Triggering and dynamic evolution of the LUSI mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Mazzini, A.; Svensen, H.; Akhmanov, G. G.; Aloisi, G.; Planke, S.; Malthe-Sørenssen, A.; Istadi, B.

2007-09-01

Mud volcanoes are geologically important manifestations of vertical fluid flow and mud eruption in sedimentary basins worldwide. Their formation is predominantly ascribed to release of overpressure from clay- and organic-rich sediments, leading to impressive build-up of mud mountains in submarine and subaerial settings. Here we report on a newly born mud volcano appearing close to an active magmatic complex in a backarc sedimentary basin in Indonesia. The location of the mud volcano close to magmatic volcanoes results in a high background temperature gradient that triggers mineralogical transformations and geochemical reactions at shallow depth. The eruption of 100 °C mud and gas that started the 29th of May 2006 flooded a large area within the Sidoarjo village in Northeast Java. Thousands of people have so far been evacuated due to the mud flood hazards from the eruption. Since the initial eruption, the flow rate escalated from 5000 to 120,000 m 3/d during the first eleven weeks. Then the erupted volume started to pulsate between almost zero and 120,000 m 3/d in the period August 14 to September 10, whereas it increased dramatically following swarms of earthquakes in September, before reaching almost 180,000 m 3/d in December 2006. Sampling and observations were completed during two fieldwork campaigns on the site. The eruption of boiling water is accompanied by mud, aqueous vapour, CO 2 and CH 4. Based on geochemical and field results, we propose a mechanism where the eruptions started following the 27th of May earthquake due to fracturing and accompanied depressurization of > 100 °C pore fluids from > 1700 m depth. This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity.

Lime-mud layers in high-energy tidal channels: A record of hurricane deposition

NASA Astrophysics Data System (ADS)

Shinn, Eugene A.; Steinen, Randolph P.; Dill, Robert F.; Major, Richard

1993-07-01

During or immediately following the transit of Hurricane Andrew (August 23-24, 1992) across the northern part of the Great Bahama Bank, thin laminated beds of carbonate mud were deposited in high-energy subtidal channels (4 m depth) through the ooid shoals of south Cat Cay and Joulters Cays. During our reconnaissance seven weeks later, we observed lime-mud beds exposed in the troughs of submarine oolite dunes and ripples. The mud layers were underlain and locally covered by ooid sand. The mud beds were lenticular and up to 5 cm thick. Their bases cast the underlying rippled surface. The layers were composed of soft silt- and sand-sized pellets and peloids and in some areas contained freshly preserved Thalassia blades and other organic debris along planes of lamination. The beds had a gelatinous consistency and locally had been penetrated by burrowers and plants. Layers of lime mud had also settled on bioturbated, plant-stabilized flats and in lagoonal settings but were quickly reworked and made unrecognizable by the burrowing of organisms. Thicker, more cohesive (and therefore older) mud beds and angular mud fragments associated with ooids from Joulters Cays have similar characteristics but lack fresh plant fragments. We infer that these older beds were similarly deposited and thus record the passage of previous hurricanes or tropical storms. Storm layers are preserved within channel sediments because migrating ooids prevent attack by the burrowing activity off organisms.

Submarine sand ridges and sand waves in the eastern part of the China Sea

NASA Astrophysics Data System (ADS)

Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

2016-04-01

Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

P-wave velocity model of mud volcano on the continental slope of the Canadian Beaufort Sea from frequency-domain full waveform inversion

NASA Astrophysics Data System (ADS)

Jang, U. G.; Kang, S. G.; Hong, J. K.; Jin, Y. K.; Dallimore, S.; Riedel, M.; Paull, C. K.

2017-12-01

2014 Expedition ARA05C was a multidisciplinary undertaking conducted in the Canadian Beaufort Sea, Arctic Ocean on the Korean ice breaker IBRV ARAON from August 30 to September 19, 2014. The program was carried out as collaboration between the Korea Polar Research Institute (KOPRI), Geological Survey of Canada (GSC), Monterey Bay Aquarium Research Institute (MBARI), Department of Fisheries and Ocean (DFO) with participation by Bremen University (BARUM). During this expedition, multi-channel seismic (MCS) data were acquired on the outer continental shelf and upper slope of the Canadian Beaufort Sea, totaling 20 lines with 1,000 line-kilometers from September 1 to September 13, 2014. Three MCS survey lines was designed to cross the three submarine mud volcanoes found in the slope at approximate water depth of 290 m, 460 m and 740 m. Submarine mud volcanoes are seafloor structures with positive topography formed by a combination of mud eruption, gas emission, and water seepage from the subsurface. MCS data will allow image subsurface structures of mud volcanoes as identification of fluid migration pathways, however, imaging its subsurface structure is difficult by using conventional seismic data processing procedure, because it is seismically characterized by acoustically transparent facies. Full waveform inversion (FWI) is non-linear data-fitting procedure to estimate the physical properties of the subsurface by minimizing the difference between the observed and modelled data. FWI uses the two-wave wave equation to compute forward/backward wavefield to calculate the gradient direction, therefore it can derive more detailed velocity model beyond travel-time tomography techniques, which use only the kinematics of seismic data, by additional information provided by the amplitude and phase of the seismic waveform. In this study, we suggest P-wave structure of mud volcanos, which were inverted by 2D acoustic FWI. It will be useful to understand the characterization of mud volcanoes on the slope of Canadian Beaufort Sea.

Anatomy of the Kitimat fiord system, British Columbia

NASA Astrophysics Data System (ADS)

Shaw, John; Stacey, Cooper D.; Wu, Yongsheng; Lintern, D. Gwyn

2017-09-01

The geomorphic complexity of the Kitimat fiord system, on the active margin of British Columbia, Canada, is analysed from several perspectives. Sub-glacial landforms and sediments show that grounded ice exiting the fiord system at the last glacial maximum streamed down Moresby Trough towards the Queen Charlotte trough mouth fan. After brief halts on the inner shelf, grounded ice margins cleared the fiord threshold perhaps by c. 15.5 ka cal. yrs BP, and certainly before 13 ka cal. yrs BP. Just outside the fiords, meltwater plumes deposited stratified glaciomarine sediments interbedded with submarine slides. Inside the fiords, thick glaciomarine sediments were deposited, and large transverse moraines formed during temporary halts in retreat. Several glacial outburst floods eroded the Kitkiata moraine and deposited distinctive mud deposits. Postglacial sedimentation on fiord floors has been spatially variable: drifts of mud > 90 m-thick corresponding with areas of low current velocity alternate with areas of non-deposition and erosion corresponding with areas of high velocity. The fiord system hosts more than a hundred morphologically diverse fan deltas that can be classified in the Prior and Bornhold (1989, 1990) system. Submarine mass transport was most frequent immediately following ice retreat (15.5-11.5 ka cal. yrs BP). The largest event ( 1.2 km3) involved failure of glaciomarine sediment on a submarine moraine at Squally Channel, and consequent movement of material into the adjacent deep basin. This event occurred post-13 ka cal. yrs BP. In the postglacial phase, mass transport continued on a lesser scale up to the present day, most intensively in Kitimat Arm. From the perspective of glacial landforms, postglacial sedimentation and mass transport, this Pacific active margin fiord system has some parallels with fiord systems on Canada's east coast passive margin, and with Norwegian fiords, but the intensive development of Holocene fan deltas is strongly distinctive.

New discoveries of mud volcanoes on the Moroccan Atlantic continental margin (Gulf of Cádiz): morpho-structural characterization

NASA Astrophysics Data System (ADS)

León, Ricardo; Somoza, Luis; Medialdea, Teresa; Vázquez, Juan Tomás; González, Francisco Javier; López-González, Nieves; Casas, David; del Pilar Mata, María; del Fernández-Puga, María Carmen; Giménez-Moreno, Carmen Julia; Díaz-del-Río, Víctor

2012-12-01

During the MVSEIS-08 cruise of 2008, ten new mud volcanoes (MVs) were discovered on the offshore Moroccan continental margin (Gulf of Cádiz) at water depths between 750 and 1,600 m, using multibeam bathymetry, backscatter imagery, high-resolution seismic and gravity core data. Mud breccias were recovered in all cases, attesting to the nature of extrusion of these cones. The mud volcanoes are located in two fields: the MVSEIS, Moundforce, Pixie, Las Negras, Madrid, Guadix, Almanzor and El Cid MVs in the western Moroccan field, where mud volcanoes have long been suspected but to date not identified, and the Boabdil and Al Gacel MVs in the middle Moroccan field. Three main morphologies were observed: asymmetric, sub-circular and flat-topped cone-shaped types, this being the first report of asymmetric morphologies in the Gulf of Cádiz. Based on morpho-structural analysis, the features are interpreted to result from (1) repeated constructive (expulsion of fluid mud mixtures) and destructive (gravity-induced collapse and submarine landsliding) episodes and (2) interaction with bottom currents.

High-Resolution Seafloor Observations of an Active Mud Volcano Offshore SW Taiwan - Results of a Repeated Survey after Four Years

NASA Astrophysics Data System (ADS)

Hsu, H. H.; Chen, T. T.; Liu, C. S.; Su, C. C.; Paull, C. K.; Caress, D. W.; Gwiazda, R.; Chen, Y. H.

2017-12-01

Mud Volcano V (MV5) is an active submarine mud volcano sitting on top of a mud diapir ridge at water depths of 600 m in the active margin offshore of southwestern Taiwan. This cone-shape mud volcano is almost 3-km-wide, 200-m-high, with 9.5° slopes, and explosively ejects streams of mud every 1.5-3 minutes. It was first mapped in 2013 with MBARI's mapping AUV (autonomous underwater vehicle). In 2017, a repeated AUV mapping survey was conducted to see if significant bathymetric changes took place since 2013, and to investigate the fluxes of fluids that pass through diapiric structures in an active continental margin. In addition to high-resolution bathymetry (1-m-resolution), sub-bottom profiling and side-scan sonar data acquired by the AUV, and videos and samples collected by MBARI's miniROV, we also incorporate multichannel seismic reflection data and gravity core sample analyses in this study. AUV bathymetry data reveal that there are two gryphons on the eastern slope of MV5. In the 2017 survey the mapped sizes of the two side cones were 80 m wide, 35 m long, 20 m relief and 40 m wide, 40 m long, 12 m relief, respectively. Comparing the bathymetry mapped in the 2017 AUV survey with that surveyed in 2013, no obvious overall morphological changes in MV5 are detected, except around the two gryphons. In the time period between the surveys, due to venting of mud from the two gryphons, two series of flow deposits which can be up to 5 meters thick are observed along the slope in the east side of both gryphons. The center depressions of these two gryphons have increased by 1-5 meters depth in their west side. Seismic and sub-bottom profiles reveal amplitude anomalies in the sub-strata of MV5 which indicate possible fluid migration paths of mud flows from deep. The trace of mud flow from the top of MV5 to its foot can be delineated from the side-scan sonar images. On the basis of 210Pbex chronology dating method, the sedimentation rate on the surface of MV5 is very slow (0.057 cm/y). High methane anomalies are discovered on MV5 based on the geochemical analysis results of gravity core samples, but the heat probe did not detect obvious temperature changes before and after venting episodes in the 2017 survey. Based on this comprehensive study, a three-step model is proposed to explain mud volcano venting processes in the active margin offshore of SW Taiwan.

Submarine fans: Characteristics, models, classification, and reservoir potential

NASA Astrophysics Data System (ADS)

Shanmugam, G.; Moiola, R. J.

1988-02-01

Submarine-fan sequences are important hydrocarbon reservoirs throughout the world. Submarine-fan sequences may be interpreted from bed-thickness trends, turbidite facies associations, log motifs, and seismic-reflection profiles. Turbidites occurring predominantly in channels and lobes (or sheet sands) constitute the major portion of submarine-fan sequences. Thinning- and thickening-upward trends are suggestive of channel and lobe deposition, respectively. Mounded seismic reflections are commonly indicative of lower-fan depositional lobes. Fan models are discussed in terms of modern and ancient fans, attached and detached lobes, highly efficient and poorly efficient systems, and transverse and longitudinal fans. In general, depositional lobes are considered to be attached to feeder channels. Submarine fans can be classified into four types based on their tectonic settings: (1) immature passive-margin fans (North Sea type); (2) mature passive-margin fans (Atlantic type); (3) active-margin fans (Pacific type); and (4) mixed-setting fans. Immature passive-margin fans (e.g., Balder, North Sea), and active-margin fans (e.g., Navy, Pacific Ocean) are usually small, sand-rich, and possess well developed lobes. Mature passive-margin fans (e.g., Amazon, Atlantic Ocean) are large, mud-rich, and do not develop typical lobes. However, sheet sands are common in the lower-fan regions of mature passive-margin fans. Mixed-setting fans display characteristics of either Atlantic type (e.g., Bengal, Bay of Bengal), or Pacific type (Orinoco, Caribbean), or both. Conventional channel-lobe models may not be applicable to fans associated with mature passive margins. Submarine fans develop primarily during periods of low sea level on both active- and passive-margin settings. Consequently, hydrocarbon-bearing fan sequences are associated generally with global lowstands of sea level. Channel-fill sandstones in most tectonic settings are potential reservoirs. Lobes exhibit the most favorable reservoir quality in terms of sand content, lateral continuity, and porosity development. Lower-fan sheet sands may also make good reservoirs. Quartz-rich sandstones of mature passive-margin fans are most likely to preserve depositional porosity, whereas lithic sandstones of active-margin fans may not.

The diversity of mud volcanoes in the landscape of Azerbaijan

NASA Astrophysics Data System (ADS)

Rashidov, Tofig

2014-05-01

As the natural phenomenon the mud volcanism (mud volcanoes) of Azerbaijan are known from the ancient times. The historical records describing them are since V century. More detail study of this natural phenomenon had started in the second half of XIX century. The term "mud volcano" (or "mud hill") had been given by academician H.W. Abich (1863), more exactly defining this natural phenomenon. All the previous definitions did not give such clear and capacious explanation of it. In comparison with magmatic volcanoes, globally the mud ones are restricted in distribution; they mainly locate within the Alpine-Himalayan, Pacific and Central Asian mobile belts, in more than 30 countries (Columbia, Trinidad Island, Italy, Romania, Ukraine, Georgia, Azerbaijan, Turkmenistan, Iran, Pakistan, Indonesia, Burma, Malaysia, etc.). Besides it, the zones of mud volcanoes development are corresponded to zones of marine accretionary prisms' development. For example, the South-Caspian depression, Barbados Island, Cascadia (N.America), Costa-Rica, Panama, Japan trench. Onshore it is Indonesia, Japan, and Trinidad, Taiwan. The mud volcanism with non-accretionary conditions includes the areas of Black Sea, Alboran Sea, the Gulf of Mexico (Louisiana coast), Salton Sea. But new investigations reveal more new mud volcanoes and in places which were not considered earlier as the traditional places of mud volcanoes development (e.g. West Nile Rive delta). Azerbaijan is the classic region of mud volcanoes development. From over 800 world mud volcanoes there are about 400 onshore and within the South-Caspian basin, which includes the territory of East Azerbaijan (the regions of Shemakha-Gobustan and Low-Kura River, Absheron peninsula), adjacent water area of South Caspian (Baku and Absheron archipelagoes) and SW Turkmenistan and represents an area of great downwarping with thick (over 25 km) sedimentary series. Generally, in the modern relief the mud volcanoes represent more or less large uplifts on surface, often of plane-conical shape, rising for 5 to 400 m and more over the country (for example, mud volcano Toragay, 400 m height). The base diameter is from 100 m to 3-4 km and more. Like the magmatic ones, the mud volcanoes are crowned with crater of convex-plane or deeply-seated shape. In Azerbaijan there are all types of mud volcanoes: active, extinct, buried, submarine, island, abundantly oil seeping. According to their morphology they are defined into cone-shaped, dome-shaped, ridge-shaped, plateau-shaped. The crater shapes are also various: conical, convex-plane, shield-shaped, deeply-seated, caldera-like. The most complete morphological classification was given in "Atlas of mud volcanoes of Azerbaijan" (Yakubov et al., 1971). Recently (Aliyev Ad. et al., 2003) it was proposed a quite new morphological classification of mud volcanoes of Azerbaijan. For the first time the mud volcanic manifestations had been defined. Volcanoes are ranged according to morphological signs, crater shape and type of activity.

Triggering and dynamic evolution of the LUSI mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Svensen, H.; Mazzini, A.; Akhmanov, G. G.; Aloisi, G.; Planke, S.; Sørenssen, A.; Istadi, B.

2007-12-01

Mud volcanoes are geologically important manifestations of vertical fluid flow and mud eruption in sedimentary basins worldwide. Their formation is predominantly ascribed to release of overpressure from clay- and organic- rich sediments, leading to impressive buildup of mud mountains in submarine and subaerial settings. Here we report data from two fieldworks on a newly born mud volcano named LUSI eruption in Eastern Java (Indonesia). The eruption site appears close to an active magmatic complex in a backarc sedimentary basin in Indonesia. Its specific location results in a high background temperature gradient that triggers mineralogical transformations and geochemical reactions at shallow depth. The eruption of 100 deg.C mud and gas that started the 29th of May 2006 flooded a large area within the Sidoarjo village in Northeast Java. Thousands of people have so far been evacuated and, since the initial eruption, the flow rate escalated from 5000 to 120,000 m3/d during the first eleven weeks. Then the erupted volume started to pulsate between almost zero and 120,000 m3/d in the period August-September, whereas it increased dramatically following swarms of earthquakes in September, before reaching almost 180,000 m3/d in December 2006. Fifteen months after the initial burst, LUSI is still vigorously erupting up to 111,000 m3/d, the average subsidence of the area reached 11 m. Seismic images show that a pre-existing structure was present before the eruption. Based on geochemical and field results, we propose a mechanism where the eruptions started following the 27th of May earthquake due to fracturing and accompanied depressurization of >100 deg.C pore fluids from > 1700 m depth released from a structure in already critical conditions. This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity.

Characteristics and features of the submarine landslides in passive and active margin southwestern offshore Taiwan

NASA Astrophysics Data System (ADS)

Yeh, Y. C.

2016-12-01

In the past decade, numerous multi-channel seismic surveys as well as near seafloor high resolution geophysical investigations were conducted in order to explore and estimate the reserves of gas hydrate southwestern offshore Taiwan. The previous object was focused on searching substitute energy (i.e. gas hydrate) rather than geo-hazards. However, it is suggested that most of the gas hydrate is generally distributed at slope area southwestern offshore Taiwan, which indicates the slope may be failed when steady state was disturbed by some factors, such as sea level or climate change. In addition, once gas hydrate was dissociated, this may induce submarine landslide that further cause devastated tsunami. Thus, it is of great urgency to investigate potential landslide area, particularly, the hydrate-rich continental slope (active and passive margins) in adjacent to populous city like Kaohsiung. In this study, we collected several high resolution multi-channel seismic data with ten seconds shooting rate and 3.125 meters group interval streamer by using R/V ORI and R/V ORV. The seismic data were processed in conventional data processing strategy: bad trace clean, geometry settings, band-pass filter, de-convolution, surface-related multiple rejection, radon filter, stacking,kirchhoff migration and time to depth conversion. Combine the results obtained from the MCS data and subbottom profiles, two major results could be raised in the active margin as followed: (1) Most of the surface creeping and landslide was occurred shallower than 500 meters in water depth, which should be related to the inter-bedded fluid activities. (2) The landslide distribution is lagly affected by the presence of diaper, suggesting the subsequent mud diapirism may destruct slope stability; (3) The submarine landslide deeper than 800 meters in water depth distributes in the thrust fold area, that is probably referred to active thrusting. In the passive margin, large volume mass transportation deposits (MTDs) were identified in deeper stratigraphic section below BSR. This indicated several big former submarine landslide events occurred. In summary, the passive margin often show typical submarine landslide features than active margin, which driven by gravity force.

The characteristics of rotational slumps and subaqueous translational slab slides of the Lower Murray River, South Australia: do they have any implications for the weak-layer hypothesis?

NASA Astrophysics Data System (ADS)

Hubble, Thomas; De Carli, Elyssa; Airey, David; Breakfree 2012-2013, Scientific Parties MV

2014-05-01

The peak of the recent prolonged 'Millennium Drought' (1997-2011) triggered an episode of widespread mass failure in the alluvial river-banks of the Lower Murray River in South Australia. Multi-beam surveying of the channel and submerged river-banks between Mannum and Murray Bridge and coring of the bank sediments has been undertaken in sections of the river where large bank failures threatened private housing or public infrastructure. This data demonstrates that the bank materials are soft, horizontally-layered muds and that translational, planar slab-slides have frequently occurred in permanently submerged portions of the Murray's river banks. Despite these riverine features being several orders of magnitude smaller than the translational submarine landslides of the continental margins, the submerged river-bank slides are strikingly similar in their morphology to their submarine equivalents. Intriguingly, the Murray River translational slide failure-surfaces are usually developed as river-floor-parallel features in a manner similar to many submarine landslides which present failure-surfaces that are developed on seafloor-parallel, bedding planes. In contrast however, the Murray's river-bank slides occur on steep slopes (>20o) and their failure surfaces must cut across the horizontal laminations and layering of the muds at a relative high angle which removes the possibility of a weak sediment layer being responsible for the occurrence of these failures. Modelling of the river-bank failures with classical soil mechanics methods and the measured physical properties of the river-bank materials indicates that the failures are probably a consequence of flood-flow scour removing the bank-slope toe in combination with pore-pressure effects related to river-level fluctuation (ie. drawdown). Nevertheless, the Murray's translational slab-slides provide a reliable example of slope-parallel planar failure in muds that does not require a stratigraphic weak layer to explain the occurrence of those failures.

Viral infections stimulate the metabolism and shape prokaryotic assemblages in submarine mud volcanoes.

PubMed

Corinaldesi, Cinzia; Dell'Anno, Antonio; Danovaro, Roberto

2012-06-01

Mud volcanoes are geological structures in the oceans that have key roles in the functioning of the global ecosystem. Information on the dynamics of benthic viruses and their interactions with prokaryotes in mud volcano ecosystems is still completely lacking. We investigated the impact of viral infection on the mortality and assemblage structure of benthic prokaryotes of five mud volcanoes in the Mediterranean Sea. Mud volcano sediments promote high rates of viral production (1.65-7.89 × 10(9) viruses g(-1) d(-1)), viral-induced prokaryotic mortality (VIPM) (33% cells killed per day) and heterotrophic prokaryotic production (3.0-8.3 μgC g(-1) d(-1)) when compared with sediments outside the mud volcano area. The viral shunt (that is, the microbial biomass converted into dissolved organic matter as a result of viral infection, and thus diverted away from higher trophic levels) provides 49 mgC m(-2) d(-1), thus fuelling the metabolism of uninfected prokaryotes and contributing to the total C budget. Bacteria are the dominant components of prokaryotic assemblages in surface sediments of mud volcanoes, whereas archaea dominate the subsurface sediment layers. Multivariate multiple regression analyses show that prokaryotic assemblage composition is not only dependant on the geochemical features and processes of mud volcano ecosystems but also on synergistic interactions between bottom-up (that is, trophic resources) and top-down (that is, VIPM) controlling factors. Overall, these findings highlight the significant role of the viral shunt in sustaining the metabolism of prokaryotes and shaping their assemblage structure in mud volcano sediments, and they provide new clues for our understanding of the functioning of cold-seep ecosystems.

Viral infections stimulate the metabolism and shape prokaryotic assemblages in submarine mud volcanoes

PubMed Central

Corinaldesi, Cinzia; Dell'Anno, Antonio; Danovaro, Roberto

2012-01-01

Mud volcanoes are geological structures in the oceans that have key roles in the functioning of the global ecosystem. Information on the dynamics of benthic viruses and their interactions with prokaryotes in mud volcano ecosystems is still completely lacking. We investigated the impact of viral infection on the mortality and assemblage structure of benthic prokaryotes of five mud volcanoes in the Mediterranean Sea. Mud volcano sediments promote high rates of viral production (1.65–7.89 × 109 viruses g−1 d−1), viral-induced prokaryotic mortality (VIPM) (33% cells killed per day) and heterotrophic prokaryotic production (3.0–8.3 μgC g−1 d−1) when compared with sediments outside the mud volcano area. The viral shunt (that is, the microbial biomass converted into dissolved organic matter as a result of viral infection, and thus diverted away from higher trophic levels) provides 49 mgC m−2 d−1, thus fuelling the metabolism of uninfected prokaryotes and contributing to the total C budget. Bacteria are the dominant components of prokaryotic assemblages in surface sediments of mud volcanoes, whereas archaea dominate the subsurface sediment layers. Multivariate multiple regression analyses show that prokaryotic assemblage composition is not only dependant on the geochemical features and processes of mud volcano ecosystems but also on synergistic interactions between bottom-up (that is, trophic resources) and top-down (that is, VIPM) controlling factors. Overall, these findings highlight the significant role of the viral shunt in sustaining the metabolism of prokaryotes and shaping their assemblage structure in mud volcano sediments, and they provide new clues for our understanding of the functioning of cold-seep ecosystems. PMID:22170423

A new model for turbidity current behavior based on integration of flow monitoring and precision coring in a submarine canyon

USGS Publications Warehouse

Symons, William O.; Sumner, Esther J.; Paull, Charles K.; Cartigny, Matthieu J.B.; Xu, Jingping; Maier, Katherine L.; Lorenson, Thomas; Talling, Peter J.

2017-01-01

Submarine turbidity currents create some of the largest sediment accumulations on Earth, yet there are few direct measurements of these flows. Instead, most of our understanding of turbidity currents results from analyzing their deposits in the sedimentary record. However, the lack of direct flow measurements means that there is considerable debate regarding how to interpret flow properties from ancient deposits. This novel study combines detailed flow monitoring with unusually precisely located cores at different heights, and multiple locations, within the Monterey submarine canyon, offshore California, USA. Dating demonstrates that the cores include the time interval that flows were monitored in the canyon, albeit individual layers cannot be tied to specific flows. There is good correlation between grain sizes collected by traps within the flow and grain sizes measured in cores from similar heights on the canyon walls. Synthesis of flow and deposit data suggests that turbidity currents sourced from the upper reaches of Monterey Canyon comprise three flow phases. Initially, a thin (38–50 m) powerful flow in the upper canyon can transport, tilt, and break the most proximal moorings and deposit chaotic sands and gravel on the canyon floor. The initially thin flow front then thickens and deposits interbedded sands and silty muds on the canyon walls as much as 62 m above the canyon floor. Finally, the flow thickens along its length, thus lofting silty mud and depositing it at greater altitudes than the previous deposits and in excess of 70 m altitude.

Deposystem architectures and lithofacies of a submarine fan-dominated deep sea succession in an orogen: A case study from the Upper Triassic Langjiexue Group of southern Tibet

NASA Astrophysics Data System (ADS)

Zhang, Chaokai; Li, Xianghui; Mattern, Frank; Mao, Guozheng; Zeng, Qinggao; Xu, Wenli

2015-11-01

Over thirty stratigraphic sections of the Himalaya orogen Upper Triassic Langjiexue Group in southern Tibet, China, were studied to interpret the environments and lithofacies. The facies associations channel (A), lobe (B), levee-interchannel (C), and basin plain (D) with nine facies (A1-3, B1-3, and C1-3) were distinguished. They form six architectural elements: channel-interchannel, overbank-levee, crevasse-splay, outer fan-lobe, fan-fringe, and basin plain. Taking into account the facies analysis, (sub-) deposystem correlation, paleocurrent dispersal pattern, and restoration of primary stratal width, the Langjiexue Group displays the architecture of a coalescing submarine fan-dominated deep sea deposystem, measuring about 400-500 km × 600-700 km in size or even more, one of the largest pre-Cenozoic submarine fans ever reported. Subdivisionally, four fans, lacking inner fans, could have coalesced laterally within the submarine fan deposystem, and at least six submarine fan developments were vertically succeeded by mid- to outer-fan deposits with progradational to retrogradational successions. According to the range of 30-70% of sandstone content, the fan deposystem is mud- and sand-rich, suggesting a medium-far (over 400-600 km) transport of sediment from the source area.

The use of rotational invariants for the interpretation of marine CSEM data with a case study from the North Alex mud volcano, West Nile Delta

NASA Astrophysics Data System (ADS)

Hölz, Sebastian; Swidinsky, Andrei; Sommer, Malte; Jegen, Marion; Bialas, Jörg

2015-04-01

Submarine mud volcanos at the seafloor are surface expressions of fluid flow systems within the seafloor. Since the electrical resistivity of the seafloor is mainly determined by the amount and characteristics of fluids contained within the sediment's pore space, electromagnetic methods offer a promising approach to gain insight into a mud volcano's internal resistivity structure. To investigate this structure, we conducted a controlled source electromagnetic experiment, which was novel in the sense that the source was deployed and operated with a remotely operated vehicle, which allowed for a flexible placement of the transmitter dipole with two polarization directions at each transmitter location. For the interpretation of the experiment, we have adapted the concept of rotational invariants from land-based electromagnetics to the marine case by considering the source normalized tensor of horizontal electric field components. We analyse the sensitivity of these rotational invariants in terms of 1-D models and measurement geometries and associated measurement errors, which resemble the experiment at the mud volcano. The analysis shows that any combination of rotational invariants has an improved parameter resolution as compared to the sensitivity of the pure radial or azimuthal component alone. For the data set, which was acquired at the `North Alex' mud volcano, we interpret rotational invariants in terms of 1-D inversions on a common midpoint grid. The resulting resistivity models show a general increase of resistivities with depth. The most prominent feature in the stitched 1-D sections is a lens-shaped interface, which can similarly be found in a section from seismic reflection data. Beneath this interface bulk resistivities frequently fall in a range between 2.0 and 2.5 Ωm towards the maximum penetration depths. We interpret the lens-shaped interface as the surface of a collapse structure, which was formed at the end of a phase of activity of an older mud volcano generation and subsequently refilled with new mud volcano sediments during a later stage of activity. Increased resistivities at depth cannot be explained by compaction alone, but instead require a combination of compaction and increased cementation of the older sediments, possibly in connection to trapped, cooled down mud volcano fluids, which have a depleted chlorinity. At shallow depths (≤50 m) bulk resistivities generally decrease and for locations around the mud volcano's centre 1-D models show bulk resistivities in a range between 0.5 and 0.7 Ωm, which we interpret in terms of gas saturation levels by means of Archie's Law. After a detailed analysis of the material parameters contained in Archie's Law we derive saturation levels between 0 and 25 per cent, which is in accordance with observations of active degassing and a reflector with negative polarity in the seismics section just beneath the seafloor, which is indicative of free gas.

Atribacteria from the Subseafloor Sedimentary Biosphere Disperse to the Hydrosphere through Submarine Mud Volcanoes.

PubMed

Hoshino, Tatsuhiko; Toki, Tomohiro; Ijiri, Akira; Morono, Yuki; Machiyama, Hideaki; Ashi, Juichiro; Okamura, Kei; Inagaki, Fumio

2017-01-01

Submarine mud volcanoes (SMVs) are formed by muddy sediments and breccias extruded to the seafloor from a source in the deep subseafloor and are characterized by the discharge of methane and other hydrocarbon gasses and deep-sourced fluids into the overlying seawater. Although SMVs act as a natural pipeline connecting the Earth's surface and subsurface biospheres, the dispersal of deep-biosphere microorganisms and their ecological roles remain largely unknown. In this study, we investigated the microbial communities in sediment and overlying seawater at two SMVs located on the Ryukyu Trench off Tanegashima Island, southern Japan. The microbial communities in mud volcano sediments were generally distinct from those in the overlying seawaters and in the well-stratified Pacific margin sediments collected at the Peru Margin, the Juan de Fuca Ridge flank off Oregon, and offshore of Shimokita Peninsula, northeastern Japan. Nevertheless, in-depth analysis of different taxonomic groups at the sub-species level revealed that the taxon affiliated with Atribacteria , heterotrophic anaerobic bacteria that typically occur in organic-rich anoxic subseafloor sediments, were commonly found not only in SMV sediments but also in the overlying seawater. We designed a new oligonucleotide probe for detecting Atribacteria using the catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). CARD-FISH, digital PCR and sequencing analysis of 16S rRNA genes consistently showed that Atribacteria are abundant in the methane plumes of the two SMVs (0.58 and 1.5 × 10 4 cells/mL, respectively) but not in surrounding waters, suggesting that microbial cells in subseafloor sediments are dispersed as "deep-biosphere seeds" into the ocean. These findings may have important implications for the microbial transmigration between the deep subseafloor biosphere and the hydrosphere.

Atribacteria from the Subseafloor Sedimentary Biosphere Disperse to the Hydrosphere through Submarine Mud Volcanoes

PubMed Central

Hoshino, Tatsuhiko; Toki, Tomohiro; Ijiri, Akira; Morono, Yuki; Machiyama, Hideaki; Ashi, Juichiro; Okamura, Kei; Inagaki, Fumio

2017-01-01

Submarine mud volcanoes (SMVs) are formed by muddy sediments and breccias extruded to the seafloor from a source in the deep subseafloor and are characterized by the discharge of methane and other hydrocarbon gasses and deep-sourced fluids into the overlying seawater. Although SMVs act as a natural pipeline connecting the Earth’s surface and subsurface biospheres, the dispersal of deep-biosphere microorganisms and their ecological roles remain largely unknown. In this study, we investigated the microbial communities in sediment and overlying seawater at two SMVs located on the Ryukyu Trench off Tanegashima Island, southern Japan. The microbial communities in mud volcano sediments were generally distinct from those in the overlying seawaters and in the well-stratified Pacific margin sediments collected at the Peru Margin, the Juan de Fuca Ridge flank off Oregon, and offshore of Shimokita Peninsula, northeastern Japan. Nevertheless, in-depth analysis of different taxonomic groups at the sub-species level revealed that the taxon affiliated with Atribacteria, heterotrophic anaerobic bacteria that typically occur in organic-rich anoxic subseafloor sediments, were commonly found not only in SMV sediments but also in the overlying seawater. We designed a new oligonucleotide probe for detecting Atribacteria using the catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). CARD-FISH, digital PCR and sequencing analysis of 16S rRNA genes consistently showed that Atribacteria are abundant in the methane plumes of the two SMVs (0.58 and 1.5 × 104 cells/mL, respectively) but not in surrounding waters, suggesting that microbial cells in subseafloor sediments are dispersed as “deep-biosphere seeds” into the ocean. These findings may have important implications for the microbial transmigration between the deep subseafloor biosphere and the hydrosphere. PMID:28676800

Diversity and abundance of aerobic and anaerobic methane oxidizers at the Haakon Mosby Mud Volcano, Barents Sea.

PubMed

Lösekann, Tina; Knittel, Katrin; Nadalig, Thierry; Fuchs, Bernhard; Niemann, Helge; Boetius, Antje; Amann, Rudolf

2007-05-01

Submarine mud volcanoes are formed by expulsions of mud, fluids, and gases from deeply buried subsurface sources. They are highly reduced benthic habitats and often associated with intensive methane seepage. In this study, the microbial diversity and community structure in methane-rich sediments of the Haakon Mosby Mud Volcano (HMMV) were investigated by comparative sequence analysis of 16S rRNA genes and fluorescence in situ hybridization. In the active volcano center, which has a diameter of about 500 m, the main methane-consuming process was bacterial aerobic oxidation. In this zone, aerobic methanotrophs belonging to three bacterial clades closely affiliated with Methylobacter and Methylophaga species accounted for 56%+/-8% of total cells. In sediments below Beggiatoa mats encircling the center of the HMMV, methanotrophic archaea of the ANME-3 clade dominated the zone of anaerobic methane oxidation. ANME-3 archaea form cell aggregates mostly associated with sulfate-reducing bacteria of the Desulfobulbus (DBB) branch. These ANME-3/DBB aggregates were highly abundant and accounted for up to 94%+/-2% of total microbial biomass at 2 to 3 cm below the surface. ANME-3/DBB aggregates could be further enriched by flow cytometry to identify their phylogenetic relationships. At the outer rim of the mud volcano, the seafloor was colonized by tubeworms (Siboglinidae, formerly known as Pogonophora). Here, both aerobic and anaerobic methane oxidizers were found, however, in lower abundances. The level of microbial diversity at this site was higher than that at the central and Beggiatoa species-covered part of the HMMV. Analysis of methyl-coenzyme M-reductase alpha subunit (mcrA) genes showed a strong dominance of a novel lineage, mcrA group f, which could be assigned to ANME-3 archaea. Our results further support the hypothesis of Niemann et al. (54), that high methane availability and different fluid flow regimens at the HMMV provide distinct niches for aerobic and anaerobic methanotrophs.

Diversity and Abundance of Aerobic and Anaerobic Methane Oxidizers at the Haakon Mosby Mud Volcano, Barents Sea▿

PubMed Central

Lösekann, Tina; Knittel, Katrin; Nadalig, Thierry; Fuchs, Bernhard; Niemann, Helge; Boetius, Antje; Amann, Rudolf

2007-01-01

Submarine mud volcanoes are formed by expulsions of mud, fluids, and gases from deeply buried subsurface sources. They are highly reduced benthic habitats and often associated with intensive methane seepage. In this study, the microbial diversity and community structure in methane-rich sediments of the Haakon Mosby Mud Volcano (HMMV) were investigated by comparative sequence analysis of 16S rRNA genes and fluorescence in situ hybridization. In the active volcano center, which has a diameter of about 500 m, the main methane-consuming process was bacterial aerobic oxidation. In this zone, aerobic methanotrophs belonging to three bacterial clades closely affiliated with Methylobacter and Methylophaga species accounted for 56% ± 8% of total cells. In sediments below Beggiatoa mats encircling the center of the HMMV, methanotrophic archaea of the ANME-3 clade dominated the zone of anaerobic methane oxidation. ANME-3 archaea form cell aggregates mostly associated with sulfate-reducing bacteria of the Desulfobulbus (DBB) branch. These ANME-3/DBB aggregates were highly abundant and accounted for up to 94% ± 2% of total microbial biomass at 2 to 3 cm below the surface. ANME-3/DBB aggregates could be further enriched by flow cytometry to identify their phylogenetic relationships. At the outer rim of the mud volcano, the seafloor was colonized by tubeworms (Siboglinidae, formerly known as Pogonophora). Here, both aerobic and anaerobic methane oxidizers were found, however, in lower abundances. The level of microbial diversity at this site was higher than that at the central and Beggiatoa species-covered part of the HMMV. Analysis of methyl-coenzyme M-reductase alpha subunit (mcrA) genes showed a strong dominance of a novel lineage, mcrA group f, which could be assigned to ANME-3 archaea. Our results further support the hypothesis of Niemann et al. (54), that high methane availability and different fluid flow regimens at the HMMV provide distinct niches for aerobic and anaerobic methanotrophs. PMID:17369343

GIS-based technology for marine geohazards in LW3-1 Gas Field of the South China Sea

NASA Astrophysics Data System (ADS)

Su, Tianyun; Liu, Lejun; Li, Xishuang; Hu, Guanghai; Liu, Haixing; Zhou, Lin

2013-04-01

The exploration and exploitation of deep-water oil-gas are apt to be suffered from high-risk geo-hazards such as submarine landslide, soft clay creep, shallow gas, excess pore-water pressure, mud volcano or mud diaper, salt dome and so on. Therefore, it is necessary to survey the seafloor topography, identify the unfavourable geological risks and investigate their environment and mechanism before exploiting the deep-water oil-gas. Because of complex environment, the submarine phenomenon and features, like marine geohazards, can not be recognized directly. Multi-disciplinary data are acquired and analysed comprehensively in order to get more clear understanding about the submarine processes. The data include multi-beam bathymetry data, sidescan sonar images, seismic data, shallow-bottom profiling images, boring data, etc.. Such data sets nowadays increase rapidly to large amounts, but may be heterogeneous and have different resolutions. It is difficult to make good management and utilization of such submarine data with traditional means. GIS technology can provide efficient and powerful tools or services in such aspects as spatial data management, processing, analysis and visualization. They further promote the submarine scientific research and engineering development. The Liwan 3-1 Gas Field, the first deep-water gas field in China, is located in the Zhu II Depression in the Zhujiang Basin along the continental slope of the northern South China Sea. The exploitation of this field is designed to establish subsea wellhead and to use submarine pipeline for the transportation of oil. The deep-water section of the pipeline route in the gas field is to be selected to pass through the northern continental slope of the South China Sea. To avoid huge economic loss and ecological environmental damage, it is necessary to evaluate the geo-hazards for the establishment and safe operation of the pipeline. Based on previous scientific research results, several survey cruises have been carried out with ships and AUV to collect multidisciplinary and massive submarine data such as multi-beam bathymetric data, sidescan sonar images, shallow-bottom profiling images, high-resolution multi-channel seismic data and boring test data. In order to make good use of these precious data, GIS technology is used in our research. Data model is designed to depict the structure, organization and relationship between multi disciplinary submarine data. With these data models, database is established to manage and share the attribute and spatial data effectively. The spatial datasets, such as contours, TIN models, DEM models, etc., can be generated. Some submarine characteristics, such as slope, aspects, curvature, landslide volume, etc., can be calculated and extracted with spatial analysis tools. The thematic map can be produced easily based on database and generated spatial dataset. Through thematic map, the multidisciplinary data spatial relationship can be easily established and provide helpful information for regional submarine geohazards identification, assessments and prediction. The produced thematic map of the LW3-1 Gas Field, reveal the strike of the seafloor topography to be NE to SW. Five geomorphological zones have been divided, which include the outer continental shelf margin zone with sand waves and mega-ripples, the continental slope zone with coral reefs and sand waves, the continental slope zone with a monocline shape, the continental slope zone with fault terraces and the continental slope zone with turbidity current deposits.

Towards an impact assessment of bauxite red mud waste on the knowledge of the structure and functions of bathyal ecosystems: The example of the Cassidaigne canyon (north-western Mediterranean Sea).

PubMed

Dauvin, Jean-Claude

2010-02-01

Since 1967, the alumina plants in the Marseilles area (Barasse and Gardanne) have been discharging the mineral residue (i.e., red mud) resulting from the alkaline processing of bauxite into the submarine Cassidaigne canyon (north-western Mediterranean Sea) through pipes situated at 320-330 m in depth. The Barasse pipe stopped being used in 1988. From 1987 to 1996, many decrees and regulations were promulgated by the French State to rule the conditions under which the Gardanne alumina refinery was authorized to dispose of the bauxite residue in the sea. The refinery was required: (i) to study the hydrodynamic circulation in the Cassidaigne canyon to evaluate the potential dispersion and transport of fine elements discharged into the water mass and their impact on the pelagic ecosystem; (ii) to survey the marine environment every five years to control the expansion and thickness of the red mud deposit and compare the evolution of the benthic macrofauna at representative sampling sites in the environment affected by the red mud discharge with that of reference sites outside of the red mud plume; (iii) to study the effect of the discharge on fishing activities; and (iv) to investigate the toxicity of the red mud, particularly its persistence, accumulation, interaction and effect on the marine ecosystem, paying special attention to the bio-accumulation of chromium and vanadium. A Scientific Committee was created to insure an independent evaluation of the studies promised by the manufacturer in response to the State's regulations. Since the beginning of the 1960s, data have been accumulating on the structure and long-term functioning of the Cassidaigne bathyal ecosystem. This paper presents the collaborative efforts of the State-Manufacturer-Committee triplet and summarizes the main results obtained during the last period's sea campaigns (1991-2007). This paper also illustrates how national regulations concerning manufacturers, such as Gardanne alumina refinery, have provided new knowledge about the structure and functioning of a bathyal ecosystem in the Cassidaigne canyon in the north-western Mediterranean Sea. Copyright 2009 Elsevier Ltd. All rights reserved.

