regions, the Bonaparte basin is one of the Phanerozoic basins of what is now called the North West Shelf of Australia. This basin consists of a number of Paleozoic and Mesozoic synclines and horsts. Drilling success rate for this basin is one of the highest in Australia in the last 5 years. New opportunities are available in the southeastern Bonaparte basin, where seven vacant tracts have just been released for application for exploration permits. The paper discusses the regional geology, previous exploration activities, and potentials of the southern Petrel sub-basin and Darwin shelf.

  8. Basin development and petroleum potential of offshore Otway basin, Australia

    SciTech Connect

    Williamson, P.E.; O'Brien, G.W.; Swift, M.G.; Scherl, A.S.; Marlow, M.S.; Exon, N.F.; Falvey, D.A.; Lock, J.; Lockwood, K.

    1987-05-01

    The Bass Strait region in southeastern Australia contains three sedimentary basins, which are, from east to west, the Gippsland, Bass, and Otway basins. The offshore Gippsland basin is Australia's most prolific petroleum-producing province and supplies over 90% of the country's production. In contrast, exploration has been unsuccessful in the offshore portion of the Otway basin; 17 wells have been drilled, and although shows of oil and gas have been common, no commercial discoveries have been made. Many of these wells, drilled in the 1960s and 1970s, were sited using poor-quality seismic data and, as a consequence, were frequently off structure. Seismic data quality has, however, improved significantly in recent years. The present study by the Australian Bureau of Mineral Resources (BMR) involved the collection, in the offshore Otway basin, of 3700 km of high-quality, 48-channel seismic reflection data by the BMR research vessel R/V Rig Seismic. These data have been integrated with existing industry seismic data, well data, limited dredged material, and geohistory analyses in a framework study of basin development and hydrocarbon potential in this under-explored area. The offshore Otway basin extends 500 km along the southern coastline and is typically 50 km wide in water depths of less than 200 m. It contains up to 10 km of predominantly late Mesozoic to early Cenozoic sediments, which are overlain by a thin sequence of middle to late Tertiary shelf carbonates. It has been divided into three main structural elements: the Mussel Platform in the east, the central Voluta Trough, and the Crayfish Platform in the west. The basin was initiated at the end of the Jurassic as part of the Bassian rift. Up to 6 km of Lower Cretaceous sediments were deposited prior to breakup at the end of the Early Cretaceous and the onset of sea-floor spreading between Australia and Antarctica.

  9. Cenozoic evolution of San Joaquin basin, California

    SciTech Connect

    Bartow, J.A.

    1988-03-01

    The Neogene San Joaquin basin in the southern part of the 700-km long Great Valley of California is a successor to a late Mesozoic and earliest Tertiary forearc basin. The transition from forearc basin to the more restricted Neogene marine basin occurred principally during the Paleogene as the plate tectonic setting changed from oblique convergence to normal convergence, and finally to the initiation of tangential (transform) movement near the end of the Oligocene. Regional-scale tectonic events that affected the basin include: (1) clockwise rotation of the southernmost Sierra Nevada, and large-scale en echelon folding in the southern Diablo Range, both perhaps related to Late Cretaceous and early Tertiary right slip on the proto-San-Andreas fault; (2) regional uplift of southern California in the Oligocene that resulted from the subduction of the Pacific-Farallon spreading ridge: (3) extensional tectonism in the Basin and Range province, particularly in the Miocene; (4) wrench tectonism adjacent to the San Andreas fault in the Neogene; (5) northeastward emplacement of a wedge of the Franciscan complex at the west side of the Sierran block, with associated deep-seated thrusting in the late Cenozoic; and (6) the accelerated uplift of the Sierra Nevada beginning in the late Miocene. Neogene basin history was controlled principally by the tectonic effects of the northwestward migration of the Mendocino triple junction along the California continental margin and by the subsequent wrench tectonism associated with the San Andreas fault system. East-west compression in the basin, resulting from extension in the Basin and Range province was an important contributing factor to crustal shortening at the west side of the valley. Analysis of the sedimentary history of the basin, which was controlled to some extent by eustatic sea level change, enables reconstruction of the basin paleogeography through the Cenozoic.

  10. Late Paleozoic structural evolution of Permian basin

    SciTech Connect

    Ewing, T.E.

