Sample records for act outer continental
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-09
... Outer Continental Shelf Minor Source/Title V Minor Permit Modification Issued to Shell Offshore, Inc. for the Kulluk Conical Drilling Unit AGENCY: United States Environmental Protection Agency (EPA... decision granting Shell Offshore Inc.'s (``Shell'') request for minor modifications of Clean Air Act Outer...
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75 FR 1076 - Outer Continental Shelf Civil Penalties
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-08
...The Outer Continental Shelf Lands Act requires the MMS to review the maximum daily civil penalty assessment for violations of regulations governing oil and gas operations in the Outer Continental Shelf at least once every 3 years. This review ensures that the maximum penalty assessment reflects any increases in the Consumer Price Index as prepared by the Bureau of Labor Statistics, U.S. Department of Labor. After conducting the required review in August 2009, the MMS determined that no adjustment is necessary at this time.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-18
...: Availability of Revised North American Datum of 1983 (NAD 83) Outer Continental Shelf Official Protraction... that effective with this publication, the following NAD 83-based Outer Continental Shelf (OCS) Official...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-10
... Shelf Permits Issued to Shell Gulf of Mexico, Inc., and Shell Offshore, Inc. for the Discoverer... Clean Air Act Outer Continental Shelf (OCS) permit applications, one from Shell Gulf of Mexico, Inc., for operation of the Discoverer drillship in the Chukchi Sea and one from Shell Offshore, Inc...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-02
... sensitivity of the environmental and subsistence importance to the indigenous population; (4) the lack of any... Outer Continental Shelf Lands Act and 33 C.F.R 147. Accordingly, State and Local law enforcement... due to the location of the MODU KULLUK on the Outer Continental Shelf and its distance from both land...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-02
.... ACTION: Availability of revised North American Datum of 1927 (NAD 27) Outer Continental Shelf Official...: Notice is hereby given that effective with this publication, the following NAD 27-based Outer Continental...
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Gas hydrates of outer continental margins
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kvenvolden, K.A.
1990-05-01
Gas hydrates are crystalline substances in which a rigid framework of water molecules traps molecules of gas, mainly methane. Gas-hydrate deposits are common in continental margin sediment in all major oceans at water depths greater than about 300 m. Thirty-three localities with evidence for gas-hydrate occurrence have been described worldwide. The presence of these gas hydrates has been inferred mainly from anomalous lacoustic reflectors seen on marine seismic records. Naturally occurring marine gas hydrates have been sampled and analyzed at about tensites in several regions including continental slope and rise sediment of the eastern Pacific Ocean and the Gulf ofmore » Mexico. Except for some Gulf of Mexico gas hydrate occurrences, the analyzed gas hydrates are composed almost exclusively of microbial methane. Evidence for the microbial origin of methane in gas hydrates includes (1) the inverse relation between methane occurence and sulfate concentration in the sediment, (2) the subparallel depth trends in carbon isotopic compositions of methane and bicarbonate in the interstitial water, and (3) the general range of {sup 13}C depletion ({delta}{sub PDB}{sup 13}C = {minus}90 to {minus}60 {per thousand}) in the methane. Analyses of gas hydrates from the Peruvian outer continental margin in particular illustrate this evidence for microbially generated methane. The total amount of methane in gas hydrates of continental margins is not known, but estimates of about 10{sup 16} m{sup 3} seem reasonable. Although this amount of methane is large, it is not yet clear whether methane hydrates of outer continental margins will ever be a significant energy resource; however, these gas hydrates will probably constitute a drilling hazard when outer continental margins are explored in the future.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-05
... all requirements of NEPA, the Coastal Zone Management Act, Outer Continental Shelf Lands Act, and... consistent with each affected state's federally approved Coastal Zone Management program. Finally, the MMS...-circulation modeling, ecological effects of oil and gas activities, and hurricane impacts on coastal...
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77 FR 24980 - Notice on Outer Continental Shelf Oil and Gas Lease Sales
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-26
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Notice on Outer Continental Shelf Oil... Outer Continental Shelf oil and gas lease sales to be held during the bidding period May 1, 2012... Corporation ExxonMobil Exploration Company Group II. Shell Oil Company Shell Offshore Inc. SWEPI LP Shell...