Open Architecture Framework for Improved Early Stage Submarine Design

DTIC Science & Technology

2010-06-01

Figure 12 Data Structure Example – VPH ..................................................................................... 41 Figure 13 SUBSTART Data...in the MIT SMM (e.g. – VPH -VB, pressure hull volume without volume of the in-hull variable ballast). Tables 4 and 5 list the variables by module...MUD1frac FFsurf θ(x,t) V(t) VPH ∆ff VCGLEADs BTf MUDfwd GMt R(x) Vambt VPHguess ∆mbt VCGnsc BTops OBambt ηa tenvsurf Vaux VPH -VB ∆nsc VCGVL

Deep-sea geohazards in the South China Sea

NASA Astrophysics Data System (ADS)

Wu, Shiguo; Wang, Dawei; Völker, David

2018-02-01

Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods. These features include submarine landslides, pockmark fields, shallow free gas, gas hydrates, mud diapirs and earthquake tsunami, which are widely distributed in the continental slope and reefal islands of the South China Sea. Although the study and assessment of geohazards in the South China Sea came into operation only recently, advances in various aspects are evolving at full speed to comply with National Marine Strategy and `the Belt and Road' Policy. The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances. This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.

The 2006 Pingtung Earthquake Doublet Triggered Seafloor Liquefaction: Revisiting the Evidence with Ultra-High-Resolution Seafloor Mapping

NASA Astrophysics Data System (ADS)

Su, C. C.; Chen, T. T.; Paull, C. K.; Gwiazda, R.; Chen, Y. H.; Lundsten, E. M.; Caress, D. W.; Hsu, H. H.; Liu, C. S.

2017-12-01

Since Heezen and Ewing's (1952) classic work on the 1929 Grand Banks earthquake, the damage of submarine cables have provided critical information on the nature of seafloor mass movements or sediment density flows. However, the understanding of the local conditions that lead to particular seafloor failures earthquakes trigger is still unclear. The Decemeber 26, 2006 Pingtung earthquake doublet which occurred offshore of Fangliao Township, southwestern Taiwan damaged 14 submarine cables between Gaoping slope to the northern terminus of the Manila Trench. Local fisherman reported disturbed waters at the head of the Fangliao submarine canyon, which lead to conjectures that eruptions of mud volcanoes which are common off the southwestern Taiwan. Geophysical survey were conducted to evaluate this area which revealed a series of faults, liquefied strata, pockmarks and acoustically transparent sediments with doming structures which may relate to the submarine groundwater discharge. Moreover, shipboard multi-beam bathymetric survey which was conducted at the east of Fangliao submarine canyon head shows over 10 km2 area with maximum depth around 40 m of seafloor subsidence after Pingtung earthquake. The north end of the subsidence is connected to the Fangliao submarine canyon where the first cable failed after Pingtung earthquake. The evidences suggests the earthquake triggered widespeard liquefaction and generated debris flows within Fangliao submarine canyon. In May 2017, an IONTU-MBARI Joint Survey Cruise (OR1-1163) was conducted on using MBARI Mapping AUV and miniROV to revisit the area where the cable damaged after Pingtung earthquake. From newly collected ultra-high-resolution (1-m lateral resolution) bathymetry data, the stair-stepped morphology is observed at the edge of canyon. The comet-shaped depressions are located along the main headwall of the seafloor failure. The new detailed bathymetry reveal details which suggest Fangliao submarine canyon head is preconditioned to failure. Submarine groundwater discharge from the Pingtung Plain and the southern tip of the Central Mountains is inferred to generate elevated pore pressures leaving the area susceptible to liquefaction and failure when triggered by earthquakes.

Outcrop-scale acoustic facies analysis and latest Quaternary development of Hueneme and Dume submarine fans, offshore California

USGS Publications Warehouse

Piper, D.J.W.; Hiscott, R.N.; Normark, W.R.

1999-01-01

The uppermost Quaternary deposits of the Hueneme and Dume submarine fans in the Santa Monica Basin have been investigated using a closed-spaced grid of boomer seismic-reflection profiles, which give vertical resolution of a few tens of centimetres with acoustic penetration to 50 m. Acoustic facies integrated with geometry define six architectural elements, some with discrete subelements that are of a scale that can be recognized in outcrops of ancient turbidite systems. In the Santa Monica Basin, the relationship of these elements to fan morphology, stratigraphy and sediment source is precisely known. The width of upper Hueneme fan valley has been reduced from 5 km since the last glacial maximum to 1 km at present by construction of laterally confined sandy levees within the main valley. The middle fan comprises three main subelements: thick sand deposits at the termination of the fan valley, low-gradient sandy lobes typically 5 km long and < 10 m thick, and scoured lobes formed of alternating sand and mud beds with many erosional depressions. The site of thickest lobe sediment accumulation shifts through time, with each sand bed deposited in a previous bathymetric low (i.e. compensation cycles). The lower fan and basin plain consists of sheet-like alternations of sand and mud with shallow channels and lenses. Variations in the rate of late Quaternary sea level rise initiated changes in sediment facies distribution. At lowstand, and during the approximately 11 ka stillstand in sea level, the Hueneme Fan was fed largely by hyperpycnal flow from the Santa Clara River delta, depositing high sediment waves on the right hand levee and thick sandy lobes on the middle fan. At highstand of sea level, most turbidity currents were generated by failure of silty prodelta muds. In contrast, the smaller Dume Fan was apparently always fed from littoral drift of sand through a single-canyon point source.

Morphodynamic Model of Submarine Canyon Incision by Sandblasting

NASA Astrophysics Data System (ADS)

Zhang, L.; Parker, G.; Izumi, N.; Cartigny, M.; Li, T.; Wang, G.

2017-12-01

Submarine canyons are carved by turbidity currents under the deep sea. As opposed to subaerial canyons, the relevant processes are not easy to observe directly. Turbidity currents are bottom-hugging sediment gravity flows of that can incise or deposit on the seafloor to create submarine canyons or fans. The triggers of turbidity currents can be storms, edge waves, internal waves, canyon wall sapping, delta failure, breaching and hyperpycnal flows. The formation and evolution mechanisms of submarine canyons are similar to those of subaerial canyons, but have substantial differences. For example, sandblasting, rather than wear due to colliding gravel clasts is more likely to be the mechanism of bedrock incision. Submarine canyons incise downward, and often develop meander bends and levees within the canyon, so defining "fairways". Here we propose a simple model for canyon incision. The starting point of our model is the Macro Roughness Saltation Abrasion Alluviation model of Zhang et al. [2015], designed for bedrock incision by gravel clasts in mixed bedrock-alluvial rivers. We adapt this formulation to consider sandblasting as a means of wear. We use a layer-averaged model for turbidity current dynamics. The current contains a mixture of mud, which helps drive the flow but which does not cause incision, and sand, which is the agent of incision. We show that the model can successfully model channel downcutting, and indeed illustrate the early formation of net incisional cyclic steps, i.e. upstream-migrating undulations on the bed associated with transcritical (in the Froude sense) flow. These steps can be expected to abet the process of incision.

Sedimentary Facies of the West Crocker Formation North Kota Kinabalu-Tuaran Area, Sabah, Malaysia

NASA Astrophysics Data System (ADS)

Mohamed, Azfar; Hadi Abd Rahman, Abdul; Suhaili Ismail, Mohd

2016-02-01

Newly outcrops exposed in the West Crocker Formation have led to the detail sedimentolgical analysis of the formation. Eight sedimentary facies have been recognised in which it was divided into three main groups: (1) sand-dominated facies (F1-F2), (2) poorly- sorted unit mixed sand and mud-dominated facies (F3), and (3) mud-dominated facies (F4-F5). These are: F1- graded sandstone (massive to planar laminated), F2-ripple-cross laminated, wavy and convolute lamination sandstone, F3-chaotic beds of mixed sandstone and mudstone blocks and clasts, F4-lenticular bedded of sandstone, and F5-shale. The studies of the formation has come out that it was deposited in a sand-rich submarine fan with specific location located at (1) inner fan channel-levee complex; (2) mid-fan channelised lobes, and (3) outer fan.

Carbonate apron models: Alternatives to the submarine fan model for paleoenvironmental analysis and hydrocarbon exploration

USGS Publications Warehouse

Mullins, H.T.; Cook, H.E.

1986-01-01

Sediment gravity flow deposition along the deep-water flanks of carbonate platforms typically does not produce submarine fans. Rather, wedge-shaped carbonate aprons develop parallel to the adjacent shelf/slope break. The major difference between submarine fans and carbonate aprons is a point source with channelized sedimentation on fans, versus a line source with sheet-flow sedimentation on aprons. Two types of carbonate aprons may develop. Along relatively gentle (< 4??) platform-margin slopes, aprons form immediately adjacent to the shallow-water platform and are referred to as carbonate slope aprons. Along relatively steep (4-15??) platform margin slopes, redeposited limestones accumulate in a base-of-slope setting, by-passing an upper slope via a multitude of small submarine canyons, and are referred to as carbonate base-of-slope aprons. Both apron types are further subdivided into inner and outer facies belts. Inner apron sediments consist of thick, mud-supported conglomerates and megabreccias (Facies F) as well as thick, coarse-grained turbidites (Facies A) interbedded with subordinate amounts of fine-grained, peri-platform ooze (Facies G). Outer apron sediments consist of thinner, grain-supported conglomerates and turbidites (Facies A) as well as classical turbidites (Facies C) with recognizable Bouma divisions, interbedded with approximately equal proportions of peri-platform ooze (Facies G). Seaward, aprons grade laterally into basinal facies of thin, base-cut-out carbonate turbidites (Facies D) that are subordinate to peri-platform oozes (Facies G). Carbonate base-of-slope aprons grade shelfward into an upper slope facies of fine-grained peri-platform ooze (Facies G) cut by numerous small canyons that are filled with coarse debris, as well as intraformational truncation surfaces which result from submarine sliding. In contrast, slope aprons grade shelfward immediately into shoal-water, platform-margin facies without an intervening by-pass slope. The two carbonate apron models presented here offer alternatives to the submarine-fan model for paleoenvironmental analysis and hydrocarbon exploration for mass-transported carbonate facies. ?? 1986.

Giant Scour on Eel Fan, California Records Decadal Trubidite Recurrence Interval

NASA Astrophysics Data System (ADS)

Paull, C. K.; McGann, M.; Edwards, B. D.; Barnes, P.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Sumner, E.; Caress, D. W.

2013-12-01

Analysis of an exceptional exposure of thinly bedded turbidites in the headwall of a giant submarine scour on Eel Submarine Fan reveals that turbidites were being emplaced with a remarkably high frequency during the late Pleistocene to early Holocene. ROV observations, vibracores and push cores show an 87 m thick outcrop of fine-grained turbidites that are between 3 and 40 cm thick. The turbidites are composed of fining-upwards cycles grading from fine or very fine sand through to silty-mud. Within turbidites reversals in grain size occur representing fluctuating flow conditions. An abundance of woody material and shallow dwelling foraminifera within the turbidites demonstrates the flows originated in shallow water. The silty-mud horizons are barren of pelagic foraminifera, suggesting that they are the late stages of turbidites and that intervening hemipelagic material is absent. Twenty-one 14C measurements made on the transported shallow-water foraminifera and wood fragments within eighteen push cores taken from the scarp reveal that the entire 87 m section was deposited 6 to 14 thousand years BP. Shipboard video observations indicate the appearance of the scarp face is similar throughout the exposed face. In a 10 m section with excellent video, 88 turbidites were counted. Assuming that the entire 87 m face comprises the same rhythmic alterations, more than 766 turbidites were deposited during this ~8,000 year interval. This requires a decadal turbidite recurrence interval. As these deposits are downstream of the Eel River, these data have intriguing implications about the enhanced impact of the Eel River during the late Pleistocene and early Holocene.

Effect of inter- and intra-annual thermohaline variability on acoustic propagation

NASA Astrophysics Data System (ADS)

Chu, Peter C.; McDonald, Colleen M.; Kucukosmanoglu, Murat; Judono, Albert; Margolina, Tetyana; Fan, Chenwu

2017-05-01

This paper is to answer the question "How can inter- and intra-annual variability in the ocean be leveraged by the submarine Force?" through quantifying inter- and intra-annual variability in (T, S) fields and in turn underwater acoustic characteristics such as transmission loss, signal excess, and range of detection. The Navy's Generalized Digital Environmental Model (GDEM) is the climatological monthly mean data and represents mean annual variability. An optimal spectral decomposition method is used to produce a synoptic monthly gridded (SMG) (T, S) dataset for the world oceans with 1° ×1° horizontal resolution, 28 vertical levels (surface to 3,000 m depth), monthly time increment from January 1945 to December 2014 now available at the NOAA/NCEI website: http://data.nodc.noaa.gov/cgibin/iso?id=gov.noaa.nodc:0140938. The sound velocity decreases from 1945 to 1975 and increases afterwards due to global climate change. Effect of the inter- and intra-annual (T, S) variability on acoustic propagation in the Yellow Sea is investigated using a well-developed acoustic model (Bellhop) in frequencies from 3.5 kHz to 5 kHz with sound velocity profile (SVP) calculated from GDEM and SMG datasets, various bottom types (silty clay, fine sand, gravelly mud, sandy mud, and cobble or gravel) from the NAVOCEANO`s High Frequency Environmental Algorithms (HFEVA), source and receiver depths. Acoustic propagation ranges are extended drastically due to the inter-annual variability in comparison with the climatological SVP (from GDEM). Submarines' vulnerability of detection as its depth varies and avoidance of short acoustic range due to inter-annual variability are also discussed.

Methanoculleus sediminis sp. nov., a methanogen from sediments near a submarine mud volcano.

PubMed

Chen, Sheng-Chung; Chen, Mei-Fei; Lai, Mei-Chin; Weng, Chieh-Yin; Wu, Sue-Yao; Lin, Saulwood; Yang, Tsanyao F; Chen, Po-Chun

2015-07-01

A mesophilic, hydrogenotrophic methanogen, strain S3Fa(T), was isolated from sediments collected by Ocean Researcher I cruise ORI-934 in 2010 near the submarine mud volcano MV4 located at the upper slope of south-west Taiwan. The methanogenic substrates utilized by strain S3Fa(T) were formate and H2/CO2 but not acetate, secondary alcohols, methylamines, methanol or ethanol. Cells of strain S3Fa(T) were non-motile, irregular cocci, 0.5-1.0 μm in diameter. The surface-layer protein showed an Mr of 128,000.The optimum growth conditions were 37 °C, pH 7.1 and 0.17 M NaCl. The DNA G+C content of the genome of strain S3Fa(T) was 62.3 mol%. Phylogenetic analysis revealed that strain S3Fa(T) was most closely related to Methanoculleus marisnigri JR1(T) (99.3% 16S rRNA gene sequence similarity). Genome relatedness between strain S3Fa(T) and Methanoculleus marisnigri JR1(T) was computed using both genome-to-genome distance analysis (GGDA) and average nucleotide identity (ANI) with values of 46.3-55.5% and 93.08%, respectively. Based on morphological, phenotypic, phylogenetic and genomic relatedness data, it is evident that strain S3Fa(T) represents a novel species of the genus Methanoculleus, for which the name Methanoculleus sediminis sp. nov. is proposed. The type strain is S3Fa(T) ( = BCRC AR10044(T) = DSM 29354(T)).

Hydrate-bearing Submarine Landslides in the Orca Basin, Gulf of Mexico

NASA Astrophysics Data System (ADS)

Sawyer, D.; Mason, A.; Cook, A.; Portnov, A.; Hillman, J.

2017-12-01

The co-occurrence of submarine landslides and hydrate-bearing sediment suggests that hydrates may play a role in landslide triggering and/or the mobility and dynamic characteristics of the submarine landslide. In turn, the removal of large sections of seafloor perturbs the hydrate stability field by removing overburden pressure and disturbing the temperature field. These potential hydrate-landslide feedbacks are not well understood. Here we combine three-dimensional seismic and petrophysical logs to characterize the deposits of submarine landslides that failed from hydrate-bearing sediments in the Orca Basin in the northern Gulf of Mexico. The Orca Basin contains a regionally mappable bottom simulating reflector, hydrate saturations within sands and muds, as well as numerous landslides. In addition, the Orca Basin features a well-known 123 km2 anoxic hypersaline brine pool that is actively being fed by outcropping salt. Lying at the bottom of the brine pool are deposits of submarine landslides. Slope instability in the Orca Basin is likely associated with near-seafloor salt tectonics. The most prominent landslide scar observable on the seafloor has a correlative deposit that now lies at the bottom of the brine pool 11.6 km away. The headwall is amphitheater-shaped with an average height of 80 meters and with only a minor amount of rubble remaining near the headwall. A total of 8.7 km3 of material was removed and deposited between the lower slopes of the basin and the base of the brine pool. Around the perimeter of the landslide headwall, two industry wells were drilled and well logs show elevated resistivity that are likely caused by gas hydrate. The slide deposits have a chaotic seismic facies with large entrained blocks and the headwall area does not retain much original material, which together suggests a relatively mobile style of landslide and therefore may have generated a wave upon impacting the brine pool. Such a slide-induced wave may have sloshed hypersaline water along the basin walls and potentially out of the confining basin. Local chemosynthetic marine communities could have been affected as they were bathed in the brine, which has been previously measured to be a factor of eight higher than normal seawater salinity.

Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

NASA Astrophysics Data System (ADS)

Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

2016-02-01

Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer), overlying 1-3 m of post-dredge deposition that is concentrated along the western wall and center of the pit. The Sandy Point MCDP lies within a clockwise gyre, and its relief may serve as a significant trap of suspended sediment. These findings emphasize the role MCDPs play in sediment dynamics as well as their potential for submarine geohazards.

Characterization of the Spatial and Temporal Variations of Submarine Groundwater Discharge Using Electrical Resistivity and Seepage Measurements

NASA Astrophysics Data System (ADS)

Durand, Josephine Miryam Kalyanie

Submarine groundwater discharge (SGD) encompasses all fluids crossing the sediment/ocean interface, regardless of their origin, composition or driving forces. SGD provides a pathway for terrestrial contaminants that can significantly impact coastal ecosystems. Overexploitation of groundwater resources can decrease SGD which favors seawater intrusion at depth. Understanding SGD is therefore crucial for water quality and resource management. Quantifying SGD is challenging due to its diffuse and heterogeneous nature, in addition to significant spatio-temporal variations at multiple scales. In this thesis, an integrated approach combining electrical resistivity (ER) surveys, conductivity and temperature point measurements, seepage rates using manual and ultrasonic seepage meters, and pore fluid salinities was used to characterize SGD spatio-temporal variations and their implications for contaminant transport at several locations on Long Island, NY. The influence of surficial sediments on SGD distribution was investigated in Stony Brook Harbor. A low-permeability mud layer, actively depositing in the harbor, limits SGD at the shoreline, prevents mixing with seawater and channels a significant volume of freshwater offshore. SGD measured at locations without mud is high and indicates significant mixing between porewater and seawater. A 2D steady-state density-difference numerical model of the harbor was developed using SEAWAT and was validated by our field observations. Temporal variations of SGD due to semi-diurnal tidal forcing were studied in West Neck Bay, Shelter Island, using a 12-hr time-lapse ER survey together with continuous salinity and seepage measurements in the intertidal zone. The observed dynamic patterns of groundwater flux and salinity distribution disagree with published standard transient state numerical models, suggesting the need for developing more specific models of non-homogeneous anisotropic aquifers. SGD distribution and composition were characterized in Forge River, a tidal river that experiences chronic hypoxia due to nitrogen contamination. We found that nitrogen speciation and concentration are linked to different SGD regimes. Near shore sandy zones with high SGD show little nitrate reduction and constitute the major source of nitrogen input to surface waters. Offshore areas rich in silt and organic matter exhibit low SGD and higher denitrification. Dredging activities have altered the sediment distribution and subsequently have created preferential flow paths focusing freshwater discharge into the center of the river.

Mud volcanoes of the Orinoco Delta, Eastern Venezuela

USGS Publications Warehouse

Aslan, A.; Warne, A.G.; White, W.A.; Guevara, E.H.; Smyth, R.C.; Raney, J.A.; Gibeaut, J.C.

2001-01-01

Mud volcanoes along the northwest margin of the Orinoco Delta are part of a regional belt of soft sediment deformation and diapirism that formed in response to rapid foredeep sedimentation and subsequent tectonic compression along the Caribbean-South American plate boundary. Field studies of five mud volcanoes show that such structures consist of a central mound covered by active and inactive vents. Inactive vents and mud flows are densely vegetated, whereas active vents are sparsely vegetated. Four out of the five mud volcanoes studied are currently active. Orinoco mud flows consist of mud and clayey silt matrix surrounding lithic clasts of varying composition. Preliminary analysis suggests that the mud volcano sediment is derived from underlying Miocene and Pliocene strata. Hydrocarbon seeps are associated with several of the active mud volcanoes. Orinoco mud volcanoes overlie the crest of a mud-diapir-cored anticline located along the axis of the Eastern Venezuelan Basin. Faulting along the flank of the Pedernales mud volcano suggests that fluidized sediment and hydrocarbons migrate to the surface along faults produced by tensional stresses along the crest of the anticline. Orinoco mud volcanoes highlight the proximity of this major delta to an active plate margin and the importance of tectonic influences on its development. Evaluation of the Orinoco Delta mud volcanoes and those elsewhere indicates that these features are important indicators of compressional tectonism along deformation fronts of plate margins. ?? 2001 Elsevier Science B.V. All rights reserved.

Cyclic Activity of Mud Volcanoes: Evidences from Trinidad (SE Caribbean)

NASA Astrophysics Data System (ADS)

Deville, E.

2007-12-01

Fluid and solid transfer in mud volcanoes show different phases of activity, including catastrophic events followed by periods of relative quiescence characterized by moderate activity. This can be notably shown by historical data onshore Trinidad. Several authors have evoked a possible link between the frequencies of eruption of some mud volcanoes and seismic activity, but in Trinidad there is no direct correlation between mud eruptions and seisms. It appears that each eruptive mud volcano has its own period of catastrophic activity, and this period is highly variable from one volcano to another. The frequency of activity of mud volcanoes seems essentially controlled by local pressure regime within the sedimentary pile. At the most, a seism can, in some cases, activate an eruption close to its term. The dynamics of expulsion of the mud volcanoes during the quiescence phases has been studied notably from temperature measurements within the mud conduits. The mud temperature is concurrently controlled by, either, the gas flux (endothermic gas depressurizing induces a cooling effect), or by the mud flux (mud is a vector for convective heat transfer). Complex temperature distribution was observed in large conduits and pools. Indeed, especially in the bigger pools, the temperature distribution characterizes convective cells with an upward displacement of mud above the deep outlet, and ring-shaped rolls associated with the burial of the mud on the flanks of the pools. In simple, tube-like shaped, narrow conduits, the temperature is more regular, but we observed different types of profiles, with either downward increasing or decreasing temperatures. If the upward flow of mud would be regular, we should expect increasing temperatures and progressively decreasing gradient with depth within the conduits. However, the variable measured profiles from one place to another, as well as time-variable measured temperatures within the conduits and especially, at the base of the conduits, shows that the fluid flow expelled by the studied mud volcanoes is not constant but highly variable through short time-periods. We notably observed very short time-period cyclic variations with a frequency of about 10 minutes. These high frequencies temperature changes could be related to the dynamics of two-phase flows (gas and mud) through the mud volcano conduits. We also observed locally a significant daily changes of the temperature of the expelled mud which shows also that the mud flux is changing very rapidly from one day to another.

Pozzolanic Activity Assessment of LUSI (LUmpur SIdoarjo) Mud in Semi High Volume Pozzolanic Mortar

PubMed Central

Hardjito, Djwantoro; Antoni; Wibowo, Gunadi M.; Christianto, Danny

2012-01-01

LUSI mud obtained from the mud volcano in Sidoarjo, Indonesia, is a viable aluminosilicate material to be utilized as pozzolanic material. LUSI is an abbreviation of the local name of the mud, i.e., Lumpur Sidoarjo, meaning Sidoarjo mud. This paper reports the results of an investigation to assess the pozzolanic activity of LUSI mud, especially in semi high volume pozzolanic mortar. In this case, the amount of mud incorporated is between 30% to 40% of total cementitious material, by mass. The content of SiO2 in the mud is about 30%, whilst the total content of SiO2, Fe2O3 and Al2O3 is more than 70%. Particle size and degree of partial cement replacement by treated LUSI mud affect the compressive strength, the strength activity index (SAI), the rate of pozzolanic activity development, and the workability of mortar incorporating LUSI mud. Manufacturing semi high volume LUSI mud mortar, up to at least 40% cement replacement, is a possibility, especially with a smaller particle size of LUSI mud, less than 63 μm. The use of a larger percentage of cement replacement by LUSI mud does not show any adverse effect on the water demand, as the flow of the fresh mortar increased with the increase of percentage of LUSI mud usage.

Neogene marine sedimentary record of the Gulf of Alaska: from the glaciers to the distal submarine fan systems

NASA Astrophysics Data System (ADS)

Ridgway, K. D.; Bahlburg, H.; Childress, L. B.; Cowan, E. A.; Forwick, M.; Moy, C. M.; Müller, J.; Ribeiro, F.; Gupta, S.; Gulick, S. P.; Jaeger, J. M.

2013-12-01

The marine sedimentary record of Miocene to Pleistocene tectonics and glaciation is well preserved along the southern Alaska convergent margin. This margin is well suited for linking proximal to distal sediment transport processes because sediment is being generated by glacial erosion in the highest coastal mountain range on earth and subsequently being transported to the Aleutian subduction zone. We will discuss the sedimentary record from two end members of this system: (1) the proximal marine record now exposed onshore in the high peaks of the coastal ranges, and (2) the offshore distal record preserved in the Surveyor submarine fan system that was cored during the 2013 IODP Expedition 341. Onshore the Miocene non-glacial strata are represented by the Poul Creek Fm. This unit is 2000 m thick and in its upper part consists of mudstone, thin sandstone beds (10-30 cm thick), and thick bedded (1-2 m) highly bioturbated green sandstone beds that contain hummocky stratification. We interpret this unit as being deposited mainly in marine shelf environments. A gradational contact between the Poul Creek and the overlying upper Miocene-Pleistocene Yakataga Formation is marked by a transition to mudstone, thick bedded sandstone and glacial diamictite. This transition to glacial dominated deposition is interpreted to have occurred around 5 Ma based on previous studies. The onshore glacimarine strata are 5 km thick and grade up section from submarine fan to marine shelf strata. In the distal submarine fan record at IODP Site U1417, the upper Miocene strata in the lower part of the Site consist of 340 m of highly bioturbated gray to green mud interbedded with coarse sand and sandy diamict. These coarse-grained units are lithic rich with mainly sedimentary, volcanic, and coal clasts. We interpret these units as being derived from coal-bearing sedimentary strata exposed in the onshore thrust belt. These facies are interbedded with diatom ooze; we interpret this combination of facies as representing deposition of coarse-grained detritus originating from sedimentary gravity flows followed by longer periods of hemipelagic deposition. The first clear record of glacial sediment input in the distal submarine fan environment is late Pliocene - early Pleistocene muddy diamict beds that probably are the products of ice-rafting. This unit is about 30 m in thickness. The overlying 260 m of the core are mainly dark gray mud with thin beds of volcanic ash and sand/silt beds. Lonestones are common and are mainly argillite and metasiltstone clasts suggesting at least a component of sediment derivation from onshore metamorphosed parts of the Mesozoic accretionary prism. In general, the overall Neogene sedimentary record in both the proximal and distal marine settings appears to be similar but requires a sediment link between the proximal strata deposited on the Yakutat microplate and the Surveyor fan system deposited on the Pacific Plate.

Recent Findings on Tsunami Hazards in the Makran Subduction Zone, NW Indian Ocean

NASA Astrophysics Data System (ADS)

Heidarzadeh, M.; Satake, K.

2014-12-01

We present recent findings on tsunami hazards in the Makran subduction zone (MSZ), NW Indian Ocean, based on the results of tsunami source analyses for two Makran tsunamis of 1945 and 2013. A re-analysis of the source of the 27 November 1945 tsunami in the MSZ showed that the slip needs to be extended to deep waters around the depth contour of 3000 m in order to reproduce the observed tide gauge waveforms at Karachi and Mumbai. On the other hand, coastal uplift report at Ormara (Pakistan) implies that the source fault needs to be extended inland. In comparison to other existing fault models, our fault model is longer and includes a heterogeneous slip with larger maximum slip. The recent tsunami on 24 September 2013 in the Makran region was triggered by an inland Mw 7.7 earthquake. While the main shock and all aftershocks were located inland, a tsunami with a dominant period of around 12 min was recorded on tide gauges and a DART station. We examined different possible sources for this tsunami including a mud volcano, a mud/shale diapir, and a landslide/slump through numerical modeling. Only a submarine slump with a source dimension of 10-15 km and a thickness of around 100 m, located 60-70 km offshore Jiwani (Pakistan) at the water depth of around 2000m, was able to reasonably reproduce the observed tsunami waveforms. In terms of tsunami hazards, analyses of the two tsunamis provide new insights: 1) large runup heights can be generated in the coastal areas due to slip in deep waters, and 2) even an inland earthquake may generate tsunamigenic submarine landslides.

Origins of hydrocarbon gas seeping out from offshore mud volcanoes in the Nile delta

NASA Astrophysics Data System (ADS)

Prinzhofer, Alain; Deville, Eric

2013-04-01

This paper discusses the origin of gas seepages (free gas or dissolved gas in ground water or brine) sampled with the Nautile submarine during the Nautinil cruise at the seafloor of the deep water area of the Nile turbiditic system on different mud volcanoes and brine pools. Generally, the gas is wet and includes C1, C2, C3, iC4, nC4, CO2. These gas samples show no evidence of biodegradation which is not the case of the gas present in the deep hydrocarbon accumulations at depth. It indicates that the gas expelled by the mud volcanoes is not issued from direct leakages from deep gas fields. The collected gas samples mainly have a thermogenic origin and show different maturities. Some samples show very high maturities indicating that these seepages are sourced from great depths, below the Messinian salt. Moreover, the different chemical compositions of the gas samples reflect not only differences in maturity but also the fact that the gas finds its origin in different deep source rocks. Carbon dioxide has an organic signature and cannot result from carbonate decomposition or mantle fluids. The crustal-derived radiogenic isotopes show that the analyzed gas samples have suffered a fractionation processes after the production of the radiogenic isotopes, due either to oil occurrence at depth interacting with the flux of gas, and/or fractionation during the fluid migration.

Geomorphologic Features and Age Estimation of Submarine Landslides in the Southwestern Colombian Caribbean

NASA Astrophysics Data System (ADS)

Idarraga Garcia, J.; Vargas-Jimenez, C. A.

2013-05-01

We analyzed ~17000 km2 of high-resolution-bathymetric data in the southwestern Caribbean Sea of Colombia between the La Aguja Submarine Canyon (LASC) and the Gulf of Urabá. The data allowed us to identify and describe submarine landslides and to calculate their ages based on scarp dating by using numerical solutions of the diffusion equation. The ages are presented in terms of the constant k of diffusivity due to the absence of well constrained values for submarine environments. In the northeastern sector of the study area we differentiated 31 submarine failures associated with the LASC flanks, between 1200 and 3285 m depth, with escarpments slopes ranging between 6.1° and 36.8°; estimated ages suggest ranges between ~407 and ~103.5 k (m2). Triggering mechanisms of these landslides are close related to the occurrence of earthquakes originated in the convergence zone of the Santa Marta and Oca fault systems, and to the flanks instabilities product of the mud diapirism phenomena that is present in the area. In the central sector of the study zone, the continental margin is dominated by the presence of the Magdalena Submarine Fan (MSF). Here, most of the submarine failures are disintegrative (i.e. with no obvious deposit near or at the base of the scar) and all are related to a system of canyons belonging to the Magdalena turbidite system and to an abrupt slope break at the border of the continental shelf. Scarp dating suggests a wide range of ages fluctuating between ~207.1 and ~146427.8 k (m2). Landslides at southernmost sector of the study zone are mainly associated to anticline-related ridges of the Sinú Accretionary Prism. These ridges are structural highs cut by channels and canyons, and are associated with slopes of 10°-25°. In many cases, the failures are disintegrative and it is probable that the associated landslide deposits are buried by subsequent sediments related to broad fans forming in the mouth of channels and canyons. Additionally, some cohesive landslides identified exhibit blocky deposits with rubbles up to 50 m high and runout distances between 3.6 and 11 km. Ages of these failures range between ~182.9 and ~15476.3 k (m2)

Sea level controls on the textural characteristics and depositional architecture of the Hueneme and associated submarine fan systems, Santa Monica Basin, California

USGS Publications Warehouse

Normark, W.R.; Piper, D.J.W.; Hiscott, R.N.

1998-01-01

Hueneme and Dume submarine fans in Santa Monica Basin consist of sandy channel and muddy levee facies on the upper fan. lenticular sand sheets on the middle fan. and thinly bedded turbidite and hemipelagic facies elsewhere. Fifteen widely correlatable key seismic reflections in high-resolution airgun and deep-towed boomer profiles subdivide the fan and basin deposits into time-slices that show different thickness and seismic-facies distributions, inferred to result from changes in Quaternary sea level and sediment supply. At times of low sea level, highly efficient turbidity currents generated by hyperpycnal flows or sediment failures at river deltas carry sand well out onto the middle-fan area. Thick, muddy flows formed rapidly prograding high levees mainly on the western (right-hand) side of three valleys that fed Hueneme fan at different times: the most recently active of the lowstand fan valleys. Hueneme fan valley, now heads in Hueneme Canyon. At times of high sea level, fans receive sand from submarine canyons that intercept littoral-drift cells and mixed sediment from earthquake-triggered slumps. Turbidity currents are confined to 'underfit' talweg channels in fan valleys and to steep, small, basin-margin fans like Dume fan. Mud is effectively separated from sand at high sea level and moves basinward across the shelf in plumes and in storm-generated lutite flows, contributing to a basin-floor blanket that is locally thicker than contemporary fan deposits and that onlaps older fans at the basin margin. The infilling of Santa Monica Basin has involved both fan and basin-floor aggradation accompanied by landward and basinward facies shifts. Progradation was restricted to the downslope growth of high muddy levees and the periodic basinward advance of the toe of the steeper and sandier Dume fan. Although the region is tectonically active, major sedimentation changes can be related to eustatic sea-level changes. The primary controls on facies shifts and fan growth appear to be an interplay of texture of source sediment, the efficiency with which turbidity currents transport sand, and the effects of delta distributary switching, all of which reflect sea-level changes.

A Gradually Varied Approach to Model Turbidity Currents in Submarine Channels

NASA Astrophysics Data System (ADS)

Bolla Pittaluga, M.; Frascati, A.; Falivene, O.

2018-01-01

We develop a one-dimensional model to describe the dynamics of turbidity current flowing in submarine channels. We consider the flow as a steady state polydisperse suspension accounting for water detrainment from the clear water-turbid interface, for spatial variations of the channel width and for water and sediment lateral overspill from the channel levees. Moreover, we account for sediment exchange with the bed extending the model to deal with situations where the current meets a nonerodible bed. Results show that when water detrainment is accounted for, the flow thickness becomes approximately constant proceeding downstream. Similarly, in the presence of channel levees, the flow tends to adjust to channel relief through the lateral loss of water and sediment. As more mud is spilled above the levees relative to sand, the flow becomes more sand rich proceeding downstream when lateral overspill is present. Velocity and flow thickness predicted by the model are then validated by showing good agreement with laboratory observations. Finally, the model is applied to the Monterey Canyon bathymetric data matching satisfactorily the December 2002 event field measurements and predicting a runout length consistent with observations.

Base surge in recent volcanic eruptions

USGS Publications Warehouse

Moore, J.G.

1967-01-01

A base surge, first identified at the Bikini thermonuclear undersea explosion, is a ring-shaped basal cloud that sweeps outward as a density flow from the base of a vertical explosion column. Base surges are also common in shallow underground test explosions and are formed by expanding gases which first vent vertically and then with continued expansion rush over the crater lip (represented by a large solitary wave in an underwater explosion), tear ejecta from it, and feed a gas-charged density flow, which is the surge cloud. This horizontally moving cloud commonly has an initial velocity of more than 50 meters per second and can carry clastic material many kilometers. Base surges are a common feature of many recent shallow, submarine and phreatic volcanic eruptions. They transport ash, mud, lapilli, and blocks with great velocity and commonly sandblast and knock down trees and houses, coat the blast side with mud, and deposit ejecta at distances beyond the limits of throw-out trajectories. Close to the eruption center, the base surge can erode radial channels and deposit material with dune-type bedding. ?? 1967 Stabilimento Tipografico Francesco Giannini & Figli.

Slippiń and Slidiń: Capturing the Earth in Motion below the Seafloor

NASA Astrophysics Data System (ADS)

Strasser, M.

2017-12-01

Since the beginning of ocean drilling, sampling and dating seismically imaged tectono-stratigraphic sections and recovering rocks from active faults of marine plate-boundary systems has advanced our understanding of subduction zone structures and evolution. It further evidenced the dynamic nature of deformation, fluid flow and fluxes within such systems. With the advancement in developing borehole observatories, monitoring data is increasingly becoming available to analyze and quantify the dynamic processes, such as those leading to and resulting from earthquakes, slides and tsunamis. Combined with knowledge gained from seismological studies, IODP drilling efforts at Costa Rica, Hikurangi, Japan Trench, Nankai and Sumatra margins contribute invaluable observatory data and core samples, the analyses and derived research results of which are fundamentally changing the way fault slip behavior, seafloor instability and tsunamigenesis are understood. Short instrumental records, however, limit our perspective of maximum magnitude and recurrence of such submarine geohazard processes. Examining past events expressed as sedimentary or geochemical perturbations preserved in the marine record provides IODP the key to address this challenge: Recent efforts included sampling mass-transport deposits to study causes and consequences of submarine slides. For the Nankai accretionary margin, we documented the submarine landslide history spanning ˜2.5 million years. The modes and scales of slides were linked to the different morphotectonic settings in which they occurred. The timing of major slides hints at climate preconditioning for sediment instability and reveals that margin destabilization does not occur systematically during all megathrust earthquakes. However, new observation after recent earthquakes and studies using lakes as model basins discovered a new mode of dynamic earthquake ground motion response for surficial (<5-10 cm) seafloor sediments. This can trigger remobilization of the surficial, mostly fine-grained, young and organic carbon-rich sediments over large areas into terminal basins, where the stratigraphic record of respective mud turbidities provides paleoseismic event records of high continuity and documents event-triggered carbon export the deep sea.

Removal of hexavalent chromium by using red mud activated with cetyltrimethylammonium bromide.

PubMed

Li, Deliang; Ding, Ying; Li, Lingling; Chang, Zhixian; Rao, Zhengyong; Lu, Ling

2015-01-01

The removal of hexavalent chromium [Cr(VI)] from aqueous solution by using red mud activated with cetyltrimethylammonium bromide (CTAB) was studied. The optimum operation parameters, such as CTAB concentration, pH values, contact time, and initial Cr(VI) concentration, were investigated. The best concentration of CTAB for modifying red mud was found to be 0.50% (mCTAB/VHCl,0.6 mol/L). The lower pH (<2) was found to be much more favourable for the removal of Cr(VI). Red mud activated with CTAB can greatly improve the removal ratio of Cr(VI) as high as four times than that of original red mud. Adsorption equilibrium was reached within 30 min under the initial Cr(VI) concentration of 100 mg L(-1). The isotherm data were analysed using Langmuir and Freundlich models. The adsorption of Cr(VI) on activated red mud fitted well to the Langmuir isotherm model, and the maximum adsorption capacity was estimated as 22.20 mg g(-1) (Cr/red mud). The adsorption process could be well described using the pseudo-second-order model. The result shows that activated red mud is a promising agent for low-cost water treatment.

Forecasting Ocean Acidification in the coastal waters of the Pacific Northwest

NASA Astrophysics Data System (ADS)

Siedlecki, S. A.; Alin, S. R.; Feely, R. A.; Hermann, A. J.; Bednarsek, N.; Nguyen, T.; Officer, S.; Kaplan, I.; Bond, N.; Newton, J.; Fisher, J. L.; Morgan, C.; Saenger, C.

2016-12-01

The co-occurrence of submarine landslides and hydrate-bearing sediment suggests that hydrates may play a role in landslide triggering and/or the mobility and dynamic characteristics of the submarine landslide. In turn, the removal of large sections of seafloor perturbs the hydrate stability field by removing overburden pressure and disturbing the temperature field. These potential hydrate-landslide feedbacks are not well understood. Here we combine three-dimensional seismic and petrophysical logs to characterize the deposits of submarine landslides that failed from hydrate-bearing sediments in the Orca Basin in the northern Gulf of Mexico. The Orca Basin contains a regionally mappable bottom simulating reflector, hydrate saturations within sands and muds, as well as numerous landslides. In addition, the Orca Basin features a well-known 123 km2 anoxic hypersaline brine pool that is actively being fed by outcropping salt. Lying at the bottom of the brine pool are deposits of submarine landslides. Slope instability in the Orca Basin is likely associated with near-seafloor salt tectonics. The most prominent landslide scar observable on the seafloor has a correlative deposit that now lies at the bottom of the brine pool 11.6 km away. The headwall is amphitheater-shaped with an average height of 80 meters and with only a minor amount of rubble remaining near the headwall. A total of 8.7 km3 of material was removed and deposited between the lower slopes of the basin and the base of the brine pool. Around the perimeter of the landslide headwall, two industry wells were drilled and well logs show elevated resistivity that are likely caused by gas hydrate. The slide deposits have a chaotic seismic facies with large entrained blocks and the headwall area does not retain much original material, which together suggests a relatively mobile style of landslide and therefore may have generated a wave upon impacting the brine pool. Such a slide-induced wave may have sloshed hypersaline water along the basin walls and potentially out of the confining basin. Local chemosynthetic marine communities could have been affected as they were bathed in the brine, which has been previously measured to be a factor of eight higher than normal seawater salinity.

Did the Mississippian Lodgepole buildup at Dickinson Field (North Dakota) form as a gas seep ({open_quotes}vent{close_quotes}) community?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Longman, M.W.

1996-10-01

The Lower Mississippian Lodgepole carbonate buildup reservoir at Dickinson Field in Stark County, North Dakota, has been widely reported as being a Waulsortian (or Waulsortian-like) mound. The term {open_quotes}Waulsortian mound{close_quotes} is used for a variety of Early Mississippian carbonate buildups that share a number of features including an abundance of carbonate mud, a {open_quotes}framework{close_quotes} of organisms such as fenestrate bryozoans and crinoids that tended to trap or baffle sediment, and a general absence of marine-cemented reef framework. Although the age of the Lodgepole mound at Dickinson Field qualifies it to be a Waulsortian mound, petrographic study of cores reveals thatmore » the reservoir rocks are quite unlike those in true Waulsortian mounds. Instead of being dominated by carbonate mud, the Lodgepole mound core is dominated by marine cement. Furthermore, ostracods and microbial limestones are common in the mound core where they occur with crinoid debris and small amounts of bryozoan, coral, and brachiopod debris. The abundant microbial limestones and marine cement indicate that the Dickinson mound formed as a lithified reef on the sea floor rather than as a Waulsortian mud mound. The microbial limestones, marine cement, and common ostracods in the mount core, and the fact that the mound nucleated almost directly o top of the Bakken Shale, suggest that the Dickinson Lodgepole mound formed at the site of a submarine spring and gas seep.« less

Paraformaldehyde-Resistant Starch-Fermenting Bacteria in “Starch-Base” Drilling Mud

PubMed Central

Myers, G. E.