    1984-04-01

    The southern Permian basin is underlain by the NNW-trending Central Basin disturbed belt of Wolfcamp age (Lower Permian), the deep Delaware basin to its west, and the shallower Midland basin to its eat. The disturbed belt is highly segmented with zones of left-lateral offset. Major segments from south to north are: the Puckett-Grey Ranch zone; the Fort Stockton uplift; the Monahans transverse zone; the Andector ridges and the Eunice ridge; the Hobbs transverse zone; and the Tatum ridges, which abut the broad Roosevelt uplift to the north. The disturbed belt may have originated along rift zones of either Precambrian or Cambrian age. The extent of Lower and Middle Pennsylvanian deformation is unclear; much of the Val Verde basin-Ozona arch structure may have formed then. The main Wolfcamp deformation over thrust the West Texas crustal block against the Delaware block, with local denudation of the uplifted edge and eastward-directed backthrusting into the Midland basin. Latter in the Permian, the area was the center of a subcontinental bowl of subsidence - the Permian basin proper. The disturbed belt formed a pedestal for the carbonate accumulations which created the Central Basin platform. The major pre-Permian reservoirs of the Permian basin lie in large structural and unconformity-bounded traps on uplift ridges and domes. Further work on the regional structural style may help to predict fracture trends, to assess the timing of oil migration, and to evaluate intrareservoir variations in the overlying Permian giant oil fields.

  11. Thumb-pads up-a new species of thick-thumbed bat from Sumatra (Chiroptera: Vespertilionidae: Glischropus).

    PubMed

    Csorba, Gábor; Görföl, Tamás; Wiantoro, Sigit; Kingston, Tigga; Bates, Paul J J; Huang, Joe Chun-Chia

    2015-01-01

    To date, three species of the genus Glischropus are recognized from the Indomalayan zoogeographic region-G. bucephalus from the Indochinese subregion, G. tylopus from the Sundaic subregion (Peninsular Thailand and Malaysia, Borneo, Sumatra, Moluccas) and G. javanus, restricted to Java. The investigation of the holotype and three topotype specimens of G. batjanus supported the view that the name was previously correctly regarded as the junior subjective synonym of G. tylopus. During review of material recently collected in southwestern Sumatra, Indonesia, one specimen of a yet undescribed species of Thick-thumbed bat was identified. G. aquilus n. sp. markedly differs from its congeners by its dark brown pelage, nearly black ear and tragus, and in skull proportions. The phylogenetic analysis based on cytb sequences also supports the specific distinctness of G. aquilus n. sp. Its discovery brings the count to 88 species of bats known from Sumatra. PMID:26249952

  12. 36. View of Wolslegal Basin from State Route 410 bridge, ...

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

    36. View of Wolslegal Basin from State Route 410 bridge, looking west. Photo by Brian C. Morris, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  13. 61. View of bellmouth which empties into Printz Basin, looking ...

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

    61. View of bellmouth which empties into Printz Basin, looking west. Photo by Robin Lee Tedder, Puget Power, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  14. OVERVIEW OF VALVE TOWER FROM EASTERN SIDE OF BASIN SHOWING ...

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

    OVERVIEW OF VALVE TOWER FROM EASTERN SIDE OF BASIN SHOWING BRIDGE SUPPORTS ON HILLTOP. VIEW FACING WEST - Schofield Barracks Military Reservation, Ku Tree Reservoir, Valve Tower, Kalakoa Stream, East Range, Wahiawa, Honolulu County, HI

  15. 41. MISSISSIPPI BASIN MODEL AT CLINTON SUBSTATION. ATCHAFALAYA FLOODWAY SECTION, ...

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

    41. MISSISSIPPI BASIN MODEL AT CLINTON SUBSTATION. ATCHAFALAYA FLOODWAY SECTION, LOOKING WEST FROM OLD RIVER. - Waterways Experiment Station, Hydraulics Laboratory, Halls Ferry Road, 2 miles south of I-20, Vicksburg, Warren County, MS

  16. Correlation chart of Pennsylvanian rocks in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania showing approximate position of coal beds, coal zones, and key stratigraphic units: Chapter D.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.; Slucher, Ernie R.

    2014-01-01

    Because of the many names used to identify individual coal beds and coal zones in the historic Appalachian basin coal-mining districts, coal bed designations may differ even more than stratigraphic nomenclature. In eastern Kentucky, northwest of the Pine Mountain thrust fault on the Cumberland overthrust sheet, for example, coal beds or coal zones equivalent to the Lower Elkhorn coal zone (within the Pikeville Formation) are identified also as the Eagle coal zone, Pond Creek coal zone, and Blue Gem coal bed (fig. 1). Southeast of the Pine Mountain thrust fault, yet still in Kentucky, equivalent coals in this same interval are known as the Imboden and Rich Mountain. Moreover, this same interval of coal is identified as the Blue Gem coal in Tennessee, the Imboden coal bed or Campbell Creek or Pond Creek coal zones in Virginia, and the Eagle coal zone in West Virginia.

