Structure and Distribution of Cold Seep Communities Along the Peruvian Active Margin: Relationship to Geological and Fluid Patterns
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Preliminary Catalog of the Sedimentary Basins of the United States
Preliminary Catalog of the Sedimentary Basins of the United States By James L. Coleman, Jr., and Steven M. Cahan Open-File Report 2012–1111 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Coleman, J.L., Jr., and Cahan, S.M., 2012, Preliminary catalog of the sedimentary basins of the United States: U.S. Geological Survey Open-File Report 2012–1111, 27 p. (plus 4 figures and 1 table available as separate files) Available online at http://pubs.usgs.gov/of/2012/1111/. iii Contents Abstract ...........................................................................................................................................................1 -
7.014 Handout PRODUCTIVITY: the “METABOLISM” of ECOSYSTEMS
7.014 Handout PRODUCTIVITY: THE “METABOLISM” OF ECOSYSTEMS Ecologists use the term “productivity” to refer to the process through which an assemblage of organisms (e.g. a trophic level or ecosystem assimilates carbon. Primary producers (autotrophs) do this through photosynthesis; Secondary producers (heterotrophs) do it through the assimilation of the organic carbon in their food. Remember that all organic carbon in the food web is ultimately derived from primary production. DEFINITIONS Primary Productivity: Rate of conversion of CO2 to organic carbon (photosynthesis) per unit surface area of the earth, expressed either in terns of weight of carbon, or the equivalent calories e.g., g C m-2 year-1 Kcal m-2 year-1 Primary Production: Same as primary productivity, but usually expressed for a whole ecosystem e.g., tons year-1 for a lake, cornfield, forest, etc. NET vs. GROSS: For plants: Some of the organic carbon generated in plants through photosynthesis (using solar energy) is oxidized back to CO2 (releasing energy) through the respiration of the plants – RA. Gross Primary Production: (GPP) = Total amount of CO2 reduced to organic carbon by the plants per unit time Autotrophic Respiration: (RA) = Total amount of organic carbon that is respired (oxidized to CO2) by plants per unit time Net Primary Production (NPP) = GPP – RA The amount of organic carbon produced by plants that is not consumed by their own respiration. It is the increase in the plant biomass in the absence of herbivores. For an entire ecosystem: Some of the NPP of the plants is consumed (and respired) by herbivores and decomposers and oxidized back to CO2 (RH). -
Cold Seep Benthic Communities in Japan Subduction Zones: Spatial Organization, Trophic Strategies and Evidence for Temporal Evolution*
MARINE ECOLOGY - PROGRESS SERIES Vol. 40: 115-126. 1987 Published October 7 Mar. Ecol. Prog. Ser. Cold seep benthic communities in Japan subduction zones: spatial organization, trophic strategies and evidence for temporal evolution* S. Kim Juniper", Myriam Sibuet IFREMER, Centre de Brest. BP 337. F-29273 Brest Cedex. France ABSTRACT: Submersible exploration of the Japan subduction zones has revealed benthic communities dominated by clams (Calyptogena spp.) around sed~mentporewater seeps at depths from 3850 to 6000 m. Photographic and video records were used to produce microcartographlc reconstructions of 3 contrasting cold seep sites. Spatial and abundance relations of megafauna lead us to propose several hypotheses regard~ngthe ecological functioning of these cold seep communities. We dlst~nguish between the likely direct use of reducing substances in venting fluids by Calyptogena-bacteria symbioses and indirect usage by accompanying abyssal species not known to harbour symbionts. Microdistribution and known or presumed feedmg modes of the accompanying species indicate 2 different sources of organic matter enrichment within cold seep sites: organic debris originating from bivalve colonies, and enrichment of extensive areas of surrounding surface sediments where weaker, more hffuse porewater seepage may support chemosynthetic production by free-living bacteria. The occurrence of colony-like groupings of empty Calyptogena valves indicates that cold seeps are ephemeral, with groups of living clams, mixed living and dead clams, and empty dissolving shells marlung the course of a cycle of porewater venting and offering clues to the recent history of cold seep activity. INTRODUCTION al. 1985). One of the bivalve species from this area has been shown to harbour symbiotic bacteria in its gill The discovery of deep-sea hydrothermal vents has tissue and to oxidise methane (Childress et al. -