1962-01-01

Starch-fermenting bacteria were found in each of 12 samples of nonfermenting starch-base drilling mud examined. Of the 12 samples, 3 contained very active starch-fermenting gram-positive spore-bearing bacilli closely resembling Bacillus subtilis. Similar active starch-fermenting bacteria were found in fermenting starch-base drilling mud and in corn starch and slough water used to prepare such mud. The active starch-fermenting microorganisms completely hydrolyzed 1% (w/v) corn starch within 24 hr at 37.5 C. The active starch-fermenting bacteria isolated from fermenting drilling mud were capable of surviving 12 hr of continuous exposure to 0.1% (w/w) paraformaldehyde or 1 hr of continuous exposure to 0.5% (w/w) paraformaldehyde, with no diminution in starch-fermenting ability. The same organisms fermented starch after 3 hr of continuous exposure to 0.5% (w/w) paraformaldehyde, but not after 4 hr of exposure. The phenomenon of rapid disappearance of paraformaldehyde from fermenting drilling mud was observed in the laboratory using a modified sodium sulfite test. Paraformaldehyde, initially present in a concentration of 0.192 lb per barrel of mud, completely disappeared in 9 hr at 22 to 23 C. A significant decrease in paraformaldehyde concentration was detected 0.5 hr after preparation of the mud. It is suggested that the presence of relatively high concentrations of ammonia and chloride in the mud may facilitate the disappearance of paraformaldehyde. The failure of 0.1% (w/w) paraformaldehyde to inhibit the strong starch-fermenting microorganisms isolated from fermenting drilling mud, and the rapid disappearance of paraformaldehyde from the mud, explains the fermentation of starch which occurred in this mud, despite the addition of paraformaldehyde. PMID:13936949

Limitations of microbial hydrocarbon degradation at the Amon Mud Volcano (Nile Deep Sea Fan)

NASA Astrophysics Data System (ADS)

Felden, J.; Lichtschlag, A.; Wenzhöfer, F.; de Beer, D.; Feseker, T.; Pop Ristova, P.; de Lange, G.; Boetius, A.

2013-01-01

The Amon mud volcano (MV), located at 1250 m water depth on the Nile Deep Sea Fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulphate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition and microbial activities over three years, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulphide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. Furthermore, within three years, cell numbers and hydrocarbon degrading activity increased at the gas-seeping sites. The low microbial activity in the hydrocarbon-vented areas of Amon mud volcano is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer mud volcano area is limited by hydrocarbon transport.

Mineralogy of Gas Hydrate Bearing Sediment in Green Canyon Block 955 Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Heber, R.; Kinash, N.; Cook, A.; Sawyer, D.; Sheets, J.; Johnson, J. E.

2017-12-01

Natural gas hydrates are of interest as a future hydrocarbon source, however, the formation and physical properties of such systems are not fully understood. In May 2017, the University of Texas drilled two holes in Green Canyon Block 955, northern Gulf of Mexico to collect pressurized core from a thick, 100 m accumulation of gas hydrate in a silt dominated submarine canyon levee system. The expedition, known as UT-GOM2-01, collected 21, 10-m pressure cores from Holes H002 and H005. Approximately half of the cores successfully pressurized and were fully recovered. Unsuccessful cores that did not pressurize generally had low core recovery. By analyzing the sediment composition in known gas hydrate reservoirs, we can construct a more detailed picture of how and why gas hydrates accumulate, as mineralogy can affect physical properties such as porosity and permeability as well as geophysical measurements such as resistivity. Using X-ray diffraction (XRD) on bulk sediment powders, we determined the bulk mineralogy of the samples. Moreover, we investigated drilling mud contamination using XRD and light optical analysis. In some cores, contamination was easily recognized visually as dense sludge between the core barrel and the recovered sediment core, however drilling mud is best observed both along the liner and interbedded within the sediment on X-ray computed tomography scans. To fully identify the presence and influence of drilling mud, we use XRD to analyze samples on cores collected both while drilling mud was used in hole and when only seawater was used in hole and consider the density anomalies observed on the XCT scans. The preliminary XRD light optical microscopy results show that the silt-dominated reservoir is primarily composed of quartz, with minor alkali feldspar, amphibole, muscovite, dolomite, and calcite. Samples from intervals with suspected drilling mud contamination show a similar composition, but with the addition of barite, a common component in drilling mud. Understanding why contamination occurs will improve the coring process and ensure maximum recovery in the future. The XRD data also show the presence of 7-angstrom clay minerals, most likely chlorite and serpentine, but more analysis is required in order to verify the identification and to establish relative abundances of each mineral.

Geoloogic slip on offshore San Clemente fault, Southern California, understated in GPS data

NASA Astrophysics Data System (ADS)

Legg, M. R.

2005-12-01

The San Clemente fault offshore southern California exhibits prominent geomorphic evidence of major late Quaternary right-slip. Like the San Andreas fault, where modern Pacific-North America transform motion is focused, the San Clemente fault stretches more than 700 km along the continental margin with a well-defined principal displacement zone (PDZ). Lateral offset is generally concentrated in a zone less than about 1 km wide, and linear seafloor fault scarps cutting across active submarine fans and basin-filling turbidites demonstrate Holocene activity. Dextral offset of middle Miocene circular crater structures suggest as much as 60 km of Neogene and younger displacement. Offset submarine fan depositional features suggest a rate of about 4-7 mm/yr of late Quaternary slip. Nearly 75 years of seismograph recording in southern California registered at least three moderate (M~6) earthquakes, activity which exceeds that of the Elsinore fault with a similar measured slip rate. Geodetic data based only on a few decades of GPS observations have been interpreted to show less than 1 mm/yr right-slip on the San Clemente fault, whereas larger rates, of about 5-10 mm/yr are described in the Inner Borderland between Catalina Island and the coast. Extrapolations of data from GPS stations on the Pacific Plate offshore Baja California also suggest larger rates west of San Clemente Island. Because there are few offshore locations (islands) for GPS observations, and San Clemente Island is likely within the broader zone of deformation of its namesake fault, these data miss the full slip rate. Seafloor observations from submersible discovered youthful fault scarps in turbidite muds that are inferred to represent large prehistoric earthquakes, (M~7). The potential for large offshore earthquakes, with tsunami generation that would affect the heavily populated adjacent coastal areas underscores the importance of resolving the slip rate and quantifying the hazard potential.

Submarine landslides in the Santa Barbara Channel as potential tsunami sources

USGS Publications Warehouse

Greene, H. Gary; Murai, L.Y.; Watts, P.; Maher, N.A.; Fisher, M.A.; Paull, C.E.; Eichhubl, P.

2006-01-01

Recent investigations using the Monterey Bay Aquarium Research Institutes (MBARI) Remotely Operated Vehicles (ROVs) "Ventana" and "Tiburon" and interpretation of MBARI's EM 300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. Of particular concern is the large (130 km2) Goleta landslide complex located off Coal Oil Point near the town of Goleta, that measures 14.6-km long extending from a depth of 90 m to nearly 574 m deep and is 10.5 km wide. We estimate that approximately 1.75 km3 has been displaced by this slide during the Holocene. This feature is a complex compound submarine landslide that contains both surfical slump blocks and mud flows in three distinct segments. Each segment is composed of a distinct head scarp, down-dropped head block and a slide debris lobe. The debris lobes exhibit hummocky topography in the central areas that appear to result from compression during down slope movement. The toes of the western and eastern lobes are well defined in the multibeam image, whereas the toe of the central lobe is less distinct. Continuous seismic reflection profiles show that many buried slide debris lobes exist and comparison of the deformed reflectors with ODP Drill Site 149, Hole 893 suggest that at least 200 000 years of failure have occurred in the area (Fisher et al., 2005a). Based on our interpretation of the multibeam bathymetry and seismic reflection profiles we modeled the potential tsunami that may have been produced from one of the three surfical lobes of the Goleta slide. This model shows that a 10 m high wave could have run ashore along the cliffs of the Goleta shoreline. Several other smaller (2 km2 and 4 km2) slides are located on the northern flank of the Santa Barbara Basin, both to the west and east of Goleta slide and on the Concepcion fan along the western flank of the basin. One slide, named the Gaviota slide, is 3.8 km2, 2.6 km long and 1.7 km wide. A distinct narrow scar extends from near the eastern head wall of this slide for over 2 km eastward toward the Goleta slide and may represent either an incipient failure or a remnant of a previous failure. Push cores collected within the main head scar of this slide consisted of hydrogen sulfide bearing mud, possibly suggesting active fluid seepage and a vibra-core penetrated ???50 cm of recent sediment overlying colluvium or landslide debris confirming the age of ???300 years as proposed by Lee et al. (2004). However, no seeps or indications of recent movement were observed during our ROV investigation within this narrow head scar indicating that seafloor in the scar is draped with mud. ?? 2006 Author(s). This work is licensed under a Creative Commons License.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lagunova, I.A.

A characteristic feature of the products of mud-volcano activity in the Kerch-Taman region is their high boron content. Distribution of boron in waters of mud volcanoes is characterized by restriction of anomalously high concentrations of boron to mud volcanoes actively operating at the present time in general, and to the most active period of operation of the individual volcano; there is a direct correlation between boron and the hydrocarbonate ion (r/sub B//HCO/sub 3// = 0.5), and between boron and carbon dioxide from the mud-volcano gases (r/sub B//CO/sub 2// = 0.4). The correlation is lacking between boron and mineralization, and betweenmore » boron and chlorine, the correlation is close to inverse. A spatial connection between areas of development of mud volcanism and belts of boron mineralization has been established. Anomalously high boron concentrations in the products of mud volcanism in the Kerch-Taman region are part of the overall increased boron capacity of the Crimea and the Caucasus, which has been controlled by recent magmatic activity.« less

Linked halokinesis and mud volcanism at the Mercator mud volcano, Gulf of Cadiz

NASA Astrophysics Data System (ADS)

Perez-Garcia, Carolina; Berndt, Christian; Klaeschen, Dirk; Mienert, Jürgen; Haffert, Laura; Depreiter, Davy; Haeckel, Matthias

2011-05-01

Mud volcanoes are seafloor expressions of focused fluid flow that are common in compressional tectonic settings. New high-resolution 3-D seismic data from the Mercator mud volcano (MMV) and an adjacent buried mud volcano (BMV) image the internal structure of the top 800 m of sediment at both mud volcanoes, revealing that both are linked and have been active episodically. The total volumes of extruded mud range between 0.15 and 0.35 km3 and 0.02-0.05 km3 for the MMV and the BMV, respectively. The pore water composition of surface sediment samples suggests that halokinesis has played an important role in the evolution of the mud volcanoes. We propose that erosion of the top of the Vernadsky Ridge that underlies the mud volcanoes activated salt movement, triggering deep migration of fluids, dissolution of salt, and sediment liquefaction and mobilization since the end of the Pliocene. Since beginning of mud volcanism in this area, the mud volcanoes erupted four times while there was only one reactivation of salt tectonics. This implies that there are other mechanisms that trigger mud eruptions. The stratigraphic relationship of mudflows from the MMV and BMV indicates that the BMV was triggered by the MMV eruptions. This may either be caused by loading-induced hydrofracturing within the BMV or due to a common feeder system for both mud volcanoes. This study shows that the mud volcanoes in the El Arraiche mud volcano field are long-lived features that erupt with intervals of several tens of thousands of years.

Biological properties of mud extracts derived from various spa resorts.

PubMed

Spilioti, Eliana; Vargiami, Margarita; Letsiou, Sophia; Gardikis, Konstantinos; Sygouni, Varvara; Koutsoukos, Petros; Chinou, Ioanna; Kassi, Eva; Moutsatsou, Paraskevi

2017-08-01

Spa resorts are known for thousands of years for their healing properties and have been empirically used for the treatment of many inflammatory conditions. Mud is one of the most often used natural materials for preventive, healing and cosmetic reasons and although it has been used since the antiquity, little light has been shed on its physical, chemical and biological properties. In this study we examined the effect of mud extracts on the expression of adhesion molecules (CAMs) by endothelial cells as well as their effects on monocyte adhesion to activated endothelial cells. Most of mud extracts inhibited the expression of VCAM-1 by endothelial cells and reduced monocyte adhesion to activated endothelial cells, indicating a potent anti-inflammatory activity. Furthermore, the mud extracts were tested for their antimicrobial activity; however, most of them appeared inactive against S. aureus and S. epidermidis. One of the mud extracts (showing the best stabilization features) increased significantly the expression of genes involved in cell protection, longevity and hydration of human keratinocytes, such as, collagen 6A1, forkhead box O3, sirtuin-1, superoxide dismutase 1 and aquaporin-3. The present study reveals that mud exerts important beneficial effects including anti-inflammatory and anti-aging activity as well as moisturizing effects, implicating important cosmeceutical applications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cross, S.L.; Lighty, R.G.

Coral-rudist reefs of the Lower Cretaceous Mural limestone, southeastern Arizona, show a pronounced relationship between specific reef facies, primary porosity, and early submarine diagenesis. These large open-shelf reefs differ from the well-studied low-relief rudist buildups, and provide an alternate analog for many Cretaceous reef reservoirs. Arizona buildups have diverse corals, high depositional relief, and a well-developed facies zonation from fore reef to back reef: skeletal grainstone talus, muddy fore reef with branching and lamellar corals, massive reef crest with abundant lamellar corals and sandy matrix, protected thickets of delicate branching corals and large rudist mounds, and a wide sediment apronmore » of well-washed coral, rudist, and benthic foraminiferal sands. These well-exposed outcrops permit a detailed facies comparison of primary interparticle porosity. Porosity as high as 40% in grainstones was occluded by later subsurface cements. Reef-framework interparticle porosity was negligible because fore-reef coral and back-reef rudist facies were infilled by muds, and high-energy reef-crest frameworks were filled by peloidal submarine cement crusts and muddy skeletal sands. These thick crusts coated lamellar corals in cryptic and open reef-crest areas, and are laminated with ripple and draped bed forms that suggest current influence. Similar peloidal crusts and laminated textures are common magnesium-calcite submarine cement features in modern reefs. By documenting specific facies control on early cementation and textural variability, patterns of late-stage subsurface diagenesis and secondary porosity may be more easily explained for Cretaceous reef reservoirs. Significant primary porosity might be retained between sands in back-reef facies and within coral skeletons.« less

A Possible Origin of the Gas Hydrate in Southwest Taiwan Offshore Area

NASA Astrophysics Data System (ADS)

Lee, C.; Lee, J.; Oung, J.

2003-12-01

The southwest Taiwan locate at the eastward subduction zone of the Eurasian plate, which is currently converging with the Philippine Sea plate at a rate of several few centimeters per year. The geological setting of this region is characterized by the appearance of thick accreted sediments up to several kilometers, numerous submarine canyons, active faults, and mud diapirs/volcanoes. The origin of mud diapir/volcano is probably related to the plate convergence. During the tectonic processes, the organic matters were "cooked" thermogenically and biogenically to produce the natural gases, and possibly the oil in the sediment. Beneath the seafloor, if the natural gases were at the appropriate temperature and pressure condition, they would become the gas hydrate, and preserved in the top sediment layers. The formation of gas hydrate is situated under the water depth at about 300 to 3000 meters in this region. In the seismic profiles, the Bottom Simulation Reflector (BSR) probably represents the boundary between the solid-state and gas-state natural gas. The BSR is also regarded as an important marker as an existence of gas hydrate. It is extensively distributed in the continental margin off southwest Taiwan, but unstable, especially along the active fault zones. The natural gas as well as the mud and hydraulic fluid in the deep sediment are pushed into the surface layer. In order to investigate the relationship between mud diapir and gas hydrate, we conduct the geophysical and geological methods: using a 38/150 kHz high-frequency echo sounder system to guide and select the sites for mud diapirs, and take 1-3 m gravity core samples. We, then, adopt an up-side-down "headspace" tin-can technique to preserve the gases, and use a gas chromatography to analyze its contents. Oil companies commonly use the method. The first result shows that the existence of methane, ethane, propane and possible other higher hydrocarbon contents in the core samples. The methane is the most abundant gas, up to 1859 parts per million in volume (ppm); the others are not significant, probably due to a leaking in the sampling and transportation. We have reduced the "headspace" in order to preserve more concentrated gases in the second attempt, and the result shows similar. Nonetheless, our results suggest that the gases are probably a mixture of thermogenic and biogenic origin. Due to the existence of higher hydrocarbon contents, we believe that the thermogenic gases are produced in the deep source sediments, while the shallow biogenic methane is mixing with them in the top sediment. In the mud diapir/volcano area, the contents of natural gases are usually higher than that in a flat seafloor. As several high gas values have been founded in the near shore area (e.g., 1604 ppm of C1 plus C2 and C3 found at a water depth of 23 m), we suggest that the 300-3000 m gas hydrate zone is probably in a dynamic balance of which the deep gases are continuously migrating to the BSR and the free gases are being evaporating from this zone. Our data illustrate the potential existence of natural gases in this region; however, we cannot quantify the reserve at this time. Further investigations with a long core and better-improved techniques are needed.

Geologic characteristics of benthic habitats in Glacier Bay, southeast Alaska

USGS Publications Warehouse

Harney, Jodi N.; Cochrane, Guy R.; Etherington, Lisa L.; Dartnell, Pete; Golden, Nadine E.; Chezar, Hank

2006-01-01

In April 2004, more than 40 hours of georeferenced submarine digital video was collected in water depths of 15-370 m in Glacier Bay to (1) ground-truth existing geophysical data (bathymetry and acoustic reflectance), (2) examine and record geologic characteristics of the sea floor, and (3) investigate the relation between substrate types and benthic communities, and (4) construct predictive maps of seafloor geomorphology and habitat distribution. Common substrates observed include rock, boulders, cobbles, rippled sand, bioturbated mud, and extensive beds of living horse mussels and scallops. Four principal sea-floor geomorphic types are distinguished by using video observations. Their distribution in lower and central Glacier Bay is predicted using a supervised, hierarchical decision-tree statistical classification of geophysical data.

Exploring the Gas Chemistry of Old Submarine Technologies Using Plastic Bottles as Reaction Vessels and Models

ERIC Educational Resources Information Center

Horikoshi, Ryo; Takeiri, Fumitaka; Kobayashi, Yoji; Kageyama, Hiroshi

2016-01-01

We describe an activity that is suitable for high school students and makes use of plastic bottles. This activity allows students to familiarize themselves with gas chemistry by introducing technologies that were applied in old submarine systems. Plastic bottles, which are representative of submarines, are used as reaction vessels. Three simple…

Oceanography, bathymetry and syndepositional tectonics of a Precambrian intracratonic basin: integrating sediments, storms, earthquakes and tsunamis in the Belt Supergroup (Helena Formation, ca. 1.45 Ga), western North America

NASA Astrophysics Data System (ADS)

Pratt, Brian R.

2001-06-01

The carbonate-dominated Helena Formation of the Mesoproterozoic Belt Supergroup of western North America provides an instructive example of how a range of regional depositional and environmental characteristics of an ancient sea can be deduced on the basis of micron- to metre-scale features. Particularly revealing is the window opened by the presence of abundant molar-tooth structure onto the paleoceanography, paleobathymetry, paleoclimate and tectonic regime of this intracratonic Precambrian basin. The facies hosting molar-tooth structure is composed dominantly of lime mud with substantial subangular quartz and feldspar silt and clay derived from the western and southwestern side of the basin. These are low-energy tempestites deposited on a remarkably flat sea bottom at the limit of storm-wave base, at about 50 m. Sporadic domical, stromatolite patch reefs confirm that the sea bottom was normally within the photic zone. The ubiquity of molar-tooth structure suggests frequent, near-field seismic activity during subsidence, which generated ground motion sufficient to liquefy granular lime mud and terrigenous silt. Sporadic tsunamis from major submarine faults far to the west pounded the shallow-water platform to the east. Tsunami off-surge swept ooids and rounded, coarse-grained, feldspathic quartz sand westward into deeper water, and created strongly erosive currents that left gutter casts composed of lags of preferentially cemented molar-tooth structure in otherwise relatively low-energy facies. Mineralogical and geochemical evidence, confirms that the Belt basin was marine. Organic matter was essentially fully oxidized in the water column. Original high-Mg composition and cementation of lime mud in molar-tooth structure indicate that calcite precipitated above the thermocline in supersaturated seawater under tropical conditions. Scattered bimineralic ooids in allochthonous grainstones indicate that shoals on the platform to the east were intermittently above a shallow aragonite compensation depth in warm water. Rare vestiges of halite and gypsum demonstrate occasional, temporary salinity stratification for periods of up to a few years. Unaltered feldspar and mica grains point to a generally arid climate, but the large volume of clay is suggestive of protracted weathering and transport.

Anaerobic methanotrophic communities thrive in deep submarine permafrost.

PubMed

Winkel, Matthias; Mitzscherling, Julia; Overduin, Pier P; Horn, Fabian; Winterfeld, Maria; Rijkers, Ruud; Grigoriev, Mikhail N; Knoblauch, Christian; Mangelsdorf, Kai; Wagner, Dirk; Liebner, Susanne

2018-01-22

Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic assemblages of marine and terrestrial origin (ANME-2a/b, ANME-2d) both in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in anaerobic oxidation of methane (AOM) we found a large diversity of archaea mainly belonging to Bathyarchaeota, Thaumarchaeota, and Euryarchaeota. Methane concentrations and δ 13 C-methane signatures distinguish horizons of potential AOM coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescence in situ hybridization (FISH) corroborate potential activity of AOM communities in submarine permafrost sediments at low temperatures. Modeled potential AOM consumes 72-100% of submarine permafrost methane and up to 1.2 Tg of carbon per year for the total expected area of submarine permafrost. This is comparable with AOM habitats such as cold seeps. We thus propose that AOM is active where submarine permafrost thaws, which should be included in global methane budgets.

Facies and Depositional History of Arc-Related, Deep-Marine Volcaniclastic Rocks in Core Recovered on International Ocean Discovery Program Expedition 351, Philippine Sea

NASA Astrophysics Data System (ADS)

Johnson, K. E.; Waldman, R.; Marsaglia, K. M.

2016-12-01

The Izu-Bonin-Mariana (IBM) Arc System, south of Japan, hosts a multitude of active and extinct (remnant) volcanic arcs and associated basins partly filled with volcanic sediment. Core extracted adjacent to the proto-IBM arc (Kyushu-Palau Ridge; KPR), in the Amami-Sankaku Basin (ASB) during International Ocean Discovery Program (IODP) Expedition 351, contains an incredibly well-preserved record of backarc sedimentation resulting from changing tectonic regimes during arc development and decline. Approximately 1000 meters of Eocene to Oligocene volcaniclastic sedimentary rocks were analyzed via shipboard core photos, core descriptions, and thin sections with the intention of understanding the depositional history at this site. A database of stratigraphic columns, 539 section and 147 core summaries, was created to display grain size trends, sedimentary structures, bedding characteristics, and facies changes. Individual depositional events were classified using existing and slightly modified classification schemes for muddy, sandy, and gravel-rich gravity flow deposits, as well as muddy deposits and tuffs. Downhole trends show repeating coarsening-upward intervals that grade from fine-grained turbidites to coarser turbidites and debrites. These trends indicate how the active depositional systems evolved upsection as the arc matured. Following arc initiation, facies deposited were primarily mud-rich; these coarsened-upward into 12 stacked sequences of submarine lobe and channel facies with sediment from one or more volcanic sources. These are interpreted to represent the building of the arc edifice that began 41 Ma. Four distinct periods of coarse lobe accumulation created a thick submarine fan over a period of nearly 13 million years. An abrupt shift to muddy turbidites at 30 Ma represents the onset of rifting of the paleo-IBM arc as backarc spreading in the Shikoku Basin was initiated and volcaniclastic supply to the ASB waned with formation of the KPR remnant arc.

Sediment composition and texture of Pleistocene deep-sea turbidites in the eastern Nankai Trough gas hydrate field

NASA Astrophysics Data System (ADS)

Egawa, K.; Nishimura, O.; Izumi, S.; Ito, T.; Konno, Y.; Yoneda, J.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Nagao, J.

2013-12-01

In the 2012 JOGMEC/JAPEX pressure coring operation, we collected a totally 60-m-long core sample from the interval of gas hydrate concentration zone at the planned site of the world's first offshore production test of natural gas hydrates in the eastern Nankai Trough area. In this contribution, the cored sediments were sedimentologically, mineralogically, and paleontologically analyzed to know sediment composition and texture of reservoir formation, which are known to provide useful geological information to discuss sedimentation, diagenesis, and permeability. The targeted interval belongs to a Middle Pleistocene deep-sea turbidite sequence distributed around the Daini Atsumi Knoll, east of the Kumano forearc basin, and consists of the lower (thick sand-dominant), middle (thin-bedded sand-and-mud alteration), and upper (mud-dominant) formations in ascending order. X-ray powder diffraction analysis and scanning electron microscopic observation revealed that pore space in turbidite sands is commonly filled with clay fractions (mostly phyllosilicates) in the lower formation. Such a pore filling of clay fractions is reflected in particle size distribution showing high standard deviation and clay content, and thus is expected to have an impact on permeability. There is the older Pliocene to Early Pleistocene fossil coccolith record in the middle formation, indicating sediment reworking probably induced by submarine landslide. The coexistence of authigenic siderite and framboidal pyrite in the middle formation strongly suggests anoxic microbial activity under methane oxidation and sulfide reduction conditions at least before the hydrate cementation. This contribution was financially supported by the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) planned by the Ministry of Economy, Trade and Industry (METI).

Thermal mud maturation: organic matter and biological activity.

PubMed

Centini, M; Tredici, M R; Biondi, N; Buonocore, A; Maffei Facino, R; Anselmi, C

2015-06-01

Many of the therapeutic and cosmetic treatments offered in spas are centred on mud therapy, to moisturize the skin and prevent skin ageing and rheumatic diseases. Thermal mud is a complex matrix composed of organic and inorganic elements which contribute to its functions. It is a natural product derived from the long mixing of clay and thermal water. During its maturation, organic substances are provided by the microalgae, which develop characteristic of the composition of thermal water. The aim of this study was to identify methods for introducing objective parameters as a basis for characterizing thermal mud and assessing its efficacy. Samples of thermal mud were collected at the Saturnia spa, where there are several sulphureous pools. The maturation of the mud was evaluated by organic component determination using extractive methods and chromatographic analysis (HPLC, GC-MS, SPME). We also studied the radical scavenging activity of mud samples at different stages of maturation, in a homogeneous phase, using several tests (DPPH, ORAC, ABTS). We identified several classes of compounds: saturated and unsaturated fatty acids, hydroxyl acids, dicarboxylic acids, ketoacids, alcohols and others. SPME analysis showed the presence of various hydrocarbons compounds (C(11) -C(17)) and long-chain alcohols (C(12) -C(16)). Six or seven months seemed appropriate to complete the process of maturation, and the main effect of maturation time was the increase of lipids. Six-month mud showed the highest activity. The hydrophilic extract was more active than the lipophilic extract. The results indicate that maturation of thermal mud can be followed on the basis of the changes in its organic composition and antioxidant properties along the time. They also highlight the need to develop reference standards for thermal muds in relation to assess their use for therapeutic and cosmetic purposes. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Seawater-groundwater exchange and nutrients carried by submarine groundwater discharge in different types of wetlands at Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Qu, Wenjing; Li, Hailong; Huang, Hao; Zheng, Chunmiao; Wang, Chaoyue; Wang, Xuejing; Zhang, Yan

2017-12-01

In Jiaozhou Bay, there are four wetland types, including sandy beaches, mud flats, tidal marshes, and estuarine intertidal zones. Four typical transects representing each of the wetland types were selected to investigate the flow dynamics, seawater-groundwater exchange and nutrients carried by submarine groundwater discharge (SGD). Based on field measurements of groundwater heads and salinity along each transect, the SGD averaged over the observation period was estimated using generalized Darcy's law. The SGD along the four transects ranges from 3.6 × 10-3 to 7.6 cm/d with the maximum occurring at the sandy beach. The SGD rate has a good correlation with the hydraulic conductivities of the wetland sediments. There is a positive correlation between the ratio of NO3-N/DIN and SGD rates. The SGD-associated nutrient output rate ranges from 3.3 × 10-2 to 9.5 mmol/m2/d for DIN (dissolved inorganic nitrogen), and from 6.2 × 10-5 to 1.8 × 10-2 mmol/m2/d for DIP (dissolved inorganic phosphorus). Compared to the nutrients delivered by the river, nutrients carried by SGD provide a more important source for the phosphate-limited environment to plankton in Jiaozhou Bay.

Ice-sheet sourced juxtaposed turbidite systems in Labrador Sea

USGS Publications Warehouse

Hesse, R.; Klaucke, I.; Ryan, William B. F.; Piper, D.J.W.

1997-01-01

Ice-sheet sourced Pleistocene turbidite systems of the Labrador Sea are different from non-glacially influenced systems in their facies distribution and depositional processes. Two large-scale sediment dispersal systems are juxtaposed, one mud-dominated and associated with the Northwest Atlantic Mid-Ocean Channel (NAMOC), the other sand-dominated and forming a huge submarine braided sandplain. Co-existence of the two systems reflects grain-size separation of the coarse and fine fractions on an enormous scale, caused by sediment winnowing at the entrance points of meltwater from the Laurentide Ice Sheet (LIS) to the sea (Hudson Strait, fiords) and involves a complex interplay of depositional and redepositional processes. The mud-rich NAMOC system is multisourced and represents a basinwide converging system of tributary canyons and channels. It focusses its sand load to the central trunk channel in basin centre, in the fashion of a "reverse" deep-sea fan. The sand plain received its sediment from the Hudson Strait by turbidity currents that were generated either by failure of glacial prodelta slopes at the ice margin, or by direct meltwater discharges with high bedload concentration. We speculate that the latter might have been related to subglacial-lake outburst flooding through the Hudson Strait, possibly associated with ice-rafting (Heinrich) events.

Internal wave deposits in Jurassic Kermanshah pelagic carbonates and radiolarites (Kermanshah area, West Iran)

NASA Astrophysics Data System (ADS)

Abdi, Asad; Gharaie, Mohamad Hosein Mahmudy; Bádenas, Beatriz

2014-12-01

We report eventites generated by turbulence events triggered by breaking internal waves in Jurassic pelagic muds deposited in a graben area located between the Arabian and Bisotoun carbonate platforms, at the Kermanshah basin (West Iran). The 43 m-thick studied Pliensbachian-Aalenian succession at Kermanshah includes sponge spicule-radiolarian limestones and cherts with cm- to dm-thick intercalations of pyroclastic beds and coarse-grained deposits formed by neritic-derived grains and reworked pelagic material. Breaking of internal waves in localized areas reworked the available sediment on sea floor, including the erosion of cohesive pelagic muds and the resuspension of neritic-derived grains, which were resedimented from the Bisotoun platform most probably by storms or turbidity currents. The generated internal wave deposits include: flat- and round pebble limestone conglomerates, formed by deposition of pelagic clasts and neritic-derived grains near the breaker zone; laminated packstone-grainstones deposited by high-energy, upslope (swash) and downslope (backswash) flows; cm-thick packstone-grainstones with asymmetrical starved ripples and hummocy crossstratification, generated downdip by waning of backwash flows and internal wave oscillatory flows. These internal wave deposits predominate in the Pliensbachian-early Toarcian, and were related to internal waves developed along a thermocline linked to climate warming and excited by submarine volcanic eruptions, storms or tectonic shaking.

Submarine slumps, slides, and flows dominate sculpting of Beringian Margin, Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, P.R.; Karl, H.A.; Edwards, B.D.

1990-06-01

The 1,400 km long Beringian margin is characterized by several very large submarine canyons and by a large oceanic plateau at the southern end. GLORIA sidescan-sonar imagery provides a perspective of this margin that is unattainable with conventional acoustic profiles. The broad coverage of GLORIA images emphasizes that, of all the sedimentary processes affecting this vast margin, mass movement is clearly the dominant shaping process. Styles of failure include mud and debris flows, slumps, and massive block slides, some covering areas greater than 1,500 km{sup 2}. GLORIA imagery and seismic-reflection profiles show evidence for a wide variety of slides andmore » slumps in the canyons of the northern margin, Navarin and Pervenets. The 100 km long shelf edge between these two canyons is characterized by a series of scalloped slide scars and incipient scars associated with blocks of sedimentary material, 1 to 2 km across. One of the largest single slide masses is a huge block tens of kilometers wide that occurs on the rise in the central part of the margin beyond the mouth of Zhemchug Canyon. Sliding of this block may have initiated the incision of the world's largest submarine canyon. The removal of this block accelerated headward erosion by retrograde failure until Zhemchug Canyon was cut back to a fault parallel to the shelf edge. Mass movement along the southern margin is widespread at the edges of Umnak Plateau. One mass failure, well-defined by GLORIA, is about 30 km wide and 55 km long. This and other slides along the plateau are associated with diapiric-like structures, suggesting relatively recent tectonism.« less

Limitations of microbial hydrocarbon degradation at the Amon mud volcano (Nile deep-sea fan)

NASA Astrophysics Data System (ADS)

Felden, J.; Lichtschlag, A.; Wenzhöfer, F.; de Beer, D.; Feseker, T.; Pop Ristova, P.; de Lange, G.; Boetius, A.

2013-05-01

The Amon mud volcano (MV), located at 1250 m water depth on the Nile deep-sea fan, is known for its active emission of methane and non-methane hydrocarbons into the hydrosphere. Previous investigations showed a low efficiency of hydrocarbon-degrading anaerobic microbial communities inhabiting the Amon MV center in the presence of sulfate and hydrocarbons in the seeping subsurface fluids. By comparing spatial and temporal patterns of in situ biogeochemical fluxes, temperature gradients, pore water composition, and microbial activities over 3 yr, we investigated why the activity of anaerobic hydrocarbon degraders can be low despite high energy supplies. We found that the central dome of the Amon MV, as well as a lateral mud flow at its base, showed signs of recent exposure of hot subsurface muds lacking active hydrocarbon degrading communities. In these highly disturbed areas, anaerobic degradation of methane was less than 2% of the methane flux. Rather high oxygen consumption rates compared to low sulfide production suggest a faster development of more rapidly growing aerobic hydrocarbon degraders in highly disturbed areas. In contrast, the more stabilized muds surrounding the central gas and fluid conduits hosted active anaerobic hydrocarbon-degrading microbial communities. The low microbial activity in the hydrocarbon-vented areas of Amon MV is thus a consequence of kinetic limitations by heat and mud expulsion, whereas most of the outer MV area is limited by hydrocarbon transport.

Massive Pyroclastic Eruptions Accompanied the Sector Collapse of Oahu and the Nu`uanu Landslide: Petrological Evidence for a Submarine Directed Blast

NASA Astrophysics Data System (ADS)

Natland, J. H.; Atlas, Z.

2003-12-01

During ODP Leg 200 in December, 2002, a series of thinly bedded volcaniclastic turbidites and silty muds interbedded with two thicker and strongly indurated vitric tuffs was drilled at Site 1223 on the crest of the Hawaiian arch east of the island of Oahu. The massive Nu`uanu landslide debris field, derived from a massive collapse of the eastern half of Oahu at about 2 Ma, lies in the flexural moat between the site and the island. The shipboard interpretation (1) was that the muds and silts are typical turbidites derived by redeposition from beaches and nearshore benches, but that the tuffs represent the distal portions of large submarine pyroclastic eruptions that may have attended the landslide. We report electron probe microanalyses of basaltic glass, olivine, Cr-spinel, palagonite and secondary minerals in the tuffs supporting the shipboard interpretation. In particular, the glass compositions from individual thin sections match precisely the range of compositions obtained from numerous samples of coarse volcaniclastic breccia sampled from the steep flanks of landslide blocks in the moat (2). This includes somewhat higher SiO2 and lower total iron as FeO(T) at given MgO than similar basaltic glasses from other Hawaiian volcanoes, a distinctive attribute of tholeiitic basalt from Oahu's Ko`olau volcano. Key attributes of the glasses in the tuffs and the minerals in them are that they are poly-compositional and they are strongly differentiated, with a range of compositions typical of those erupted from modern Hawaiian volcanic rift systems supplied by lateral diking from central conduits. The finer-grained tuffs at Site 1223 thus are indeed a distal pyroclastic facies that seemingly tapped much of the suddenly exposed, magma-inflated, deep flanking rift system of Ko`olau volcano. Over-steepening of the NE flank of the volcano coupled with internal weakening provided by near saturation of its rift system with magma may have triggered the landslide. This was almost immediately followed by massive submarine pyroclastic eruptions of magma mainly at submarine levels in the rift that, accelerated by steep downslope descent, were directed all the way to the ENE in rapidly-moving debris flows. These sorted themselves by size (mass) with the coarsest material plastering the sides of the landslide blocks, and the finer grained material, mainly glass and olivine grains, reaching the crest of the Hawaiian arch. The palagonite is compositionally-modified glass that probably formed by leaching in response to lateral migration of warm hydrothermal fluids from beneath thicker and still hot proximal pyroclastic material that was abruptly deposited in the moat to the west following the landslide. (1)Shipboard Scientific Party, 2003. Site 1223. In Stephen, R.A., Kasahara, J., Acton, G.D., et al., Proc. ODP, Init. Rept. 200 [CD-ROM], College Station, TX (Ocean Drill. Prog), 1-159. (2)Clague, D.A., Moore, J.G., and Davis, A.S., 2002. In Takahashi, E.,Lipman, P., Garcia, M.O., and Aramaki, S., (Eds.), Geophys. Monog. 128: Washington (AGU), 279-296.

Cellular immune responses and phagocytic activity of fishes exposed to pollution of volcano mud.

PubMed

Risjani, Yenny; Yunianta; Couteau, Jerome; Minier, Christophe

2014-05-01

Since May 29, 2006, a mud volcano in the Brantas Delta of the Sidoarjo district has emitted mud that has inundated nearby villages. Pollution in this area has been implicated in detrimental effects on fish health. In fishes, leukocyte and phagocytic cells play a vital role in body defenses. We report for the first time the effect of "LUSI" volcano mud on the immune systems of fish in the Brantas Delta. The aim of this study was to find biomarkers to allow the evaluation of the effects of volcanic mud and anthropogenic pollution on fish health in the Brantas Delta. The study took places at the Brantas Delta, which was polluted by volcano mud, and at reference sites in Karangkates and Pasuruan. Leukocyte numbers were determined using a Neubauer hemocytometer and a light microscope. Differential leukocyte counts were determined using blood smears stained with May Grunwald-Giemsa, providing neutrophil, lymphocyte and monocyte counts. Macrophages were taken from fish kidney, and their phagocytic activity was measured. In vitro analyses revealed that leukocyte and differential leukocyte counts (DLC) were higher in Channa striata and Chanos chanos caught from the polluted area. Macrophage numbers were higher in Oreochromis mossambicus than in the other species, indicating that this species is more sensitive to pollution. In areas close to volcanic mud eruption, all specimens had lower phagocytic activity. Our results show that immune cells were changed and phagocytic activity was reduced in the polluted area indicating cytotoxicity and alteration of the innate immune system in fishes exposed to LUSI volcano mud and anthropogenic pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Making a Submarine.

ERIC Educational Resources Information Center

Cornacchia, Deborah J.

2002-01-01

Describes Archimedes principle and why a ship sinks when it gets a hole in it. Suggests an activity for teaching the concept of density and water displacement through the construction of a simple submarine. Includes materials and procedures for this activity. (KHR)

Submarine landslide and tsunami hazards offshore southern Alaska: Seismic strengthening versus rapid sedimentation

NASA Astrophysics Data System (ADS)

Sawyer, Derek E.; Reece, Robert S.; Gulick, Sean P. S.; Lenz, Brandi L.

2017-08-01

The southern Alaskan offshore margin is prone to submarine landslides and tsunami hazards due to seismically active plate boundaries and extreme sedimentation rates from glacially enhanced mountain erosion. We examine the submarine landslide potential with new shear strength measurements acquired by Integrated Ocean Drilling Program Expedition 341 on the continental slope and Surveyor Fan. These data reveal lower than expected sediment strength. Contrary to other active margins where seismic strengthening enhances slope stability, the high-sedimentation margin offshore southern Alaska behaves like a passive margin from a shear strength perspective. We interpret that seismic strengthening occurs but is offset by high sedimentation rates and overpressure. This conclusion is supported by shear strength outside of the fan that follow an active margin trend. More broadly, seismically active margins with wet-based glaciers are susceptible to submarine landslide hazards because of the combination of high sedimentation rates and earthquake shaking.

Large-scale dam removal on the Elwha River, Washington, USA: coastal geomorphic change

USGS Publications Warehouse

Gelfenbaum, Guy R.; Stevens, Andrew W.; Miller, Ian M.; Warrick, Jonathan A.; Ogston, Andrea S.; Eidam, Emily

2015-01-01

Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of mud, sand, and gravel since 1927, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams, initiated in September 2011, induced massive increases in river sediment supply and provided an unprecedented opportunity to examine the geomorphic response of a coastal delta to these increases. Detailed measurements of beach topography and nearshore bathymetry show that ~ 2.5 million m3 of sediment was deposited during the first two years of dam removal, which is ~ 100 times greater than deposition rates measured prior to dam removal. The majority of the deposit was located in the intertidal and shallow subtidal region immediately offshore of the river mouth and was composed of sand and gravel. Additional areas of deposition include a secondary sandy deposit to the east of the river mouth and a muddy deposit west of the mouth. A comparison with fluvial sediment fluxes suggests that ~ 70% of the sand and gravel and ~ 6% of the mud supplied by the river was found in the survey area (within about 2 km of the mouth). A hydrodynamic and sediment transport model, validated with in-situ measurements, shows that tidal currents interacting with the larger relict submarine delta help disperse fine sediment large distances east and west of the river mouth. The model also suggests that waves and currents erode the primary deposit located near the river mouth and transport sandy sediment eastward to form the secondary deposit. Though most of the substrate of the larger relict submarine delta was unchanged during the first two years of dam removal, portions of the seafloor close to the river mouth became finer, modifying habitats for biological communities. These results show that river restoration, like natural changes in river sediment supply, can result in rapid and substantial coastal geomorphological responses.

Radioactivity of natural medicinal preparations contained extracts from peat mud available in retail trade used externally.

PubMed

Karpińska, Maria; Kapała, Jacek; Raciborska, Agnieszka; Kulesza, Grzegorz; Milewska, Anna; Mnich, Stanisław

2017-08-01

In this work were identified and measured the activity of radioactive isotopes present in medicinal preparations from peat mud and estimated the doses obtained from them during therapy. Radioactivity of 22 preparations from peat mud and 20 water samples from water of the North-East region of Poland was studied. The median of the total activity was 24.8 Bq kg -1 . Total maximal isotope activity was observed in the Iwonicka Cube 146 Bq kg -1 while considerable amounts of isotopes were found in the Kolobrzeska Peat Mud Paste 112 Bq kg -1 . The doses obtained during therapy were within the range of 11 nSv-13 μSv depending on extracts of medicinal preparations from peat mud. The probability that such a small dose would stimulate biological effects is low. However, some clinicians believe that one of the possible therapeutic mechanisms in the treatment of rheumatoid disorders is the induction of immune response by ionising radiation.

Hydration kinetics of cementitious materials composed of red mud and coal gangue

NASA Astrophysics Data System (ADS)

Zhang, Na; Li, Hong-xu; Liu, Xiao-ming

2016-10-01

To elucidate the intrinsic reaction mechanism of cementitious materials composed of red mud and coal gangue (RGC), the hydration kinetics of these cementitious materials at 20°C was investigated on the basis of the Krstulović-Dabić model. An isothermal calorimeter was used to characterize the hydration heat evolution. The results show that the hydration of RGC is controlled by the processes of nucleation and crystal growth (NG), interaction at phase boundaries (I), and diffusion (D) in order, and the pozzolanic reactions of slag and compound-activated red mud-coal gangue are mainly controlled by the I process. Slag accelerates the clinker hydration during NG process, whereas the compound-activated red mud-coal gangue retards the hydration of RGC and the time required for I process increases with increasing dosage of red mud-coal gangue in RGC.

Teaching Ecological Interactions with Mud Dauber Nests.

ERIC Educational Resources Information Center

Matthews, Robert W.