  17. Biological science in the Great Basin

    USGS Publications Warehouse

    U.S. Geological Survey

    2005-01-01

    The Great Basin is an expanse of desert and high moun-tains situated between the Rocky Mountains and the Sierra Nevada of the western United States. The most explicit description of the Great Basin is that area in the West where surface waters drain inland. In other words, the Great Basin is comprised of many separate drainage areas - each with no outlet. What at first glance may appear as only a barren landscape, the Great Basin upon closer inspection reveals island mountains, sagebrush seas, and intermittent aquatic habitats, all teeming with an incredible number and variety of plants and animals. Biologists at the USGS are studying many different species and ecosystems in the Great Basin in order to provide information about this landscape for policy and land-management decision-making. The following stories represent a few of the many projects the USGS is conducting in the Great Basin.

  18. Seismic evidence of bending and unbending of subducting oceanic crust and the presence of mantle megathrust in the 2004 Great Sumatra earthquake rupture zone

    NASA Astrophysics Data System (ADS)

    Singh, Satish C.; Chauhan, Ajay P. S.; Calvert, Andrew J.; Hananto, Nugroho D.; Ghosal, Dibakar; Rai, Abhishek; Carton, Helene

    2012-03-01

    In subduction zones the plate interface (megathrust) is typically poorly imaged at depths > 12 km, however its precise geometry and nature as well as the positions of updip and downdip limits of the seismogenic zone are important elements to understand the generation of megathrust earthquakes. Using deep marine seismic reflection and refraction data, we observed discontinuous reflections off the top of the subducting oceanic crust down to 60 km depth in the 2004 great Sumatra-Andaman earthquake rupture zone. We find that the top of the downgoing plate does not dip gently into the subduction zone but instead displays a staircase geometry with three successive, 5-15 km vertical steps, spaced ~ 50 km apart. Micro-earthquake data indicate that most of the seismicity lies below this interface, suggesting that the oceanic plate is deforming actively. Along part of the profile, we also image a second reflector located 8-10 km below the top of the oceanic crust. The forward modelling of the gravity data along the profile supports the presence of a high-density material above this reflector. The presence of a staircase shape for the top of the oceanic crust, together with constraints from gravity data and earthquake data, require that the megathrust goes through this second reflector. This leads us to conclude that the megathrust is at least partly located in the oceanic mantle and that underplating of oceanic crust beneath the wedge and underplating of upper mantle beneath the forearc basin are taking place in this region.

  19. Seismicity associated with the Sumatra-Andaman Islands earthquake of 26 December 2004

    USGS Publications Warehouse

    Dewey, J.W.; Choy, G.; Presgrave, B.; Sipkin, S.; Tarr, A.C.; Benz, H.; Earle, P.; Wald, D.

    2007-01-01

    The U.S. Geological Survey/National Earthquake Information Center (USGS/ NEIC) had computed origins for 5000 earthquakes in the Sumatra-Andaman Islands region in the first 36 weeks after the Sumatra-Andaman Islands mainshock of 26 December 2004. The cataloging of earthquakes of mb (USGS) 5.1 and larger is essentially complete for the time period except for the first half-day following the 26 December mainshock, a period of about two hours following the Nias earthquake of 28 March 2005, and occasionally during the Andaman Sea swarm of 26-30 January 2005. Moderate and larger (mb ???5.5) aftershocks are absent from most of the deep interplate thrust faults of the segments of the Sumatra-Andaman Islands subduction zone on which the 26 December mainshock occurred, which probably reflects nearly complete release of elastic strain on the seismogenic interplate-thrust during the mainshock. An exceptional thrust-fault source offshore of Banda Aceh may represent a segment of the interplate thrust that was bypassed during the mainshock. The 26 December mainshock triggered a high level of aftershock activity near the axis of the Sunda trench and the leading edge of the overthrust Burma plate. Much near-trench activity is intraplate activity within the subducting plate, but some shallow-focus, near-trench, reverse-fault earthquakes may represent an unusual seismogenic release of interplate compressional stress near the tip of the overriding plate. The interplate-thrust Nias earthquake of 28 March 2005, in contrast to the 26 December aftershock sequence, was followed by many interplate-thrust aftershocks along the length of its inferred rupture zone.

  20. Parathelphusa pardus, a new species of lowland freshwater crab from swamps in central Sumatra, Indonesia (Crustacea: Brachyura: Gecarcinucidae).