Relationships Between Net Primary Production, Water Transparency, Chlorophyll A, and Total Phosphorus in Oak Lake, Brookings County, South Dakota
Proceedings of the South Dakota Academy of Science, Vol. 92 (2013) 67 RELATIONSHIPS BETWEEN NET PRIMARY PRODUCTION, WATER TRANSPARENCY, CHLOROPHYLL A, AND TOTAL PHOSPHORUS IN OAK LAKE, BROOKINGS COUNTY, SOUTH DAKOTA Lyntausha C. Kuehl and Nels H. Troelstrup, Jr.* Department of Natural Resource Management South Dakota State University Brookings, SD 57007 *Corresponding author email: [email protected] ABSTRACT Lake trophic state is of primary concern for water resource managers and is used as a measure of water quality and classification for beneficial uses. Secchi transparency, total phosphorus and chlorophyll a are surrogate measurements used in the calculation of trophic state indices (TSI) which classify waters as oligotrophic, mesotrophic, eutrophic or hypereutrophic. Yet the relationships between these surrogate measurements and direct measures of lake productivity vary regionally and may be influenced by external factors such as non-algal tur- bidity. Prairie pothole basins, common throughout eastern South Dakota and southwestern Minnesota, are shallow glacial lakes subject to frequent winds and sediment resuspension. Light-dark oxygen bottle methodology was employed to evaluate vertical planktonic production within an eastern South Dakota pothole basin. Secchi transparency, total phosphorus and planktonic chlorophyll a were also measured from each of three basin sites at biweekly intervals throughout the 2012 growing season. Secchi transparencies ranged between 0.13 and 0.25 meters, corresponding to an average TSISD value of 84.4 (hypereutrophy). Total phosphorus concentrations ranged between 178 and 858 ug/L, corresponding to an average TSITP of 86.7 (hypereutrophy). Chlorophyll a values corresponded to an average TSIChla value of 69.4 (transitional between eutrophy and hypereutro- phy) and vertical production profiles yielded areal net primary productivity val- ues averaging 288.3 mg C∙m-2∙d-1 (mesotrophy). -
Tsunami Risk Analysis of the East Coast of the United States
Tsunami Risk Analysis of the East Coast of the United States INTRODUCTION METHODOLOGY In the wake of the 2004 Indian Ocean tsunami and the 2011 Japan tsunami and Given the large area of the east coast, a rudimentary analysis was performed. corresponding nuclear disaster, much more attention has been focused on coastal Elevation is the most important factor in analyzing the risk of flooding in a coastal vulnerability to tsunamis. Areas near active tectonic margins have a much higher area; the lower the elevation, the greater the potential for damage. Elevation data risk of being hit by a tsunami, due to proximity. People who live in these areas are was reclassified into no risk, medium risk, and high risk zones. These zones were: more aware of the danger than their counterparts on passive tectonic margins. It is 25+ m above sea level, 10 to 25 m above sea level, and below 10 m above sea lev- generally a good assumption that the risk of a tsunami is low in places like the el. Essentially, most land adjacent to the coast that falls in the final category eastern seaboard of the United States. would be badly damaged by a 10m tsunami from the Canary Islands, unless buff- Despite the low risk, the east coast has been hit by tsunamis in the past. Ex- ered by another portion of land blocking the coast. If a larger tsunami were to oc- amples include the Newfoundland tsunami caused by the Grand Banks earth- cur, up to the max wave height predicted by Ward and Day of 25 m, any land ad- quake. -
Coupled Onshore Erosion and Offshore Sediment Loading As Causes of Lower Crust Flow on the Margins of South China Sea Peter D