1997-01-01

Describes the use of mud dauber wasp nests in laboratory activities in ecology and behavior and life science classes. Provides students with an opportunity to develop and practice basic skills including dissection, identification, observation, measurement, and communication. Discusses the life of mud daubers, obtaining and storing nests,…

78 FR 58524 - Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-24

... and testing activities: anti-surface warfare; anti- submarine warfare; mine warfare; naval special warfare; major training activities; Naval Air Systems Command (NAVAIR) testing; anti-surface warfare testing; anti-submarine warfare testing; Naval Sea Systems Command (NAVSEA) testing; and Office of Naval...

Evidence from acoustic imaging for submarine volcanic activity in 2012 off the west coast of El Hierro (Canary Islands, Spain)

NASA Astrophysics Data System (ADS)

Pérez, Nemesio M.; Somoza, Luis; Hernández, Pedro A.; de Vallejo, Luis González; León, Ricardo; Sagiya, Takeshi; Biain, Ander; González, Francisco J.; Medialdea, Teresa; Barrancos, José; Ibáñez, Jesús; Sumino, Hirochika; Nogami, Kenji; Romero, Carmen

2014-12-01

We report precursory geophysical, geodetic, and geochemical signatures of a new submarine volcanic activity observed off the western coast of El Hierro, Canary Islands. Submarine manifestation of this activity has been revealed through acoustic imaging of submarine plumes detected on the 20-kHz chirp parasound subbottom profiler (TOPAS PS18) mounted aboard the Spanish RV Hespérides on June 28, 2012. Five distinct "filament-shaped" acoustic plumes emanating from the flanks of mounds have been recognized at water depth between 64 and 88 m on a submarine platform located NW El Hierro. These plumes were well imaged on TOPAS profiles as "flares" of high acoustic contrast of impedance within the water column. Moreover, visible plumes composed of white rafts floating on the sea surface and sourcing from the location of the submarine plumes were reported by aerial photographs on July 3, 2012, 5 days after acoustic plumes were recorded. In addition, several geophysical and geochemical data support the fact that these submarine vents were preceded by several precursory signatures: (i) a sharp increase of the seismic energy release and the number of daily earthquakes of magnitude ≥2.5 on June 25, 2012, (ii) significant vertical and horizontal displacements observed at the Canary Islands GPS network (Nagoya University-ITER-GRAFCAN) with uplifts up to 3 cm from June 25 to 26, 2012, (iii) an anomalous increase of the soil gas radon activity, from the end of April until the beginning of June reaching peak values of 2.7 kBq/m3 on June 3, 2012, and (iv) observed positive peak in the air-corrected value of 3He/4He ratio monitored in ground waters (8.5 atmospheric 3He/4He ratio ( R A)) at the northwestern El Hierro on June 16, 2012. Combining these submarine and subaerial information, we suggest these plumes are the consequence of submarine vents exhaling volcanic gas mixed with fine ash as consequence of an event of rapid rise of volatile-rich magma beneath the NW submarine ridge of El Hierro. These precursory signals have revealed important to improve and optimize the detection of early warning signals of volcanic unrest episodes at El Hierro.

Inscuteable Regulates the Pins-Mud Spindle Orientation Pathway

PubMed Central

Mauser, Jonathon F.; Prehoda, Kenneth E.

2012-01-01

During asymmetric cell division, alignment of the mitotic spindle with the cell polarity axis ensures that the cleavage furrow separates fate determinants into distinct daughter cells. The protein Inscuteable (Insc) is thought to link cell polarity and spindle positioning in diverse systems by binding the polarity protein Bazooka (Baz; aka Par-3) and the spindle orienting protein Partner of Inscuteable (Pins; mPins or LGN in mammals). Here we investigate the mechanism of spindle orientation by the Insc-Pins complex. Previously, we defined two Pins spindle orientation pathways: a complex with Mushroom body defect (Mud; NuMA in mammals) is required for full activity, whereas binding to Discs large (Dlg) is sufficient for partial activity. In the current study, we have examined the role of Inscuteable in mediating downstream Pins-mediated spindle orientation pathways. We find that the Insc-Pins complex requires Gαi for partial activity and that the complex specifically recruits Dlg but not Mud. In vitro competition experiments revealed that Insc and Mud compete for binding to the Pins TPR motifs, while Dlg can form a ternary complex with Insc-Pins. Our results suggest that Insc does not passively couple polarity and spindle orientation but preferentially inhibits the Mud pathway, while allowing the Dlg pathway to remain active. Insc-regulated complex assembly may ensure that the spindle is attached to the cortex (via Dlg) before activation of spindle pulling forces by Dynein/Dynactin (via Mud). PMID:22253744

Submarine geology and geomorphology of active Sub-Antarctic volcanoes: Heard and McDonald Islands

NASA Astrophysics Data System (ADS)

Watson, S. J.; Coffin, M. F.; Whittaker, J. M.; Lucieer, V.; Fox, J. M.; Carey, R.; Arculus, R. J.; Bowie, A. R.; Chase, Z.; Robertson, R.; Martin, T.; Cooke, F.

2016-12-01

Heard and McDonald Islands (HIMI) are World Heritage listed sub-Antarctic active volcanic islands in the Southern Indian Ocean. Built atop the Kerguelen Plateau by Neogene-Quaternary volcanism, HIMI represent subaerial exposures of the second largest submarine Large Igneous Province globally. Onshore, processes influencing island evolution include glaciers, weathering, volcanism, vertical tectonics and mass-wasting (Duncan et al. 2016). Waters surrounding HIMI are largely uncharted, due to their remote location. Hence, the extent to which these same processes shape the submarine environment around HIMI has not been investigated. In early 2016, we conducted marine geophysical and geologic surveys around HIMI aboard RV Investigator (IN2016_V01). Results show that volcanic and sedimentary features prominently trend east-west, likely a result of erosion by the eastward flowing Antarctic Circumpolar Current and tidal currents. However, spatial patterns of submarine volcanism and sediment distribution differ substantially between the islands. >70 sea knolls surround McDonald Island suggesting substantial submarine volcanism. Geophysical data reveals hard volcanic seafloor around McDonald Island, whereas Heard Island is characterised by sedimentary sequences tens of meters or more thick and iceberg scours - indicative of glacial processes. Differences in submarine geomorphology are likely due to the active glaciation of Heard Island and differing rock types (Heard: alkali basalt, McDonald: phonolite), and dominant products (clastics vs. lava). Variations may also reflect different magmatic plumbing systems beneath the two active volcanoes (Heard produces larger volumes of more focused lava, whilst McDonald extrudes smaller volumes of more evolved lavas from multiple vents across the edifice). Using geophysical data, corroborated with new and existing geologic data, we present the first geomorphic map revealing the processes that shape the submarine environment around HIMI.

Increased methane emissions from deep osmotic and buoyant convection beneath submarine seeps as climate warms

PubMed Central

Cardoso, Silvana S. S.; Cartwright, Julyan H. E.

2016-01-01

High speeds have been measured at seep and mud-volcano sites expelling methane-rich fluids from the seabed. Thermal or solute-driven convection alone cannot explain such high velocities in low-permeability sediments. Here we demonstrate that in addition to buoyancy, osmotic effects generated by the adsorption of methane onto the sediments can create large overpressures, capable of recirculating seawater from the seafloor to depth in the sediment layer, then expelling it upwards at rates of up to a few hundreds of metres per year. In the presence of global warming, such deep recirculation of seawater can accelerate the melting of methane hydrates at depth from timescales of millennia to just decades, and can drastically increase the rate of release of methane into the hydrosphere and perhaps the atmosphere. PMID:27807343

Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons

PubMed Central

Azpiroz-Zabala, Maria; Cartigny, Matthieu J. B.; Talling, Peter J.; Parsons, Daniel R.; Sumner, Esther J.; Clare, Michael A.; Simmons, Stephen M.; Cooper, Cortis; Pope, Ed L.

2017-01-01

Seabed-hugging flows called turbidity currents are the volumetrically most important process transporting sediment across our planet and form its largest sediment accumulations. We seek to understand the internal structure and behavior of turbidity currents by reanalyzing the most detailed direct measurements yet of velocities and densities within oceanic turbidity currents, obtained from weeklong flows in the Congo Canyon. We provide a new model for turbidity current structure that can explain why these are far more prolonged than all previously monitored oceanic turbidity currents, which lasted for only hours or minutes at other locations. The observed Congo Canyon flows consist of a short-lived zone of fast and dense fluid at their front, which outruns the slower moving body of the flow. We propose that the sustained duration of these turbidity currents results from flow stretching and that this stretching is characteristic of mud-rich turbidity current systems. The lack of stretching in previously monitored flows is attributed to coarser sediment that settles out from the body more rapidly. These prolonged seafloor flows rival the discharge of the Congo River and carry ~2% of the terrestrial organic carbon buried globally in the oceans each year through a single submarine canyon. Thus, this new structure explains sustained flushing of globally important amounts of sediment, organic carbon, nutrients, and fresh water into the deep ocean. PMID:28983506

Newly recognized turbidity current structure can explain prolonged flushing of submarine canyons.

PubMed

Azpiroz-Zabala, Maria; Cartigny, Matthieu J B; Talling, Peter J; Parsons, Daniel R; Sumner, Esther J; Clare, Michael A; Simmons, Stephen M; Cooper, Cortis; Pope, Ed L

2017-10-01

Seabed-hugging flows called turbidity currents are the volumetrically most important process transporting sediment across our planet and form its largest sediment accumulations. We seek to understand the internal structure and behavior of turbidity currents by reanalyzing the most detailed direct measurements yet of velocities and densities within oceanic turbidity currents, obtained from weeklong flows in the Congo Canyon. We provide a new model for turbidity current structure that can explain why these are far more prolonged than all previously monitored oceanic turbidity currents, which lasted for only hours or minutes at other locations. The observed Congo Canyon flows consist of a short-lived zone of fast and dense fluid at their front, which outruns the slower moving body of the flow. We propose that the sustained duration of these turbidity currents results from flow stretching and that this stretching is characteristic of mud-rich turbidity current systems. The lack of stretching in previously monitored flows is attributed to coarser sediment that settles out from the body more rapidly. These prolonged seafloor flows rival the discharge of the Congo River and carry ~2% of the terrestrial organic carbon buried globally in the oceans each year through a single submarine canyon. Thus, this new structure explains sustained flushing of globally important amounts of sediment, organic carbon, nutrients, and fresh water into the deep ocean.

Comparison of Copper Scavenging Capacity between Two Different Red Mud Types

PubMed Central

Ma, Yingqun; Si, Chunhua; Lin, Chuxia

2012-01-01

A batch experiment was conducted to compare the Cu scavenging capacity between two different red mud types: the first one was a highly basic red mud derived from a combined sintering and Bayer process, and the second one was a seawater-neutralized red mud derived from the Bayer process. The first red mud contained substantial amounts of CaCO3, which, in combination with the high OH− activity, favored the immobilization of water-borne Cu through massive formation of atacamite. In comparison, the seawater-neutralized red mud had a lower pH and was dominated by boehmite, which was likely to play a significant role in Cu adsorption. Overall, it appears that Cu was more tightly retained by the CaCO3-dominated red mud than the boehmite-dominated red mud. It is concluded that the heterogeneity of red mud has marked influences on its capacity to immobilize water-borne Cu and maintain the long-term stability of the immobilized Cu species. The research findings obtained from this study have implications for the development of Cu immobilization technology by using appropriate waste materials generated from the aluminium industry.

The effects of drilling muds on marine invertebrate larvae and adults

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raimondi, P.T.; Barnett, A.M.; Krause, P.R.

1997-06-01

A series of laboratory experiments tested the effects of drilling muds from an active platform off southern California on larvae and adults of marine invertebrates. Red abalone (Haliotis rufescens) were used to determine effects of drilling muds on fertilization, early development, survivorship, and settlement, and experiments on adult brown cup corals (Paracyathus stearnsii) tested effects on adult survivorship, viability, and tissue loss. Exposures to drilling muds did not have an effect on abalone fertilization or early development. However, several exposures to drilling muds resulted in weak, but significant, positive effects of drilling muds on settlement of competent larvae. In contrast,more » settlement of red abalone larvae on natural coralline algal crusts decreased with increasing concentrations of drilling muds. This suggests that drilling muds affect either the abalone`s ability to detect natural settlement inducers, or they affect the inducer itself. Exposure of brown cup corals to concentrations of drilling muds adversely impacted their survivorship and viability. These effects were likely caused by increased tissue mortality of the coral polyps.« less

Environmental dust effects on aluminum surfaces in humid air ambient.

PubMed

Yilbas, Bekir Sami; Hassan, Ghassan; Ali, Haider; Al-Aqeeli, Nasser

2017-04-05

Environmental dusts settle on surfaces and influence the performance of concentrated solar energy harvesting devices, such as aluminum troughs. The characteristics of environmental dust and the effects of mud formed from the dust particles as a result of water condensing in humid air conditions on an aluminum wafer surface are examined. The dissolution of alkaline and alkaline earth compounds in water condensate form a chemically active mud liquid with pH 8.2. Due to gravity, the mud liquid settles at the interface of the mud and the aluminum surface while forming locally scattered patches of liquid films. Once the mud liquid dries, adhesion work to remove the dry mud increases significantly. The mud liquid gives rise to the formation of pinholes and local pit sites on the aluminum surface. Morphological changes due to pit sites and residues of the dry mud on the aluminum surface lower the surface reflection after the removal of the dry mud from the surface. The characteristics of the aluminum surface can address the dust/mud-related limitations of reflective surfaces and may have implications for the reductions in the efficiencies of solar concentrated power systems.

Environmental dust effects on aluminum surfaces in humid air ambient

PubMed Central

Yilbas, Bekir Sami; Hassan, Ghassan; Ali, Haider; Al-Aqeeli, Nasser

2017-01-01

Environmental dusts settle on surfaces and influence the performance of concentrated solar energy harvesting devices, such as aluminum troughs. The characteristics of environmental dust and the effects of mud formed from the dust particles as a result of water condensing in humid air conditions on an aluminum wafer surface are examined. The dissolution of alkaline and alkaline earth compounds in water condensate form a chemically active mud liquid with pH 8.2. Due to gravity, the mud liquid settles at the interface of the mud and the aluminum surface while forming locally scattered patches of liquid films. Once the mud liquid dries, adhesion work to remove the dry mud increases significantly. The mud liquid gives rise to the formation of pinholes and local pit sites on the aluminum surface. Morphological changes due to pit sites and residues of the dry mud on the aluminum surface lower the surface reflection after the removal of the dry mud from the surface. The characteristics of the aluminum surface can address the dust/mud-related limitations of reflective surfaces and may have implications for the reductions in the efficiencies of solar concentrated power systems. PMID:28378798

The use of red mud as an immobiliser for metal/metalloid-contaminated soil: A review.

PubMed

Hua, Yumei; Heal, Kate V; Friesl-Hanl, Wolfgang

2017-03-05

This review focuses on the applicability of red mud as an amendment for metal/metalloid-contaminated soil. The varying properties of red muds from different sources are presented as they influence the potentially toxic element (PTE) concentration in amended soil. Experiments conducted worldwide from the laboratory to the field scale are screened and the influencing parameters and processes in soils are highlighted. Overall red mud amendment is likely to contribute to lowering the PTE availability in contaminated soil. This is attributed to the high pH, Fe and Al oxide/oxyhydroxide content of red mud, especially hematite, boehmite, gibbsite and cancrinite phases involved in immobilising metals/metalloids. In most cases red mud amendment resulted in a lowering of metal concentrations in plants. Bacterial activity was intensified in red mud-amended contaminated soil, suggesting the toxicity from PTEs was reduced by red mud, as well as indirect effects due to changes in soil properties. Besides positive effects of red mud amendment, negative effects may also appear (e.g. increased mobility of As, Cu) which require site-specific risk assessments. Red mud remediation of metal/metalloid contaminated sites has the potential benefit of reducing red mud storage and associated problems. Copyright © 2016 Elsevier B.V. All rights reserved.

Clueless Newbies in the MUDs: An Introduction to Multiple-User Environments.

ERIC Educational Resources Information Center

LeNoir, W. David

1998-01-01

Describes Multiple-User Dungeons (MUDs), multiple-user computer programs that allow participants to interact with others in "real time" exchanges. Discusses their potential in the writing classroom and beyond, and notes their potential for faculty development activities. Offers a list of Internet resources, some actual MUD addresses, and other…

Valorisation of waste ilmenite mud in the manufacture of sulphur polymer cement.

PubMed

Contreras, Manuel; Gázquez, Manuel Jesús; García-Díaz, Irene; Alguacil, Francisco J; López, Félix A; Bolívar, Juan Pedro

2013-10-15

This paper reports the preparation of sulphur polymer cements (SPCs) incorporating waste ilmenite mud for use in concrete construction works. The ilmenite mud raw material and the mud-containing SPCs (IMC-SPCs) were characterised physico-chemically and radiologically. The optimal IMC-SPC mixture had a sulphur/mud ratio (w/w) of 1.05 (mud dose 20 wt%); this cement showed the greatest compressive strength (64 MPa) and the lowest water absorption coefficient (0.4 g cm(-2) at 28 days). Since ilmenite mud is enriched in natural radionuclides, such as radium isotopes (2.0·10(3) Bq kg(-1)(228)Ra and 5.0·10(2) Bq kg(-1)(226)Ra), the IMC-SPCs were subjected to leaching experiments, which showed their environmental impact to be negligible. The activity concentration indices for the different radionuclides in the IMC-SPCs containing 10% and 20% ilmenite mud met the demands of international standards for materials used in the construction of non-residential buildings. Copyright © 2013 Elsevier Ltd. All rights reserved.

A descriptive analysis of asthma in the U.S. Navy Submarine Force.

PubMed

Sims, J R; Tibbles, P M; Jackman, R P

1999-12-01

The U.S. Navy Submarine Force offers a unique opportunity to study asthma because of the relative socioeconomic and physical homogeneity of the population and the closed environment occupational exposure. Currently, asthma is disqualifying from submarine service, which results in a significant loss of experienced personnel. We performed a retrospective analysis of 119 U.S. Navy submariner disqualification packages for asthma between 1989-1993. We found a 0.16% annual period prevalence of asthma in the active duty enlisted Atlantic Fleet Submarine Force. Two groups of asthma disqualifications were identified with a significant increase above their proportional representation in the fleet: enlisted personnel (p < 0.01) and submarine recruits (p < 0.0001). The proportion of African-American personnel also had a tendency toward increased asthma disqualification (p < 0.08). There were no differences in prevalence of asthma between crews of ballistic missile submarines or fast attack submarines. Asthma risk factors reported in the civilian literature (childhood history of asthma, family history of asthma and non-drug allergies) were highly represented in our study (41%, 46% and 68% of submariners, respectively). Most disqualified submariners had "mild" asthma based on the diagnostic work-up. The methacholine challenge test appeared to carry a disproportionate diagnostic weight despite its low specificity. Although the period prevalence of asthma is low in the U.S. Navy Submarine Force, submariners disqualified for asthma have similar historical and ethnic risk factors as the civilian population.

Submarine Landslide Hazards Offshore Southern Alaska: Seismic Strengthening Versus Rapid Sedimentation

NASA Astrophysics Data System (ADS)

Sawyer, D.; Reece, R.; Gulick, S. P. S.; Lenz, B. L.

2017-12-01

The southern Alaskan offshore margin is prone to submarine landslides and tsunami hazards due to seismically active plate boundaries and extreme sedimentation rates from glacially enhanced mountain erosion. We examine the submarine landslide potential with new shear strength measurements acquired by Integrated Ocean Drilling Program Expedition 341 on the continental slope and Surveyor Fan. These data reveal lower than expected sediment strength. Contrary to other active margins where seismic strengthening enhances slope stability, the high-sedimentation margin offshore southern Alaska behaves like a passive margin from a shear strength perspective. We interpret that seismic strengthening occurs but is offset by high sedimentation rates and overpressure within the slope and Surveyor Fan. This conclusion is supported because shear strength follows an expected active margin profile outside of the fan, where background sedimentation rates occur. More broadly, seismically active margins with wet-based glaciers are susceptible to submarine landslide hazards because of the combination of high sedimentation rates and earthquake shaking

Submarine Landslides: A Multidisciplinary Crossroad

NASA Astrophysics Data System (ADS)

Moscardelli, L. G.

2014-12-01

The study of submarine landslides has advanced considerably in the last decade. A multitude of geoscience disciplines, including marine, petroleum and planetary geology, as well as geohazard assessments, are concerned with the study of these units. Oftentimes, researchers working in these fields disseminate their findings within their own communities and a multidisciplinary approach seems to lack. This presentation showcases several case studies in which a broader approach has increased our understanding of submarine landslides in a variety of geologic settings. Three-dimensional seismic data from several continental margins (Trinidad, Brazil, Morocco, Canada, GOM), as well as data from outcrop localities are shown to explore geomorphological complexities associated with submarine landslides. Discussion associated with the characterization and classification of submarine landslides is also part of this work. Topics that will be cover include: 1) how data from conventional oil and gas exploration activities can be used to increase our understanding of the dynamic behavior of submarine landslides, 2) analogies between terrestrial submarine landslides and potential Martian counterparts, 3) impact of submarine landslides in margin construction, as well as their economic significance and 4) the importance of quantifying the morphology of submarine landslides in a systematic fashion.

Toxicity of used drilling fluids to mysids (Mysidopsis bahia)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaetz, C.T.; Montgomery, R.; Duke, T.W.

1986-01-01

Static, acute toxicity tests were conducted with mysids (Mysidopsis bahia) and 11 used drilling fluids (also called drilling muds) obtained from active drilling platforms in the Gulf of Mexico, U.S.A. Each whole mud was tested, along with three phases of each mud: a liquid phase with all particulate materials removed; a suspended particulate phase composed of soluble and lighter particulate fractions; and a solid phase composed mainly of drill cuttings and rapidly settling particulates. These muds represented seven of the eight generic mud types described by the U.S. Environmental Protection Agency for use on the U.S. Outer Continental Shelf. Themore » toxicity of the 11 muds tested was apparently enhanced by the presence of aromatics. Furthermore, one mud tested repeatedly showed loss of toxicity with time, possibly from volatilization of aromatic fractions. The data demonstrated that aromatics in the drilling fluids affected their toxicity to M. bahia.« less

[Effect of naphthalan and therapeutic mud applications on clinical and roentgenological characteristics in patients with protracted pneumonia].

PubMed

Rassulova, M A; Siziakova, L A; Aĭrapetova, N S

2009-01-01

The influence of application of naftalan and therapeutic muds on clinical and roentgenological parameters, external respiration function, biochemical and immunological characteristics of the inflammatory process was studied in 82 patients presenting with protracted pneumonia and compared with the outcome of therapy using no physical factors. The application of naftalan and therapeutic muds was shown to reduce activity of inflammatory processes, improve airway patency and the state ofbronchial mucosa. Naftalan produced better therapeutic effect than muds.

Heterogeneous Catalysts for VOC Oxidation from Red Mud and Bagasse Ash Carbon

NASA Astrophysics Data System (ADS)

Pande, Gaurav

A range of VOC oxidation catalysts have been prepared in this study from agricultural and industrial waste as the starting point. The aim is to prepare catalysts with non-noble metal oxides as the active catalytic component (iron in red mud). The same active component was also supported on activated carbon obtained from unburned carbon in bagasse ash. Red mud which is an aluminum industry waste and rich in different phases of iron as oxide and hydroxide is used as the source for the catalytically active species. It is our aim to enhance the catalytic performance of red mud which though high in iron concentration has a low surface area and may not have the properties of an ideal catalyst by itself. In one of the attempts to enhance the catalytic performance, we have tried to leach red mud for which we have explored a range of leaching acids for effecting the leaching most efficiently and then precipitated the iron from the leachate as its hydroxide by precipitating with alkali solution followed by drying and calcination to give high surface area metal oxide material. Extensive surface characterization and VOC oxidation catalytic testing were performed for these solids. In a step to further enhance the catalytic activity towards oxidation, copper was introduced by taking another industrial waste from the copper tubing industry viz. the pickling acid. Copper has a more favourable redox potential making it catalytically more effective than iron. To make the mixed metal oxide, red mud leachate was mixed with the pickling acid in a pre-decided ratio before precipitating with alkali solution followed by drying and calcination as was done with the red mud leachate. The results from these experiments are encouraging. The temperature programmed reduction (TPR) of the solids show that the precipitate of red mud leachates show hydrogen uptake peak at a lower temperature than for just the calcined red mud. This could be due to the greatly enhanced surface area of the prepared solids. The highest surface area of 311 m2/g was for the sample prepared from oxalic acid and l-ascorbic acid as the leaching acid; as received red mud has a surface area of 11.5 m2/g. This sample showed better catalytic performance than the ones made from hydrochloric acid as the leaching acid in spite of a similar increase in surface area. High temperature XRD shows the reason for this difference in catalytic properties could be due to both the solids reducing in a different way to give different phases though they are both derived from red mud as the starting material. Also, the sample prepared with oxalic acid leachate had higher surface iron concentration. For the best catalyst (oxalic acid derived) the light off temperature is about 300 °C for toluene oxidation. For solids prepared from red mud leachate for iron source and pickling acid for copper source, it was seen that the TPR gave hydrogen absorption at temperatures even lower than that for red mud leachate precipitates. In another set of experiments, iron oxide impregnated on activated carbon supports were prepared. Activated carbon is known for its adsorption properties which could give a better access of the impregnated metal oxide catalyst to perform the catalytic oxidation on the adsorbed substrate. Unburned carbon in bagasse ash which is a sugar industry agricultural waste was used to get the activated carbon. This material was separated from the ash and further modified to enhance the activity and increase the porosity. To this effect steam activation was performed. To impart thermal stability for oxidation reaction, the carbon was impregnated by phosphoric acid at activated at high temperatures in inert atmosphere. These carbons were thermally stable due to the surface C--O--P groups. Toluene adsorption studies were also performed for both the steam activated as well as phosphoric acid activated carbon and it was found that the steam activated carbons with less surface oxygen had reasonable adsorption attributes. For iron impregnation onto the prepared bagasse ash carbons, two different methods of impregnation viz. incipient wetness method as well as impregnation by precipitation of the red mud leachate by adding alkali to a slurry of carbon and leachate (Pratt method) was used. It was found that impregnation by precipitation led to better butanol oxidation performing catalyst than the one prepared by impregnating by incipient wetness method. The best performing catalyst amongst the iron impregnated on carbon types was found to give 100% butanol conversion at 200 °C. It was also observed that red mud leachate precipitated catalyst performed well for toluene oxidation and not for butanol oxidation while carbon supported iron oxide catalysts worked better for butanol oxidation than for toluene oxidation.

In situ stabilization of cadmium-, lead-, and zinc-contaminated soil using various amendments.

PubMed

Lee, Sang-Hwan; Lee, Jin-Soo; Choi, Youn Jeong; Kim, Jeong-Gyu

2009-11-01

Chemical stabilization is an in situ remediation method that uses inexpensive amendments to reduce contaminant availability in polluted soil. We tested the effects of several amendments (limestone, red-mud, and furnace slag) on the extractability of heavy metals, microbial activities, phytoavailability of soil metals (assessed using lettuce, Lactuca sativa L.), and availability of heavy metals in ingested soil to the human gastrointestinal system (assessed using the physiologically based extraction test). The application of soil amendments significantly decreased the amount of soluble and extractable heavy metals in the soil (p<0.05). The decreased extractable metal content of soil was accompanied by increased microbial activity and decreased plant uptake of heavy metals. Soil microbial activities (soil respiration, urease, and dehydrogenase activity) significantly increased in limestone and red-mud-amended soils. Red-mud was the most effective treatment in decreasing heavy-metal concentrations in lettuce. Compared to non-amended control soil, lettuce uptake of Cd, Pb, and Zn was reduced 86%, 58%, and 73%, respectively, by the addition of red-mud.

Sedimentological and geochemical record of submarine mine tailing footprint in Repparfjorden (Northern Norway)

NASA Astrophysics Data System (ADS)

Sternal, Beata; Junttila, Juho; Pedersen, Kristine Bondo; Skirbekk, Kari; Forwick, Matthias; Carroll, JoLynn

2016-04-01

The knowledge on understanding the physical, chemical and biological processes dominating in marine system affected by submarine tailings disposal (STD) remains limited and further knowledge to make reliable long-term predictions of future environmental impacts is needed. One way of contributing to this is by investigation of marine environments already affected by the tailings discharge in the past. We present preliminary results from a multidisciplinary study of marine sediments from Repparfjorden in northern Norway, a fjord that was influenced by the deposition of tailings from a copper mine during the 1970's. The study is a part of the competence cluster Environmental Waste Management (EWMA) that as one of its important aims has advancing the knowledge of spreading of mine-tailing related contaminants. Here we give particular attention to the reconstruction of sedimentation style, rate of sediment accumulation, as well as potential sediment transport paths (contaminants dispersion). Seventeen short cores (up to 21 cm long) were retrieved from sites covering the entire area of Repparfjorden. The cores were sliced into 1-cm intervals that are and will be analysed for grain-size, concentration of heavy metals and total organic carbon content of bulk sediment. Sediment chronologies are and will be derived using 210Pb and 137Cs dating techniques. An approximately 7-cm thick interval which is different from present fjord sedimentation was observed below c. 10 cm depth in three of the cores retrieved from the area of tailings deposition in the 1970's. Sediments of this discrete depth interval are mainly composed of mud or sandy mud with bimodal grain-size distribution (first mode: medium silt fraction; second mode: very coarse silt). They are characterised by very high Cu concentrations (>250 mg/kg). Preliminary measurements of the 210Pb activity indicate an increase in sediment accumulation rate during the deposition of this interval. Therefore, we interpret it to be mainly composed of mine tailing sediments. As this sediment interval was only observed in 3 of 17 cores, we suggest that the lateral extent of the tailings is restricted to a relatively small area of the fjord. However, elevated concentrations of Cu (40-80 mg/kg) were also detected in a discrete sediment interval (3-10 cm) in one core ˜3 km beyond the tailing deposition site. In addition, high Cu concentrations (60-190 mg/kg) in sediments between the seafloor and the tailing deposit, as well as some centimetres below the deposit (in all cores from the old tailing deposition site) suggest possible dispersion of Cu to the immediate surrounding sediments in the cores.

Mud volcano monitoring and seismic events along the North Anatolian Fault (Sea of Marmara)

NASA Astrophysics Data System (ADS)

Javad Fallahi, Mohammad; Lupi, Matteo; Mazzini, Adriano; Polonia, Alina; D'Alessandro, Antonino; D'Anna, Giuseppe; Gasperini, Luca

2017-04-01

The Sea of Marmara, a pull-apart basin formed along the northern strand of the North Anatolian Fault (NAF) system, is considered a seismic gap, that will be filled in the next decades by a large magnitude (M>7) earthquake, close to the Istanbul Metropolitan area (12 million inhabitants). For this reason, several marine geological and geophysical studies have been carried out in this region, starting from the destructive 1999 Mw 7.4 Izmit earthquake, to gather information relative to seismogenic potential of major fault strands. Together with these studies, in the frame of EC projects (i.e., MarmESONET and Marsite, among others), an intensive program of long-term monitoring of seismogenic faults was carried out using seafloor observatories deployed during several expeditions led by Italian, French and Turkish groups. These expeditions included MARM2013, on board of the R/V Urania, of the Italian CNR, when four ocean bottom seismometers (OBS) were deployed in the central part of the Sea of Marmara, at depths between 550 and 1000 m. One of the main aims of the experiment was to assess the long-term seismic activity along an active segment of the NAF, which connects the central and the western basins (depocenters), where the principal deformation zone appears relatively narrow and almost purely strike-slip. The present study shows the results of processing and analysis of continuous data records from these OBS stations during 50 days. We were able to detect seismic signal produced by an active mud volcano located close to the NAF trace, from about 3 to 6 km of distance from the OBS stations. Additionally, we captured the May 24, 2014, Mw 6.9 strike-slip earthquake occurred in the northern Aegean Sea between Greece and Turkey, which caused serious damage on the Turkish island of Imbros and the cities of Edirne and Çanakkale, as well as on the Greek island of Lemnos. The earthquake nucleated on the westward continuation of the NAF system in the NE Aegean Sea, and was felt in Bulgaria and southern Romania. Several aftershocks followed the main shock, the strongest measuring 5.3 of magnitude. To verify the effects of this external forcing on the activity of the submarine mud volcano in Marmara, we calculated the root-mean-square (RMS) and standard deviation (STD) on three-minute waveform segments in a period from 2014.04.11 to 2014.05.31 in the 10-25 Hz frequency band. In addition, we also calculated auto- and cross-correlation of seismic ambient noise in the same time-period and frequency range to assess the variations of waveform coherency prior to the earthquake. Preliminary results show periodic changes of RMS and STD amplitudes, which may result from the effects of tides, but no short- or long-term precursory signs of the earthquake detected by our approach.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

PubMed Central

Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

2015-01-01

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

Diplomacy Through Earth Sciences: An Overview of US Geological Survey Technical Assistance Regarding the Ongoing LUSI Mud Eruption, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Casadevall, T. J.

2009-12-01

In June 2007, the US Department of State (DOS) requested assistance from the USGS to provide technical guidance and advice to the US Mission in Indonesia regarding the Lumpur Sidoarjo (LUSI) mud crisis. In May 2006, LUSI began as a mud eruption from a series of mud springs adjacent to an oil and gas exploration well being drilled near Surabaya, East Java, Indonesia. The production of mud and waters from the LUSI crater area has now continued for more than 3 years with no significant change in mud production rate (~110,000 cubic meters per day) nor in temperature of the mud (70-80 degrees C). Engineers suggest that mud production will continue at these rates for years to decades to come. Regardless of future activity at LUSI, the current mud accumulation of more than 100 million cubic meters poses a physical and environmental hazard which requires continuous monitoring and observation. The first response to the 2007 DOS request involved a site visit to Indonesia in September 2007. The result of that visit was to recommend to the Government of Indonesia (GOI) that they focus on long-term management of the mud rather than focus on the controversy as to the cause of the eruption or the debate about stopping the flow. Other recommendations from the initial 2007 technical visit included contracting for a US scientist to be co-located with engineers of the Sidoarjo Mud Management Board (BPLS) in Surabaya, East Java, to advise and consult on day-to-day developments at the site of the mud eruption. A second technical team visit by USGS scientists and an engineer from the US Army Corps of Engineers in October-November 2008 made additional recommendations on the long-term management of the mud and was followed in December by the start of a 6 month contract for the US mud adviser. From the start of activity in mid-2006 through late-2008, there was a clear sense of urgency at the US Mission in Indonesia to provide guidance and advice and included the personal intervention of the new US Ambassador. The USGS has completed the requests made in the June 2007 DOS cable, including an initial characterization of the mud and fluids; an analysis of land surface changes using the INSAR method; and an assessment of the seismic hazards in East Java. In the coming year, USGS will assist DOI agencies in the geophysical monitoring of the LUSI area and in the continued characterization of mud and fluids produced by the eruption.

Large historical eruptions at subaerial mud volcanoes, Italy

NASA Astrophysics Data System (ADS)

Manga, M.; Bonini, M.

2012-11-01

Active mud volcanoes in the northern Apennines, Italy, currently have gentle eruptions. There are, however, historical accounts of violent eruptions and outbursts. Evidence for large past eruptions is also recorded by large decimeter rock clasts preserved in erupted mud. We measured the rheological properties of mud currently being erupted in order to evaluate the conditions needed to transport such large clasts to the surface. The mud is well-characterized by the Herschel-Bulkley model, with yield stresses between 4 and 8 Pa. Yield stresses of this magnitude can support the weight of particles with diameters up to several mm. At present, particles larger than this size are not being carried to the surface. The transport of larger clasts to the surface requires ascent speeds greater than their settling speed in the mud. We use a model for the settling of particles and rheological parameters from laboratory measurements to show that the eruption of large clasts requires ascent velocities > 1 m s-1, at least three orders of magnitude greater than during the present, comparatively quiescent, activity. After regional earthquakes on 20 May and 29 May 2012, discharge also increased at locations where the stress changes produced by the earthquakes would have unclamped feeder dikes below the mud volcanoes. The magnitude of increased discharge, however, is less than that inferred from the large clasts. Both historical accounts and erupted deposits are consistent in recording episodic large eruptions.

Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

USGS Publications Warehouse

Abessa, D.M.S.; Carr, R.S.; Rachid, B.R.F.; Sousa, E.C.P.M.; Hortelani, M.A.; Sarkis, J.E.

2005-01-01

The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the “Threshold Effect Level” values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted.

Discovery of siderite in marine sediment: Source and effect of violent gas venting at the Tsanyao Mud Volcano, offshore SW Taiwan

NASA Astrophysics Data System (ADS)

Tseng, Y.; Lin, S.; Hsieh, I. C.; Lien, K. L.

2016-12-01

Tsanyao mud volcano is a 400 meters high, 5 kilometers in diameter, a center crater of 50 meters width activing venting mud diapir. The gigantic size of mud volcano indicate massive transportation of material, i.e., gas, fluid, and breccia from deep to the sea floor in building up the mud volcano. The mud volcano is located at the upper slope of the accretionary wedge with a surrounding water depth of about xx m, offshore Southwestern Taiwan. On shore, a series of active mud volcanos also exist in a trend similar to those found offshore. In order to understand sources of gas, fluid, solid materials and the effect of gas migration and associate authigenic mineral formation, we have obtained multibeam bathymetry, water column echo sounding, together with sediment XRD and SEM and pore water composition of methane, sulfide, sulfate, chloride, potassium, lithium, boron, and water O-18 at the study mud volcano. We have observed more than 30 flares around the main cone within a perimeter of 10 square miles. δ13C values of methane in the pore water ranged from -30 to -50 ‰. The lower C13 ratios, together with high C2+/C1 ratios demonstrated that vent gas is mostly thermogenic in origin. Higher thermal gradient and water temperature indicated that cone top is unfavorable for gas-hydrate formation, however, gas hydrate may exist at a deeper part of the mud volcano system. High concentration of sulfide presence right near the sulfate-methane interface, a result of anoxic methane oxidation. However, low concentrations of pyrite in sediments indicated that AOM did not favor pyrite formation at depth. In addition, abundant siderite were found in the sediments collected in the mud volcano cone. Rapid consumption of sulfate through AOM reaction generated a condition favor the siderite fomation, instead of the typical pyrite formation commonly observed.

Deciphering Depositional Signals in the Bed-Scale Stratigraphic Record of Submarine Channels

NASA Astrophysics Data System (ADS)

Sylvester, Z.; Covault, J. A.

2017-12-01

Submarine channels are important conduits of sediment transfer from rivers and shallow-marine settings into the deep sea. As such, the stratigraphic record of submarine-channel systems can store signals of past climate- and other environmental changes in their upstream sediment-source areas. This record is highly fragmented as channels are primarily locations of sediment bypass; channelized turbidity currents are likely to leave a more complete record in areas away from and above the thalweg. However, the link between the thick-bedded axial channel deposits that record a small number of flows and the much larger number of thin-bedded turbidites forming terrace- and levee deposits is poorly understood. We have developed a relatively simple two-dimensional model that, given a number of input flow parameters (mean velocity, grain size, duration of deposition, flow thickness), predicts the thickness and composition of the turbidite that is left behind in the channel and in the overbank areas. The model is based on a Rouse-type suspended sediment concentration profile and the Garcia-Parker entrainment function. In the vertical direction, turbidites tend to rapidly become thinner and finer-grained with height above thalweg, due to decreasing concentration. High near-thalweg concentrations result in thick axial beds. However, an increase in flow velocity can result in high entrainment and no deposition at the bottom of the channel, yet a thin layer of sand and mud is still deposited higher up on the channel bank. If channel thalwegs are largely in a bypass condition, relatively minor velocity fluctuations result in a few occasionally preserved thick beds in the axis, and numerous thin turbidites - and a more complete record - on the channel banks. We use near-seafloor data from the Niger Delta slope and an optimization algorithm to show how our model can be used to invert for likely flow parameters and match the bed thickness and grain size of 100 turbidites observed in a core taken from a slope channel terrace.

Giant submarine canyons: Is size any clue to their importance in the rock record?

USGS Publications Warehouse

Normark, William R.; Carlson, Paul R.

2003-01-01

Submarine canyons are the most important conduits for funneling sediment from continents to oceans. Submarine canyons, however, are zones of sediment bypassing, and little sediment accumulates in the canyon until it ceases to be an active conduit. To understand the potential importance in the rock record of any given submarine canyon, it is necessary to understand sediment-transport processes in, as well as knowledge of, deep-sea turbidite and related deposits that moved through the canyons. There is no straightforward correlation between the final volume of the sedimentary deposits and size of the associated submarine canyons. Comparison of selected modern submarine canyons together with their deposits emphasizes the wide range of scale differences between canyons and their impact on the rock record.Three of the largest submarine canyons in the world are incised into the Beringian (North American) margin of the Bering Sea. Zhemchug Canyon has the largest cross-section at the shelf break and greatest volume of incision of slope and shelf. The Bering Canyon, which is farther south in the Bering Sea, is first in length and total area. In contrast, the largest submarine fans-e.g., Bengal, Indus, and Amazon-have substantially smaller, delta-front submarine canyons that feed them; their submarine drainage areas are one-third to less than one-tenth the area of Bering Canyon. some very large deep-sea channels and tubidite deposits are not even associated with a significant submarine canyon; examples include Horizon Channel in the northeast Pacific and Laurentian Fan Valley in the North Atlantic. Available data suggest that the size of turbidity currents (as determined by volume of sediment transported to the basins) is also not a reliable indicator of submarine canyon size.

Influence of red mud on soil microbial communities: Application and comprehensive evaluation of the Biolog EcoPlate approach as a tool in soil microbiological studies.

PubMed

Feigl, Viktória; Ujaczki, Éva; Vaszita, Emese; Molnár, Mónika

2017-10-01

Red mud can be applied as soil ameliorant to acidic, sandy and micronutrient deficient soils. There are still knowledge gaps regarding the effects of red mud on the soil microbial community. The Biolog EcoPlate technique is a promising tool for community level physiological profiling. This study presents a detailed evaluation of Biolog EcoPlate data from two case studies. In experiment "A" red mud from Ajka (Hungary) was mixed into acidic sandy soil in soil microcosms at 5-50 w/w%. In experiement "B" red mud soil mixture was mixed into low quality subsoil in a field experiment at 5-50 w/w%. According to average well color development, substrate average well color development and substrate richness 5-20% red mud increased the microbial activity of the acidic sandy soil over the short term, but the effect did not last for 10months. Shannon diversity index showed that red mud at up to 20% did not change microbial diversity over the short term, but the diversity decreased by the 10th month. 30-50% red mud had deteriorating effect on the soil microflora. 5-20% red mud soil mixture in the low quality subsoil had a long lasting enhancing effect on the microbial community based on all Biolog EcoPlate parameters. However, 50% red mud soil mixture caused a decrease in diversity and substrate richness. With the Biolog EcoPlate we were able to monitor the changes of the microbial community in red mud affected soils and to assess the amount of red mud and red mud soil mixture applicable for soil treatment in these cases. Copyright © 2017 Elsevier B.V. All rights reserved.

Warts phosphorylates Mud to promote Pins-mediated mitotic spindle orientation in Drosophila independent of Yorkie

PubMed Central

Dewey, Evan B.; Sanchez, Desiree; Johnston, Christopher A.