    PubMed

    Ng, Peter K L; Riady, Rikhi; Windarti, Windarti

    2016-01-01

    A new species of gecarcinucid freshwater crab of the genus Parathelphusa H. Milne Edwards, 1853, is described from freshwater swamp habitats in Pekanbaru, Riau Province, in central-eastern Sumatra, Indonesia. Parathelphusa pardus sp. nov., has a very distinctive colour pattern, and in this respect, resembles P. maindroni (Rathbun, 1902) from Sumatra and Peninsular Malaysia; P. batamensis Ng, 1992, from Batam Island, Indonesia; P. reticulata Ng, 1990, from Singapore; and P. oxygona Nobili, 1901, from western Sarawak. It can be distinguished from these species and congeners by a suite of carapace, ambulatory leg, thoracic sternal and most importantly, male first gonopod characters. PMID:27394277

  1. Tectonic evolution of Abu Gharadig basin

    SciTech Connect

    Meshref, W.M.; Beleity, A.E.H.; Hammouda, H.; Kamel, M.

    1988-08-01

    The Abu Gharadig basin, northwestern desert of Egypt, is considered the most petroliferous basin in the Western Desert as far as hydrocarbon production and potential. The basin is believed to be growing and developing throughout geologic time. Aeromagnteic data and subsurface information, derived from a set of isopach maps from wells including complete sections only, revealed that the Abu Gharadig basin was subjected to different tectonic events that resulted in different tectonic trends. These trends include (1) north-south to north-northwest-south-southeast of Precambrian age, (2) east-west (Y-trends) of Paleozoic to Jurassic age, (3) west-northwest (R-trends) of Late Jurassic to Early Cretaceous, and (4) east-northeast (P-trends) of Late Cretaceous to Eocene age. The previously mentioned tectonic trends can be explained by a convergent wrench model that affected northern Egypt.

  2. The Sumatra-Andaman Earthquake and Tsunami of 2004: the hazards, events, and damage.

    PubMed

    Kohl, Patrice A; O'Rourke, Ann P; Schmidman, Dana L; Dopkin, Wendy A; Birnbaum, Marvin L

    2005-01-01

    The Sumatra-Andaman Earthquake and subsequent Asian Tsunami of 26 December 2004 affected multiple countries in the Indian Ocean and beyond, creating disasters of a scale unprecedented in recorded history. Using the Conceptual Framework and terminology described in the Disaster Health Management: Guidelines for Evaluation and Research in the Utstein Style, the hazard, events, and damage associated with the Earthquake and Tsunami are described. Many gaps in the available information regarding this event are present. Standardized indicators and reporting criteria are necessary for research on future disasters and the development of best practice standards internationally. PMID:16496614

  3. Crustal dilatation observed by GRACE after the 2004 Sumatra-Andaman earthquake.

    PubMed

    Han, Shin-Chan; Shum, C K; Bevis, Michael; Ji, Chen; Kuo, Chung-Yen

    2006-08-01

    We report the detection of an earthquake by a space-based measurement. The Gravity Recovery and Climate Experiment (GRACE) satellites observed a +/-15-microgalileo gravity change induced by the great December 2004 Sumatra-Andaman earthquake. Coseismic deformation produces sudden changes in the gravity field by vertical displacement of Earth's layered density structure and by changing the densities of the crust and mantle. GRACE's sensitivity to the long spatial wavelength of gravity changes resulted in roughly equal contributions of vertical displacement and dilatation effects in the gravity measurements. The GRACE observations provide evidence of crustal dilatation resulting from an undersea earthquake. PMID:16888136

  4. Periodically triggered seismicity at Mount Wrangell, Alaska, after the Sumatra earthquake.

    PubMed

    West, Michael; Sánchez, John J; McNutt, Stephen R

    2005-05-20

    As surface waves from the 26 December 2004 earthquake in Sumatra swept across Alaska, they triggered an 11-minute swarm of 14 local earthquakes near Mount Wrangell, almost 11,000 kilometers away. Earthquakes occurred at intervals of 20 to 30 seconds, in phase with the largest positive vertical ground displacements during the Rayleigh surface waves. We were able to observe this correlation because of the combination of unusually long surface waves and seismic stations near the local earthquakes. This phase of Rayleigh wave motion was dominated by horizontal extensional stresses reaching 25 kilopascals. These observations imply that local events were triggered by simple shear failure on normal faults. PMID:15905395