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Outer continental shelf, Beaufort Sea, oil and gas lease sale 170 (proposed notice of sale)
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1997-12-31
The Minerals Management Service (MMS) is issuing this proposed Notice of Sale under the Outer Continental Shelf (OCS) Lands Act (43 U.S.C. 1331-1356, as amended) and the regulations issued thereunder (30 CFR Part 256). A `Sale Notice Package,` containing this Notice and several supporting and essential documents referenced in the Notice, is available from the MMS Alaska OCS Regional Office Public Information Unit.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-06
...-2011-0039] Commercial Lease of Submerged Lands for Renewable Energy Development on the Outer... renewable energy leases on the Outer Continental Shelf. In the preamble to the April 29, 2009, Final Rule, ``Renewable Energy and Alternate Uses of Existing Facilities on the Outer Continental Shelf,'' BOEMRE stated...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-03
... Wind Lease Sale 2 (ATLW2) Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore...), Interior. ACTION: Proposed Sale Notice for commercial leasing for wind power on the Outer Continental Shelf... sale of commercial wind energy leases on the Outer Continental Shelf (OCS) offshore Rhode Island and...
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Coral forests diversity in the outer shelf of the south Sardinian continental margin
NASA Astrophysics Data System (ADS)
Cau, Alessandro; Moccia, Davide; Follesa, Maria Cristina; Alvito, Andrea; Canese, Simonepietro; Angiolillo, Michela; Cuccu, Danila; Bo, Marzia; Cannas, Rita
2017-04-01
Ecological theory predicts that heterogeneous habitats allow more species to co-exist in a given area, but to date, knowledge on relationships between habitat heterogeneity and biodiversity of coral forests in the outer shelf and upper slope along continental margins is rather limited. We investigated biodiversity of coral forests from 8 sites spread over two different geomorphological settings (namely, pinnacles vs. canyons) in the outer shelf along Sardinian continental margin. Using a combination of multivariate statistical analyses, we show here that differences in the composition of coral assemblages among contrasting geomorphological settings were not statistically significant, whereas significant differences emerged among sites within similar geomorphologies (i.e. among pinnacles and among canyons). Our results reveal that environmental and bathymetric factors such as sediment coverage, slope of the substrate, terrain ruggedness, bathymetric positioning index and aspect were important drivers of the observed patterns of coral biodiversity, in both settings. Spatial variability of coral forests' biodiversity is affected by environmental factors that act at the scale of each geomorphological setting (i.e. within each pinnacle and canyon) rather than by the contrasting geomorphological settings themselves. This result allows us to suggest that simple categorization of benthic communities according topographically defined habitat is unlikely to be sufficient for addressing conservation purposes.
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-13
... Protraction Diagram, Lease Maps, and Supplemental Official Outer Continental Shelf Block Diagrams AGENCY... Supplemental Official OCS Block Diagrams (SOBDs); Correction. SUMMARY: BOEM (formerly the Bureau of Ocean... Official OCS Shelf Block Diagrams'' that contained an error. This notice corrects the address of the Web...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-29
... No. BOEM-2010-0063] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore..., Interior. ACTION: RFI in Commercial Wind Energy Leasing Offshore Massachusetts, and Invitation for Comments... the construction of a wind energy project(s) on the Outer Continental Shelf (OCS) offshore...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-23
...-AA00 Safety Zone; NOBLE DISCOVERER, Outer Continental Shelf Drillship, Chukchi and Beaufort Seas... Chukchi and Beaufort Seas Outer Continental Shelf, Alaska, from 12:01 a.m. on July 1, 2012 through 11:59 p... order to drill exploratory wells in several prospects located in the Chukchi and Beaufort Seas during...
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Adams, Maurice V.; John, C.B.; Kelly, R.F.; LaPointe, A.E.; Meurer, R.W.