2015-01-01

SUMMARY Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control spindle orientation remain incompletely defined. Here we describe a role for the Hippo (Hpo) kinase complex in promoting Partner of Inscuteable (Pins)-mediated spindle orientation. Knockdown of Hpo, Salvador (Sav), or Warts (Wts) each result in a partial loss of spindle orientation, a phenotype previously described following loss of the Pins-binding protein Mushroom body defect (Mud). Similar to orthologs spanning yeast to mammals, Wts kinase localizes to mitotic spindle poles, a prominent site of Mud localization. Wts directly phosphorylates Mud in vitro within its C-terminal coiled-coil domain. This Mud coiled-coil domain directly binds the adjacent Pins-binding domain to dampen the Pins/Mud interaction, and Wts-mediated phosphorylation uncouples this intramolecular Mud interaction. Loss of Wts prevents cortical Pins/Mud association without affecting Mud accumulation at spindle poles, suggesting phosphorylation acts as a molecular switch to specifically activate cortical Mud function. Finally, loss of Wts in Drosophila imaginal disc epithelial cells results in diminished cortical Mud and defective planar spindle orientation. Our results provide new insights into the molecular basis for dynamic regulation of the cortical Pins/Mud spindle positioning complex and highlight a novel link with an essential, evolutionarily-conserved cell proliferation pathway. PMID:26592339

Warts phosphorylates mud to promote pins-mediated mitotic spindle orientation in Drosophila, independent of Yorkie.

PubMed

Dewey, Evan B; Sanchez, Desiree; Johnston, Christopher A

2015-11-02

Multicellular animals have evolved conserved signaling pathways that translate cell polarity cues into mitotic spindle positioning to control the orientation of cell division within complex tissue structures. These oriented cell divisions are essential for the development of cell diversity and the maintenance of tissue homeostasis. Despite intense efforts, the molecular mechanisms that control spindle orientation remain incompletely defined. Here, we describe a role for the Hippo (Hpo) kinase complex in promoting Partner of Inscuteable (Pins)-mediated spindle orientation. Knockdown of Hpo, Salvador (Sav), or Warts (Wts) each result in a partial loss of spindle orientation, a phenotype previously described following loss of the Pins-binding protein Mushroom body defect (Mud). Similar to orthologs spanning yeast to mammals, Wts kinase localizes to mitotic spindle poles, a prominent site of Mud localization. Wts directly phosphorylates Mud in vitro within its C-terminal coiled-coil domain. This Mud coiled-coil domain directly binds the adjacent Pins-binding domain to dampen the Pins/Mud interaction, and Wts-mediated phosphorylation uncouples this intramolecular Mud interaction. Loss of Wts prevents cortical Pins/Mud association without affecting Mud accumulation at spindle poles, suggesting phosphorylation acts as a molecular switch to specifically activate cortical Mud function. Finally, loss of Wts in Drosophila imaginal disc epithelial cells results in diminished cortical Mud and defective planar spindle orientation. Our results provide new insights into the molecular basis for dynamic regulation of the cortical Pins/Mud spindle positioning complex and highlight a novel link with an essential, evolutionarily conserved cell proliferation pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selective transport of palynomorphs in marine turbiditic deposits: An example from the Ascension-Monterey Canyon system offshore central California

USGS Publications Warehouse

McGann, Mary

2017-01-01

The pollen assemblage of a deep-sea core (15G) collected at lower bathyal depths (3491 m) on a levee of Monterey Canyon off central California was investigated to gain insights into the delivery processes of terrigenous material to submarine fans and the effect this transport has on the palynological record. Thirty-two samples were obtained down the length of the core, 19 from hemipelagic and mixed mud deposits considered to be the background record, and 13 others from displaced flow deposits. The pollen record obtained from the background samples documents variations in the terrestrial flora as it adapted to changing climatic conditions over the last 19,000 cal yrs BP. A Q-mode cluster analysis defined three pollen zones: a Glacial Pollen Zone (ca. 20,000–17,000 cal yr BP), an overlying Transitional Pollen Zone (ca. 17,000–11,500 cal yr BP), and an Interglacial Pollen Zone (ca. 11,500 cal yr BP to present). Another Q-mode cluster analysis, of both the background mud and flow deposits, also defined these three pollen zones, but four of the 13 turbiditic deposits were assigned to pollen zones older than expected by their stratigraphic position. This was due to these samples containing statistically significant fewer palynomorphs than the background muds as well as being enriched (∼10–35% in some cases) in hydraulically-efficient Pinus pollen. A selective bias in the pollen assemblage, such as demonstrated here, may result in incorrect interpretations (e.g., climatic shifts or environmental perturbations) based on the floral record, indicating turbiditic deposits should be avoided in marine palynological studies. Particularly in the case of fine-grained flow deposits that may not be visually distinct, granulometry and grain size frequency distribution curves may not be enough to identify these biased deposits. Determining the relative abundance and source of displaced shallow-water benthic foraminifera entrained in these sediments serves as an excellent additional tool to do so.

Seasonal influence over serum and urine metabolic markers in submariners during prolonged patrols

PubMed Central

Holy, Xavier; Bégot, Laurent; Renault, Sylvie; Butigieg, Xavier; André, Catherine; Bonneau, Dominique; Savourey, Gustave; Collombet, Jean-Marc

2015-01-01

Within the framework of earlier publications, we have consistently dedicated our investigations to eliciting the effects of both seasonal vitamin D deficiency and submarine-induced hypercapnia on serum parameters for acid–base balance and bone metabolism in submariners over a 2-month winter (WP) or summer (SP) patrols. The latest findings reported herein, contribute further evidence with regard to overall physiological regulations in the same submariner populations that underwent past scrutiny. Hence, urine and blood samples were collected in WP and SP submariners at control prepatrol time as well as on submarine patrol days 20, 41, and 58. Several urine and serum metabolic markers were quantified, namely, deoxypyridinoline (DPD), lactate, albumin, creatinine, nonesterified fatty acids (NEFA), and ionized sodium (Na+) or potassium (K+), with a view to assessing bone, muscle, liver, or kidney metabolisms. We evidenced bone metabolism alteration (urine DPD, calcium, and phosphorus) previously recorded in submarine crewmembers under prolonged patrols. We also highlighted transitory modifications in liver metabolism (serum albumin) occurring within the first 20 days of submersion. We further evidenced changes in submariners’ renal physiology (serum creatinine) throughout the entire patrol time span. Measurements of ionic homeostasis (serum Na+ and K+) displayed potential seasonal impact over active ionic pumps in submariners. Finally, there is some evidence that submersion provides beneficial conditions prone to fend off seasonal lactic acidosis (serum lactate) detected in WP submariners. PMID:26265754

Origin of Abiotic Methane in Submarine Hydrothermal Systems

NASA Astrophysics Data System (ADS)

Seewald, J. S.; German, C. R.; Grozeva, N. G.; Klein, F.; McDermott, J. M.; Ono, S.; Reeves, E. P.; Wang, D. T.

2018-05-01

Results of recent investigations into the chemical and isotopic composition of actively venting submarine hydrothermal fluids and volatile species trapped in fluid inclusions will be discussed in the context of processes responsible for abiotic CH4 formation.

The Relationship of Job Performance to Physical Fitness and Its Application to U. S. Navy Submariners

DTIC Science & Technology

1981-09-29

stressful conditions. Limitation of physical activity, desynchronization of circadian rhythms, adverse work -rest cycles, lack of privacy, and altered...Physical Fitness Aboard Submarines 11 6.2 Disease and Coronary Artery Disease Risk Factors in Submarines 12 6.3 Fatigue, Work -Rest Cycles, and...1974). Stress and disease appear to be related, since organ systems function poorly during periods of stress . Therefore, stress has been viewed as

Calcium, Magnesium, and Phosphorus Metabolism, and Parathyroid- Calcitonin Function during Prolonged Exposure to Elevated CO2 Concentrations on Submarines

DTIC Science & Technology

1975-12-01

renal regulation, determine acid- base balance. calcitonin activity calcium excretion chronic hypercapnia magnesium parathyroid phosphorus...Mg increased. An important aspect of acid- base and electrolyte balance is the renal handling of an acid load. Figure 2 presents data on urine...E. SCHAEFER Navat Submarine Medical Research Laboratory, Naval Submarine Base , Groton, CT 06340 Messier, A. A., E. Heyder, W. R. Braithwaite, C

Aerial monitoring in active mud volcano by UAV technique

NASA Astrophysics Data System (ADS)

Pisciotta, Antonino; Capasso, Giorgio; Madonia, Paolo

2016-04-01

UAV photogrammetry opens various new applications in the close range domain, combining aerial and terrestrial photogrammetry, but also introduces low-cost alternatives to the classical manned aerial photogrammetry. Between 2014 and 2015 tree aerial surveys have been carried out. Using a quadrotor drone, equipped with a compact camera, it was possible to generate high resolution elevation models and orthoimages of The "Salinelle", an active mud volcanoes area, located in territory of Paternò (South Italy). The main risks are related to the damages produced by paroxysmal events. Mud volcanoes show different cyclic phases of activity, including catastrophic events and periods of relative quiescence characterized by moderate activity. Ejected materials often are a mud slurry of fine solids suspended in liquids which may include water and hydrocarbon fluids, the bulk of released gases are carbon dioxide, with some methane and nitrogen, usually pond-shaped of variable dimension (from centimeters to meters in diameter). The scope of the presented work is the performance evaluation of a UAV system that was built to rapidly and autonomously acquire mobile three-dimensional (3D) mapping data in a volcanic monitoring scenario.

“Edifice Rex” Sulfide Recovery Project: Analysis of submarine hydrothermal, microbial habitat

NASA Astrophysics Data System (ADS)

Delaney, John R.; Kelley, Deborah S.; Mathez, Edmond A.; Yoerger, Dana R.; Baross, John; Schrenk, Matt O.; Tivey, Margaret K.; Kaye, Jonathan; Robigou, Veronique

Recent scientific developments place inquiries about submarine volcanic systems in a broad planetary context. Among these is the discovery that submarine eruptions are intimately linked with massive effusions of microbes and their products from below the sea floor [Holden et al., 1998]. This material includes microbes that only grow at temperatures tens of degrees higher than the temperatures of the vent fluids from which they were sampled. Such results lend support for the existence of a potentially extensive, but currently unexplored sub-sea floor microbial biosphere associated with active submarine volcanoes [Deming and Baross, 1993; Delaney et al., 1998; Summit and Baross, 1998].

Methanogenic activity and diversity in the centre of the Amsterdam Mud Volcano, Eastern Mediterranean Sea.

PubMed

Lazar, Cassandre Sara; John Parkes, R; Cragg, Barry A; L'Haridon, Stephane; Toffin, Laurent

2012-07-01

Marine mud volcanoes are geological structures emitting large amounts of methane from their active centres. The Amsterdam mud volcano (AMV), located in the Anaximander Mountains south of Turkey, is characterized by intense active methane seepage produced in part by methanogens. To date, information about the diversity or the metabolic pathways used by the methanogens in active centres of marine mud volcanoes is limited. (14)C-radiotracer measurements showed that methylamines/methanol, H(2)/CO(2) and acetate were used for methanogenesis in the AMV. Methylotrophic methanogenesis was measured all along the sediment core, Methanosarcinales affiliated sequences were detected using archaeal 16S PCR-DGGE and mcrA gene libraries, and enrichments of methanogens showed the presence of Methanococcoides in the shallow sediment layers. Overall acetoclastic methanogenesis was higher than hydrogenotrophic methanogenesis, which is unusual for cold seep sediments. Interestingly, acetate porewater concentrations were extremely high in the AMV sediments. This might be the result of organic matter cracking in deeper hotter sediment layers. Methane was also produced from hexadecanes. For the most part, the methanogenic community diversity was in accordance with the depth distribution of the H(2)/CO(2) and acetate methanogenesis. These results demonstrate the importance of methanogenic communities in the centres of marine mud volcanoes. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

U.S. Geological survey program on toxic waste--ground-water contamination; proceedings of the Second technical meeting, Cape Cod, Massachusetts, October 21-25, 1985

USGS Publications Warehouse

Ragone, S.E.

1988-01-01

This study characterizes the clay minerals in sediments associated with a plume of creosote-contaminated groundwater. The plume of contaminated groundwater near Pensacola, FL, is in shallow, permeable, Miocene to Holocene quartz sand and flows southward toward Pensacola Bay. Clay-size fractions were separated from 41 cores, chiefly split-spoon samples at 13 drill sites. The most striking feature of the chemical analyses of the clay fractions from uncontaminated site 2 and contaminated sites 4,5,6, and 7 is the variability of iron oxide (species in some samples as Fe2O3); total iron oxide abundance is lowest (2.5%) in uncontaminated sample 2-40, but is > 4.5% (4.5 to 8.5%) in the remaining assemblages. One feature suggesting interaction between the indigenous clays and the waste plume is the presence of nontronite-rich smectite. Nontronite commonly has been identified as the product of hydrothermal alteration and deep-sea weathering of submarine basalts; it is not a common constituent of Cenozoic Gulf Coast sediments. At the Pensacola site, relatively abundant nontronitic smectite is confined to contaminated sands or associated muds; it is least abundant or absent in sands and muds peripheral to the waste plume. The geochemistry of the waste plume, its substantial dissolved, (chiefly ferrous iron), mildly acidic (pH 5-6), and low redox composition, provides an environment similar to that previously determined for the low-temperature synthesis of nontronite. Data from clay-size fractions confirm conclusions that neoformed pyrite in some grain coatings occurs in an assemblage with excess iron over that required in the pyrite. Continuing studies to evaluate these tentative conclusions include: (1) chemical analysis of clay fractions from remaining sites to further examine the apparent relation between iron content and abundance of nontronitic smectite; (2) clay separation and analysis, and pore fluid extraction (squeezing or ultracentrifugation) and analysis from a continuous core through the mud lens to determine pore fluid composition (presence or absence of waste fluid), and character of associated clay minerals; and (3) clay separation and analysis in both permeable sands and the intervening mud lens that are clearly outside the limits of the waste plume to further document the effects of the plume. (See also W90-00022) (Lantz-PTT)

Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

NASA Astrophysics Data System (ADS)

López-Rodríguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruíz, F.; Comas, M.; Sinninghe Damsté, J. S.

2013-11-01

Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the Western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocenter containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, Anaerobic Oxidation of Methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n-alkane-distributions and n-alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S + 22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotropic archaea (irregular isoprenoids and DGDs) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected GDGTs, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggest no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

Gas hydrates and active mud volcanism on the South Shetland continental margin, Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Tinivella, U.; Accaino, F.; Della Vedova, B.

2008-04-01

During the Antarctic summer of 2003 2004, new geophysical data were acquired from aboard the R/V OGS Explora in the BSR-rich area discovered in 1996 1997 along the South Shetland continental margin off the Antarctic Peninsula. The objective of the research program, supported by the Italian National Antarctic Program (PNRA), was to verify the existence of a potential gas hydrate reservoir and to reconstruct the tectonic setting of the margin, which probably controls the extent and character of the diffused and discontinuous bottom simulating reflections. The new dataset, i.e. multibeam bathymetry, seismic profiles (airgun and chirp), and two gravity cores analysed by computer-aided tomography as well as for gas composition and content, clearly shows active mud volcanism sustained by hydrocarbon venting in the region: several vents, located mainly close to mud volcanoes, were imaged during the cruise and their occurrence identified in the sediment samples. Mud volcanoes, vents and recent slides border the gas hydrate reservoir discovered in 1996 1997. The cores are composed of stiff silty mud. In core GC01, collected in the proximity of a mud volcano ridge, the following gases were identified (maximum contents in brackets): methane (46 μg/kg), pentane (45), ethane (35), propane (34), hexane (29) and butane (28). In core GC02, collected on the flank of the Vualt mud volcano, the corresponding data are methane (0 μg/kg), pentane (45), ethane (22), propane (0), hexane (27) and butane (25).

The Keelung Submarine volcanoes and gas plumes in the nearshore of northern Taiwan

NASA Astrophysics Data System (ADS)

Huang, J. C.; Tsia, C. H.; Hsu, S. K.; Lin, S. S.

2016-12-01

Taiwan is located in the collision zone between Philippine Sea Plate and Eurasian Plate. The Philippine Sea Plate subducts northward beneath the Ryukyu arc system while the Eurasian Plate subducts eastward beneath the Luzon arc system. The Taiwan mountain building started at 9 My ago and the most active collision has migrated to middle Taiwan. In consequence, the northern Taiwan has changed its stress pattern from forms a series of thrust faults to normal faults. The stress pattern change has probably induced the post-collisional extension and volcanism in and off northern Taiwan. Under such a tectonic environment, the volcanism and gas plumes are widespread in northern Taiwan and its offshore area. Among the volcanoes of the northern Taiwan volcanic zone, the Tatun Volcano Group is the most obvious one. In this study, we use sub-bottom profiler, EK500 echo sounder, and multibeam echo sounder to study the geophysical structure of a submarine volcano in the nearshore of northern Taiwan. We have analyzed the shallow structures and identified the locations of the gas plumes. The identification of the gas plumes can help us understand the nature of the submarine volcano. Our results show that the gas plumes appear near the Kanchiao Fault and Keelung islet. Some intrusive volcanoes can be observed in the subbottom profiler data. Finally, according to the observations, we found that the Keelung Submarine Volcano is still active. We need the monitor of the active Keelung Submarine Volcano to avoid the volcanic hazard. Additionally, we need to pay attention to the earthquakes related to the Keelung Submarine Volcano.

Multi-stage formation of La Fossa Caldera (Vulcano Island, Italy) from an integrated subaerial and submarine analysis

NASA Astrophysics Data System (ADS)

Casalbore, D.; Romagnoli, C.; Bosman, A.; De Astis, G.; Lucchi, F.; Tranne, C. A.; Chiocci, F. L.

2018-06-01

The analysis of multibeam bathymetry, seismic profiles, ROV dive and seafloor sampling, integrated with stratigraphic and geological data derived from subaerial field studies, provides information on the multi-stage formation and evolution of La Fossa Caldera at the active volcanic system of Vulcano (Aeolian Islands). The caldera is mostly subaerial and delimited by well-defined rims associated to three different collapse events occurred at about 80, 48-24, and 13-8 ka, respectively. The NE part of the caldera presently lies below the sea-level and is delimited by two partially degraded rim segments, encompassing a depressed and eroded area of approximately 2 km2. We present here further morphological and petrochemical evidence linking the subaerial caldera rims to its submarine counterparts. Particularly, one of the submarine rims can be directly correlated with the subaerial eastern caldera border related to the intermediate (48-24 ka) collapse event. The other submarine rim cannot be directly linked to any subaerial caldera rim, because of the emplacement of the Vulcanello lava platform during the last 2 millennia that interrupts the caldera border. However, morphological interpretation and the trachyte composition of dredged lavas allow us to associate this submarine rim with the younger (13-8 ka) caldera collapse event that truncated the trachyte-rhyolite Monte Lentia dome complex in the NW sector of Vulcano. The diachronicity of the different collapse events forming the La Fossa Caldera can also explain the morpho-structural mismatch of some hundreds of meters between the two submarine caldera rims. A small part of this offset could be also accounted by tectonic displacement along NE-SW trending lineaments breaching and dismantling the submarine portion of the caldera. A network of active erosive gullies, whose headwall arrive up to the coast, is in fact responsible of the marked marine retrogressive erosion affecting the NE part of the caldera, where remnants of intra-caldera volcanic activity are still evident. Submarine morphological features associated to the entrance of subaerial lava flow units into the sea are presented, particularly related to the construction of the La Fossa Cone and Vulcanello. More generally, this study demonstrates the utility of integrated marine and subaerial studies to unravel the volcano-tectonic evolution of active insular volcanoes.

A comprehensive sediment dynamics study of a major mud belt system on the inner shelf along an energetic coast.

PubMed

Liu, James T; Hsu, Ray T; Yang, Rick J; Wang, Ya Ping; Wu, Hui; Du, Xiaoqin; Li, Anchun; Chien, Steven C; Lee, Jay; Yang, Shouye; Zhu, Jianrong; Su, Chih-Chieh; Chang, Yi; Huh, Chih-An

2018-03-09

Globally mud areas on continental shelves are conduits for the dispersal of fluvial-sourced sediment. We address fundamental issues in sediment dynamics focusing on how mud is retained on the seabed on shallow inner shelves and what are the sources of mud. Through a process-based comprehensive study that integrates dynamics, provenance, and sedimentology, here we show that the key mechanism to keep mud on the seabed is the water-column stratification that forms a dynamic barrier in the vertical that restricts the upward mixing of suspended sediment. We studied the 1000 km-long mud belt that extends from the mouth of the Changjiang (Yangtze) River along the coast of Zhejiang and Fujian Provinces of China and ends on the west coast of Taiwan. This mud belt system is dynamically attached to the fluvial sources, of which the Changjiang River is the primary source. Winter is the constructive phase when active deposition takes place of fine-grained sediment carried mainly by the Changjiang plume driven by Zhe-Min Coastal Currents southwestward along the coast.

Multidisciplinary research for the safe fruition of an active geosite: the Salse di Nirano mud volcanoes (Northern Apennines, Italy)

NASA Astrophysics Data System (ADS)

Coratza, Paola; Albarello, Dario; Cipriani, Anna; Cantucci, Barbara; Castaldini, Doriano; Conventi, Marzia; Dadomo, Andrea; De Nardo, Maria Teresa; Macini, Paolo; Martinelli, Giovanni; Mesini, Ezio; Papazzoni, Cesare Andrea; Quartieri, Simona; Ricci, Tullio; Santagata, Tommaso; Sciarra, Alessandra; Vezzalini, Giovanna

2017-04-01

Mud volcanoes are emissions of cold mud due to the ascent to the surface of salty and muddy waters mixed with gaseous (methane) and, in minor part, fluid hydrocarbons (petroleum veils) along faults and fractures. In the Northern Apennines mud volcanoes are closely linked to the active tectonic compression associated with thrusts of regional importance. They are mostly cone-shaped and show variable geometry and size, ranging from one to few metres, and are located in 19 sites in the northwestern part of the Apennines. Particularly noteworthy is the Nirano mud volcano field, located in the Fiorano Modenese district, which, with a surface area of approximately 75,000 m2, is one of the best developed and largest mud volcano field of the entire Italian territory and among the largest in Europe; it is thus protected as natural reserve (Salse di Nirano) since 1982. The Nirano mud volcanoes are found at the bottom of an elliptical depression, interpreted as a collapse-like structure (caldera) that may have developed in response to the deflation of a shallow mud chamber triggered by several ejections and evacuation of fluid sediments. There are several individual or multiple cones within the field of the mud volcanoes of Nirano, with a rather discontinuous activity; apparatuses become dormant or even extinct whereas new vents can appear in other spots. In the research here presented about 50 vents have been mapped and few of them appeared in May 2016. The mud volcanoes of the region have been known since a long time and have always aroused great interest due to their outstanding scenic value, and, in the past the mud volcano emissions have been used in many ways. Beside their cultural value, the mud volcanoes of the study area represent a tourist attractiveness as testified by the increasing number of visitors (e.g. about 70,000 visitors in 2015 in the Salse di Nirano Natural Reserve). Numerous initiatives, targeted at various potential users, have been developed in the last decades. In particular, tourist environmental maps, geotourism maps, books in hard copy and digital format, videos, virtual flights, multimedia and audio CDs have been implemented. Although the hazard from mud volcanoes is generally low, sometimes they may lead to sudden and violent eruptions and isolated casualties have been reported. Very notable case in this regard is the event that occurred in September 2014 in the Natural Reserve of Macalube di Aragona in Sicily where a mud volcano erupted, with an ejection of mud up to about 20 m above the ground and causing the burial of two children killing them. When a given geological site acquires a tourism value, it is necessary to assess the possible natural hazard processes which might threaten the safety of visitors. In particular, fast-occurring processes might directly involve tourists in proximity of the site of interest or along access roads and footpaths. In this context, multidisciplinary research, aiming at analysing the causes and understanding triggering mechanisms of paroxysmal and dangerous phenomena in the Natural Reserve of Nirano, are in progress, funded by the Fiorano municipality. The research team is composed by experts of different disciplines (geology, geomorphology, geophysics, geochemistry, palaeontology, mineralogy, topography) from different institutions. The first results of the multidisciplinary research here presented seem to confirm that no significant and dangerous phenomena can affect visitors along the pathways of the Reserve.

Prokaryotic diversity of an active mud volcano in the Usu City of Xinjiang, China.

PubMed

Yang, Hong-Mei; Lou, Kai; Sun, Jian; Zhang, Tao; Ma, Xiao-Long

2012-02-01

The Usu mud volcanoes are the largest group of terrestrial mud volcanoes in China. The volcanoes are located in a typical arid and semi-arid region, and the group consists of 36 erupting active mud volcanoes. In this study, the prokaryotic diversity and community structure in the sediment of an active mud volcano were investigated by constructing bacterial and archaeal clone libraries of the 16S rRNA gene. A total of 100 bacterial and 100 archaeal clones were analysed and found to comprise 11 and 7 distinct phylotypes, respectively. The bacterial phylotypes were classified into three phyla (Proteobacteria, Actinobacteria, and Fusobacteria). Of these, Proteobacteria were the most abundant bacterial group, with Deltaproteobacteria dominating the sediment community, and these were affiliated with the order Desulfuromonadales. The archaeal phylotypes were all closely related to uncultivated species, and the majority of the members were related to the orders Methanosarcinales and Halobacteriales of the Euryarchaeota originating from methane hydrate bearing or alkaline sediments. The rest of the archaeal phylotypes belonged to the phylum Crenarchaeota, with representatives from similar habitats. These results suggested that a large number of novel microbial groups and potential methanogenesis may exist in this unique ecosystem. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Utilization of red mud and Pb/Zn smelter waste for the synthesis of a red mud-based cementitious material.

PubMed

Li, Yuan-Cheng; Min, Xiao-Bo; Ke, Yong; Chai, Li-Yuan; Shi, Mei-Qing; Tang, Chong-Jian; Wang, Qing-Wei; Liang, Yan-Jie; Lei, Jie; Liu, De-Gang

2018-02-15

A new method in which Pb/Zn smelter waste containing arsenic and heavy metals (arsenic sludge), red mud and lime are utilized to prepare red mud-based cementitious material (RCM) is proposed in this study. XRD, SEM, FTIR and unconfined compressive strength (UCS) tests were employed to assess the physicochemical properties of RCM. In addition, ettringite and iron oxide-containing ettringite were used to study the hydration mechanism of RCM. The results show that the UCS of the RCM (red mud+arsenic sludge+lime) was higher than that of the binder (red mud+arsenic sludge). When the mass ratio of m (binder): m (lime) was 94:6 and then maintained 28days at ambient temperature, the UCS reached 12.05MPa. The red mud has potential cementitious characteristics, and the major source of those characteristics was the aluminium oxide. In the red mud-arsenic sludge-lime system, aluminium oxide was effectively activated by lime and gypsum to form complex hydration products. Some of the aluminium in ettringite was replaced by iron to form calcium sulfoferrite hydrate. The BCR and leaching toxicity results show that the leaching concentration was strongly dependent on the chemical speciation of arsenic and the hydration products. Therefore, the investigated red mud and arsenic sludge can be successfully utilized in cement composites to create a red mud-based cementitious material. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-term eruptive activity at a submarine arc volcano.

PubMed

Embley, Robert W; Chadwick, William W; Baker, Edward T; Butterfield, David A; Resing, Joseph A; de Ronde, Cornel E J; Tunnicliffe, Verena; Lupton, John E; Juniper, S Kim; Rubin, Kenneth H; Stern, Robert J; Lebon, Geoffrey T; Nakamura, Ko-ichi; Merle, Susan G; Hein, James R; Wiens, Douglas A; Tamura, Yoshihiko

2006-05-25

Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes.

Biogeochemical interactions among the arsenic, iron, humic substances, and microbes in mud volcanoes in southern Taiwan.

PubMed

Liu, Chia-Chuan; Maity, Jyoti Prakash; Jean, Jiin-Shuh; Sracek, Ondra; Kar, Sandeep; Li, Zhaohui; Bundschuh, Jochen; Chen, Chien-Yen; Lu, Hsueh-Yu

2011-01-01

Fluid and mud samples collected from Hsiaokunshui (HKS), Wushanting (WST), Yenshuikeng (YSK), Kunshuiping (KSP), Liyushan (LYS), and Sinyangnyuhu (SYNH) mud volcanoes of southwestern Taiwan were characterized for major ions, humic substances (HS) and trace elements concentrations. The relationship between the release of arsenic (As) and activities of sulfate-reducing bacteria has been assessed to understand relevant geochemical processes in the mud volcanoes. Arsenic (0.02-0.06 mg/L) and humic substances (4.13 × 10(-4) to 1.64 × 10(-3) mM) in the fluids of mud volcanoes showed a positive correlation (r = 0.99, p < 0.05) except in Liyushan mud volcano. Arsenic and iron in mud sediments formed two separate groups i) high As, but low Fe in HKS, WST, and SYNH; and ii) low As, but high Fe in the YSK, KSP, and LYS mud volcanoes. The Eh(S.H.E.) values of the mud volcano liquids were characterized by mild to strongly reducing conditions. The HKS, SYNH, and WST mud volcanoes (near the Chishan Fault) belongs to strong reducing environment (-33 to -116 mV), whereas the LYS, YSK, and KSP mud volcanoes located near the coastal plain are under mild reducing environment (-11 to 172 mV). At low Eh values mud volcanoes, saturation index (SI) values of poorly crystalline phases such as amorphous ferric hydroxide indicate understaturation, whereas saturation is reached in relatively high Eh(S.H.E.) values mud volcanoes. Arsenic contents in sediments are low, presumably due to its release to fluids (As/Fe ratio in YSK, KSP, and LYS sediment: 4.86 × 10(-4)-6.20 × 10(-4)). At low Eh(S.H.E.) values (mild to strong reducing environment), arsenic may co-precipitate with sulfides as a consequence of sulfate reduction (As/Fe ratios in WST, HKS, and SYNH sediments: 0.42-0.69).

H2O Contents of Submarine and Subaerial Silicic Pyroclasts from Oomurodashi Volcano, Northern Izu-Bonin Arc

NASA Astrophysics Data System (ADS)

McIntosh, I. M.; Tani, K.; Nichols, A. R.

2014-12-01

Oomurodashi volcano is an active shallow submarine silicic volcano in the northern Izu-Bonin Arc, located ~20 km south of the inhabited active volcanic island of Izu-Oshima. Oomurodashi has a large (~20km diameter) flat-topped summit located at 100 - 150 metres below sea level (mbsl), with a small central crater, Oomuro Hole, located at ~200 mbsl. Surveys conducted during cruise NT12-19 of R/V Natsushima in 2012 using the remotely-operated vehicle (ROV) Hyper-Dolphin revealed that Oomuro Hole contains numerous active hydrothermal vents and that the summit of Oomurodashi is covered by extensive fresh rhyolitic lava and pumice clasts with little biogenetic or manganese cover, suggesting recent eruption(s) from Oomuro Hole. Given the shallow depth of the volcano summit, such eruptions are likely to have generated subaerial eruption columns. A ~10ka pumiceous subaerial tephra layer on the neighbouring island of Izu-Oshima has a similar chemical composition to the submarine Oomurodashi rocks collected during the NT12-19 cruise and is thought to have originated from Oomurodashi. Here we present FTIR measurements of the H2O contents of rhyolitic pumice from both the submarine deposits sampled during ROV dives and the subaerial tephra deposit on Izu-Oshima, in order to assess magma degassing and eruption processes occurring during shallow submarine eruptions.

Red mud enhances methanogenesis with the simultaneous improvement of hydrolysis-acidification and electrical conductivity.

PubMed

Ye, Jie; Hu, Andong; Ren, Guoping; Zhou, Ting; Zhang, Guangming; Zhou, Shungui

2018-01-01

The role of red mud in the improvement of methanogenesis during sludge anaerobic digestion was innovatively investigated in this study. The results demonstrated that the addition of 20g/L red mud resulted in a 35.5% increase in methane accumulation. Red mud effectively promoted the hydrolysis-acidification of organic compounds in the sludge, which resulted in the increase of protein, polysaccharide, and VFAs by 5.1-94.5%. The activities of key enzymes were improved by 41.4-257.3%. Electrochemical measurements presented direct evidence that the electrical conductivity was significantly improved with red mud. More conductive magnetite was formed during the secondary mineralization after Fe(III) reduction by Fe (III)-reducing genes such as Clostridiaceae and Ruminococcaceae. The higher conductivity enhanced the electron transfer between the syntrophic bacteria (Geobacteraceae) and methanogens (Methanosaeta and Methanosarcina), and then improved the methanogenesis. This research provides a novel perspective on the synergism between sludge and red mud for methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Possible multihazard events (tsunamis, earthquakes, landslides) expected on the North Bulgarian Black sea coast

NASA Astrophysics Data System (ADS)

Ranguelov, B.; Gospodinopv, D.

2009-04-01

Earthquakes The area is famous with its seismic regime. The region usually shows non regular behavior of the strong events occurrence. There are episodes of activation and between them long periods of seismic quiescence. The most important one is at the I-st century BC when according to the chronicler Strabo, the ancient Greek colony "Bisone sank in the waters of the sea". The seismic source is known as Shabla-Kaliakra zone with the best documented seismic event of 31st March 1901. This event had a magnitude of 7.2 (estimated by the macroseismic transformation formula) with a source depth of about 10-20 km. The epicenter was located in the aquatory of the sea. The observed macroseismic intensity on the land reached the maximum value of X degree MSK. This event produced a number of secondary effects - landslides, rockfalls, subsidence, extensive destruction of the houses located around and tsunami (up to 3 meters height observed at Balchik port. This event is selected as referent one. Tsunamis Such earthquakes (magnitude greater then 7.0) almost always trigger tsunamis. They could be generated by the earthquake rupture process, or more frequently by the secondary triggered phenomena - landslides (submarine or surface) and/or other geodynamic phenomena - rock falls, degradation of gas hydrates, etc. the most famous water level change is described by Strabo - related to the great catastrophe. The area shows also some other expressions about tsunamis - the last one - a non seismic tsunami at 7th May, 2007 with maximum observed amplitudes of about 3 meters water level changes. Landslides The area on the north Bulgarian Black Sea coast is covered by many active landslides. They have different size, depth and activation time. Most of them are located near the coast line thus presenting huge danger about the beaches, tourist infrastructure, population and historical heritage. The most famous landslide (subsidence) is related with the I-st century BC seismic event, when a huge mass slide in the waters, buried Bisone and created the peak Chirakman. The event of 1901 also created landslides, subsidence of a huge land block with dimensions of about 1x1 km. and rock falls with large boulders. The landslide could be also submarine; creating is such way turbidities and/or mud flows from the bottom deposits like sapropel breccia and mud volcano depositions. The time dependent scenario The initial data about the time development of the hazards phenomena is based on their main physical properties - size, location, velocity of the process, intensity (magnitude), etc. The table about the main parameters, possible consequences and general threaten objects is created. The main time development of the disasters in case of the referent event (magnitude 7.2) is presented at the time chart diagram. The time chart development of the selected hazardous processes is presented as follows: Conclusions The time dependent scenario in case of a referent M7.2 seismic event is developed. The investigations about the consecutive and simultaneous action of all expected hazards and their multirisk effects are performed. The results obtained show the complex possible consequences and interrelated dependencies. Acknowledgments: This study is supported by the SCHEMA and TRANSFER EU Projects.

A Volcano of Mud or Lava?

NASA Image and Video Library

2018-06-11

This image from NASA's Mars Reconnaissance Orbiter (MRO) shows a hill with a central crater. Such features have been interpreted as both mud volcanoes (really a sedimentary structure) and as actual volcanoes (the erupting lava kind). They occur on the floor of Valles Marineris below a closed topographic contour that could have held a lake, and the compaction of wet sediments may have created mud volcanoes. The fracture pattern of the bright flow unit surrounding the hill resembles mud cracks. However, there have also been observations from the CRISM instrument interpreted as high-temperature minerals, suggesting actual volcanism, although not necessarily at this location. Fine layers in the hill are consistent with either volcanism or mud flows. Either way, this activity is relatively recent in geologic time and may mark habitable subsurface environments. https://photojournal.jpl.nasa.gov/catalog/PIA22514

Streamlined Approach for Environmental Restoration (SAFER) Plan for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada Test Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark Krauss

2010-07-01

This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the actions needed to achieve closure for Corrective Action Unit (CAU) 544, Cellars, Mud Pits, and Oil Spills, identified in the Federal Facility Agreement and Consent Order (FFACO). Corrective Action Unit 544 comprises the following 20 corrective action sites (CASs) located in Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada Test Site (NTS): • 02-37-08, Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mudmore » Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills This plan provides the methodology for field activities needed to gather the necessary information for closing each CAS. There is sufficient information and process knowledge from historical documentation and investigations of similar sites regarding the expected nature and extent of potential contaminants to recommend closure of CAU 544 using the SAFER process. Using the approach approved for previous mud pit investigations (CAUs 530–535), 14 mud pits have been identified that • are either a single mud pit or a system of mud pits, • are not located in a radiologically posted area, and • have no evident biasing factors based on visual inspections. These 14 mud pits are recommended for no further action (NFA), and further field investigations will not be conducted. For the sites that do not meet the previously approved closure criteria, additional information will be obtained by conducting a field investigation before selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible recommendation for closure of the remaining CASs in CAU 544. This will be presented in a closure report (CR) that will be prepared and submitted to the Nevada Division of Environmental Protection (NDEP) for review and approval. The sites will be investigated based on the data quality objectives (DQOs) developed on April 27, 2010, by representatives of NDEP and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). The DQO process was used to identify and define the type, amount, and quality of data needed to determine and implement appropriate corrective actions for each CAS in CAU 544. The DQO process developed for this CAU identified the following expected closure options: (1) investigation and confirmation that no contamination exists above the final action levels (FALs) leading to an NFA declaration, (2) characterization of the nature and extent of contamination leading to closure in place with use restrictions, (3) clean closure by remediation and verification, (4) closure in place with use restrictions with no investigation if CASs are in crater areas that have been determined to be unsafe to enter, or (5) NFA if the mud pit CAS meets the criteria established during the CAUs 530–535 SAFER investigation. The following summarizes the SAFER activities that will support the closure of CAU 544: • Perform visual inspection of all CASs. • Perform site preparation activities (e.g., utilities clearances, construction of temporary site exclusion zones). • Removal of easily managed, nonhazardous, and nonradioactive debris, including vegetation (e.g., tumbleweeds), at various CASs that interfere with sampling, if required to inspect soil surface or collect soil sample. • Collect environmental samples from designated target populations (e.g., mud pits, cellars, stained soil) to confirm or disprove the presence of contaminants of concern (COCs) as necessary to supplement existing information. • If no COCs are present at a CAS, establish NFA as the corrective action. • If COCs exist, collect environmental samples from designated target populations (e.g., clean soil adjacent to contaminated soil) and submit for laboratory analyses to define the extent of COC contamination. • If a COC is present at a CAS, either - Establish clean closure as the corrective action. The material to be remediated will be removed, disposed of as waste, and verification samples will be collected from remaining soil, or - Establish closure in place as the corrective action and implement the appropriate use restrictions. • Confirm the preferred closure option is sufficient to protect human health and the environment.« less

A giant, submarine creep zone as a precursor of large-scale slope instability offshore the Dongsha Islands (South China Sea)

NASA Astrophysics Data System (ADS)

Li, Wei; Alves, Tiago M.; Wu, Shiguo; Rebesco, Michele; Zhao, Fang; Mi, Lijun; Ma, Benjun

2016-10-01

A giant submarine creep zone exceeding 800 km2 on the continental slope offshore the Dongsha Islands, South China Sea, is investigated using bathymetric and 3D seismic data tied to borehole information. The submarine creep zone is identified as a wide area of seafloor undulations with ridges and troughs. The troughs form NW- and WNW-trending elongated depressions separating distinct seafloor ridges, which are parallel or sub-parallel to the continental slope. The troughs are 0.8-4.7 km-long and 0.4 to 2.1 km-wide. The ridges have wavelengths of 1-4 km and vertical relief of 10-30 m. Slope strata are characterised by the presence of vertically stacked ridges and troughs at different stratigraphic depths, but remaining relatively stationary in their position. The interpreted ridges and troughs are associated with large-scale submarine creep, and the troughs can be divided into three types based on their different internal characters and formation processes. The large-scale listric faults trending downslope below MTD 1 and horizon T0 may be the potential glide planes for the submarine creep movement. High sedimentation rates, local fault activity and the frequent earthquakes recorded on the margin are considered as the main factors controlling the formation of this giant submarine creep zone. Our results are important to the understanding of sediment instability on continental slopes as: a) the interpreted submarine creep is young, or even active at present, and b) areas of creeping may evolve into large-scale slope instabilities, as recorded by similar large-scale events in the past.

New access to the deep interior of the Nankai accretionary complex and comprehensive characterization of subduction inputs and recent mega splay fault activity (IODP-NanTroSEIZE Expedition 338)

NASA Astrophysics Data System (ADS)

Strasser, Michael; Moore, Gregory F.; Kanagawa, Kyuichi; Dugan, Brandon; Fabbri, Olivier; Toczko, Sean; Maeda, Lena

2013-04-01

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is a coordinated, multi-expedition Integrated Ocean Drilling Program (IODP) drilling project designed to investigate fault mechanics and seismogenesis along subduction megathrusts through direct sampling, in situ measurements, and long-term monitoring in conjunction with allied laboratory and numerical modeling studies. IODP Expedition 338 (1 October 2012 - 13 January 2013), extended riser Hole C0002F from 856 meters below the sea floor (mbsf) to 2005 mbsf. Site C0002 is the centerpiece of the NanTroSEIZE project, and is planned to be deepened to eventually reach the seismogenic fault zone during upcoming drilling expeditions. The original Exp. 338 operational plan to case the hole to 3600 mbsf had to be revised as sudden changes in sea conditions resulted in damage to parts of the riser system, thus the hole was suspended at 2005 mbsf but left for future re-entry. The revised operation plan included additional riserless logging and coring of key targets not sampled during previous NanTroSEIZE expeditions, but relevant to comprehensively characterize the alteration stage of the oceanic basement input to the subduction zone, the early stage of Kumano Basin evolution and the recent activity of the shallow mega splay fault zone system and submarine landslides. Here we present preliminary results from IODP Exp. 338: Logging While Drilling (LWD), mud gas monitoring and analysis on cuttings from the deep riser hole characterize two lithological units within the internal accretionary prism, separated by a prominent fault zone at ~1640 mbsf. Internal style of deformation, downhole increase of thermogenically formed formation gas and evidence for mechanical compaction and cementation document a complex structural evolution and provide unprecedented insights into the mechanical state and behavior of the wedge at depth. Additionally, multiple samples of the unconformity between the Kumano Basin and accretionary prism at Site C0002 shed new light on this debatable unconformity boundary and suggest variable erosional processes active on small spatial scales. Results from riserless drilling at input Site C0012 include 178.7 m of detailed LWD characterization of the oceanic basement, indicating an upper ~100 m zone of altered pillow basalts and sheet flow deposits, and a lower, presumably less altered basement unit without indication for interlayered sediment horizons. Low angle faults identified in X-ray Computed Tomography images and structural investigation on cores from Site C0022, located in the slope basin immediately seaward of the megasplay fault zone, indicate splay-fault-related, out-of-sequence thrusting within slope basin sediments and shed new light on recent activity of the megasplay. Lastly, Exp. 338 added additional coring to improve our understanding of submarine landslides in the slope basins seaward of the splay fault and yields new LWD data to characterize in situ internal structures and properties of mass-transport deposits as it relates to the dynamics and kinematics of submarine landslides.

Influence of dust and mud on the optical, chemical, and mechanical properties of a pv protective glass

NASA Astrophysics Data System (ADS)

Yilbas, Bekir Sami.; Ali, Haider; Khaled, Mazen M.; Al-Aqeeli, Nasser; Abu-Dheir, Numan; Varanasi, Kripa K.

2015-10-01

Recent developments in climate change have increased the frequency of dust storms in the Middle East. Dust storms significantly influence the performances of solar energy harvesting systems, particularly (photovoltaic) PV systems. The characteristics of the dust and the mud formed from this dust are examined using various analytical tools, including optical, scanning electron, and atomic force microscopies, X-ray diffraction, energy spectroscopy, and Fourier transform infrared spectroscopy. The adhesion, cohesion and frictional forces present during the removal of dry mud from the glass surface are determined using a microtribometer. Alkali and alkaline earth metal compounds in the dust dissolve in water to form a chemically active solution at the glass surface. This solution modifies the texture of the glass surface, thereby increasing the microhardness and decreasing the transmittance of the incident optical radiation. The force required to remove the dry mud from the glass surface is high due to the cohesive forces that result from the dried mud solution at the interface between the mud and the glass. The ability altering the characteristics of the glass surface could address the dust/mud-related limitations of protective surfaces and has implications for efficiency enhancements in solar energy systems.