  5. Remittances and circulation behavior in the livelihood process: transmigrant families in South Sumatra, Indonesia.

    PubMed

    Leinbach, T R; Watkins, J F

    1998-01-01

    The impact of migrant remittances in Indonesia is examined using data gathered in interviews undertaken in 21 households and with village leaders participating in the transmigration program in Cinta Karya, Sumatra, Indonesia. "Our findings illustrate that remittance behavior is spatially controlled and temporally variable, as families balance their labor and capital resources among farm production, local industry and investments, and the often unpredictable nature of circulation employment and remittances. We emphasize the linked and recursive nature of elements in the livelihood process and the related importance of temporal family dynamics in decision-making strategies." PMID:12321332

  6. Frontier sedimentary basins of New Zealand region

    SciTech Connect

    Beggs, J.M. )

    1991-03-01

    Petroleum-prospective basins of New Zealand began to form by mid-Cretaceous rifting of crustal elements previously assembled at the Gondwana continental margin. During the latest Cretaceous-early Cenozoic New Zealand separated from Australia and Antarctica by sea-floor spreading. An overall transgression in widely recorded in this post-rift phase, with decreasing clastic sediment supply as land area and relief were reduced. Mid-Cenozoic initiation of the modern plate boundary has resulted in uplift of mountain ranges, subsidence and filling of troughs, progradation of the shelf, and common reactivation or eversion of older structures. Petroleum potential of less explored basins can be compared to the productive Taranki basin. Source rocks are coal-rich deposits of the rift phase, also developed in Great South, Canterbury/Chatham, Western Southland, West Coast, and Northland basins. A different source contributes to oil and gas seeps on the East Coast, a continental margin during Late Cretaceous. The main reservoirs of Taranaki are early Cenozoic coastal and fluvial sands, also present in Great South, Canterbury, and West Coast and possibly other basins. Other Taranaki reservoirs include mid-Cenozoic limestone and Miocene turbidites, which are widespread in most other basins. Pliocene limestones have excellent reservoir potential on the East Coast. Late Cenozoic tectonics, essential to trap development and significant for maturation in Taranaki, have created similar structures in basins near the plate boundary but are less significant in the development of Great South, eastern Canterbury/Chatham, and Northland basins.

  7. RESERVES IN WESTERN BASINS PART IV: WIND RIVER BASIN

    SciTech Connect

    Robert Caldwell

    1998-04-01

    Vast quantities of natural gas are entrapped within various tight formations in the Rocky Mountain area. This report seeks to quantify what proportion of that resource can be considered recoverable under today's technological and economic conditions and discusses factors controlling recovery. The ultimate goal of this project is to encourage development of tight gas reserves by industry through reducing the technical and economic risks of locating, drilling and completing commercial tight gas wells. This report is the fourth in a series and focuses on the Wind River Basin located in west central Wyoming. The first three reports presented analyses of the tight gas reserves and resources in the Greater Green River Basin (Scotia, 1993), Piceance Basin (Scotia, 1995) and the Uinta Basin (Scotia, 1995). Since each report is a stand-alone document, duplication of language will exist where common aspects are discussed. This study, and the previous three, describe basin-centered gas deposits (Masters, 1979) which contain vast quantities of natural gas entrapped in low permeability (tight), overpressured sandstones occupying a central basin location. Such deposits are generally continuous and are not conventionally trapped by a structural or stratigraphic seal. Rather, the tight character of the reservoirs prevents rapid migration of the gas, and where rates of gas generation exceed rates of escape, an overpressured basin-centered gas deposit results (Spencer, 1987). Since the temperature is a primary controlling factor for the onset and rate of gas generation, these deposits exist in the deeper, central parts of a basin where temperatures generally exceed 200 F and drill depths exceed 8,000 feet. The abbreviation OPT (overpressured tight) is used when referring to sandstone reservoirs that comprise the basin-centered gas deposit. Because the gas resources trapped in this setting are so large, they represent an important source of future gas supply, prompting studies to

  8. Raindrop axis ratios, fall velocities and size distribution over Sumatra from 2D-Video Disdrometer measurement

    NASA Astrophysics Data System (ADS)

    Marzuki; Randeu, Walter L.; Kozu, Toshiaki; Shimomai, Toyoshi; Hashiguchi, Hiroyuki; Schönhuber, Michael