Clift Geosci. Lett. (2015) 2:13 DOI 10.1186/s40562-015-0029-9 REVIEW Open Access Coupled onshore erosion and offshore sediment loading as causes of lower crust flow on the margins of South China Sea Peter D. Clift1,2* Abstract Hot, thick continental crust is susceptible to ductile flow within the middle and lower crust where quartz controls mechanical behavior. Reconstruction of subsidence in several sedimentary basins around the South China Sea, most notably the Baiyun Sag, suggests that accelerated phases of basement subsidence are associated with phases of fast erosion onshore and deposition of thick sediments offshore. Working together these two processes induce pressure gradients that drive flow of the ductile crust from offshore towards the continental interior after the end of active extension, partly reversing the flow that occurs during continental breakup. This has the effect of thinning the continental crust under super-deep basins along these continental margins after active extension has finished. This is a newly recognized form of climate-tectonic coupling, similar to that recognized in orogenic belts, especially the Himalaya. Climatically modulated surface processes, especially involving the monsoon in Southeast Asia, affects the crustal structure offshore passive margins, resulting in these “load-flow basins”. This further suggests that reorganiza- tion of continental drainage systems may also have a role in governing margin structure. If some crustal thinning occurs after the end of active extension this has implications for the thermal history of hydrocarbon-bearing basins throughout the area where application of classical models results in over predictions of heatflow based on observed accommodation space. -
Passive Margin Salt Tectonics: Effects of Margin Tilt, Sediment Progradation, and Regional Extension
Passive Margin Salt Tectonics: Effects of Margin Tilt, Sediment Progradation, and Regional Extension Steven J. Ings* Department of Earth Sciences, Dalhousie University, Halifax, NS, B3H 3J5 [email protected] and Lykke Gemmer and Chris Beaumont Department of Oceanography, Dalhousie University, Halifax, NS, B3H 4J1 ABSTRACT Deformation of many passive continental margin sedimentary packages is dominated by salt tectonics (e.g., offshore west Africa, east Brazil, eastern Canada). In many cases, salt became mobilized at an early stage of basin formation. In cases where salt deposition was syn-rift or immediately post-rift (e.g., Scotian margin, offshore eastern Canada), early salt mobilization may have been initiated by a combination of tilting and regional extension of the margin. On the Scotian margin, salt tectonics has been long-lived; once salt was initially mobilized, it continued to deform well into the Tertiary. Sediment progradation and aggradation into the Scotian Basin was likely the primary control on long- lived salt tectonics on the Nova Scotian margin. We analyze the driving mechanisms of passive margin salt tectonics using finite element numerical models of a viscous substratum (salt) overlain by a frictional- plastic overburden (sedimentary rocks), and present results of models incorporating margin tilting, regional extension, and sedimentation. The numerical models show that sediment progradation combined with basinward tilt destabilizes the salt-overburden system more than progradation alone. A basinward margin tilt of 1 degree accelerates the evolution of the system, and thereby produces landward extensional structures and basinward contractional salt structures earlier in the model evolution than with progradation alone, resulting in the formation of long allochthonous salt sheets extending greater lateral distances than in equivalent models without tilt. -
Productivity Is Defined As the Ratio of Output to Input(S)