Influence of dust and mud on the optical, chemical, and mechanical properties of a pv protective glass.

PubMed

Yilbas, Bekir Sami; Ali, Haider; Khaled, Mazen M; Al-Aqeeli, Nasser; Abu-Dheir, Numan; Varanasi, Kripa K

2015-10-30

Recent developments in climate change have increased the frequency of dust storms in the Middle East. Dust storms significantly influence the performances of solar energy harvesting systems, particularly (photovoltaic) PV systems. The characteristics of the dust and the mud formed from this dust are examined using various analytical tools, including optical, scanning electron, and atomic force microscopies, X-ray diffraction, energy spectroscopy, and Fourier transform infrared spectroscopy. The adhesion, cohesion and frictional forces present during the removal of dry mud from the glass surface are determined using a microtribometer. Alkali and alkaline earth metal compounds in the dust dissolve in water to form a chemically active solution at the glass surface. This solution modifies the texture of the glass surface, thereby increasing the microhardness and decreasing the transmittance of the incident optical radiation. The force required to remove the dry mud from the glass surface is high due to the cohesive forces that result from the dried mud solution at the interface between the mud and the glass. The ability altering the characteristics of the glass surface could address the dust/mud-related limitations of protective surfaces and has implications for efficiency enhancements in solar energy systems.

Are by-products from beeswax recycling process a new promising source of bioactive compounds with biomedical properties?

PubMed

Giampieri, Francesca; Quiles, José L; Orantes-Bermejo, Francisco J; Gasparrini, Massimiliano; Forbes-Hernandez, Tamara Y; Sánchez-González, Cristina; Llopis, Juan; Rivas-García, Lorenzo; Afrin, Sadia; Varela-López, Alfonso; Cianciosi, Danila; Reboredo-Rodriguez, Patricia; Fernández-Piñar, Cristina Torres; Iglesias, Ruben Calderón; Ruiz, Roberto; Aparicio, Silvia; Crespo, Jorge; Dzul Lopez, Luis; Xiao, Jianbo; Battino, Maurizio

2018-02-01

During the process of beeswax recycling, many industrial derivatives are obtained. These matrices may have an interesting healthy and commercial potential but to date they have not been properly studied. The aim of the present work was to evaluate the proximal and phytochemical composition, the antioxidant capacity and cytotoxic effects of two by-products from beeswax recycling process named MUD 1 and MUD 2 on liver hepatocellular carcinoma. Our results showed that MUD 1 presented the highest (P < .05) fiber, protein, carbohydrate, polyphenol and flavonoid concentration, as well as the highest (P < .05) total antioxidant capacity than the MUD 2 samples. MUD1 exerted also anticancer activity on HepG2 cells, by reducing cellular viability, increasing intracellular ROS levels and affecting mitochondrial functionality in a dose-dependent manner. We showed for the first time that by-products from beeswax recycling process can represent a rich source of phytochemicals with high total antioxidant capacity and anticancer activity; however, further researches are necessary to evaluate their potentiality for human health by in vivo studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Frequency-Magnitude relationships for Underwater Landslides of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Urgeles, R.; Gràcia, E.; Lo Iacono, C.; Sànchez-Serra, C.; Løvholt, F.

2017-12-01

An updated version of the submarine landslide database of the Mediterranean Sea contains 955 MTDs and 2608 failure scars showing that submarine landslides are ubiquitous features along Mediterranean continental margins. Their distribution reveals that major deltaic wedges display the larger submarine landslides, while seismically active margins are characterized by relatively small failures. In all regions, landslide size distributions display power law scaling for landslides > 1 km3. We find consistent differences on the exponent of the power law depending on the geodynamic setting. Active margins present steep slopes of the frequency-magnitude relationship whereas passive margins tend to display gentler slopes. This pattern likely responds to the common view that tectonically active margins have numerous but small failures, while passive margins have larger but fewer failures. Available age information suggests that failures exceeding 1000 km3 are infrequent and may recur every 40 kyr. Smaller failures that can still cause significant damage might be relatively frequent, with failures > 1 km3 likely recurring every 40 years. The database highlights that our knowledge of submarine landslide activity with time is limited to a few tens of thousand years. Available data suggest that submarine landslides may preferentially occur during lowstand periods, but no firm conclusion can be made on this respect, as only 149 landslides (out of 955 included in the database) have relatively accurate age determinations. The timing and regional changes in the frequency-magnitude distribution suggest that sedimentation patterns and pore pressure development have had a major role in triggering slope failures and control the sediment flux from mass wasting to the deep basin.

Fine-Scale Volume Heterogeneity in a Mixed Sand/Mud Sediment Off Fort Walton Beach, FL

DTIC Science & Technology

2010-07-01

by Vaughan et al. [4]. Subsequent to the mud drape, wind-wave activity mobilized sediment and some of the mud layer was resuspended, and sand from...hardening effects, which is a common issue with polychromatic energy sources, such as the HD-500 and medical CT systems. Beam hardening is a process...provides a convenient characterization of levels of heterogeneity. The CV is defined as the standard devi - ation divided by the mean and multiplied by

Long-term eruptive activity at a submarine arc volcano

USGS Publications Warehouse

Embley, R.W.; Chadwick, W.W.; Baker, E.T.; Butterfield, D.A.; Resing, J.A.; de Ronde, Cornel E. J.; Tunnicliffe, V.; Lupton, J.E.; Juniper, S.K.; Rubin, K.H.; Stern, R.J.; Lebon, G.T.; Nakamura, K.-I.; Merle, S.G.; Hein, J.R.; Wiens, D.A.; Tamura, Y.

2006-01-01

Three-quarters of the Earth's volcanic activity is submarine, located mostly along the mid-ocean ridges, with the remainder along intraoceanic arcs and hotspots at depths varying from greater than 4,000 m to near the sea surface. Most observations and sampling of submarine eruptions have been indirect, made from surface vessels or made after the fact. We describe here direct observations and sampling of an eruption at a submarine arc volcano named NW Rota-1, located 60 km northwest of the island of Rota (Commonwealth of the Northern Mariana Islands). We observed a pulsating plume permeated with droplets of molten sulphur disgorging volcanic ash and lapilli from a 15-m diameter pit in March 2004 and again in October 2005 near the summit of the volcano at a water depth of 555 m (depth in 2004). A turbid layer found on the flanks of the volcano (in 2004) at depths from 700 m to more than 1,400 m was probably formed by mass-wasting events related to the eruption. Long-term eruptive activity has produced an unusual chemical environment and a very unstable benthic habitat exploited by only a few mobile decapod species. Such conditions are perhaps distinctive of active arc and hotspot volcanoes. ?? 2006 Nature Publishing Group.

Radioactivity of peat mud used in therapy.

PubMed

Karpińska, Maria; Mnich, Krystian; Kapała, Jacek; Bielawska, Agnieszka; Kulesza, Grzegorz; Mnich, Stanisław

2016-02-01

The aim of the study was to determine the contents of natural and artificial isotopes in peat mud and to estimate the radiation dose absorbed via skin in patients during standard peat mud treatment. The analysis included 37 samples collected from 8 spas in Poland. The measurements of isotope concentration activity were conducted with the use of gamma spectrometry methods. The skin dose in a standard peat mud bath therapy is approximately 300 nSv. The effective dose of such therapy is considered to be 22 nSv. The doses absorbed during peat mud therapy are 5 orders of magnitude lower than effective annual dose absorbed from the natural radiation background by a statistical Pole (3.5 mSv). Neither therapeutic nor harmful effect is probable in case of such a small dose of ionising radiation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Origin of lipid biomarkers in mud volcanoes from the Alboran Sea, western Mediterranean

NASA Astrophysics Data System (ADS)

López-Rodríguez, C.; Stadnitskaia, A.; De Lange, G. J.; Martínez-Ruíz, F.; Comas, M.

2014-06-01

Mud volcanoes (MVs) are the most prominent indicators of active methane/hydrocarbon venting at the seafloor on both passive and active continental margins. Their occurrence in the western Mediterranean is patent at the West Alboran Basin, where numerous MVs develop overlaying a major sedimentary depocentre containing overpressured shales. Although some of these MVs have been studied, the detailed biogeochemistry of expelled mud so far has not been examined in detail. This work provides the first results on the composition and origin of organic matter, anaerobic oxidation of methane (AOM) processes and general characteristics on MV dynamics using lipid biomarkers as the main tool. Lipid biomarker analysis was performed on MV expelled material (mud breccias) and interbedded hemipelagic sediments from Perejil, Kalinin and Schneider's Heart MVs located in the northwest margin of the Alboran Sea. The n alkane distributions and n alkane-derived indices (CPI and ACL), in combination with the epimerization degree of hopanes (22S/(22S+22R)) indicate that all studied mud breccia have a similar biomarker composition consisting of mainly thermally immature organic matter with an admixture of petroleum-derived compounds. This concordant composition indicates that common source strata must feed all three studied MVs. The past or present AOM activity was established using lipid biomarkers specific for anaerobic methanotrophic archaea (irregular isoprenoids and dialkyl glycerol diethers) and the depleted carbon isotope composition (δ13C) of crocetane/phytane. The presence of these lipid biomarkers, together with the low amounts of detected glycerol dialkyl glycerol tetraethers, is consistent with the dominance of anaerobic methanotrophs of the ANME-2 over ANME-1, at least in mud breccia from Perejil MVs. In contrast, the scarce presence or lack of these AOM-related lipid biomarkers in sediments from Kalinin and Schneider's Heart MVs, suggests that no recent active methane seepage has occurred at these sites. Moreover, the observed methane concentrations support the current activity of Perejil MV, and the very low methane seepage activity in Kalinin and Schneider's Heart MVs.

Comparison of authigenic carbonates formation at mud volcanoes and pockmarks in the Portuguese Margin vs. at the Yinazao serpentinite mud volcano in the Marianas forearc

NASA Astrophysics Data System (ADS)

Magalhaes, V. H.; Freitas, M.; Azevedo, M. R.; Pinheiro, L. M.; Salgueiro, E.; Abrantes, F. F. G.

2017-12-01

On the Portuguese passive continental margin, active and past seepage processes form mud volcanoes and pockmarks at the seafloor. Often associated with these structures are extensive methane-derived authigenic carbonates that form from deep-sourced methane-rich fluids that ascend from deep to the upper sedimentary column and often discharge at the seafloor. These carbonates form within the sediments and are either dominated by dolomite and high-Mg calcites, when formed under a restricted seawater circulation environment, anoxic and low sulphate conditions; or by aragonite and calcite when formed close to or at the seafloor in a high sulphate system. The δ13C values (-56.2‰ VPDB) found on the carbonate-cemented material clearly indicates methane as the major carbon source. On the Yinazao serpentinite mud volcano at an active, non-accretionary, convergent margin, sediment samples from IODP Sites U1491 and U1492 (Exp. 366) contain authigenic minerals such as aragonite, calcite, brucite, gypsum among others. Authigenic aragonite occurs predominantly within the top meters of the cores where both oxidation and seawater circulation in the sedimentary column are higher. In this system, initial results indicate that the major carbon source is most probably not methane but seawater related. This work discusses and compares the major carbon sources in both systems: sedimentary mud volcanoes and pockmarks of a passive margin vs. a serpentinite mud volcano of an active, non-accretionary, convergent margin. We acknowledge the support from the PES project - Pockmarks and fluid seepage in the Estremadura Spur: implications for regional geology, biology, and petroleum systems (PTDC/GEOFIQ/5162/2014) financed by the Portuguese Foundation for Science and Technology (FCT).

The active submarine NW termination of the South Aegean Active Volcanic Arc: The Submarine Pausanias Volcanic Field

NASA Astrophysics Data System (ADS)

Foutrakis, Panagiotis M.; Anastasakis, George

2018-05-01

Methana peninsula shows the longest recorded volcanic history at the western end of the South Aegean Active Volcanic Arc, including volcanic products from the Upper Pliocene to recent times. The volcanic rocks comprise widespread dacite domes and andesite lava flows from several small volcanic centers and are only imprecisely dated. In this paper, the integrated analysis of swath bathymetry, side scan sonar data, and high resolution seismic reflection profiles correlated with core samples, has allowed detailed mapping, characterization and precise chronological identification of the Pausanias submarine volcanic field activity offshore northern Methana. Six volcanic cones or domes are recognized, typically 1-3 km in diameter, some elongated NE-SW and some with a small central crater. On their flanks, the acoustically reflective volcanic rocks pass laterally into incoherent transparent seismic facies interpreted as volcaniclastic deposits, possibly including hyaloclastites, that interfinger with the regional basin sediments. A sea-bottom hummocky field, is interpreted as volcanic avalanche and appears to be the submarine continuation of the volcaniclastic apron of northern Methana peninsula. A robust chronostratigraphic framework has been established, based on the recognition of shoreline progradational units and their connection with Quaternary eustatic sea level cycles. Relative dating of the different phases of submarine volcanic activity during the Upper Quaternary has been achieved by correlating the imaged volcaniclastic flows, interlayered within the chronostratigraphically dated sediments. Dating by stratigraphic position, relative to 2D imaged eustatic sea level clinoform wedges appears to be more precise than radiometric methods on land. Three main submarine Volcanic Events (VE) are recognized: VE3 at 450 ka, a less precisely dated interval at 200-130 ka (VE2), and VE1 at 14 ka. Based on chronostratigraphic constraints, subsidence rates of 0.16 (±0.008) m/ka in-between Marine Isotopic Stages 6 and 12 and 0.19 (±0.009) m/ka in-between Marine Isotopic Stages 12 and 16 were estimated for the marine basin north of Methana. The morphological similarity to the onshore volcanoes of Methana Peninsula implies that magmatic constructive processes were dominant, regardless of whether in air or in water. The Upper Quaternary submarine volcanic rocks of Methana differ from those known from stratovolcanoes elsewhere in the Mediterranean, (e.g. Kos-Nisyros, Stromboli) and in other volcanic arcs (e.g., Montserrat, St Vincent), in the submarine development of domes or small cones, the paucity of volcano flank failure deposits and the lack of explosive events. Pausanias volcanic products date the onset of NE-SW faulting as well as the following tectonic phase of E-W striking faults, possibly related to basin inversion, caused by a major rifting phase that also affected most of the South Aegean Arc and the adjacent Gulfs of Corinth and Argolikos.

Multiphase modelling of mud volcanoes

NASA Astrophysics Data System (ADS)

Colucci, Simone; de'Michieli Vitturi, Mattia; Clarke, Amanda B.

2015-04-01

Mud volcanism is a worldwide phenomenon, classically considered as the surface expression of piercement structures rooted in deep-seated over-pressured sediments in compressional tectonic settings. The release of fluids at mud volcanoes during repeated explosive episodes has been documented at numerous sites and the outflows resemble the eruption of basaltic magma. As magma, the material erupted from a mud volcano becomes more fluid and degasses while rising and decompressing. The release of those gases from mud volcanism is estimated to be a significant contributor both to fluid flux from the lithosphere to the hydrosphere, and to the atmospheric budget of some greenhouse gases, particularly methane. For these reasons, we simulated the fluid dynamics of mud volcanoes using a newly-developed compressible multiphase and multidimensional transient solver in the OpenFOAM framework, taking into account the multicomponent nature (CH4, CO2, H2O) of the fluid mixture, the gas exsolution during the ascent and the associated changes in the constitutive properties of the phases. The numerical model has been tested with conditions representative of the LUSI, a mud volcano that has been erupting since May 2006 in the densely populated Sidoarjo regency (East Java, Indonesia), forcing the evacuation of 40,000 people and destroying industry, farmland, and over 10,000 homes. The activity of LUSI mud volcano has been well documented (Vanderkluysen et al., 2014) and here we present a comparison of observed gas fluxes and mud extrusion rates with the outcomes of numerical simulations. Vanderkluysen, L.; Burton, M. R.; Clarke, A. B.; Hartnett, H. E. & Smekens, J.-F. Composition and flux of explosive gas release at LUSI mud volcano (East Java, Indonesia) Geochem. Geophys. Geosyst., Wiley-Blackwell, 2014, 15, 2932-2946

Effects of mud supply on large-scale estuary morphology and development over centuries to millennia

NASA Astrophysics Data System (ADS)

Braat, Lisanne; van Kessel, Thijs; Leuven, Jasper R. F. W.; Kleinhans, Maarten G.

2017-10-01

Alluvial river estuaries consist largely of sand but are typically flanked by mudflats and salt marshes. The analogy with meandering rivers that are kept narrower than braided rivers by cohesive floodplain formation raises the question of how large-scale estuarine morphology and the late Holocene development of estuaries are affected by cohesive sediment. In this study we combine sand and mud transport processes and study their interaction effects on morphologically modelled estuaries on centennial to millennial timescales. The numerical modelling package Delft3D was applied in 2-DH starting from an idealised convergent estuary. The mixed sediment was modelled with an active layer and storage module with fluxes predicted by the Partheniades-Krone relations for mud and Engelund-Hansen for sand. The model was subjected to a range of idealised boundary conditions of tidal range, river discharge, waves and mud input. The model results show that mud is predominantly stored in mudflats on the side of the estuary. Marine mud supply only influences the mouth of the estuary, whereas fluvial mud is distributed along the whole estuary. Coastal waves stir up mud and remove the tendency to form muddy coastlines and the formation of mudflats in the downstream part of the estuary. Widening continues in estuaries with only sand, while mud supply leads to a narrower constant width and reduced channel and bar dynamics. This self-confinement eventually leads to a dynamic equilibrium in which lateral channel migration and mudflat expansion are balanced on average. However, for higher mud concentrations, higher discharge and low tidal amplitude, the estuary narrows and fills to become a tidal delta.

Macrophage migration inhibitory factor (MIF) family in arthropods: Cloning and expression analysis of two MIF and one D-dopachrome tautomerase (DDT) homologues in mud crabs, Scylla paramamosain.

PubMed

Huang, Wen-Shu; Duan, Li-Peng; Huang, Bei; Wang, Ke-Jian; Zhang, Cai-Liang; Jia, Qin-Qin; Nie, Pin; Wang, Tiehui

2016-03-01

The macrophage migration inhibitory factor (MIF) family, consisting of MIF and D-dopachrome tautomerase (DDT) in vertebrates, is evolutionarily ancient and has been found across Kingdoms including vertebrates, invertebrates, plants and bacteria. The mammalian MIF family are chemokines at the top of the inflammatory cascade in combating infections. They also possess enzymatic activities, e.g. DDT catalysis results in the production of 5,6-dihydroxyindole (DHI), a precursor of eumelanin. MIF-like genes are widely distributed, but DDT-like genes have only been described in vertebrates and a nematode. In this report, we cloned a DDT-like gene, for the first time in arthropods, and a second MIF in mud crab. The mud crab MIF family have a three exon/two intron structure as seen in vertebrates. The identification of a DDT-like gene in mud crab and other arthropods suggests that the separation of MIF and DDT preceded the divergence of protostomes and deuterostomes. The MIF family is differentially expressed in tissues of adults and during embryonic development and early life. The high level expression of the MIF family in immune tissues, such as intestine and hepatopancreas, suggests an important role in mud crab innate immunity. Mud crab DDT is highly expressed in early embryos, in megalops and crablets and this coincides with the requirement for melanisation in egg chorion tanning and cuticular hardening in arthropods, suggesting a potential novel role of DDT in melanogenesis via its tautomerase activity to produce DHI in mud crab. The clarification of the presence of both MIF and DDT in this report paves the way for further investigation of their functional roles in immunity and in melanogenesis in mud crab and other arthropods. Copyright © 2016 Elsevier Ltd. All rights reserved.

Episodic Deep Fluid Expulsion at Mud Volcanoes in the Kumano Forearc Basin, SE Offshore Japan

NASA Astrophysics Data System (ADS)

Hammerschmidt, S.; Kopf, A.

2014-12-01

Compressional forces at convergent margins govern a variety of processes, most prominently earthquakes, landslides and mud volcanoes in the forearc. Although all seem related to fluid pressure changes, mud volcanoes are not only characterized by expulsion of fluids, but also fluidized mud and clasts that got ripped-up during mud ascension. They hence provide information regarding mobilization depth, diagenetic overprint, and geodynamic pathways. At the Nankai Trough subduction zone, SE offshore Japan, mud volcanism id common and supposed to be related to seismogenic processes. During MARUM Expedition SO-222 with R/V SONNE, mud volcanoes in the Kumano forearc basin were mapped, cored and sampled. By extending the Integrated Ocean Drilling Program (IODP) Kumano transect landwards, 5 new mud volcanoes were identified by multibeam mapping. Cores revealed mud breccia with semi-consolidated silt- to claystone clasts and gaseous fluid escape structures, while the hemipelagic background sediments are characterized by intercalations of turbidites, ash layers and calcareous fossils. Clasts were subject to thin-section analyses, and the cores were sampled for XRD analyses and radiocarbon dating. Clasts showed prominent deformation structures, neomorphism and pores and fractures filled with polycrystalline quartz and/or calcite cement, probably formed during deep burial and early metamorphosis. Illite crystallinity based on XRD measurements varies between 0.24 and 0.38, which implies that the material originates from the Anchizone at depths ≥ 4 km. Radiocarbon dating revealed ages between 4450 and 30300 yr cal. BP, with age reversals occurring not earlier than 17000 yr cal. BP. Radiocarbon dating beneath turbidites and ash layers found at mud volcano #9 points to an episodic occurrence of these earthquake-related features in intervals of ca. 620 yr, while the mud volcano itself remained inactive. In summary, the preliminary results suggest that the mud volcanoes are nurtured from a reservoir within the older part of the accretionary prism, but that mud volcanic activity is less frequent than major earthquakes. Future models will focus on source depth and temperature, and might elucidate the prerequisites for fluid migration and its role in seismogenesis at the Nankai Trough subduction zone.

A kuroko-type polymetallic sulfide deposit in a submarine silicic caldera

PubMed

Iizasa; Fiske; Ishizuka; Yuasa; Hashimoto; Ishibashi; Naka; Horii; Fujiwara; Imai; Koyama

1999-02-12

Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knoll submarine caldera. The sulfide body is located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a large Kuroko-type polymetallic sulfide deposit in this arc-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits.

Measuring currents in submarine canyons: technological and scientific progress in the past 30 years

USGS Publications Warehouse

Xu, J. P.

2011-01-01

The development and application of acoustic and optical technologies and of accurate positioning systems in the past 30 years have opened new frontiers in the submarine canyon research communities. This paper reviews several key advancements in both technology and science in the field of currents in submarine canyons since the1979 publication of Currents in Submarine Canyons and Other Sea Valleys by Francis Shepard and colleagues. Precise placements of high-resolution, high-frequency instruments have not only allowed researchers to collect new data that are essential for advancing and generalizing theories governing the canyon currents, but have also revealed new natural phenomena that challenge the understandings of the theorists and experimenters in their predictions of submarine canyon flow fields. Baroclinic motions at tidal frequencies, found to be intensified both up canyon and toward the canyon floor, dominate the flow field and control the sediment transport processes in submarine canyons. Turbidity currents are found to frequently occur in active submarine canyons such as Monterey Canyon. These turbidity currents have maximum speeds of nearly 200 cm/s, much smaller than the speeds of turbidity currents in geological time, but still very destructive. In addition to traditional Eulerian measurements, Lagrangian flow data are essential in quantifying water and sediment transport in submarine canyons. A concerted experiment with multiple monitoring stations along the canyon axis and on nearby shelves is required to characterize the storm-trigger mechanism for turbidity currents.

Pre-eruptive ground deformation of Azerbaijan mud volcanoes detected through satellite radar interferometry (DInSAR)

NASA Astrophysics Data System (ADS)

Antonielli, Benedetta; Monserrat, Oriol; Bonini, Marco; Righini, Gaia; Sani, Federico; Luzi, Guido; Feyzullayev, Akper A.; Aliyev, Chingiz S.

2014-12-01

Mud volcanism is a process that leads to the extrusion of subsurface mud, fragments of country rocks, saline waters and gases. This mechanism is typically linked to hydrocarbon traps, and the extrusion of this material builds up a variety of conical edifices with a similar morphology to those of magmatic volcanoes, though smaller in size. The Differential Interferometry Synthetic Aperture Radar (DInSAR) technique has been used to investigate the ground deformation related to the activity of the mud volcanoes of Azerbaijan. The analysis of a set of wrapped and unwrapped interferograms, selected according to their coherence, allowed the detection of significant superficial deformation related to the activity of four mud volcanoes. The ground displacement patterns observed during the period spanning from October 2003 to November 2005 are dominated by uplift, which reach a cumulative value of up to 20 and 10 cm at the Ayaz-Akhtarma and Khara-Zira Island mud volcanoes, respectively. However, some sectors of the mud volcano edifices are affected by subsidence, which might correspond to deflation zones that coexist with the inflation zones characterized by the dominant uplift. Important deformation events, caused by fluid pressure and volume variations, have been observed both (1) in connection with main eruptive events in the form of pre-eruptive uplift, and (2) in the form of short-lived deformation pulses that interrupt a period of quiescence. Both deformation patterns show important similarities to those identified in some magmatic systems. The pre-eruptive uplift has been observed in many magmatic volcanoes as a consequence of magma intrusion or hydrothermal fluid injection. Moreover, discrete short-duration pulses of deformation are also experienced by magmatic volcanoes and are repeated over time as multiple inflation and deflation events.

Indian Nuclear Command and Control Dilemma

DTIC Science & Technology

2006-09-01

Submarine Communications .............................................................53 a. ELF Communications ...system is activated and deployed. The crews of submarines are informed through this system and other long wave ( ELF and VLF) radio communication ...through connectivity links of ELF , VLF and TACAMO airborne VLF communication systems. a. ELF Communications The U.S. Navy’s ELF Communication

Stratigraphic architecture and depositional history of lower Miocene, Planulina Zone, Southern Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gates, B.C.; Galloway, W.E.

1988-01-01

The Planulina zone is a wedge of clastic sediment positioned between the Anahuac shale below and the Oakville sandstone interval above. Planulna sediments were deposited on an erosional surface, during a general rise in the sea level, and formed a retrogradational wedge. Within the study area, the Planulina zone consists of two large depositional complexes: the Mud Lake complex in west Cameron Parish, Louisiana, and the East Cameron complex in east Cameron Parish. The lowermost depositional sequence in the East Cameron complex is preserved in a network of submarine canyons that were eroded into the upper slope. Framework sands weremore » deposited in channel systems confined to the axis of the canyons, and the sands are encased in marine shale containing benthonic foraminifera indicative of an upper to middle slope paleoenvironment. Two younger depositional sequences overlie the submarine canyon facies and were deposited by deltaic systems that prograded basinward. A zone of expansion extends east to west through the Planulina interval and is named the ''Planulina flexure.'' The flexure is a large fault located at the relict shelf edge and soles out downdip inn the Anahuac shale. Several thousand feet of sediment downthrown on the flexure is equivalent to several hundred feet upthrown, and the flexure represented the boundary dividing updip deltaic processes from downdip slope processes during the beginning of Planulina deposition. The Planulina depositional history and stratigraphic architecture are directly related to the displacement along the flexure and the structural deformation of the underlying Anahuac shale.« less

Comparing the efficacy of mature mud pack and hot pack treatments for knee osteoarthritis.

PubMed

Sarsan, Ayşe; Akkaya, Nuray; Ozgen, Merih; Yildiz, Necmettin; Atalay, Nilgun Simsir; Ardic, Fusun

2012-01-01

The objective of this study is to compare the efficacy of mature mud pack and hot pack therapies on patients with knee osteoarthritis. This study was designed as a prospective, randomized-controlled, and single-blinded clinical trial. Twenty-seven patients with clinical and radiologic evidence of knee osteoarthritis were randomly assigned into two groups and were treated with mature mud packs (n 15) or hot packs (n=12). Patients were evaluated for pain [based on the visual analog scale (VAS)], function (WOMAC, 6 min walking distance), quality of life [Short Form-36 (SF-36)], and serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and insulin-like growth factor-1 (IGF-1) at baseline, post-treatment, and 3 and 6~months after treatment. The mud pack group shows a significant improvement in VAS, pain, stifness, and physical function domains of WOMAC. The difference between groups of pain and physical activity domains is significant at post-treatment in favor of mud pack. For a 6 min walking distance, mud pack shows significant improvement, and the difference is significant between groups in favor of mud pack at post-treatment and 3 and 6 months after treatment. Mud pack shows significant improvement in the pain subscale of SF-36 at the third month continuing until the sixth month after the treatment. Significant improvements are found for the social function, vitality/energy, physical role disability, and general health subscales of SF-36 in favor of the mud pack compared with the hot pack group at post-treatment. A significant increase is detected for IGF-1 in the mud pack group 3 months after treatment compared with the baseline, and the difference is significant between groups 3 months after the treatment. Mud pack is a favorable option compared with hotpack for pain relief and for the improvement of functional conditions in treating patients with knee osteoarthritis.

CHARACTERIZATION OF MUD/DIRT CARRYOUT ONTO PAVED ROADS FROM CONSTRUCTION AND DEMOLITION ACTIVITIES

EPA Science Inventory

The report characterizes fugitive dust generated by vehicular traffic on paved streets and highways resulting from mud/dirt carryout from unpaved areas as a primary source of PM-10 (particles = or < 10 micrometers in aerodynamic diameter), and evaluates three technologies for eff...

CLEW: A Cooperative Learning Environment for the Web.

ERIC Educational Resources Information Center

Ribeiro, Marcelo Blois; Noya, Ricardo Choren; Fuks, Hugo

This paper outlines CLEW (collaborative learning environment for the Web). The project combines MUD (Multi-User Dimension), workflow, VRML (Virtual Reality Modeling Language) and educational concepts like constructivism in a learning environment where students actively participate in the learning process. The MUD shapes the environment structure.…

Capping hazardous red mud using acidic soil with an embedded layer of zeolite for plant growth.

PubMed

Ma, Yingqun; Si, Chunhua; Lin, Chuxia

2014-01-01

A nearly three-year microcosm experiment was conducted to test the effectiveness of capping red mud using acidic soil with an embedded layer of zeolite in sustaining the growth of a grass species. This 'sandwich-structured' design allowed self-sustaining growth of the plants under rain-fed conditions no matter whether the underlying red mud was neutralized or not. During the initial stage, the plants grew better when the red mud was not neutralized with MgCl2 probably due to pH rise in the root zone. Neutralization of red mud led to salinization and pH decrease in the root zone. However, the difference in plant growth performance between these scenarios became less remarkable over time due to gradual improvement of soil conditions in the neutralized scenarios. Continuous leaching of soluble salts and alkali by rainwater extended the root zone to the red mud layer. As a result of vegetative production, soil organic matter rapidly accumulated. This, combined with increase in pH and decrease in salinity, markedly facilitated microbial activities and consequently improved the supply of nutrients. This study provides abasis for field-scale experimental design that will have implications for effectively establishing vegetative cover in red mud disposal sites to control dust hazards.

Influence of dust and mud on the optical, chemical, and mechanical properties of a pv protective glass

PubMed Central

Yilbas, Bekir Sami.; Ali, Haider; Khaled, Mazen M.; Al-Aqeeli, Nasser; Abu-Dheir, Numan; Varanasi, Kripa K.

2015-01-01

Recent developments in climate change have increased the frequency of dust storms in the Middle East. Dust storms significantly influence the performances of solar energy harvesting systems, particularly (photovoltaic) PV systems. The characteristics of the dust and the mud formed from this dust are examined using various analytical tools, including optical, scanning electron, and atomic force microscopies, X-ray diffraction, energy spectroscopy, and Fourier transform infrared spectroscopy. The adhesion, cohesion and frictional forces present during the removal of dry mud from the glass surface are determined using a microtribometer. Alkali and alkaline earth metal compounds in the dust dissolve in water to form a chemically active solution at the glass surface. This solution modifies the texture of the glass surface, thereby increasing the microhardness and decreasing the transmittance of the incident optical radiation. The force required to remove the dry mud from the glass surface is high due to the cohesive forces that result from the dried mud solution at the interface between the mud and the glass. The ability altering the characteristics of the glass surface could address the dust/mud-related limitations of protective surfaces and has implications for efficiency enhancements in solar energy systems. PMID:26514102

Linking Anomalously Low Topographic Relief in the Taiwan Arc-Continent Collision to a Submarine Plateau South of the Collision.

NASA Astrophysics Data System (ADS)

Byrne, T. B.; Lin, A. T.; Su, C. C.; Lewis, J. C.; Liu, C. S.; Ouimet, W. B.; Chen, T. T.; Huang, C.

2015-12-01

Ouimet et al. (2014; submitted) have recently described broad areas of anomalously low relief and slope that straddle the topographic ridge crest in Taiwan. The areas are anomalous because Taiwan also preserves some of the steepest topography in the world, as expected from the high rates of convergence, exhumation and erosion. In addition, several age-elevation data sets (see Hsu et al. this meeting), using new and previously published ZrnFT, ZrnHe and ApFT ages, show exhumation cooling rates of 3 to 5 mm/yr since ~1.5-2.0 Ma, which is consistent with the exposure of reset zircons beneath the surfaces. Erosion rates of this magnitude, however, are expected to produce significant topographic relief, making it difficult to generate a topographic surface of low slope and low relief centered on the ridge crest. Very young ApFT and ZrnHe ages (e.g., < 0.5 Ma) also suggest a more recent acceleration in exhumation cooling. A relatively large area of low relief centered on the top of the submarine accretionary prism south of Taiwan may provide a solution for this conundrum. The area covers ca 1000 km2, has a mean elevation of ca 450 m below sea level and appears to be composed of hard, intact rocks rather than unlithified deep sea muds. Several attempts at gravity and piston coring failed to penetrate the substrate and samples retrieved in the core catcher include rounded clasts of quartz and siltstone. Geophysical studies also show high Vp velocities at relatively shallow depths beneath the sea floor, suggesting the removal of a significant volume of sediment and rock, presumably through erosion. We propose that this low relief plateau serves as a modern analog for the formation of the low relief surfaces that currently straddle the ridge crest in Taiwan. If this interpretation is correct, it suggests a tectonic model in which submarine erosion processes modulate vertical growth of the prism until collision of thick continental crust promotes uplift that outpaces erosion. This requires significant erosion rates (e.g., mm/yr) in the shallow water marine environment. Based on the young ApFT and ZrnHe ages, we propose that emergence of the prism occurred less than about a half a million years ago, and that this hypothesis could be tested by chronologic and thermochronologic data from cores retrieved through submarine drilling.

Monitoring and Characterizing the Geysering and Seismic Activity at the Lusi Mud Eruption Site, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Karyono, Karyono; Obermann, Anne; Mazzini, Adriano; Lupi, Matteo; Syafri, Ildrem; Abdurrokhim, Abdurrokhim; Masturyono, Masturyono; Hadi, Soffian

2016-04-01

The Lusi eruption began on May 29, 2006 in the northeast of Java Island, Indonesia, and to date is still active. Lusi is a newborn sedimentary-hosted hydrothermal system characterized by continuous expulsion of liquefied mud and breccias and geysering activity. Lusi is located upon the Watukosek fault system, a left lateral wrench system connecting the volcanic arc and the bakarc basin. This fault system is still periodically reactivated as shown by field data. In the framework of the Lusi Lab project (ERC grant n° 308126) we conducted several types of monitoring. Based on camera observations, we characterized the Lusi erupting activity by four main behaviors occurring cyclically: (1) Regular activity, which consists in the constant emission of water and mud breccias (i.e. viscous mud containing clay, silt, sand and clasts) associated with the constant expulsion of gas (mainly aqueous vapor with minor amounts of CO2 and CH4) (2) Geysering phase with intense bubbling, consisting in reduced vapor emission and more powerful bursting events that do not seem to have a regular pattern. (3) Geysering phase with intense vapor and degassing discharge and a typically dense plume that propagates up to 100 m height. (4) Quiescent phase marking the end of the geysering activity (and the observed cycle) with no gas emissions or bursts observed. To investigate the possible seismic activity beneath Lusi and the mechanisms controlling the Lusi pulsating behaviour, we deployed a network of 5 seismic stations and a HD camera around the Lusi crater. We characterize the observed types of seismic activity as tremor and volcano-tectonic events. Lusi tremor events occur in 5-10 Hz frequency band, while volcano tectonic events are abundant in the high frequencies range from 5 Hz until 25 Hz. We coupled the seismic monitoring with the images collected with the HD camera to study the correlation between the seismic tremor and the different phases of the geysering activity. Key words: Lusi mud eruption, geysering activity, seismic activity

An active dealkalization of red mud with roasting and water leaching.

PubMed

Zhu, Xiaobo; Li, Wang; Guan, Xuemao

2015-04-09

The research has focused on the dealkalization of red mud after active roasting and water leaching, which is obtained from bauxite during alumina production. The main factors such as roasting temperature, roasting time, water leaching stage, leaching temperature, leaching reaction time and liquid to solid ratio were investigated. The mechanism of dealkalization was in-depth studied by using ICP-AES, XRD, TG-DSC, SEM-EDS and leaching kinetic. The results show that the dealkalization rate reached 82% under the condition of roasting temperature of 700 °C, roasting time of 30 min, four stage water leaching, liquid to solid ratio of 7 mL/g, leaching temperature of 90 °C and reaction time of 60 min. The diffraction peak of Na6CaAl6Si6(CO3)O24 · 2H2O in red mud was decreased during the active roasting process, whereas the mineral phases of NaOH · H2O and Na2Ca(CO3)2 were appeared. The content of alkali obviously decreased and the grade of other elements increased during the process of active roasting and water leaching, which was in favor of next application process of red mud. The water leaching was controlled by internal diffusion of SCM and the apparent activation energy was 22.63 kJ/mol. Copyright © 2014 Elsevier B.V. All rights reserved.

Antimicrobial Activity of Bacillus Persicus 24-DSM Isolated from Dead Sea Mud.

PubMed

Al-Karablieh, Nehaya

2017-01-01

Dead Sea is a hypersaline lake with 34% salinity, gains its name due to the absence of any living macroscopic creatures. Despite the extreme hypersaline environment, it is a unique ecosystem for various halophilic microorganisms adapted to this environment. Halophilic microorganisms are known for various potential biotechnological applications, the purpose of the current research is isolation and screening of halophilic bacteria from Dead Sea mud for potential antimicrobial applications. Screening for antagonistic bacteria was conducted by bacterial isolation from Dead Sea mud samples and agar plate antagonistic assay. The potential antagonistic isolates were subjected to biochemical characterization and identification by 16S-rRNA sequencing. Among the collected isolates, four isolates showed potential antagonistic activity against Bacillus subtilis 6633 and Escherichia coli 8739. The most active isolate (24-DSM) was subjected for antagonistic activity and minimal inhibitory concentration against different gram positive and negative bacterial strains after cultivation in different salt concentration media. Results: The results of 16S-rRNA analysis revealed that 24-DSM is very closely related to Bacillus persicus strain B48, which was isolated from hypersaline lake in Iran. Therefore, the isolate 24-DSM is assigned as a new strain of B. persicusi isolated from the Dead Sea mud. B. persicusi 24-DSM showed higher antimicrobial activity, when it was cultivated with saline medium, against all tested bacterial strains, where the most sensitive bacterial strain was Corynebacterium diphtheria 51696.

CO2 flux from Javanese mud volcanism

NASA Astrophysics Data System (ADS)

Queißer, M.; Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.

2017-06-01

Studying the quantity and origin of CO2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s-1 (117 t d-1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d-1, comparable with the expected back-arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO2 fluxes.

Cardiometabolic Health in Submariners Returning from a 3-Month Patrol

PubMed Central

Gasier, Heath G.; Young, Colin R.; Gaffney-Stomberg, Erin; McAdams, Douglas C.; Lutz, Laura J.; McClung, James P.

2016-01-01

Confined space, limited exercise equipment, rotating shift work and reduced sleep may affect cardiometabolic health in submariners. To test this hypothesis, 53 male U.S. Submariners (20–39 years) were studied before and after a 3-month routine submarine patrol. Measures included anthropometrics, dietary and physical activity, biomarkers of cardiometabolic health, energy and appetite regulation, and inflammation. Before deployment, 62% of submariners had a body fat % (BF%) ≥ 25% (obesity), and of this group, 30% met the criteria for metabolic syndrome. In obese volunteers, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), leptin, the leptin/adiponectin ratio, and pro-inflammatory chemokines growth-related oncogene and macrophage-derived chemokine were significantly higher compared to non-obese submariners. Following the patrol, a significant mean reduction in body mass (5%) and fat-mass (11%) occurred in the obese group as a result of reduced energy intake (~2000 kJ) during the patrol; and, independent of group, modest improvements in serum lipids and a mean reduction in interferon γ-induced protein 10 and monocyte chemotactic protein 1 were observed. Since 43% of the submariners remained obese, and 18% continued to meet the criteria for metabolic syndrome following the patrol, the magnitude of weight loss was insufficient to completely abolish metabolic dysfunction. Submergence up to 3-months, however, does not appear to be the cause of obesity, which is similar to that of the general population. PMID:26867201

Microbial community of a hydrothermal mud vent underneath the deep-sea anoxic brine lake Urania (eastern Mediterranean).

PubMed

Yakimov, Michail M; Giuliano, Laura; Cappello, Simone; Denaro, Renata; Golyshin, Peter N

2007-04-01

The composition of a metabolically active prokaryotic community thriving in hydrothermal mud fluids of the deep-sea hypersaline anoxic Western Urania Basin was characterized using rRNA-based phylogenetic analysis of a clone library. The physiologically active prokaryotic assemblage in this extreme environment showed a great genetic diversity. Most members of the microbial community appeared to be affiliated to yet uncultured organisms from similar ecosystems, i.e., deep-sea hypersaline basins and hydrothermal vents. The bacterial clone library was dominated by phylotypes affiliated with the epsilon-Proteobacteria subdivision recognized as an ecologically significant group of bacteria inhabiting deep-sea hydrothermal environments. Almost 18% of all bacterial clones were related to delta-Proteobacteria, suggesting that sulfate reduction is one of the dominant metabolic processes occurring in warm mud fluids. The remaining bacterial phylotypes were related to alpha- and beta-Proteobacteria, Actinobacteria, Bacteroides, Deinococcus-Thermus, KB1 and OP-11 candidate divisions. Moreover, a novel monophyletic clade, deeply branched with unaffiliated 16S rDNA clones was also retrieved from deep-sea sediments and halocline of Urania Basin. Archaeal diversity was much lower and detected phylotypes included organisms affiliated exclusively with the Euryarchaeota. More than 96% of the archaeal clones belonged to the MSBL-1 candidate order recently found in hypersaline anoxic environments, such as endoevaporitic microbial mats, Mediterranean deep-sea mud volcanoes and anoxic basins. Two phylotypes, represented by single clones were related to uncultured groups DHVE-1 and ANME-1. Thus, the hydrothermal mud of hypersaline Urania Basin seems to contain new microbial diversity. The prokaryotic community was significantly different from that occurring in the upper layers of the Urania Basin since 60% of all bacterial and 40% of all archaeal phylotypes were obtained only from mud fluids. The uniqueness of the composition of the active prokaryotic community could be explained by the complex environmental conditions at the site. The interaction of oxygenated warm mud fluids with the cold hypersaline brine of the Urania Basin seems to simultaneously select for various metabolic processes, such as aerobic and anaerobic heterotrophy, sulfide- and methane-dependent chemotrophy along with anaerobic oxidation of methane, sulfate- and metal-reduction.