    2013-01-01

    Raindrop axis ratio, falling velocity and size distribution are important in broad list of applications. However, they are not frequently observed in the equatorial region. This paper elucidated the characteristics of raindrop axis ratio, falling velocity and size distribution based on 2D-Video Disdrometer (2DVD) data that have been collected in the equatorial Indonesia, particularly at Kototabang (hereafter called KT), west Sumatra, Indonesia (0.20°S, 100.32°E, 864 m above sea level). A comprehensive follow-up of the previous study on the natural variability of raindrop size distributions (DSDs) is presented. Precipitation was classified through 1.3-GHz wind profiler observation. The dependence of raindrop falling velocity and axis ratio on rainfall type was not clearly observed. Overall, measured raindrop fall velocities were in good agreement with Gunn-Kinzer's data. Raindrop axis ratio at KT was more spherical than that of artificial rain and equilibrium model, and close to the values reported in the turbulent high shear zone of surface layer which can be partially due to the effect of the instrument errors (e.g., location and container shape). Of some natural variations of DSD investigated, the dependence of DSD on rainfall rate and rainfall type as well as diurnal variation was clearly visible. A striking contrast between the stratiform and convective rains is that the size distributions from the stratiform (convective) rains tend to narrow (broaden) with increasing rainfall rates. For rainfall rate R < 10 mm/h, the size distribution of stratiform was broader than that of convective. On the other hand, at higher rainfall rate more large-sized drops were found in convective rain. During the convective rain, very large-sized drops were found mainly at the very start of rain event while for the stratiform they were found to be associated with a strong bright band. In diurnal basis, the DSDs in the morning hours were narrower than those in the evening which was

  9. ICESat Observations of Topographic Change in the Northern Segment of the 2004 Sumatra-Andaman Islands Earthquake Rupture Zone

    NASA Technical Reports Server (NTRS)

    Harding, David; Sauber, J.; Luthcke, S.; Carabajal, C.; Muller, J

    2005-01-01

    The Andaman Islands are located 120 km east of the Sunda trench in the northern quarter of the 1300 km long rupture zone of the 2004 Sumatra-Andaman Islands earthquake inferred from the distribution of aftershocks. Initial field reports indicate that several meters of uplift and up to a meter of submergence occurred on the western and eastern shorelines of the Andaman Islands, respectively, associated with the earthquake (Bilham, 2005). Satellite images also document uplift of western shoreline coral reef platforms above sea level. Body-wave (Ji, 2005; Yamamaka, 2005) and tide-gauge (Ortiz, 2005) slip inversions only resolve coseismic slip in the southern one-third to one-half of the rupture zone. The amount of coseismic slip in the Andaman Islands region is poorly constrained by these inversions. The Ice, Cloud, and land Elevation Satellite (ICESat), a part of the NASA Earth Observing System, is being used to document the spatial pattern of Andaman Islands vertical displacements in order to constrain models of slip distribution in the northern part of the rupture zone. ICESat carries the Geoscience Laser Altimeter System (GLAS) that obtains elevation measurements from 80 m diameter footprints spaced 175 m apart along profiles. For surfaces of low slope, single-footprint absolute elevation and horizontal accuracies of 10 cm and 6 m (1 sigma), respectively, referenced to the ITRF 2002 TOPEX/Poseidon ellipsoid are being obtained. Laser pulse backscatter waveforms enable separation of ground topography and overlying vegetation cover. During each 33-day observing period ICESat acquires three profiles crossing the Andaman Islands. A NNE-SSW oriented track consists of 1600 laser footprints along the western side of North, Middle, and South Andaman Islands and 240 laser footprints across the center of Great Andaman Island. Two NNW-SSE tracks consist of 440 footprints across Middle Andaman Island and 25 footprints across the west side of Sentinel Island. Cloud

  10. ICESat Observations of Topographic Change in the Northern Segment of the 2004 Sumatra-Andaman Islands Earthquake Rupture Zone

    NASA Astrophysics Data System (ADS)

    Harding, D.; Sauber, J.; Luthcke, S.; Carabajal, C.; Muller, J.