Institute for Development Policy and Management (IDPM) Development Economics and Public Policy Working Paper Series WP No. 31/2011 Published by: Development Economics and Public Policy Cluster, Institute of Development Policy and Management, School of Environment and Development, University of Manchester, Manchester M13 9PL, UK; email: [email protected]. PRODUCTIVITY MEASUREMENT IN INDIAN MANUFACTURING: A COMPARISON OF ALTERNATIVE METHODS Vinish Kathuria SJMSOM, Indian Institute of Technology Bombay [email protected] Rajesh S N Raj * Centre for Multi-Disciplinary Development Research, Dharwad [email protected] Kunal Sen IDPM, University of Manchester [email protected] Abstract Very few other issues in explaining economic growth has generated so much debate than the measurement of total factor productivity (TFP) growth. The concept of TFP and its measurement and interpretation have offered a fertile ground for researchers for more than half a century. This paper attempts to provide a review of different issues in the measurement of TFP including the choice of inputs and outputs. The paper then gives a brief review of different techniques used to compute TFP growth. Using three different techniques – growth accounting (non-parametric), production function accounting for endogeniety (semi-parametric) and stochastic production frontier (parametric) – the paper computes the TFP growth of Indian manufacturing for both formal and informal sectors from 1989-90 to 2005-06. The results indicate that the TFP growth of formal and informal sector has differed greatly during this 16-year period but that the estimates are sensitive to the technique used. This suggests that any inference on productivity growth in India since the economic reforms of 1991 is conditional on the method of measurement used, and that there is no unambiguous picture emerging on the direction of change in TFP growth in post-reform India. -
Gas Seeps and Gas Hydrates in the Amazon Deep-Sea
Gas seeps and gas hydrates in the Amazon deep-sea fan Joao Marcelo Ketzer, Adolpho Augustin, Luiz Frederico Rodrigues, Rafael Oliveira, Daniel Praeg, Maria Alejandra Gomez Pivel, Antonio Tadeu dos Reis, Cleverson Silva, Bruno Leonel To cite this version: Joao Marcelo Ketzer, Adolpho Augustin, Luiz Frederico Rodrigues, Rafael Oliveira, Daniel Praeg, et al.. Gas seeps and gas hydrates in the Amazon deep-sea fan. Geo-Marine Letters, Springer Verlag, 2018, 38 (5), pp.429-438. 10.1007/s00367-018-0546-6. hal-02196115 HAL Id: hal-02196115 https://hal.archives-ouvertes.fr/hal-02196115 Submitted on 9 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Geo-Marine Letters (2018) 38:429–438 https://doi.org/10.1007/s00367-018-0546-6 ORIGINAL Gas seeps and gas hydrates in the Amazon deep-sea fan Joao Marcelo Ketzer1,2 & Adolpho Augustin1 & Luiz Frederico Rodrigues1 & Rafael Oliveira1 & Daniel Praeg1,3 & 4 Maria Alejandra Gomez Pivel & Antonio Tadeu dos Reis5 & Cleverson Silva6 & Bruno Leonel7 Received: 10 January 2018 /Accepted: 2 August 2018 /Published online: 17 August 2018 # The Author(s) 2018 Abstract Deep-sea fans have been proposed to act as carbon sinks, rapid deposition driving shallow methanogenesis to favor net storage within the gas hydrate stability zone (GHSZ). -
Reconstructing the History of Fluid Flow at Cold Seep Sites from Ba/Ca Ratios
Limnol. Oceanogr., 46(7), 2001, 1701±1708 q 2001, by the American Society of Limnology and Oceanography, Inc. Reconstructing the history of ¯uid ¯ow at cold seep sites from Ba/Ca ratios in vesicomyid clam shells M. E. Torres1 COAS, 104 Ocean Administration Building, Oregon State University, Corvallis, Oregon 97331 J. P. Barry MBARI, 7700 Sandholdt Road, Moss Landing, California 95039 D. A. Hubbard COAS, 104 Ocean Administration Building, Oregon State University, Corvallis, Oregon 97331 E. Suess GEOMAR, 1-3 Wischhofstrasse, Kiel D-24148, Germany Abstract Hydrogen sul®de discharge at cold seep sites is recorded as enrichment in the barium to calcium (Ba/Ca) ratio in shells of vesicomyid clams collected live from cold seeps in Monterey Canyon and the Cascadia margin. A direct relationship between increased Ba ¯uxes from cold seeps and Ba incorporation into shells was established for the Cascadia margin site. For the Monterey canyon site, a 2-yr episode of high ¯uid ¯ow centered on 1992 was inferred from coherent changes in the Ba/Ca pro®les of three Calyptogena kilmeri shells. Comparison with precipitation and d18O data indicates that this high-¯ow period may have been driven by an increase in rainfall after the 1988±1990 California drought. High-resolution records preserved in clam shells are shown to be useful in elucidating charac- teristics, history, and possible mechanisms driving ¯uid discharge at continental margin seeps, thus establishing their potential use as paleotracers of ¯uid seepage events. An extensive set of geophysical and geochemical mea- seepage along continental margins. Carbon and oxygen iso- surements is currently available to document the ¯ow and tope records of calcareous macrofossils have long been used expulsion of ¯uids at transform and convergent margins. -