Mud volcano venting induced gas hydrate formation at the upper slope accretionary wedge, offshore SW Taiwan

NASA Astrophysics Data System (ADS)

Lin, Saulwood; Tseng, Yi-Ting; Cheng, Wan-Yen; Chou, Cheng-Tien; Chen, NeiChen; Hsieh, I.-Chih

2016-04-01

TsanYao Mud Volcano (TYMV) is the largest mud volcano cone in the Hengchun Mud Volcano Group (HCMVG), located at the upper slope of the accrretionary wedge, southwest of Taiwan. The region is under active tectonic activity with the Philippine Plate, moving northwestward at a rate of ~8 cm/year. This region also receives huge quantity of suspended particle load of ~100 mT/year at present time from adjacent small rivers of the Island of Taiwan. Large loads of suspended sediments influx become a major source of organic carbon and later gas and other hydrocarbon. Gas and fluid in the mud volcano are actively venting from deep to the sea floor on the upper slope of the accretionary wedge. In order to understand venting on the HCMVG, echo sounder, towcam and coring were carried out. Pore water sulfate, chloride, potassium, calcium, stable isotope O-18, gas compositions, dissolved sulfide were analysed. The HCMVG consists of 12 volcano cones of different sizes. Large quantity of gas and fluid are venting directly from deep to the TYMV structure high, as well as 50+ other vents as appeared as flares on the echo sounder. Some flares are reaching to the atmosphere and likely a source of green house gases to the atmosphere. Venting fluids include gas bubbles, suspended particle, mud, and breccia. Breccia size could reach more than 12 cm in diameter. Circular bands in different color appeared around the cone may represent stages of vent eruptions. Compositions of vent gas include methane, ethane and propane. High proportions of ethane and propane in the vent gas demonstrated that source of gas are thermogenic in origin. Patchy authigenic carbonate, bacterial mats, bivalves, tube worms and other chemosynthesis organisms were supported by venting gas AOM process near the sea floor. Pore water chloride concentrations show distinct variation pattern from center cone to the side of the volcano, with low in the center and high away from the cone. Pore water with higher than seawater chloride indicated gas hydrate formation in sediments away from the mud volcano cone.

Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system.

PubMed

Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

2016-06-17

Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report (3)He/(4)He measurements in CO2-dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a (3)He/(4)He signature of at least 7.0 Ra (being Ra the (3)He/(4)He ratio of atmospheric He equal to 1.39×10(-6)), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like (3)He/(4)He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano.

Do mud deposition events on sandy beaches affect surf zone ichthyofauna? A southern Brazilian case study

NASA Astrophysics Data System (ADS)

Mont'Alverne, Renata; Moraes, Leonardo E.; Rodrigues, Fábio L.; Vieira, João P.

2012-05-01

Using fluid mud deposition events which occur regularly at Cassino Beach in south Brazil, we evaluated the influence of such events on the structure of the ichthyofauna inhabiting its shallow surf zone. Wave action was the dominant factor in differentiating between sampling sites, being lower or even absent at the mud-influenced sectors compared to beach area without mud. Samples were collected using a beach seine net at two control locations (A1 and A2), and at three locations influenced by mud deposition (B1, B2, and B3). During the study period (21 April-04 August 2009), 15,245 fishes were captured and separated into 26 taxonomic groups, from species to family. Individuals of a total length (TL) up to 50 mm accounted for 65% of the catch, while individuals of TL < 30 mm were the most numerous and more responsible for the total abundance spatial pattern. The area with higher wave action (A2) had the lowest relative species abundance and greatest diversity, whereas the areas with mud-forced lowest wave action (B2 and B3) had the highest species abundance values. Three hypotheses were proposed to explain the higher concentration and capture of juvenile fishes at mud locations. First, longshore currents may be responsible for the displacement of juvenile aggregations toward areas of lower energy. Second, individuals may select habitats with turbid waters, which may provide greater protection from predators and increased food availability. Third, areas under the influence of fluid mud deposition show higher values of viscosity, which may reduce swimming activity and hinder the escape of juvenile fishes from nets, resulting in an increased capture of individuals compared to areas without mud.

Sequential activities of Dynein, Mud and Asp in centrosome-spindle coupling maintain centrosome number upon mitosis.

PubMed

Bosveld, Floris; Ainslie, Anna; Bellaïche, Yohanns

2017-10-15

Centrosomes nucleate microtubules and are tightly coupled to the bipolar spindle to ensure genome integrity, cell division orientation and centrosome segregation. While the mechanisms of centrosome-dependent microtubule nucleation and bipolar spindle assembly have been the focus of numerous works, less is known about the mechanisms ensuring the centrosome-spindle coupling. The conserved NuMA protein (Mud in Drosophila ) is best known for its role in spindle orientation. Here, we analyzed the role of Mud and two of its interactors, Asp and Dynein, in the regulation of centrosome numbers in Drosophila epithelial cells. We found that Dynein and Mud mainly initiate centrosome-spindle coupling prior to nuclear envelope breakdown (NEB) by promoting correct centrosome positioning or separation, while Asp acts largely independently of Dynein and Mud to maintain centrosome-spindle coupling. Failure in the centrosome-spindle coupling leads to mis-segregation of the two centrosomes into one daughter cell, resulting in cells with supernumerary centrosomes during subsequent divisions. Altogether, we propose that Dynein, Mud and Asp operate sequentially during the cell cycle to ensure efficient centrosome-spindle coupling in mitosis, thereby preventing centrosome mis-segregation to maintain centrosome number. © 2017. Published by The Company of Biologists Ltd.

New method for the detection and monitoring of subsea power cable

NASA Astrophysics Data System (ADS)

Held, Philipp; Schneider, Jens; Feldens, Peter; Wilken, Dennis

2016-04-01

Marine renewable energy farms, no matter what kind of, have in common that they need a connection with the onshore power grid. Thus, not only their offshore generation facilities could have impacts on the surrounding environment, but also associated submarine power cables. These cables have to be buried in the seabed - at least in coastal heavy shipping environments - for safety reasons. Cable laying disturbs the local seafloor and the sub-bottom. Refillment of dredged sediments are expected softer than the original material and could be washed away by currents. Therefore, buried cables have to be repeatedly monitored to ensure their burial depth. This study presents a new method for efficient cable detection. A parametric echosounder system using 15 kHz as secondary frequency was adapted to investigate the angular response of sub-bottom backscatter strength of layered mud and to introduce a new method for enhanced acoustic detection of buried targets. Adaptations to achieve both vertical (0°) and non-vertical inclination of incident sound on the seabed (1-15°, 30°, 45°, and 60°) comprise mechanical tilting of the acoustic transducer and electronic beam steering. A sample data set was acquired at a study site at 18 m water depth and a flat and muddy seafloor. At this site, a 0.1 m diameter power cable is buried 1-2 m below the sea floor. Surveying the cable with vertical incidence revealed that the buried cable can hardly be discriminated against the backscatter strength of the layered mud. However, the backscatter strength of layered mud was found to strongly decrease at >3±0.5° incidence and the layered mud echo pattern vanished beyond 5°. As a consequence the visual recognition of the cable echo in acoustic images improves for higher incidence angles of 15°, 30°, 45°, and 60°. Data analysis support this visual impression. The size of the cable echo pattern was found to linearly increase with incidence, whereas the signal-to-noise ratio peaks at about 40°. At the peak, the signal-to-noise ratio is up to 2.6 times higher than at normal incidence. The effects are attributed to reflection loss from layered mud at larger incidence and to the scattering of the 0.1 m diameter buried cable. Thus, the presented method is suitable for cable detection and monitoring and can also provide information of the surrounding sedimentological strati. One of its advantages is that it is based on small and mobile transducers and is therefore useable on reasonable small survey platforms. We foresee a large potential using the presented mechanic or electronic sound inclination approach for enhanced sub-bottom classification and to better detect shallow buried acoustic scatterers like cables, pipelines, stones, dumping material (mines, waste), submerged shipwrecks, archaeological settlement remains, manganese nodules and shallow gas.

Soil gas anomalies along the Watukosek fault system, East Java, Indonesia

NASA Astrophysics Data System (ADS)

Sciarra, A.; Ruggiero, L.; Bigi, S.; Mazzini, A.

2017-12-01

Two soil gas surveys were carried out in the Sidoarjo district (East Java, Indonesia) to investigate the gas leaking properties along fractured zones that coincide with a strike-slip system in NE Java, the Watukosek Fault System. This structure has been the focus of attention since the beginning of the spectacular Lusi mud eruption on the 29th May 2006. This fault system appear to be a sinistral strike-slip system that originates from the Arjuno-Welirang volcanic complex, intersects the active Lusi eruption site displaying a system of antithetic faults, and extends towards the NE of Java where mud volcanic structures reside. In the Lusi region we completed two geochemical surveys (222Rn and 220Rn activity, CO2 and CH4 flux and concentration) along four profiles crossing the Watukosek fault system. In May 2015 two profiles ( 1.2 km long) were performed inside the 7 km2 embankment area framing the erupted mud breccia zone and across regions characterized by intense fracturing and surface deformation. In April 2017 two additional profiles ( 4 km long) were carried out in the northern and southern part outside the Lusi embankment mud eruption area, intersecting the direction of main Watukosek fault system. All the profiles highlight that the fractured zones have the highest 222Rn activity, CO2 and CH4 flux and concentration values. The relationship existing among the measured parameters suggest that the Watukosek fault system acts as a preferential pathway for active rise of deep fluids. In addition the longer profiles outside the embankment show very high average values of CO2 (5 - 8 %,v/v) and 222Rn (17 - 11.5 kBq/m3), while soil gas collected along the profiles inside the Lusi mud eruption are CH4-dominant (up to 4.5%,v/v).This suggests that inside the embankment area (i.e. covered by tens of meters thick deposits of erupted mud breccia) the seepage is overall methane-dominated. This is likely the result of microbial reactions ongoing in the organic-rich sediments producing shallow gas that gets mixed with deeper rising fluids. In contrasts profiles collected in areas not covered by the organic rich mud breccia, and that are crossing the main Watukosek fault system, have the highest 222Rn activity and CO2 concentration values. We suggest that at these localities the rise of deep fluids is not affected by shallower gas production.

Molecular Simulation Study on Modification Mechanism of Red Mud Modified Asphalt

NASA Astrophysics Data System (ADS)

Tao, FU; Hui-ming, BAO; xing-xing, Duan

2017-12-01

This article used red mud, the aluminum industrial wastes, as modified asphalt material, through the study of the routine test of modified asphalt properties, and the micro test of electron microscope scanning, infrared spectrum and differential scanning calorimetry analysis etc. to discuss its performance and modification mechanism . The test results show that after mixing red mud, asphalt’s penetration index and 15 °C ductility reduced, softening point enhanced, thus the temperature sensitivity and high temperature stability of asphalt improved; Red mud after mixing the matrix asphalt, can form a uniform, stable and matrix asphalt blending system, and improve the asphalt’s thermal stability. Using molecular simulation technology to analyze the asphalt with the temperature change of energy and find in the process of asphalt melting, the largest is the key to influence on bituminous, and van der waals energy is small. It concludes that red mud -modified asphalt material is mainly controlled by bond energy, in order to obtain its favorable property of modification mechanism, red mud of senior activation and molecular bond energy of asphalt is needed to be enhanced.The results of molecular simulation show that the main component of hematite in red mud is the most adsorbed in the asphalt, the asphaltene is the second, the colloid is the worst, but the adsorption capacity of the colloid is the highest.

BIOGEOCHEMICAL CONTROLS ON REACTION OF SEDIMENTARY ORGANIC MATTER AND AQUEOUS SULFIDES IN HOLOCENE SEDIMENTS OF MUD LAKE FLORIDA

EPA Science Inventory

The distribution and quantity of organic sulfur and iron sulfur species were determined in the
Holocene sediments from Mud Lake, Florida. The sediments of this shallow, sinkhole lake are characterized by high sulfur and organic carbon contents as well as active sulfate reducti...

Archaeal populations in hypersaline sediments underlying orange microbial mats in the Napoli mud volcano.

PubMed

Lazar, Cassandre Sara; L'haridon, Stéphane; Pignet, Patricia; Toffin, Laurent

2011-05-01

Microbial mats in marine cold seeps are known to be associated with ascending sulfide- and methane-rich fluids. Hence, they could be visible indicators of anaerobic oxidation of methane (AOM) and methane cycling processes in underlying sediments. The Napoli mud volcano is situated in the Olimpi Area that lies on saline deposits; from there, brine fluids migrate upward to the seafloor. Sediments associated with a brine pool and microbial orange mats of the Napoli mud volcano were recovered during the Medeco cruise. Based on analysis of RNA-derived sequences, the "active" archaeal community was composed of many uncultured lineages, such as rice cluster V or marine benthic group D. Function methyl coenzyme M reductase (mcrA) genes were affiliated with the anaerobic methanotrophic Archaea (ANME) of the ANME-1, ANME-2a, and ANME-2c groups, suggesting that AOM occurred in these sediment layers. Enrichment cultures showed the presence of viable marine methylotrophic Methanococcoides in shallow sediment layers. Thus, the archaeal community diversity seems to show that active methane cycling took place in the hypersaline microbial mat-associated sediments of the Napoli mud volcano.

IODP Expedition 338: NanTroSEIZE Stage 3: NanTroSEIZE plate boundary deep riser 2

NASA Astrophysics Data System (ADS)

Moore, G. F.; Kanagawa, K.; Strasser, M.; Dugan, B.; Maeda, L.; Toczko, S.

2014-01-01

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is designed to investigate fault mechanics and seismogenesis along a subduction megathrust, with objectives that include characterizing fault slip, strain accumulation, fault and wall rock composition, fault architecture, and state variables throughout an active plate boundary system. Integrated Ocean Drilling Program (IODP) Expedition 338 was planned to extend and case riser Hole C0002F from 856 to 3600 meters below the seafloor (m b.s.f.). Riser operations extended the hole to 2005.5 m b.s.f., collecting logging-while-drilling (LWD) and measurement-while-drilling, mud gas, and cuttings data. Results reveal two lithologic units within the inner wedge of the accretionary prism that are separated by a prominent fault zone at ~ 1640 m b.s.f. Due to damage to the riser during unfavorable winds and strong currents, riser operations were suspended, and Hole C0002F left for re-entry during future riser drilling operations. Contingency riserless operations included coring at the forearc basin site (C0002) and at two slope basin sites (C0021 and C0022), and LWD at one input site (C0012) and at three slope basin sites (C0018, C0021 and C0022). Cores and logs from these sites comprehensively characterize the alteration stage of the oceanic basement input to the subduction zone, the early stage of Kumano Basin evolution, gas hydrates in the forearc basin, and recent activity of the shallow megasplay fault zone system and associated submarine landslides.

Geomorphic process fingerprints in submarine canyons

USGS Publications Warehouse

Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

2013-01-01

Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

CO2 flux from Javanese mud volcanism.

PubMed

Queißer, M; Burton, M R; Arzilli, F; Chiarugi, A; Marliyani, G I; Anggara, F; Harijoko, A

2017-06-01

Studying the quantity and origin of CO 2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO 2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO 2 with a volume fraction of at least 16 vol %. A lower limit CO 2 flux of 1.4 kg s -1 (117 t d -1 ) was determined, in line with the CO 2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO 2 flux of 3 kt d -1 , comparable with the expected back-arc efflux of magmatic CO 2 . After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO 2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO 2 , with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO 2 fluxes.

CO2 flux from Javanese mud volcanism

PubMed Central

Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.

2017-01-01

Abstract Studying the quantity and origin of CO2 emitted by back‐arc mud volcanoes is critical to correctly model fluid‐dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s−1 (117 t d−1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d−1, comparable with the expected back‐arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man‐portable active remote sensing instruments for probing natural gas releases, enabling bottom‐up quantification of CO2 fluxes. PMID:28944134

DOE Office of Scientific and Technical Information (OSTI.GOV)

K. B. Campbell

The following site closure activities were performed at the 34 Corrective Action Sites (CASs) comprising Corrective Action Unit (CAU) 417 and are documented in this report: (1) No closure action was taken at 13 CASs (17 sites): 58-05-01,58-07-01,58-05-04, 58-09-05 (Mud Pits C and D only), 58-35-01,58-05-02,58-09-06 (Mud Pits A, B, C, and D), 58-10-06,58-19-01,58-35-02,58-44-04,58-05-04, and 58-09-03 (Mud Pit E only). (2) Housekeeping activities, collecting scrap materials, and transporting to approved landfill sites at the NTS were used to close seven CASs: 58-44-01,58-44-02,58-44-05, 58-98-03,58-98-01,58-98-02, and 58-98-04. (3) Two CASs (58-05-03 and 58-99-01) were closed by excavation and removal of USTs. (4)more » Two septic tanks (CASs 58-05-05 and 58-05-06) were closed by backfilling with clean fill. (5) Site posting with above-grade monuments and attached warning signs and land-use restrictions were used to close seven CASs (nine sites): 58-09-02,58-09-05 (Mud Pit E only), 58-09-06 (Mud Pit E only), 58-10-01,58-25-01,58-09-03 (Mud Pits A, B, and D), and 58-10-05. (6) Clean closure by excavation soil with TPH levels greater than the NDEP action level of 100 mg/kg and limited regrading was used to close five CASs: 58-10-03,58-44-06, 58-44-03,58-10-02, and 58-10-04. (7) Construction of engineered covers was used to close in place two CASs: 58-09-01 and 58-09-03 (Mud Pit C only). Following construction, a fence was constructed around each cover to prevent damage to the cover or intrusion by wildlife.« less

NASA/Navy Benchmarking Exchange (NNBE). Volume 1. Interim Report. Navy Submarine Program Safety Assurance

NASA Technical Reports Server (NTRS)

2002-01-01

The NASA/Navy Benchmarking Exchange (NNBE) was undertaken to identify practices and procedures and to share lessons learned in the Navy's submarine and NASA's human space flight programs. The NNBE focus is on safety and mission assurance policies, processes, accountability, and control measures. This report is an interim summary of activity conducted through October 2002, and it coincides with completion of the first phase of a two-phase fact-finding effort.In August 2002, a team was formed, co-chaired by senior representatives from the NASA Office of Safety and Mission Assurance and the NAVSEA 92Q Submarine Safety and Quality Assurance Division. The team closely examined the two elements of submarine safety (SUBSAFE) certification: (1) new design/construction (initial certification) and (2) maintenance and modernization (sustaining certification), with a focus on: (1) Management and Organization, (2) Safety Requirements (technical and administrative), (3) Implementation Processes, (4) Compliance Verification Processes, and (5) Certification Processes.

The role of fluvial sediment supply and river-mouth hydrology in the dynamics of the muddy, Amazon-dominated Amapá-Guianas coast, South America: A three-point research agenda

NASA Astrophysics Data System (ADS)

Anthony, Edward J.; Gardel, Antoine; Proisy, Christophe; Fromard, François; Gensac, Erwan; Peron, Christina; Walcker, Romain; Lesourd, Sandric

2013-07-01

The morphology and sediment dynamics of the 1500 km-long coast of South America between the mouths of the Amazon and the Orinoco Rivers are largely dependent on the massive suspended-sediment discharge of the Amazon, part of which is transported alongshore as mud banks. These mud banks have an overwhelming impact on the geology, the geomorphology, the ecology and the economy of this coast. Although numerous field investigations and remote sensing studies have considerably enhanced our understanding of the dynamics of this coast over the last three decades, much still remains to be understood of the unique functional mechanisms and processes driving its evolution. Among the themes that we deem as requiring further attention three come out as fundamental. The first concerns the mechanisms of formation of individual mud banks from mud streaming on the shelf off the mouth of the Amazon. An unknown quantity of the fluid mud generated by offshore estuarine front activity is transported shoreward and progressively forms mud banks on the Amapá coast, Brazil. The volume of each mud bank can contain from the equivalent of the annual mud supply of the Amazon to several times this annual sediment discharge. The mechanisms by which individual banks are generated from the Amazon turbidity maximum are still to be elucidated. Areas of research include regional mesoscale oceanographic conditions and mud supply from the Amazon. The second theme is that of variations in rates of migration of mud banks, which influence patterns of coastal accretion. Research emphasis needs to be placed on the analysis of both regional meteorological-hydrodynamic forcing and distant Atlantic forcing, as well as on the hydrology of the large rivers draining the Guyana Shield. The rivers appear to generate significant offshore deflection of mud banks in transit alongshore, through a hydraulic-groyne effect. This may favour both muddy accretion on the updrift coast and downdrift mud liquefaction with probably lessened muddy deposition. The third theme concerns sand supply by the Guiana Shield rivers. The rare sand deposits are important in providing sites for human settlements and routes and for nesting by marine turtles. The limited presence of sand bodies on this coast may reflect 'mud blanketing', a hypothesis that requires verification through high-resolution seismic analyses of shelf deposits and coring operations. The large Guiana Shield rivers, especially in Surinam and Guyana, have supplied sand for the construction of significant bands of cheniers, probably enhanced by the afore-mentioned downdrift hydraulic-groyne effect on hindered mud deposition. In all the three themes of this future research agenda, two central elements are the sediment input of the rivers of the Amazon basin, starting with the massive mud supply from the Amazon catchment itself, followed by sand inputs by the Guiana Shield rivers and their river-mouth effects on mud banks.

Health Risk Assessment of Women in Submarines: Reproductive and Developmental Toxicity Evaluation of Major Submarine Atmosphere Components (CO, CO2 and O2) in Rats (Rattus norvegicus) - Phase II (Neurological and Reproductive Performance Study)

DTIC Science & Technology

2011-10-11

exposed parents. Statistically significant increases in hematopoietic activity (mild polycythemia , leukocytosis and thrombocytosis) were...Tables 25 & 26). Polycythemia (increased red blood cells, with expected increases in hemoglobin and hematocrit) is an established effect of

Kolumbo submarine volcano (Greece): An active window into the Aegean subduction system

PubMed Central

Rizzo, Andrea Luca; Caracausi, Antonio; Chavagnac, Valèrie; Nomikou, Paraskevi; Polymenakou, Paraskevi N.; Mandalakis, Manolis; Kotoulas, Georgios; Magoulas, Antonios; Castillo, Alain; Lampridou, Danai

2016-01-01

Submarine volcanism represents ~80% of the volcanic activity on Earth and is an important source of mantle-derived gases. These gases are of basic importance for the comprehension of mantle characteristics in areas where subaerial volcanism is missing or strongly modified by the presence of crustal/atmospheric components. Though, the study of submarine volcanism remains a challenge due to their hazardousness and sea-depth. Here, we report 3He/4He measurements in CO2–dominated gases discharged at 500 m below sea level from the high-temperature (~220 °C) hydrothermal system of the Kolumbo submarine volcano (Greece), located 7 km northeast off Santorini Island in the central part of the Hellenic Volcanic Arc (HVA). We highlight that the mantle below Kolumbo and Santorini has a 3He/4He signature of at least 7.0 Ra (being Ra the 3He/4He ratio of atmospheric He equal to 1.39×10−6), 3 Ra units higher than actually known for gases-rocks from Santorini. This ratio is also the highest measured across the HVA and is indicative of the direct degassing of a Mid-Ocean-Ridge-Basalts (MORB)-like mantle through lithospheric faults. We finally highlight that the degassing of high-temperature fluids with a MORB-like 3He/4He ratio corroborates a vigorous outgassing of mantle-derived volatiles with potential hazard at the Kolumbo submarine volcano. PMID:27311383

The Queen Charlotte-Fairweather Fault Zone - Geomorphology of a submarine transform fault, offshore British Columbia and southeastern Alaska

NASA Astrophysics Data System (ADS)

Walton, M. A. L.; Barrie, V.; Greene, H. G.; Brothers, D. S.; Conway, K.; Conrad, J. E.

2017-12-01

The Queen Charlotte-Fairweather (QC-FW) Fault Zone is the Pacific - North America transform plate boundary and is clearly seen for over 900 km on the seabed as a linear and continuous feature from offshore central Haida Gwaii, British Columbia to Icy Point, Alaska. Recently (July - September 2017) collected multibeam bathymetry, seismic-reflection profiles and sediment cores provide evidence for the continuous strike-slip morphology along the continental shelfbreak and upper slope, including a linear fault valley, offset submarine canyons and gullies, and right-step offsets (pull apart basins). South of central Haida Gwaii, the QC-FW is represented by several NW-SE to N-S trending faults to the southern end of the islands. Adjacent to the fault at the southern extreme and offshore Dixon Entrance (Canada/US boundary) are 400 to 600 m high mud volcanos in 1000 to 1600 m water depth that have plumes extending up 700 m into the water column and contain extensive carbonate crusts and chemosynthetic communities within the craters. In addition, gas plumes have been identified that appear to be directly associated with the fault zone. Surficial Quaternary sediments within and adjacent to the central and southern fault date either to the deglaciation of this region of the Pacific north coast (16,000 years BP) or to the last interstadial period ( 40,000 years BP). Sediment accumulation is minimal and the sediments cored are primarily hard-packed dense sands that appear to have been transported along the fault valley. The majority of the right-lateral slip along the entire QC-FW appears to be accommodated by the single fault north of the convergence at its southern most extent.

Sedimentological effects of tsunamis, with particular reference to impact-generated and volcanogenic waves

NASA Technical Reports Server (NTRS)

Bourgeois, Joanne; Wiberg, Patricia L.

1988-01-01

Impulse-generated waves (tsunamis) may be produced, at varying scales and global recurrence intervals (RI), by several processes. Meteorite-water impacts will produce tsunamis, and asteroid-scale impacts with associated mega-tsunamis may occur. A bolide-water impact would undoubtedly produce a major tsunami, whose sedimentological effects should be recognizable. Even a bolide-land impact might trigger major submarine landslides and thus tsunamis. In all posulated scenarios for the K/T boundary event, then, tsunamis are expected, and where to look for them must be determined, and how to distinguish deposits from different tsunamis. Also, because tsunamis decrease in height as they move away from their source, the proximal effects will differ by perhaps orders of magnitude from distal effects. Data on the characteristics of tsunamis at their origin are scarce. Some observations exist for tsunamis generated by thermonuclear explosions and for seismogenic tsunamis, and experimental work was conducted on impact-generated tsunamis. All tsunamis of interest have wave-lengths of 0(100) km and thus behave as shallow-water waves in all ocean depths. Typical wave periods are 0(10 to 100) minutes. The effect of these tsunamis can be estimated in the marine and coastal realm by calculating boundary shear stresses (expressed as U*, the shear velocity). An event layer at the K/T boundary in Texas occurs in mid-shelf muds. Only a large, long-period wave with a wave height of 0(50) m, is deemed sufficient to have produced this layer. Such wave heights imply a nearby volcanic explosion on the scale of Krakatau or larger, or a nearby submarine landslide also of great size, or a bolide-water impact in the ocean.

The Queen Charlotte-Fairweather Fault Zone - Geomorphology of a submarine transform fault, offshore British Columbia and southeastern Alaska

NASA Astrophysics Data System (ADS)

Walton, M. A. L.; Barrie, V.; Greene, H. G.; Brothers, D. S.; Conway, K.; Conrad, J. E.

2016-12-01

The Queen Charlotte-Fairweather (QC-FW) Fault Zone is the Pacific - North America transform plate boundary and is clearly seen for over 900 km on the seabed as a linear and continuous feature from offshore central Haida Gwaii, British Columbia to Icy Point, Alaska. Recently (July - September 2017) collected multibeam bathymetry, seismic-reflection profiles and sediment cores provide evidence for the continuous strike-slip morphology along the continental shelfbreak and upper slope, including a linear fault valley, offset submarine canyons and gullies, and right-step offsets (pull apart basins). South of central Haida Gwaii, the QC-FW is represented by several NW-SE to N-S trending faults to the southern end of the islands. Adjacent to the fault at the southern extreme and offshore Dixon Entrance (Canada/US boundary) are 400 to 600 m high mud volcanos in 1000 to 1600 m water depth that have plumes extending up 700 m into the water column and contain extensive carbonate crusts and chemosynthetic communities within the craters. In addition, gas plumes have been identified that appear to be directly associated with the fault zone. Surficial Quaternary sediments within and adjacent to the central and southern fault date either to the deglaciation of this region of the Pacific north coast (16,000 years BP) or to the last interstadial period ( 40,000 years BP). Sediment accumulation is minimal and the sediments cored are primarily hard-packed dense sands that appear to have been transported along the fault valley. The majority of the right-lateral slip along the entire QC-FW appears to be accommodated by the single fault north of the convergence at its southern most extent.

A double-regulated oncolytic adenovirus with improved safety for adenocarcinoma therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Na; Fan, Jun Kai; Gu, Jin Fa

2009-10-16

Safety and efficiency are equally important to be considered in developing oncolytic adenovirus. Previously, we have reported that ZD55, an oncolytic adenovirus with the deletion of E1B-55K gene, exhibited potent antitumor activity. In this study, to improve the safety of ZD55, we utilized MUC1 promoter to replace the native promoter of E1A on the basis of ZD55, and generated a double-regulated adenovirus, named MUD55. Our data demonstrated that the expression of early and late genes of MUD55 was both reduced in MUC1-negative cells, resulting in its stricter glandular-tumor selective progeny production. The cytopathic effect of MUD55 was about 10-fold lowermore » than mono-regulated adenovirus ZD55 or Ad.MUC1 in normal cells and not obviously attenuated in glandular tumor cells. Moreover, MUD55 showed the least liver toxicity when administrated by intravenous injection in nude mice. These results indicate that MUD55 could be a promising candidate for the treatment of adenocarcinoma.« less

Glacimarine Sedimentary Processes and Deposits at Fjord-Terminating Tidewater Glacier Margins

NASA Astrophysics Data System (ADS)

Streuff, K.; O'Cofaigh, C.; Lloyd, J. M.; Noormets, R.; Nielsen, T.; Kuijpers, A.

2016-12-01

Many fjords along Arctic coasts are influenced by tidewater glaciers, some of them fast-flowing ice sheet outlets. Such glaciers provide important links between terrestrial and marine environments, and, due to their susceptibility to climatic and oceanographic changes, have undergone a complex history of advance and retreat since the last glacial maximum (LGM). Although a growing body of evidence has led to a better understanding of the deglacial dynamics of individual glaciers since the LGM, their overall Holocene glacimarine processes and associated sedimentary and geomorphological products often remain poorly understood. This study addresses this through a detailed analysis of sediment cores, swath bathymetric and sub-bottom profiler data collected from seven fjords in Spitsbergen and west Greenland. The sediment cores preserve a complex set of lithofacies, which include laminated and massive muds in ice-proximal, and bioturbated mud in more ice-distal settings, diamicton in iceberg-dominated areas and massive sand occurring as lenses, laminae and thick beds. These facies record the interplay of three main glacimarine processes, suspension settling, iceberg rafting and sediment gravity flows, and collectively emphasise the dominance of glacial meltwater delivery to sedimentation in high Arctic fjords. The seafloor geomorphology in the fjords shows a range of landforms that include glacial lineations associated with fast ice-flow, terminal moraines and debris lobes marking former maximum glacier extents, and small transverse moraines formed during deglaciation by glaciotectonic deformation at the grounding line and crevasse-squeezing. Additional landforms such as iceberg ploughmarks, submarine channels, pockmarks, and debris lobes formed during or after deglaciation by iceberg calving, erosion by meltwater, and sediment reworking. We present here a new model for sedimentary and geomorphological processes in front of contemporary tidewater glaciers, which integrates our findings with those from Alaska, Canada, and east Greenland.

The Lusi mud eruption dynamics: constraints from field data.

NASA Astrophysics Data System (ADS)

Mazzini, Adriano; Sciarra, Alessandra; Lupi, Matteo; Mauri, Guillaume; Karyono, Karyono; Husein, Alwi; Aquino, Ida; Ricco, Ciro; Obermann, Anne; Hadi, Soffian

2017-04-01

The Indonesian Lusi eruption has been spewing boiling water, gas, and sediments since the 29th of May 2006. Initially, numerous aligned eruptions sites appeared along the Watukosek fault system that was reactivated after the Yogyakarta earthquake occurring the 27th of May in the Java Island. Since its birth Lusi erupted with a pulsating behavior showing intermittent periods of stronger activity resulting in higher fluids and solid emissions intervals. Since 2010 two active vents are constantly active. We conducted detailed monitoring of such clastic geysering activity and this allowed us to distinguish four distinct phases that follow each other and that reoccur every 30 minutes: (1) regular bubbling activity (constant emission of water, mud breccia, and gas); (2) clastic geysering phase with intense bubbling (consisting in reduced vapor emission and more powerful diffused mud bursting); (3) clastic geysering with mud bursts and intense vapour discharge (typically dense plume that propagates up to 100 m in height); (4) quiescent phase marking the end of the geysering activity (basically no gas emissions or bursts observed). In order to better understand this pulsating behavior and to constrain the mechanisms controlling its activity, we designed a multidisciplinary monitoring of the eruption site combining the deployment of numerous instruments around the crater site. Processing of the collected data reveals the dynamic activity of Lusi's craters. Satellite images show that the location of these vents migrated along a NE-SW direction. This is subparallel to the direction of the Watukosek fault system that is the zone of (left) lateral deformation upon which Lusi developed in 2006. Coupling HR camera images with broadband and short period seismic stations allowed us to describe the seismic signal generated by clastic geysering and to constrain the depth of the source generating the signal. We measure a delay between the seismic (harmonic) record and the associated clastic geyser explosion of approximately 3 s. This, in agreement with previous studies, corresponds to a source located some tens of meters depth inside the conduits. We ascribe the harmonic seismic signal to rise of batches of H2O-CO2-CH4 fluids inside the conduit. Once they approach the water-vapour region the sudden pressure drop triggers flashing and the exsolution of the dissolved CO2 and CH4. In the last part of our study we verified whether the powerful clastic geysering (emitting jets up to 20 m high) may induce local deformation of the mud edifice. During the stronger geysering events we measure an increase and drop of gravity overtime that are related to change of mud density within the feeder conduit. We process continuous camera recordings with a video magnifying tool capable of enhancing small variations in the recorded images. Results highlight that major eruptive events are preceded by a deformation of the mud edifice surrounding the vents. Ongoing studies aim to verify if these events are also captured by the tiltmeter measurements. This study represents a step forward to better understand the activity that characterizes Lusi. Further studies will help to better constrain the reactions and dynamics ongoing inside the conduit.

The effects of the Yogyakarta earthquake at LUSI mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Lupi, M.; Saenger, E. H.; Fuchs, F.; Miller, S. A.

2013-12-01

The M6.3 Yogyakarta earthquake shook Central Java on May 27th, 2006. Forty seven hours later, hot mud outburst at the surface near Sidoarjo, approximately 250 km from the earthquake epicentre. The mud eruption continued and originated LUSI, the youngest mud volcanic system on earth. Since the beginning of the eruption, approximately 30,000 people lost their homes and 13 people died due to the mud flooding. The causes that initiated the eruption are still debated and are based on different geological observations. The earthquake-triggering hypothesis is supported by the evidence that at the time of the earthquake ongoing drilling operations experienced a loss of the drilling mud downhole. In addition, the eruption of the mud began only 47 hours after the Yogyakarta earthquake and the mud reached the surface at different locations aligned along the Watukosek fault, a strike-slip fault upon which LUSI resides. Moreover, the Yogyakarta earthquake also affected the volcanic activity of Mt. Semeru, located as far as Lusi from the epicentre of the earthquake. However, the drilling-triggering hypothesis points out that the earthquake was too far from LUSI for inducing relevant stress changes at depth and highlight how upwelling fluids that reached the surface first emerged only 200 m far from the drilling rig that was operative at the time. Hence, was LUSI triggered by the earthquake or by drilling operations? We conducted a seismic wave propagation study on a geological model based on vp, vs, and density values for the different lithologies and seismic profiles of the crust beneath LUSI. Our analysis shows compelling evidence for the effects produced by the passage of seismic waves through the geological formations and highlights the importance of the overall geological structure that focused and reflected incoming seismic energy.

Enhancement of the immune response and protection against Vibrio parahaemolyticus by indigenous probiotic Bacillus strains in mud crab (Scylla paramamosain).

PubMed

Wu, Hui-Juan; Sun, Ling-Bin; Li, Chuan-Biao; Li, Zhong-Zhen; Zhang, Zhao; Wen, Xiao-Bo; Hu, Zhong; Zhang, Yue-Ling; Li, Sheng-Kang

2014-12-01

In a previous study, bacterial communities of the intestine in three populations of crabs (wild crabs, pond-raised healthy crabs and diseased crabs) were probed by culture-independent methods. In this study, we examined the intestinal communities of the crabs by bacterial cultivation with a variety of media. A total of 135 bacterial strains were isolated from three populations of mud crabs. The strains were screened for antagonistic activity against Vibrio parahaemolyticus using an agar spot assay. Antagonistic strains were then identified by 16S rRNA gene sequence analysis. Three strains (Bacillus subtilis DCU, Bacillus pumilus BP, Bacillus cereus HL7) with the strongest antagonistic activity were further evaluated for their probiotic characteristics. The results showed that two (BP and DCU) of them were able to survive low pH and high bile concentrations, showed good adherence characteristics and a broad spectrum of antibiotic resistance. The probiotic effects were then tested by feeding juvenile mud crabs (Scylla paramamosain) with foods supplemented with 10(5) CFU/g of BP or DCU for 30 days before being subjected to an immersion challenge with V. parahaemolyticus for 48 h. The treated crabs showed significantly higher expression levels of immune related genes (CAT, proPO and SOD) and activities of respiratory burst than that in controlled groups. Crabs treated with BP and DCU supplemented diets exhibited survival rates of 76.67% and 78.33%, respectively, whereas survival rate was 54.88% in crabs not treated with the probiotics. The data showed that indigenous mud-associated microbiota, such as DCU and BP, have potential application in controlling pathogenic Vibriosis in mud crab aquaculture. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Totumo mud volcano and its near-shore marine sedimentological setting (North Colombia) - From sedimentary volcanism to epithermal mineralization

NASA Astrophysics Data System (ADS)

Dill, H. G.; Kaufhold, S.

2018-04-01

The Holocene mud volcano exposed at Totumo (younger than 4150 ± 50 yr BP) lines up together with some other landforms of its kind along the Caribbean Coast in northern Colombia. It currently vents a mud of the silicate-phosphate-bearing sulfur-sodium chloride type. The mud volcanoes evolved in an active continental margin setting of the South American Cordillera with high seismicity and affected by pervasive neotectonic structural disturbances. During the Neogene and Quaternary linear terrigenous shoreline sediments alternating with delta deposits evolved on this mobile crustal segment between the Andes and ancient Precambrian cratons. Meso- to microtidal sedimentary settings during transgression and progradation created meta- to instable sedimentary and petrophysical conditions (e.g. overpressure and gas-bearing bubble sands), favorable for the formation of mud volcanoes, whose lithofacies is subdivided into (1) footwall facies (detritus from metabasic, -pelitic source rocks), (2) mud volcano plus lateral facies (material from deep-seated hydrothermal sources, hydrocarbon plays, and brine reflux from the sea), (3) hanging wall facies, sand characterized by a strong longshore drift. The sedimentary volcanism in the area is characterized by different temperatures of formation: (1) pre-stage (<100 °C) and (2) recent stage (≈25 °C). Heavy (pyroxene, amphibole, epidote-clinozoisite, Fe-Ti silicates and oxides, garnet, alumosilicates, tourmaline, zircon, barite, Fe sulfides and -sulfates), light (Ca sulfates, calcite, quartz, feldspar) and clay minerals (kaolinite, mica, pyrophyllite, chlorite, vermiculite) are efficient tools to determine the source of mud, to subdivide the mud volcano system as to its facies and describe its physical-chemical regime as to the temperature of formation, pH and Eh values. The mud volcano system of Totumo bridges the gap between sedimentary "volcanism" and epithermal hot spring deposits of intermediate to high sulfidation and forms a useful "guide" to hydrocarbon accumulation.

Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

USGS Publications Warehouse

Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

2014-01-01

Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side. Differences in microbial sulfate reduction, organic matter supply, and/or groundwater residence time likely contributed to this pattern. The contrasting features of the east and west sub-marsh zones highlight the need for multiple techniques for characterization of submarine groundwater discharge sources and the impact of biogeochemical processes on the delivery of nutrients and carbon to coastal areas via submarine groundwater discharge.

Geochemistry and microbiology at gas hydrate and mud volcano sites in the black sea

NASA Astrophysics Data System (ADS)

Drews, M.; Schmaljohann, R.; Wallmann, K.

2003-04-01

We present geochemical and microbiological results which were obtained from sediments at gas hydrate and mud volcano sites in the Sorokin Trough (northern Black Sea, south east of the Crimean peninsula) at water depths of about 1800 to 2100 m during the METEOR cruise 52-1. The surface near sub-bottom accumulations of gas hydrates (occuring at depths of several meters or less beneath the sea floor) in the Black Sea are associated with numerous mud volcanos. At stations we investigated gas hydrates occurred below 10 cm to 100 cm with a significant influence on the sediment biochemistry. Analyses revealed high methane concentrations, anoxic and sulfidic conditions, a steep sulfate gradient, carbonate precipitation, and high anaerobic methane oxidation rates. In proximity of the so called Odessa mud volcano one investigated sampling station showed maximum methane oxidation rates in the depth horizon of a firm 2 cm thick carbonate crust layer, adhered to by a bacterial mat. This observation is taken to indicate that the bacteria are causing or mediating the crust formation by their anaerobic methane oxidation metabolism. The station was further characterised by two layers of gas hydrate fragments and lenses below 1 m depth. A 2 to 4 cm thick carbonate crust with attached bacterial mat from a Yalta mud vulcano sample (2124 m water depth) was investigated under the scanning electron microscope. The stiff gelatinous mat showed a dense and morphologically uniform population of rod shaped bacteria with only a few nests of coccoid cells. Purified mat material exhibited anaerobic methane oxidation activity. These mats resemble the type previously found in the shallow NW methane seep area of the Black Sea, where it covers carbonate chimneys. Samples from two sites atop the summit of the active but flat-topped Dvurechenskii mud volcano were characterised by very high methane oxidation rates (up to 563 nmol/cm3/d) at the sediment surface. Strong pore water gradients of chloride, bromide, ammonium, methane, and temperature proved the existence of a rich upward flow of warm fluids from the deeper sediment. At both stations no carbonate crusts or bacterial mats were found. The lack of hemipelagic sediments and at the same time abundance of mud breccia gives ample evidence of the recency of the mud flow.

Volcanism, Iron, and Phytoplankton in the Heard and McDonald Islands Region, Southern Indian Ocean

NASA Astrophysics Data System (ADS)

Coffin, M. F.; Arculus, R. J.; Bowie, A. R.; Chase, Z.; Robertson, R.; Trull, T. W.; Heobi in2016 v01 Shipboard Party, T.

2016-12-01

Phytoplankton supply approximately half of the oxygen in Earth's atmosphere, and iron supply limits the growth of phytoplankton in the anemic Southern Ocean. Situated entirely within the Indian Ocean sector of the Southern Ocean are Australia's only active subaerial volcanoes, Heard and McDonald islands (HIMI) on the central Kerguelen Plateau, a large igneous province. Widespread fields of submarine volcanoes, some of which may be active, extend for distances of up to several hundred kilometers from the islands. The predominantly eastward-flowing Antarctic Circumpolar Current sweeps across the central Kerguelen Plateau, and extensive blooms of phytoplankton are observed on the Plateau down-current of HIMI. The goal of RV Investigator voyage IN2016_V01, conducted in January/February 2016, is to test the hypothesis that hydrothermal fluids, which cool active submarine volcanoes in the HIMI region, ascend from the seafloor and fertilise surface waters with iron, thereby enhancing biological productivity beginning with phytoplankton. Significant initial shipboard results include: Documentation, for the first time, of the role of active HIMI and nearby submarine volcanoes in supplying iron to the Southern Ocean. Nearshore waters had elevated dissolved iron levels. Although biomass was not correspondingly elevated, fluorescence induction data indicated highly productive resident phytoplankton. Discovery of >200 acoustic plumes emanating from the seafloor and ascending up to tens of meters into the water column near HIMI. Deep tow camera footage shows bubbles rising from the seafloor in an acoustic plume field north of Heard Island. Mapping 1,000 km2 of uncharted seafloor around HIMI. Submarine volcanic edifices punctuate the adjacent seafloor, and yielded iron-rich rocks similar to those found on HIMI, respectively. Acoustic plumes emanating from some of these features suggest active seafloor hydrothermal systems.