    2005-05-01

    The Andaman Islands are located 120 km east of the Sunda trench in the northern quarter of the 1300 km long rupture zone of the 2004 Sumatra-Andaman Islands earthquake inferred from the distribution of aftershocks. Initial field reports indicate that several meters of uplift and up to a meter of submergence occurred on the western and eastern shorelines of the Andaman Islands, respectively, associated with the earthquake (Bilham, 2005). Satellite images also document uplift of western shoreline coral reef platforms above sea level. Body-wave (Ji, 2005; Yamamaka, 2005) and tide-gauge (Ortiz, 2005) slip inversions only resolve coseismic slip in the southern one-third to one-half of the rupture zone. The amount of coseismic slip in the Andaman Islands region is poorly constrained by these inversions. The Ice, Cloud, and land Elevation Satellite (ICESat), a part of the NASA Earth Observing System, is being used to document the spatial pattern of Andaman Islands vertical displacements in order to constrain models of slip distribution in the northern part of the rupture zone. ICESat carries the Geoscience Laser Altimeter System (GLAS) that obtains elevation measurements from 80 m diameter footprints spaced 175 m apart along profiles. For surfaces of low slope, single-footprint absolute elevation and horizontal accuracies of 10 cm and 6 m (1 sigma), respectively, referenced to the ITRF 2002 TOPEX/Poseidon ellipsoid are being obtained. Laser pulse backscatter waveforms enable separation of ground topography and overlying vegetation cover. During each 33-day observing period ICESat acquires three profiles crossing the Andaman Islands. A NNE-SSW oriented track consists of 1600 laser footprints along the western side of North, Middle, and South Andaman Islands and 240 laser footprints across the center of Great Andaman Island. Two NNW-SSE tracks consist of 440 footprints across Middle Andaman Island and 25 footprints across the west side of Sentinel Island. Cloud

  11. Postseismic Displacement Following the Sumatra-Andaman Earthquake Detected by Continuous GPS Observation and the Effect of Viscoelastic Relaxation Using 3D- FEM

    NASA Astrophysics Data System (ADS)

    Katagi, T.; Hashimoto, M.; Hashizume, M.; Choosakul, N.; Takemoto, S.; Fukuda, Y.; Fujimori, K.; Satomura, M.; Wu, P.; Otsuka, Y.; Takiguchi, H.; Saito, S.; Maruyama, T.; Kato, T.

    2007-12-01

    We have studied postseismic displacement following the Sumatra-Andaman earthquake of December 26, 2004 in Thailand and other Southeast Asian countries using continuous GPS observation. We will report the results of our GPS analysis from the beginning of 2001 to the end of October 2007. We have also constructed 3D-FEM to evaluate the effect of viscoelastic relaxation following the earthquake. We will also report this result. We used continuous GPS data from 6 sites operated by Chulalongkorn Univ. and Kyoto Univ. or JAMSTEC, 2 sites by Shizuoka Univ. and JAMSTEC, 3 sites by NICT in Thailand and Myanmar, 1 site by STE-Lab, Nagoya Univ., and IGS sites which are located in countries surrounding the Indian Ocean include Japan, China and Australia. Bernese 5.0 was used for the processing of 30 sec. sampling data to obtain static solutions. From our analysis, no significant motions were detected at each site until the day of the earthquake. Although postseismic displacements still have been detected at CHMI and SIS2 in northern Thailand, far from the epicenter, they seem to be decelerated. On the other hand, at SAMP and PHKT, close to the epicenter, where postseismic displacements also became smaller, but still may take a time to stop. An about 29 cm SW-ward motion was detected at PHKT from just after the Sumatra-Andaman earthquake to June 2007, which is larger than its coseismic displacement, about 26 cm. We have constructed 3D-FEM model to estimate how much viscoelastic relaxation affects postseismic displacements after the earthquake. We adopted a Maxwell viscoelastic body as well as Katagi et al. (2006), and modeled around the Andaman-Sea area using isoparametric hexahedral elements with 8 nodes (Zienkiewicz and Cheng, 1967). The Andaman-Sea is well known as a back arc basins, and its ocean floor is still spreading. Therefore, the mantle viscosity under the Sunda-plate may be smaller because of upwelling warm mantle. We are going to investigate and report the

  12. Preliminary geothermal investigations in West Virginia

    SciTech Connect

    Hendry, R.; Hilfiker, K.; Hodge, D.; Morgan, P.; Swanberg, C.

    1981-10-01

    Deep sedimentary basins and warm spring systems are potential geothermal resources in West Virginia. A temperature gradient map based on 800 BHT for WV shows that variation of temperature gradients trend NE parallel to regional structure. Highest temperature gradient values of about 28/sup 0/C/km occur in the eastcentral WV and the lowest gradients (18/sup 0/C/km) are found over the Rome trough. Results of groundwater geochemistry indicate that the warm springs circulate in very shallow aquifers and are subject to seasonal temperature fluctuations. Silica heat flow data in WV varies from about .89 to 1.4 HFU and generally increases towards the west. Bouguer, magnetic and temperature gradient profiles suggest that an ancient rift transects the State and is the site of several deep sedimentary basins.

  13. Constraints on rupture of the December 26, 2004, Sumatra earthquake from far-field GPS observations

    NASA Astrophysics Data System (ADS)

    Catherine, Joshi K.; Gahalaut, Vineet K.; Sahu, Vipul K.