1975-01-01
An important function of the Geological Survey is the evaluation and management of the mineral resources of the Outer Continental Shelf, particularly with respect to oil and gas, salt, and sulfur. Production of oil and gas from the Outer Continental Shelf of the United States has increased substantially over the past 20 years and represents an increasing percentage of total United States production. As discovery of major onshore production of oil and gas has become more difficult, the search has moved into the surrounding waters where submerged sedimentary formations are conducive to the accumulation of oil and gas. Increased energy demands of recent years have accelerated the pace of offshore operations with a corresponding improvement in technology as exploration and development have proceeded farther from shore and into deeper water. While improved technology and enforcement of more stringent regulations have made offshore operations safer, it is unrealistic to believe that completely accident-free operations can ever be achieved. Only slightly more than six percent of the world's continental terrace is adjacent to the United States, but less than one percent has been explored for oil and gas. Since the lead time for the development of offshore oil and gas resources can be as much as a decade, they do not provide an immediate energy supply but should be viewed in the light of a near-term source with a potential of becoming a medium-range source of supply pending the development of alternative energy sources. Revenues from the Outer Continental Shelf are deposited to the general fund of the United States Treasury. A major portion of these funds is allocated to the Land and Water Conservation Fund, the largest Federal grant-in-aid program of assistance to States, counties, and cities for the acquisition and development of public parks, open space, and recreation lands and water.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-03
... Submerged Lands for Renewable Energy Development on the Outer Continental Shelf AGENCY: Bureau of Ocean... use Form 0008 to issue commercial renewable energy leases on the Outer Continental Shelf (OCS). In the preamble to the April 29, 2009, Final Rule, ``Renewable Energy and Alternate Uses of Existing Facilities on...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-03
... Wind One (ATLW1) Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Virginia... Notice for Commercial Leasing for Wind Power on the Outer Continental Shelf Offshore Virginia. SUMMARY... (FONSI) for commercial wind lease issuance and site assessment activities on the Atlantic OCS offshore...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-06
...-Way Grant of Submerged Lands on the Outer Continental Shelf to Support Renewable Energy Development... will use Form 0009 to issue a renewable energy right-of- way (ROW) grant on the Outer Continental Shelf....gov/Renewable-Energy Program/ Regulatory-Information/Index.aspx. DATES: The ROW grant form will be...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-14
...-0005; OMB Number 1014-NEW] Information Collection Activities: Operations in the Outer Continental Shelf for Minerals Other Than Oil, Gas, and Sulphur; Submitted for Office of Management and Budget (OMB... (ICR) for approval of the paperwork requirements in the regulations under Operations in the Outer...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-29
... of Submerged Lands on the Outer Continental Shelf to Support Renewable Energy Development AGENCY... would be used to issue Outer Continental Shelf (OCS) renewable energy right-of-way (ROW) grants in order... renewable energy, but does not constitute a project easement. The ability of an ROW grantee to install such...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-22
... Environmental Enforcement 30 CFR Part 250 Oil and Gas and Sulphur Operations on the Outer Continental Shelf--Oil and Gas Production Safety Systems; Proposed Rule #0;#0;Federal Register / Vol. 78 , No. 163 / Thursday...] RIN 1014-AA10 Oil and Gas and Sulphur Operations on the Outer Continental Shelf--Oil and Gas...
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76 FR 29156 - Outer Continental Shelf Air Regulations Consistency Update for California
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-20
... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 55 [OAR-2004-0091; FRL-9304-4] Outer Continental Shelf Air Regulations Consistency Update for California AGENCY: Environmental Protection Agency (EPA... ``significant regulatory action'' subject to review by the Office of Management and Budget under Executive Order...
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76 FR 7518 - Outer Continental Shelf Air Regulations Consistency Update for Alaska
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-10
... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 55 [EPA-R10-OAR-2011-0045; FRL-9265-3] Outer Continental Shelf Air Regulations Consistency Update for Alaska AGENCY: Environmental Protection Agency (``EPA... Greaves, Federal and Delegated Air Programs Unit, U.S. Environmental Protection Agency, Region 10, 1200...
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75 FR 10809 - Outer Continental Shelf (OCS) Scientific Committee-Notice of Renewal
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-09
... AGENCY: Minerals Management Service (MMS), Interior. ACTION: Notice of renewal of the Outer Continental... Minerals Management Service. The Committee reviews the relevance of the research and data being produced to meet MMS scientific information needs for decisionmaking and may recommend changes in scope, direction...
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An oilspill risk analysis for the North Atlantic outer continental shelf lease area
Smith, Richard Allmon; Slack, James Richard; Davis, Robert K.