Environmental monitoring of El Hierro Island submarine volcano, by combining low and high resolution satellite imagery

NASA Astrophysics Data System (ADS)

Eugenio, F.; Martin, J.; Marcello, J.; Fraile-Nuez, E.

2014-06-01

El Hierro Island, located at the Canary Islands Archipelago in the Atlantic coast of North Africa, has been rocked by thousands of tremors and earthquakes since July 2011. Finally, an underwater volcanic eruption started 300 m below sea level on October 10, 2011. Since then, regular multidisciplinary monitoring has been carried out in order to quantify the environmental impacts caused by the submarine eruption. Thanks to this natural tracer release, multisensorial satellite imagery obtained from MODIS and MERIS sensors have been processed to monitor the volcano activity and to provide information on the concentration of biological, chemical and physical marine parameters. Specifically, low resolution satellite estimations of optimal diffuse attenuation coefficient (Kd) and chlorophyll-a (Chl-a) concentration under these abnormal conditions have been assessed. These remote sensing data have played a fundamental role during field campaigns guiding the oceanographic vessel to the appropriate sampling areas. In addition, to analyze El Hierro submarine volcano area, WorldView-2 high resolution satellite spectral bands were atmospherically and deglinted processed prior to obtain a high-resolution optimal diffuse attenuation coefficient model. This novel algorithm was developed using a matchup data set with MERIS and MODIS data, in situ transmittances measurements and a seawater radiative transfer model. Multisensor and multitemporal imagery processed from satellite remote sensing sensors have demonstrated to be a powerful tool for monitoring the submarine volcanic activities, such as discolored seawater, floating material and volcanic plume, having shown the capabilities to improve the understanding of submarine volcanic processes.

Banning Cigarette Smoking on US Navy Submarines: A Case Study

PubMed Central

Lando, Harry A.; Michaud, Mark. E.; Poston, Walker S.C.; Jahnke, Sara A.; Williams, Larry; Haddock, Christopher K.

2014-01-01

Background The military has had a long pro-tobacco tradition. Despite official policy discouraging smoking, tobacco still is widely seen as part of military culture. While active smoking has presented a particular challenge for the military, in recent years there also has been increasing concern with secondhand smoke. This is especially true in closed environments and submarines may be deployed for months at a time. The current case study describes the successful implementation by the Navy of a comprehensive ban on smoking aboard submarines. Methods The authors searched documents on the Internet, popular media, military-based news outlets, and the scientific literature. We also conducted interviews with Navy officers who were instrumental in policy implementation. Findings Data demonstrating substantial exposure of nonsmokers to tobacco smoke aboard submarines had major impact on successful adoption of the policy. A systematic and extended roll out of the ban included establishing a working group, soliciting input and active engagement from submarine personnel, and offering cessation assistance. Support was enlisted from Chief Petty Officers who could have been strongly opposed but who became strong proponents. Fewer problems were encountered than had been expected. In contrast to a previous unsuccessful attempt by a Navy captain to ban smoking on his ship, the ban was adopted without apparent tobacco industry interference. Conclusions Lessons learned included the importance of strong empirical support, effective framing of the issue, setting a realistic timeline, soliciting support from key personnel, and providing appropriate resources. These lessons have implications for those considering further tobacco policy changes in the military and elsewhere. PMID:25163466

3D Chirp Sonar Images on Fluid Migration Pathways and Their Implications on Seafloor Stability East of the Fangliao Submarine Canyon Offshore SW Taiwan

NASA Astrophysics Data System (ADS)

Lu, Y. W.; Liu, C. S.; Su, C. C.; Hsu, H. H.; Chen, Y. H.

2015-12-01

This study utilizes both chirp sonar images and coring results to investigate the unstable seafloor strata east of the Fangliao Submarine Canyon offshore southwestern Taiwan. We have constructed 3D chirp sonar images from a densely surveyed block to trace the attitude of an acoustic transparent layer and features caused by fluid activities. Based on the distribution of this transparent layer and fluid-related features, we suggest that this transparent layer forms a pathway for fluid migration which induces fluid-related characters such as acoustic blanking and fluid chimneys in the 3D chirp sonar images. Cored seafloor samples are used in this study to investigate the sediment compositions. The 210Pb activity profiles of the cores show oscillating and unsteady values at about 20~25 cm from core top. The bulk densities of the core samples in the same section (about 20~25 cm from core top) give values lower than those at deeper parts of the cores. These results indicate that the water content is much higher in the shallow sediments than in the deeper strata. From core sample analyses, we deduce that the local sediments are disturbed by liquefaction. From the analyses of 3D chirp sonar images and core data, we suggest that the seafloor east of the Fangliao Submarine Canyon is in an unstable condition, if disturbed by earthquakes, submarine landslides and gravity flows could be easily triggered and cause some geohazards, like breaking submarine cables during the 2006 Pingtung earthquake event.

Telepresence-enabled research and developing work practices

NASA Astrophysics Data System (ADS)

Mirmalek, Z.

2016-02-01

In the fall of 2014, a group of scientists and students conducted two weeks of telepresence-enabled research from the University of Rhode Island Inner Space Center and Woods Hole Oceanographic Institution with the Exploration Vessel Nautilus, which was at sea studying the Kick'em Jenny submarine volcano and Barbados Mud Volcanoes. The way that they conducted their work was not so different from other telepresence-enabled ocean science exploration. As a group, they spanned geographic distance, science expertise, exploration experience, and telepresence-enabled research experience. They were connected through technologies and work culture (e.g., shared habits, values, and practices particular to a community). Uniquely, their project included an NSF-sponsored cultural study on the workgroups' own use of technologies and social processes. The objective of the cultural study was, in part, to identify social and technical features of the work environment that present opportunities to better support science exploration via telepresence. Drawing from this case, and related research, I present some analysis on the developing work culture of telepresence-enabled research and highlight potential adjustments.

Navy Virginia (SSN-774) Class Attack Submarine Procurement: Background and Issues for Congress

DTIC Science & Technology

2010-07-08

current and future Virginia Class submarines once they mature—advanced electromagnetic signature reduction (AESR), a conformal acoustic velocity sensor...WAA is a sensor array that is designed to detect the vibrations and acoustic signatures of targets. The Navy has stated that CAVES WAA could save...Active Shaft Grounding System, Circuit D, Ship Service Turbine Generator magnetic levitation bearings / throttle control system, etc.); • Special

Isotopic evidence for the influence of typhoons and submarine canyons on the sourcing and transport behavior of biospheric organic carbon to the deep sea

NASA Astrophysics Data System (ADS)

Zheng, Li-Wei; Ding, Xiaodong; Liu, James T.; Li, Dawei; Lee, Tsung-Yu; Zheng, Xufeng; Zheng, Zhenzhen; Xu, Min Nina; Dai, Minhan; Kao, Shuh-Ji

2017-05-01

Export of biospheric organic carbon from land masses to the ocean plays an important role in regulating the global carbon cycle. High-relief islands in the western Pacific are hotspots for such land-to-ocean carbon transport due to frequent floods and active tectonics. Submarine canyon systems serve as a major conduit to convey terrestrial organics into the deep sea, particularly during episodic floods, though the nature of ephemeral sediment transportation through such canyons remains unclear. In this study, we deployed a sediment trap in southwestern Taiwan's Gaoping submarine canyon during summer 2008, during which Typhoon Kalmaegi impacted the study area. We investigated sources of particulate organic carbon and quantified the content of fossil organic carbon (OCf) and biospheric non-fossil carbon (OCnf) during typhoon and non-typhoon periods, based on relations between total organic carbon (TOC), isotopic composition (δ13 C, 14C), and nitrogen to carbon ratios (N/C) of newly and previously reported source materials. During typhoons, flooding connected terrestrial rivers to the submarine canyon. Fresh plant debris was not found in the trap except in the hyperpycnal layer, suggesting that only hyperpycnal flow is capable of entraining plant debris, while segregation had occurred during non-hyperpycnal periods. The OCnf components in typhoon flood and trapped samples were likely sourced from aged organics buried in ancient landslides. During non-typhoon periods, the canyon is more connected to the shelf, where waves and tides cause reworking, thus allowing abiotic and biotic processes to generate isotopically uniform and similarly aged OCnf for transport into the canyon. Therefore, extreme events coupled with the submarine canyon system created an efficient method for deep-sea burial of freshly produced organic-rich material. Our results shed light on the ephemeral transport of organics within a submarine canyon system on an active tectonic margin.

The importance of submarine groundwater discharge to the nearshore nutrient supply in the Gulf of Aqaba (Israel)

USGS Publications Warehouse

Shellenbarger, G.G.; Monismith, Stephen G.; Genin, A.; Paytan, A.

2006-01-01

We used two short-lived radium isotopes (223Ra, 224Ra) and a mass balance approach applied to the radium activities to determine the nutrient contribution of saline submarine groundwater discharge to the coastal waters of the northern Gulf of Aqaba (Israel). Radium isotope activities were measured along transects during two seasons at a site that lacked any obvious surficial water input. An onshore well and an offshore end member were also sampled. For all samples, nutrients and salinity data were collected. Radium isotope activities generally decreased with distance offshore and exhibited significant tidal variability, which is consistent with a shore-derived tidally influenced source. Submarine groundwater contributes only 1-2% of the water along this coast, but this groundwater provides 8-46% of the nutrients. This saline groundwater is derived predominately from tidally pumped seawater percolating through the unconfined coastal aquifer and leaching radium and nutrients. This process represents a significant source of nutrients to the oligotrophic nearshore reef. ?? 2006, by the American Society of Limnology and Oceanography, Inc.

Microbial processes and communities in sediment samples along a transect across the Lusi mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Krueger, Martin; Straaten, Nontje; Mazzini, Adriano

2015-04-01

The Lusi eruption represents one of the largest ongoing sedimentary hosted geothermal systems. This eruption started in 2006 following to a 6.3 M earthquake that stroke Java Island. Since then it has been spewing boiling mud from a central crater with peaks reaching 180.000 m3 per day. Today an area of about 8 km2 is covered by locally dried mud breccia where a network of hundreds of satellite seeping pools is active. Numerous investigations focused on the study of offshore microbial colonies that commonly thrive at offshore methane seeps and mud volcanoes, however very little has been done for onshore seeping structures. Lusi represents a unique opportunity to complete a comprehensive study of onshore microbial communities fed by the seepage of CH4 and CO2 as well as of heavier liquid hydrocarbons originating from several km below the surface. We conducted a sampling campaign at the Lusi site collecting samples of fresh mud close to the erupting crater using a remote controlled drone. In addition we completed a transect towards outer parts of the crater to collect older, weathered samples for comparison. In all samples active microorganisms were present. The highest activities for CO2 and CH4 production as well as for CH4 oxidation and hydrocarbon degradation were observed in medium-age mud samples collected roughly in the middle of the transect. Rates for aerobic methane oxidation were high, as was the potential of the microbial communities to degrade hydrocarbons (oils, alkanes, BTEX tested). The data suggests a transition of microbial populations from an anaerobic, hydrocarbon-driven metabolism in fresher samples from center or from small seeps to more generalistic, aerobic microbial communities in older, more consolidated sediments. Currently, the microbial communities in the different sediment samples are analyzed using quantitative PCR and T-RFLP combined with MiSeq sequencing. This study represents an initial step to better understand onshore seepage systems and provides an ideal analogue for comparison with the better investigated offshore structures.

ESR dating of submarine hydrothermal activities using barite in sulfide deposition

NASA Astrophysics Data System (ADS)

Toyoda, S.; Fujiwara, T.; Ishibashi, J.; Isono, Y.; Uchida, A.; Takamasa, A.; Nakai, S.

2012-12-01

The temporal change of submarine hydrothermal activities has been an important issue in the aspect of the evolution of hydrothermal systems which is related with ore formation (Urabe, 1995) and biological systems sustained by the chemical species arising from hydrothermal activities (Macdonald et al., 1980). Determining the ages of the hydrothermal deposit will provide essential information on such studies. Dating methods using disequilibrium between radioisotopes such as U-Th method (e.g. You and Bickle, 1998), 226}Ra-{210Pb and 228}Ra-{228Th method (e.g. Noguchi et al., 2011) have been applied to date submarine hydrothermal deposits. ESR (electron spin resonance) dating method is commonly applied to fossil teeth, shells, and quartz of Quaternay period where the natural accumulated dose is obtained from the intensities of the ESR signals which are created by natural radiation. The natural dose is divided by the dose rate to the mineral/sample to deduce the age. Okumura et al., (2010) made the first practical application of ESR (electron spin resonance) dating technique to a sample of submarine hydrothermal barite (BaSO4) to obtain preliminary ages, where Kasuya et al. (1991) first pointed out that barite can be used for ESR dating. Knowing that ESR dating of barite is promising, in this paper, we will present how we have investigated each factor that contributes ESR dating of barite in submarine hydrothermal sulfide deposition. (1) The best ESR condition for measuring the SO3- signal in barite is with the microwave power of 1mW and modulation amplitude of 0.1mT. (2) As results of heating experiments, the signal was found to be stable for the dating age range of several thousands. (3) 226Ra replacing Ba in barite is the source of the radiation. The amount of radioactive elements in sulfide mineral surrounding barite is negligible. (4) The external radiation from the sea water is negligible even in the submarine hydrothermal area where the radiation level is much higher than usual sea water. (5) The decay of 226Ra has to be considered. (6) Major terms of dose rate are the internal alpha dose rate and the external beta and gamma dose rates. (7) The alpha effectiveness, the ratio of forming the radical by internal alpha particles to by beta and gamma rays, was obtained to be 0.043±0.018. (8) The shape of the chimney sample should be considered for gamma ray dose. Examples of dating results for submarine hydrothermal deposits from South Mariana and Okinawa Trough will be presented.

The missing link between submarine volcano and promising geothermal potential in Jinshan, Northern Taiwan

NASA Astrophysics Data System (ADS)

Wang, S. C.; Hutchings, L.; Chang, C. C.; Lee, C. S.

2017-12-01

The Tatun volcanic group (TVG) and the Keelung submarine volcano (KSV) are active volcanoes and surrounding three nuclear plant sites in north Taiwan. The famous Jinshan-Wanli hot springs locates between TVG and KSV, moreover, the geochemical anomalies of acidic boiling springs on the seacoast infer that the origin is from magmatic fluids, sea water and meteoric water mixture, strongly implying that mantle fluids ascends into the shallow crust. The evidence for a magma chamber, submarine volcano, and boiling springs have a close spatial relationship. Based on UNECE specifications to Geothermal Energy Resources (2016), the Jinshan-Wanli geothermal area could be classified as Known Geothermal Energy Source for geothermal direct use and Potential Geothermal Energy Source for conventional geothermal system. High resolution reservoir exploration and modeling in Jinshan-Wanli geothermal area is developing for drilling risk mitigation. The geothermal team of National Taiwan Ocean University and local experts are cooperating for further exploration drilling and geothermal source evaluation. Keywords: geothermal resource evaluation, Jinshan-Wanli geothermal area, submarine volcano

First direct observations linking confined supercritical turbidity currents to their depositional architecture and facies characteristics

NASA Astrophysics Data System (ADS)

Hage, S.; Cartigny, M.; Hughes Clarke, J. E.; Clare, M. A.; Sumner, E.; Hubbard, S. M.; Talling, P.; Lintern, G.; Stacey, C.; Vardy, M. E.; Hunt, J.; Vendettuoli, D.; Yokokawa, M.; Hizzett, J. L.; Vellinga, A. J.; Azpiroz, M.

2017-12-01

Turbidity currents transfer globally significant amounts of sediment via submarine channels from the continental margin to deep submarine fans. Submarine channel inception is thought to result from erosive, supercritical turbidity currents that are common in proximal settings of the marine realm. Recent monitoring of submarine processes have provided the first measurements of supercritical turbidity currents (Hughes Clarke, 2016), demonstrating that they drive the upstream migration of crescentic bedforms in confined submarine channels. Although upstream-migrating bedforms are common in confined channels across the world's oceans, there is considerable debate over the type of deposits that they produce. It is important to understand what types of deposit record these supercritical bedforms to potentially identify them from geological archives. For the first time, we combine direct measurements from supercritical field-scale turbidity currents with the facies and depositional architecture resulting from such flows. We show how the subsurface architecture evolves in a highly active channel at Squamish submarine delta, British Columbia, Canada. Repeated upstream migration of bedforms is found to create two main deposit geometries. First, regular back-stepping beds result from flow deceleration on the slightly-inclined sides of the bedforms. Second, lens-shaped scour fills composed of massive deposits result from erosion of the back-stepping beds by subsequent turbidity currents. We relate our findings to a range of ancient outcrop studies to demonstrate that supercritical flows are common in proximal settings through the geological record. This study provides the first direct observation-based model to identify confined supercritical turbidity currents and their associated upslope-migrating bedforms in the sedimentary record. This is important for correctly identifying the proximal sites of ancient submarine channels that served as past conduits for globally significant quantities of sediment to reach the deep sea.

Stability of submarine slopes in the northern South China Sea: a numerical approach

NASA Astrophysics Data System (ADS)

Zhang, Liang; Luan, Xiwu

2013-01-01

Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained ( Φ=0) cases. Results show that submarine slopes are stable when the slope is <16° under static conditions and without a weak interlayer. With a weak interlayer, slopes are stable at <18° in the drained case and at <9° in the undrained case. Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure. The slope became unstable at >13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.

Mineralogic-chemical and physical characteristics of the mud in Ä°zmir (western Turkey): suitability for use in pelotherapy

NASA Astrophysics Data System (ADS)

Çelik Karakaya, Muazzez; Karakaya, Necati

2013-04-01

The study conducted on peloid used spas in İzmir city region (western part of Turkey) included the investigation of the mineralogical, physico-chemical and geochemical properties of the three types of peloid samples in order to assess the suitability of the material for healing- aesthetic-related purposes. In situ formed muds in lagoons near the Aegean Sea (named as first group) and inner swamp muds (second group) unprocessed and raw have been using therapy and thermal baths. Mud and hot springs at around the Aegean Sea have been popular since ancient times for the treatment of rheumatic diseases, musculoskeletal disorders in the region. The mineralogical characteristics of the thermal muds are in accordance with the geological origin of the material and water sources. Mineralogic composition, mineral content and morphologic properties of the samples were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS). Chemical composition of the muds and thermal waters were determined by ICP-EAS and ICP-MS. Both of the sediment is fine- to medium size-grained and composed mostly of clay minerals, partially quartz, feldspar, carbonates, and halite, and rarely gypsum. The mineralogic composition of the muds controls the physico-chemical properties of the muds. Anion e.g., Cl, Br, and SO4, contents the thermal waters of the first group is extremely different and so the springs contain a high level of sodium chloride, magnesium sulphate, and calcium bicarbonate. The water temperature is 45 oC with a pH of 6.95 and electrical conductivity (EC) is 4.5 mS/lt in the first group while 71 oC with a pH 6.58 and EC is 2.52 mS/lt in the second ones. However, major and some of the trace element concentration of the mud samples are nearly similar, As, Cd, Cu, Hg, Ni, Sb, Se, T and Zn content of the first group is exceptionally lower than the second ones. And the hazardous element concentrations are extremely higher than the pharmaceutical clay in the second group peloids and also in thermal water, the element concentrations is not acceptable limits for peloids and waters. The element concentration is sourced from active fault system and low temperature precious metal deposits in the area which is widespread the thermal water circulated in. The anion contents of the water are related to sea water interaction. BET surface areas, plasticity, adsorbing, abrasiveness, hygroscopic water and cooling kinetics the characteristics both of the muds are nearly similar. However, cation exchange capacity and viscosity properties of the second group muds are better than the second, the physico-chemical properties both of the mud material are in acceptable level to some extent. Nevertheless, the appropriate characteristics of the second group muds when compared to some commercial used mud for medicinal and aesthetic purposes, if the hazardous element concentrations regulated.

Physical and Chemical Properties of Sintering Red Mud and Bayer Red Mud and the Implications for Beneficial Utilization

PubMed Central

Wang, Ping; Liu, Dong-Yan

2012-01-01

Performances of two common types of red mud, Bayer red mud and Sintering red mud, were investigated in this research. Their compositions, mechanical properties and microstructure characterization were measured through XRD, TG and SEM analysis. Their shear strength, particle size, density and hydraulic characteristics also had been performed. Huge differences between the basic mineral types of these two kinds of red mud also can be found. The comparison of compositions shows that CaCO3 content in Sintering red mud is higher, Bayer red mud has more hazardous elements such as As, Pb and Hg and both have a high concentration of radioactivity. The micro particle of Bayer red mud is finer and more disperse, but the Sintering red mud has higher shear strength. Combining the TG and hydraulic characteristics analysis, it can be shown that Bayer red mud has higher value of water content and Sintering red mud has higher hydraulic conductivity. The paper then illustrates that Sintering red mud can become the main filling material of supporting structure of red mud stocking yard. Bayer red mud has a high reuse value and also can be used as a mixing material of masonry mortar.

Influences of Different Halophyte Vegetation on Soil Microbial Community at Temperate Salt Marsh.

PubMed

Chaudhary, Doongar R; Kim, Jinhyun; Kang, Hojeong

2018-04-01

Salt marshes are transitional zone between terrestrial and aquatic ecosystems, occupied mainly by halophytic vegetation which provides numerous ecological services to coastal ecosystem. Halophyte-associated microbial community plays an important role in the adaptation of plants to adverse condition and also affected habitat characteristics. To explore the relationship between halophytes and soil microbial community, we studied the soil enzyme activities, soil microbial community structure, and functional gene abundance in halophytes- (Carex scabrifolia, Phragmites australis, and Suaeda japonica) covered and un-vegetated (mud flat) soils at Suncheon Bay, South Korea. Higher concentrations of total, Gram-positive, Gram-negative, total bacterial, and actinomycetes PLFAs (phospholipid fatty acids) were observed in the soil underneath the halophytes compared with mud flat soil and were highest in Carex soil. Halophyte-covered soils had different microbial community composition due to higher abundance of Gram-negative bacteria than mud flat soil. Similar to PLFA concentrations, the increased activities of β-glucosidase, cellulase, phosphatase, and sulfatase enzymes were observed under halophyte soil compared to mud flat soil and Carex exhibited highest activities. The abundance of archaeal 16S rRNA, fungal ITS, and denitrifying genes (nirK, nirS, and nosZ) were not influenced by the halophytes. Abundance bacterial 16S rRNA and dissimilatory (bi)sulfite (dsrA) genes were highest in Carex-covered soil. The abundance of functional genes involved in methane cycle (mcrA and pmoA) was not affected by the halophytes. However, the ratios of mcrA/pmoA and mcrA/dsrA increased in halophyte-covered soils which indicate higher methanogenesis activities. The finding of the study also suggests that halophytes had increased the microbial and enzyme activities, and played a pivotal role in shaping microbial community structure.

The Biggest Tuya or Table Mountain in the North Atlantic?

NASA Astrophysics Data System (ADS)

Helgadottir, G.; Reynisson, P.

2012-12-01

Multibeam mapping in cruise A201206 of the Marine Research Institute in June 2012 revealed a huge submarine mountain with a striking look of a tuya. Tuya is by defenition a subrectangular or circular, constructional, flat-topped mountain, made up of hyaloclastites and/or pillow lava, usually with cap lava (Mathews 1947). The mountain lies at 950-1.400 waterdepth some 120 nautical miles west of the Snaefellsnes peninsula and the mapped part of it is around 300 km2. For comparison, the largest tuya in Iceland is Eiriksjokull with a basal area of 77 km2 (Jakobsson and Gudmundsson 2008). Above the mountains edge at 1.100 m waterdepth the hight increases gradually towards the top of the mountain were some craters are exposed. The mountain has a a youthful apperance. Analysing of rock samples are needed to find out if that is the case or if it is connected with an old rifting zone. The goal of the survey was to map fishing areas (f. ex. of the Greenland halibut); to explore the environment of the strong ocean currents coming from north through the Greenland Strait (also called Denmark Strait) but also to gain additional bathymetrical data in the vicinity of what we believe are mud volcanoes, discovered in a fairly recent MRI's mapping cruise. Now, like erlier on, several mud volcanoes appeared, some of them up to 350 m high. If this proves to be right, this is the first finding of these features in Icelandic waters. The research area coincides largely with sediments of the Snorri drift. Seismic lines through this sediment show possible diapir formation (Egloff and Johnson 1978) which strengthens the idea of those features beeing mud volcanoes. The current 9.000 km2 mapping with EM 300 has added significantly to our knowledge of the morphology of the seafloor around Iceland. References: Mathews, W. H. 1947: "Tuyas": Flat-topped volcanoes in northern Brithish Columbia. Amer. J. Sci. 245, 560-570. Jakobsson, S. P. and Gudmundsson, M. T. 2008: Subglacial and intraglacial volcanic formations in Iceland. Jokull no. 58, 179-196. Egloff, J. and Johnson, G. L. 1978: Erosional and Depositional Structures of the Southwest Iceland Insular Margin: Thirteen Geophysical Profiles. AAPG Mem. Vol. 29, 43-63.

The Record of Tsunamis and Storms in a Coastal Mangrove Pond, NW Puerto Rico

NASA Astrophysics Data System (ADS)

Jaffe, B. E.; Buckley, M. L.; Watt, S. G.; Moya, J. C.; Richmond, B. M.; Gelfenbaum, G. R.; La Selle, S.

2017-12-01

The written record of tsunamis in the Caribbean extends back over 500 years, yet, is incomplete. In particular, it is not known whether great earthquakes or submarine landslides near the Puerto Rico Trench have generated large tsunamis that impact the north coast of Puerto Rico. We cored a coastal mangrove pond in NW Puerto Rico to search for tsunami deposits. The pond extends from 150 to 350 m from the shoreline, and is 0.5 m above sea level. The area between the pond and the ocean presently has a high of 3 m above sea level, but had dunes up to 10 m high before they were mined for sand beginning in the 1960s. Pond sediments are predominately mud or mangrove peat and contain prominent sand layers. At the sediment surface, a tabular sandy overwash deposit up to 40 cm thick extends inland approximately 30 m from the pond's seaward edge and abruptly ends. This sand layer contains no evidence of vertical grading and was likely formed by one or more recent hurricanes, which with the removal of coastal dunes in the 1960s are able to flood the pond. In contrast, underlying the overwash deposit and mangrove peat at a depth of approximately 60 cm is a thin (1 - 7 cm thick) sand layer extending to the landward limit of the pond. This layer has features of a tsunami deposit, including suspension grading, which is a specific type of normal grading where the entire grain-size distribution shifts to finer sizes upward that is created when sediment settles out of suspension as a high-speed flow wanes, an erosive basal contact, and an organic cap. In addition, couplets or triplets of sand inter-layered with mud are present within the thin sandy layer at some locations. Alternation of sand and mud layers at this scale is a signature of series of tsunami waves. Radiocarbon dates from organic material above and below the thin sand layer constrain deposition as occurring sometime from 1446 to 1919 AD. We present the features of the coastal mangrove pond deposits and evaluate whether these deposits could be correlated with an extreme wave overwash that left a deposit on Anegada, BVI, sometime between 1200 and 1480 AD, which would support a great Puerto Rico Trench earthquake and tsunami about 600 years ago.

Earthquakes of Loihi submarine volcano and the Hawaiian hot spot.

USGS Publications Warehouse

Klein, F.W.

1982-01-01

Loihi is an active submarine volcano located 35km S of the island of Hawaii and may eventually grow to be the next and S most island in the Hawaiian chain. The Hawaiian Volcano Observatory recorded two major earthquake swarms located there in 1971-1972 and 1975 which were probably associated with submarine eruptions or intrusions. The swarms were located very close to Loihi's bathymetric summit, except for earthquakes during the second stage of the 1971-1972 swarm, which occurred well onto Loihi's SW flank. The flank earthquakes appear to have been triggered by the preceding activity and possible rifting along Loihi's long axis, similar to the rift-flank relationship at Kilauea volcano. Other changes accompanied the shift in locations from Loihi's summit to its flank, including a shift from burst to continuous seismicity, a rise in maximum magnitude, a change from small earthquake clusters to a larger elongated zone, a drop in b value, and a presumed shift from concentrated volcanic stresses to a more diffuse tectonic stress on Loihi's flank. - Author

Induction of Fish Biomarkers by Synthetic-Based Drilling Muds

PubMed Central

Gagnon, Marthe Monique; Bakhtyar, Sajida

2013-01-01

The study investigated the effects of chronic exposure of pink snapper (Pagrus auratus Forster), to synthetic based drilling muds (SBMs). Fish were exposed to three mud systems comprised of three different types of synthetic based fluids (SBFs): an ester (E), an isomerized olefin (IO) and linear alpha olefin (LAO). Condition factor (CF), liver somatic index (LSI), hepatic detoxification (EROD activity), biliary metabolites, DNA damage and stress proteins (HSP-70) were determined. Exposure to E caused biologically significant effects by increasing CF and LSI, and triggered biliary metabolite accumulation. While ester-based SBFs have a rapid biodegradation rate in the environment, they caused the most pronounced effects on fish health. IO induced EROD activity and biliary metabolites and LAO induced EROD activity and stress protein levels. The results demonstrate that while acute toxicity of SBMs is generally low, chronic exposure to weathering cutting piles has the potential to affect fish health. The study illustrates the advantages of the Western Australian government case-by-case approach to drilling fluid management, and highlights the importance of considering the receiving environment in the selection of SBMs. PMID:23894492

47 CFR 32.2424 - Submarine & deep sea cable.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic submarine...

47 CFR 32.2424 - Submarine & deep sea cable.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic submarine...

47 CFR 32.2424 - Submarine & deep sea cable.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic submarine...

47 CFR 32.2424 - Submarine & deep sea cable.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic submarine...

47 CFR 32.2424 - Submarine & deep sea cable.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false Submarine & deep sea cable. 32.2424 Section 32... Submarine & deep sea cable. (a) This account shall include the original cost of submarine cable and deep sea... defined below, are to be maintained for nonmetallic submarine and deep sea cable and metallic submarine...

Bridging Surface and Subsurface Observations of the Pulsating Behavior of Lusi: a New-born Sedimentary Hosted Hydrothermal System in East Java.

NASA Astrophysics Data System (ADS)

Mazzini, A.; Husein, A.; Karyono, K.; Lupi, M.; Obermann, A.; Hadi, S.

2015-12-01

The Lusi eruption started the 29th of May 2006 in Eastern Java, Indonesia. Since its birth Lusi presented a pulsating behaviour with geyser-like activity. To date Lusi is still active and never stopped erupting enormous amounts of mud, clasts, water and gas with peaks of activity reaching 180.000 km3/day. The erupting activity is characterized by[ML1] three main behaviours: 1) regular activity, which consists in the constant emission of mud breccia (i.e. viscous mud containing clay, silt, sand and clasts up to 10 cm in diameter) associated with the expulsion of water both in a liquid and vapour state as well as other gasses (i.e. mostly CO2 and CH4). Occasional powerful bursts of mud may reach up ten meters in height. 2) geysering activity consisting in more powerful eruptive events that do not seem to have a regular pattern. These typically lasts up to five minutes and comprise an initial phase marked by an elevated bubbling in the crater zone followed by an increasing amount of vapour released throughout the geysering phase. 3) quasi-absence of degassing from the main crater(s). This phase follows the geysering activity and is generally short-lived In order to investigate the mechanisms controlling Lusi pulsating behaviour, we deployed a network of five seismometers around the crater. The seismic records highlight that the seismic signal of Lusi is characterised by tremor and volcano-tectonic events. Tremor events occur in 1 Hz and 3 Hz frequency bands while volcano tectonic events are rich in high frequencies (i.e. 2-15 Hz). We also identify an emerging signal lasting from approximately one to ten minutes. This signal appears throughout the dataset and it is characterized by a frequency content between 5 Hz and 10 Hz. To verify whether such long-lasting signal could be associated to the geysering phase we coupled the seismic monitoring with a HD camera to record the crater activity. Results reveal that the onset of such signal precedes the visual evidence of geysering activity at the surface. This implies that the signal is not originated in the immediate subsurface. We argue that such signal is generated by the geysering activity and it is caused by the discrete collapse of gas pockets rising through a super-heated fluid column filled with hot mud. [ML1]Comprises??

Glider monitoring of shelf suspended particle dynamics and transport during storm and flooding conditions

NASA Astrophysics Data System (ADS)

Bourrin, François; Many, Gaël; Durrieu de Madron, Xavier; Martín, Jacobo; Puig, Pere; Houpert, Loic; Testor, Pierre; Kunesch, Stéphane; Mahiouz, Karim; Béguery, Laurent

2015-10-01

Transfers of particulate matter on continental margins primarily occur during energetic events. As part of the CASCADE (CAscading, Storm, Convection, Advection and Downwelling Events) experiment, a glider equipped with optical sensors was deployed in the coastal area of the Gulf of Lions, NW Mediterranean in March 2011 to assess the spatio-temporal variability of hydrology, suspended particles properties and fluxes during energetic conditions. This deployment complemented a larger observational effort, a part of the MOOSE (Mediterranean Ocean Observing System of the Environment) network, composed of a coastal benthic station, a surface buoy and moorings on the continental slope. This set of observations permitted to measure the impact of three consecutive storms and a flood event across the entire continental shelf. Glider data showed that the sediment resuspension and transport observed at the coastal station during the largest storm (Hs>4 m) was effective down to a water depth of 80 m. The mid-shelf mud belt, located between 40 and 90 m depth, appears as the zone where the along-shelf flux of suspended sediment is maximum. Besides, the across-shelf flux of suspended sediment converges towards the outer limit of the mid-shelf mud belt, where deposition of suspended particles probably occurs and contributes to the nourishment of this area. Hydrological structures, suspended particles transport and properties changed drastically during stormy periods and the following flood event. Prior to the storms, the shelf waters were weakly stratified due in particular to the presence of cold dense water on the inner- and mid-shelf. The storms rapidly swept away this dense water, as well as the resuspended sediments, along the shelf and towards a downstream submarine canyon. The buoyant river plumes that spread along the shelf after the flooding period provoked a restratification of the water column on the inner- and mid-shelf. The analysis of glider's optical data at different wavelengths suggests that the coastal area and the bottom nepheloid layer during the largest storm are primarily composed of coarse particles, probably macroflocs, and that the size of particles decreases further offshore. A similar trend, albeit less contrasted, is observed after the flooding. This work provided a unique synoptic view across the entire shelf of the impact of a typical Mediterranean storm on bottom sediment erosion and particulate fluxes. Repeated glider transects across the south-western part of the Gulf of Lions shelf permitted for the first time to measure continuously the thermo-haline structures, the suspended particles concentrations and size, the current speed, and to estimate the particulate transport before, during and after typical Mediterranean storm events. Glider data complement and compare well with concomitant high frequency time series at fixed stations along the coast and in a downstream submarine canyon.

Rare earth element contents of the Lusi mud: An attempt to identify the environmental origin of the hot mudflow in East Java - Indonesia

NASA Astrophysics Data System (ADS)

Agustawijaya, Didi Supriadi; Karyadi, Karyadi; Krisnayanti, Baiq Dewi; Sutanto, Sutanto

2017-12-01

The Sidoarjo mudflow in East Java, Indonesia, has been erupting since May 29th, 2006. The eruption has been known as the Lusi (lumpur Sidoarjo), which was previously considered as a remote seismic event consequence, but current geyser-like activities show an association with a geothermal phenomenon. A method of characterizing rare earth elements (REE) is commonly an effective tool for recognizing a geothermal system, and here it is adapted to particularly indicate the environmental origin of the Lusi mud. Results show that the Lusi hot mud is made of a porous smectite structure of a shale rock type, which becomes an ideal tank for trapping the REE, especially the light REE. Volcanic activities seem to be an important influence in the eruption; however, since there is a lack of significant isotopic evidences in the mobilization of the REE during the eruption, the chloride neutral pH water of the Lusi may hardly contain the REE. The moderate Ce and Eu anomalies found in the REE patterns of the mud strongly indicate a sea-floor basin as the most probable environment for the REE fractionation during the sedimentary rock formation, in which the weathering processes of volcanic rock origin enriched the Lusi shale with the REE.

The effect of mud pack therapy on serum YKL-40 and hsCRP levels in patients with knee osteoarthritis.

PubMed

Güngen, Gonca; Ardic, Fusun; Fındıkoğlu, Gülin; Rota, Simin

2012-05-01

The aim of this study was to evaluate the efficacy of treatment with mud pack in knee osteoarthritis (OA) and to determine whether mud pack effects serum levels of YKL-40 and high-sensitivity C-reactive protein (hsCRP) which are reported to be biological markers for articular damage or inflammation in patients with OA. Forty-four patients with the diagnosis of knee OA assigned into two groups were treated with local natural mineral-rich mud pack or hot pack. Treatments were applied for 6 days a week for 2 weeks as a total of 12 sessions. Patients were assessed at baseline, post-treatment, and 3 months after the treatment. VAS, range of motion, 15-m walking time, WOMAC index, Nottingham Health Profile, serum YKL-40, and hsCRP levels were the outcome measures. Pain intensity and joint stiffness decreased in both groups at all follow-ups. Physical activity status was found to persist for 3 months after treatment only in mud pack group. Serum mean YKL-40 and hsCRP levels of the patients were higher compared to healthy control group. Serum YKL-40 level increased significantly only in hot pack group 3 months after the treatment (P < 0.017). No significant change was observed in hsCRP levels in both groups during the whole follow-up periods (P > 0.05). Mud pack and hot pack therapy were both demonstrated to be effective in symptomatic treatment of knee OA until the end of the 2-week treatment period, whereas only mud pack therapy was shown to be effective in functional status over time. In the hot pack group, increased serum YKL-40 level 3 months after the treatment might indicate persistence of cartilage degradation. Maintenance of YKL-40 level in mud pack therapy seems to slow down the progression of knee OA.

Evidence of episodic long-lived eruptions in the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes, Gulf of Cádiz

NASA Astrophysics Data System (ADS)

Toyos, María H.; Medialdea, Teresa; León, Ricardo; Somoza, Luis; González, Francisco Javier; Meléndez, Nieves

2016-06-01

High-resolution single channel and multichannel seismic reflection profiles and multibeam bathymetric and backscatter data collected during several cruises over the period 1999 to 2007 have enabled characterising not only the seabed morphology but also the subsurface structural elements of the Yuma, Ginsburg, Jesús Baraza and Tasyo mud volcanoes (MVs) in the Gulf of Cádiz at 1,050-1,250 m water depth. These MVs vary strongly in morphology and size. The data reveal elongated cone-shaped edifices, rimmed depressions, and scarps interpreted as flank failures developed by collapse, faulting, compaction and gravitational processes. MV architecture is characterised by both extrusive and intrusive complexes, comprising stacked edifices (including seabed cones and up to four buried bicones) underlain by chaotic vertical zones and downward-tapering cones suggesting feeder systems. These intrusive structures represent the upper layer of the feeder system linking the fluid mud sources with the constructional edifices. The overall architecture is interpreted to be the result of successive events of mud extrusion and outbuilding alternating with periods of dormancy. Each mud extrusion phase is connected with the development of an edifice, represented by a seabed cone or a buried bicone. In all four MVs, the stacked edifices and the intrusive complexes penetrate Late Miocene-Quaternary units and are rooted in the Gulf of Cádiz wedge emplaced during the late Tortonian. Major phases of mud extrusion and outbuilding took place since the Late Pliocene, even though in the Yuma and Jesús Baraza MVs mud volcanism started in the Late Miocene shortly after the emplacement of the Gulf of Cádiz wedge. This study shows that fluid venting in the eastern sector of the Gulf of Cádiz promoted the outbuilding of large long-lived mud volcanoes active since the Late Miocene, and which have been reactivated repeatedly until recent times.

Genesis of mud volcano fluids in the Gulf of Cadiz - A novel model approach

NASA Astrophysics Data System (ADS)

Schmidt, Christopher; Burwicz, Ewa; Hensen, Christian; Martínez-Loriente, Sara; Wallmann, Klaus; Gràcia, Eulàlia

2017-04-01

Mud volcanism and fluid seepage are common phenomena on the continental margin in the Gulf of Cadiz, North East Atlantic Ocean. Over the past 2 decades more than 50 mud volcanoes have been discovered and investigated interdisciplinarily. Mud volcano fluids emanating at these sites are sourced at great depths and migration is often mediated by strike slip faults in a seismically active region. The geochemical signals of the mud volcano fluids are affected by widespread various processes such as clay mineral dehydration, but also the recrystallization of ancient carbonate rocks and the alteration of oceanic crust have been suggested (Hensen et al., 2015). We developed a novel fully-coupled, basin-scale, reaction-transport model with an adaptive numerical mesh to simulate the fluid genesis in this region. An advantage of this model is the coupling of a realistic geophysical and geochemical approach, considering a growing sediment column over time together with instant compaction of sediments as well as diffusion and advection of dissolved pore water species and chemical reactions. In this proof of concept study, we looked at various scenarios to identify the processes of fluid genesis for 4 mud volcanoes, representing combinations in different subsurface settings. We can reproduce the fluid signatures (chloride, strontium, 87Sr/86Sr) of all mud volcanoes. Furthermore, we can give additional evidence that alteration of oceanic crust by fluid flow is a likely process affecting the fluid composition. Hensen, C., Scholz, F., Nuzzo, M., Valadares, V., Gràcia, E., Terrinha, P., Liebetrau, V., Kaul, N., Silva, S., Martínez-Loriente, S., Bartolome, R., Piñero, E., Magalhães, V. H., Schmidt, M., Weise, S. M., Cunha, M., Hilario, A., Perea, H., Rovelli, L., and Lackschewitz, K., 2015, Strike-slip faults mediate the rise of crustal-derived fluids and mud volcanism in the deep sea: Geology, v. 43, no. 4, p. 339-342.

Evolution of submarine eruptive activity during the 2011-2012 El Hierro event as documented by hydroacoustic images and remotely operated vehicle observations

NASA Astrophysics Data System (ADS)

Somoza, L.; González, F. J.; Barker, S. J.; Madureira, P.; Medialdea, T.; de Ignacio, C.; Lourenço, N.; León, R.; Vázquez, J. T.; Palomino, D.

2017-08-01

Submarine volcanic eruptions are frequent and important events, yet they are rarely observed. Here we relate bathymetric and hydroacoustic images from the 2011 to 2012 El Hierro eruption with surface observations and deposits imaged and sampled by ROV. As a result of the shallow submarine eruption, a new volcano named Tagoro grew from 375 to 89 m depth. The eruption consisted of two main phases of edifice construction intercalated with collapse events. Hydroacoustic images show that the eruptions ranged from explosive to effusive with variable plume types and resulting deposits, even over short time intervals. At the base of the edifice, ROV observations show large accumulations of lava balloons changing in size and type downslope, coinciding with the area where floating lava balloon fallout was observed. Peaks in eruption intensity during explosive phases generated vigorous bubbling at the surface, extensive ash, vesicular lapilli and formed high-density currents, which together with periods of edifice gravitational collapse, produced extensive deep volcaniclastic aprons. Secondary cones developed in the last stages and show evidence for effusive activity with lava ponds and lava flows that cover deposits of stacked lava balloons. Chaotic masses of heterometric boulders around the summit of the principal cone are related to progressive sealing of the vent with decreasing or variable magma supply. Hornitos represent the final eruptive activity with hydrothermal alteration and bacterial mats at the summit. Our study documents the distinct evolution of a submarine volcano and highlights the range of deposit types that may form and be rapidly destroyed in such eruptions.