    2005-09-01

    We use Global Positioning System (GPS) data from nine permanent GPS sites surrounding the epicentre of the December 26, 2004, Sumatra earthquake to infer coseismic displacements at these sites. The results suggest that GPS site at SAMP, Medan in Sumatra Island, the nearest site from the epicentre, experienced a westward coseismic horizontal displacement of about 14 cm, while sites in southern India, namely, HYDE and IISC experienced predominantly eastward coseismic horizontal displacement of about 6-11 mm. We estimated the slip on the mainshock rupture and rupture extent in a uniform half space by analysing these coseismic displacements. We estimate an average reverse slip of about 11 m on the southern part of the rupture and an oblique slip of about 10 m on the northern part of the 1200 × 100-175-km 2 rupture. Our results of estimated coseismic horizontal displacement in the Andaman and Nicobar region using the above rupture parameters are also consistent with the near-field GPS measured coseismic displacements in the region.

  14. Constraints on 2004 Sumatra Andaman earthquake rupture from GPS measurements in Andaman Nicobar Islands

    NASA Astrophysics Data System (ADS)

    Gahalaut, V. K.; Nagarajan, B.; Catherine, J. K.; Kumar, S.

    2006-02-01

    The 26 December 2004 Sumatra-Andaman earthquake (Mw 9.0-9.3) is the greatest earthquake of the modern seismological era. The rupture characteristics of the earthquake, particularly in the Andaman-Nicobar region, are not well resolved from seismological or far-field geodetic data. Here, in this article we present, campaign mode Global Positioning System (GPS) measurements of coseismic displacements at 13 sites in the Andaman-Nicobar Islands before and after the 2004 Sumatra-Andaman earthquake. These measurements provide improved estimates of rupture characteristics in the region. Coseismic horizontal ground displacement of 1.5-6.5 m towards the southwest and coseismic vertical displacement, mostly subsidence, of 0.5-2.8 m occurred along the Andaman-Nicobar Islands with maximum displacements in the Nicobar Islands. We estimate coseismic slip under the Andaman and Nicobar Islands as 3.8-7.9 m and 11-15 m, respectively. The length of the rupture is estimated to be about 1500 km with a width varying from 120 km under Middle Andaman Island to 160 km under Great Nicobar Island. GPS measurements during January 11-22, 2005 from Port Blair suggest rapid afterslip in the postseismic period. Limited GPS data available from 1995 measurements at two sites in Andaman provide evidence of strain accumulation that varied significantly in the 10 yr preceding the earthquake.

  15. The goblin spider genus Ischnothyreus (Araneae, Oonopidae) in Java and Sumatra.

    PubMed

    Richard, Miguel; Graber, Werner; Kropf, Christian

    2016-01-01

    The genus Ischnothyreus Simon, 1893 from Java and Sumatra is revised with the description of seven new species from Java (I. baltenspergerae sp. nov., I. bauri sp. nov., I. gigeri sp. nov., I. ligulatus sp. nov., I. nentwigorum sp. nov., I. sigridae sp. nov., I. ujungkulon sp. nov) and eight from Sumatra (I. ascifer sp. nov., I. concavus sp. nov., I. habeggeri sp. nov., I. haymozi sp. nov., I. lucidus sp. nov., I. marggii sp. nov., I. microphthalmus sp. nov., I. obscurus sp. nov.). Furthermore the male of I. serpentinum Saaristo, 2001 is described for the first time and the female redescribed in detail. Special morphological features of Ischnothyreus males and females are described and discussed, such as peculiar trochanter projections, partially fused pedipalp segments, processes on the cheliceral fang base in males and external and internal genitalic structures in females. This work is part of the Planetary Biodiversity Inventory (PBI) of goblin spiders (http://research.amnh.org/oonopidae/).. PMID:27615819

  16. Exploratory emphasis shifts to the west

    SciTech Connect

    Tao, W. )

    1990-01-01

    This paper presents an interview with the president of China National Petroleum Corp. He discusses development priorities and the current expansion of exploration, drilling and producing operations on the far western frontier. China's first priority is to develop the far west's Tarim basin, where 150 rigs are already at work. Another major goal is to develop vast natural gas resources, estimated at 1,165 tcf.

  17. Biological control of Black Pod Disease and Seedling Blight of cacao caused by Phytophthora Species using Trichoderma from Aceh Sumatra

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cocoa tree, Theobroma cacao L., suffers large yield losses in Aceh Indonesia to the disease black pod rot, caused by Phytophthora spp. Despite having the largest area under cacao production in Sumatra, farmers in the Aceh region have low ov