Diversity and Distribution of Cold-Seep Fauna Associated With
Marine Biology Archimer June 2011, Volume 158, Issue 6, Pages 1187-1210 http://archimer.ifremer.fr http://dx.doi.org/10.1007/s00227-011-1679-6 © 2011, Springer-Verlag The original publication is available at http://www.springerlink.com ailable on the publisher Web site Diversity and distribution of cold-seep fauna associated with different geological and environmental settings at mud volcanoes and pockmarks of the Nile Deep-Sea Fan Bénédicte Ritta, *, Catherine Pierreb, Olivier Gauthiera, c, d, Frank Wenzhöfere, f, Antje Boetiuse, f and Jozée Sarrazina, * blisher-authenticated version is av aIfremer, Centre de Brest, Département Etude des Ecosystèmes Profonds/Laboratoire Environnement Profond, BP 70, 29280 Plouzané, France bLOCEAN, UMR 7159, Université Pierre et Marie Curie,75005 Paris, France cLEMAR, UMR 6539, Universiteé de Bretagne Occidentale, Place N. Copernic, 29200 Plouzaneé, France dEcole Pratique des Hautes Etudes CBAE, UMR 5059, 163 rue Auguste Broussonet, 34000 Montpellier, France eMPI, Habitat Group, Celsiusstrasse 1, 28359 Bremen, Germany fAWI, HGF MPG Research Group on Deep Sea Ecology and Technology, 27515 Bremerhaven, Germany *: Corresponding authors : Bénédicte Ritt, email address : [email protected] ; [email protected] Jozée Sarrazin, Tel.: +33 2 98 22 43 29, Fax: +33 2 98 22 47 57, email address : [email protected] Abstract : The Nile Deep-Sea Fan (NDSF) is located on the passive continental margin off Egypt and is characterized by the occurrence of active fluid seepage such as brine lakes, pockmarks and mud volcanoes. This study characterizes the structure of faunal assemblages of such active seepage systems of the NDSF. Benthic communities associated with reduced, sulphidic microhabitats such as ccepted for publication following peer review. -
54. Mesozoic–Tertiary Tectonic Evolution of the Easternmost Mediterranean Area: Integration of Marine and Land Evidence1
Robertson, A.H.F., Emeis, K.-C., Richter, C., and Camerlenghi, A. (Eds.), 1998 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 160 54. MESOZOIC–TERTIARY TECTONIC EVOLUTION OF THE EASTERNMOST MEDITERRANEAN AREA: INTEGRATION OF MARINE AND LAND EVIDENCE1 Alastair H.F. Robertson2 ABSTRACT This paper presents a synthesis of Holocene to Late Paleozoic marine and land evidence from the easternmost Mediterra- nean area, in the light of recent ODP Leg 160 drilling results from the Eratosthenes Seamount. The synthesis is founded on three key conclusions derived from marine- and land-based study over the last decade. First, the North African and Levant coastal and offshore areas represent a Mesozoic rifted continental margin of Triassic age, with the Levantine Basin being under- lain by oceanic crust. Second, Mesozoic ophiolites and related continental margin units in southern Turkey and Cyprus repre- sent tectonically emplaced remnants of a southerly Neotethyan oceanic basin and are not far-travelled units derived from a single Neotethys far to the north. Third, the present boundary of the African and Eurasian plates runs approximately east-west across the easternmost Mediterranean and is located between Cyprus and the Eratosthenes Seamount. The marine and land geology of the easternmost Mediterranean is discussed utilizing four north-south segments, followed by presentation of a plate tectonic reconstruction for the Late Permian to Holocene time. INTRODUCTION ocean (Figs. 2, 3; Le Pichon, 1982). The easternmost Mediterranean is defined as that part of the Eastern Mediterranean Sea located east ° The objective here is to integrate marine- and land-based geolog- of the Aegean (east of 28 E longitude).