1976-01-01
The Federal Government has proposed to lease 1,172,795 acres of Outer Continental Shelf (OCS) lands on Georges Bank off the New England Coast for oil and gas development. Estimated recoverable petroleum resources for the proposed 206 tract sale area range from 180 to 650 million barrels. Contingent upon actual discovery of this quantity of oil, production is expected to span a period of about 20 years. An oilspill risk analysis was conducted to determine relative environmental hazards of developing oil in the North Atlantic Outer Continental Shelf lease area. The study analyzed probability of spill occurrence, likely path of pollutants from spills, and locations in space and time of recreational and biological resources likely to be vulnerable. These results are combined to yield estimates of the overall oilspill risk associated with development of the lease area. (Woodard-USGS)
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-09
... Continental Shelf Air Permit for Anadarko Petroleum Corporation AGENCY: Environmental Protection Agency (EPA... final Outer Continental Shelf (OCS) air permit for Anadarko Petroleum Corporation (Anadarko). The permit... Petroleum Corporation regarding the project. EPA carefully reviewed each of the comments submitted and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-15
...-AA00 Safety Zone; VERMILION 380A at Block 380 Outer Continental Shelf Fixed Platform in the Gulf of... safety zone around VERMILION 380A, a fixed platform, at Block 380 in the Outer Continental Shelf, approximately 90 miles south of Vermilion Bay, Louisiana. The fixed platform is on fire and the safety zone is...
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75 FR 24966 - Notice on Outer Continental Shelf Oil and Gas Lease Sales
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-06
... DEPARTMENT OF THE INTERIOR Minerals Management Service Notice on Outer Continental Shelf Oil and Gas Lease Sales AGENCY: Minerals Management Service, Interior. ACTION: List of Restricted Joint Bidders. SUMMARY: Pursuant to the authority vested in the Director of the Minerals Management Service by...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-12
... 1625-AC05 Safety and Environmental Management System Requirements for Vessels on the U.S. Outer... ``Safety and Environmental Management System Requirements for Vessels on the U.S. Outer Continental Shelf... of industry to ensure stakeholders have adequate time to submit complete responses. DATES: Comments...
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76 FR 13205 - Notice on Outer Continental Shelf Oil and Gas Lease Sales
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-10
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement Notice on Outer Continental Shelf Oil and Gas Lease Sales AGENCY: Bureau of Ocean Energy Management, Regulation... the name of an oil company listed under Group VIII in that notice. FOR FURTHER INFORMATION CONTACT...
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75 FR 20859 - Outer Continental Shelf (OCS) Policy Committee; Notice and Agenda for Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-21
... DEPARTMENT OF THE INTERIOR Minerals Management Service Outer Continental Shelf (OCS) Policy Committee; Notice and Agenda for Meeting AGENCY: Minerals Management Service (MMS), Interior. ACTION: Notice.... Jeryne Bryant at Minerals Management Service, 381 Elden Street, Mail Stop 4001, Herndon, Virginia 20170...
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77 FR 19321 - Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS)
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-30
... by BOEM: (1) Oil and gas exploration and development; (2) renewable energy; and (3) marine minerals... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS) AGENCY: Bureau of Ocean Energy Management (BOEM...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-05
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement Intent To Prepare a Supplemental Environmental Impact Statement: Outer Continental Shelf, Alaska OCS Region, Chukchi Sea Planning Area, Oil and Gas Lease Sale 193 AGENCY: Bureau of Ocean Energy Management, Regulation...
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Philip A. Marcus; Ethan T. Smith
1979-01-01
Five petroleum-related facilities often sited in the coastal zone during development of Outer Continental oil and gas can change the visual appearance of coastal areas. These facilities are service bases, platform fabrication yards, marine terminals and associated storage facilities, oil and gas processing facilities, and liquified natural gas terminals. Examples of...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-03
...-0006; OMB Control Number 1014-NEW] Information Collection Activities: Oil, Gas, and Sulphur Operations in the Outer Continental Shelf, Subpart A, General; Submitted for Office of Management and Budget... Office of Management and Budget (OMB) for review and approval. The information collection request (ICR...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-28
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement [Docket ID No. BOEM-2010-0069] BOEMRE Information Collection Activities: 1010-0081, Operations in the Outer Continental Shelf for Minerals Other Than Oil, Gas, and Sulphur, Submitted for Office of Management and Budget...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-07
... for all Mobile Offshore Drilling Units and Floating Outer Continental Shelf Facilities (as defined in... Commander. Vessels requiring Coast Guard inspection include Mobile Offshore Drilling Units (MODUs), Floating... engage directly in oil and gas exploration or production in the offshore waters of the Eighth Coast Guard...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-22
.... BSEE-2011-0005; OMB Control Number 1014-NEW] Information Collection Activities: Operations in the Outer Continental Shelf for Minerals Other than Oil, Gas, and Sulphur; Submitted for Office of Management and Budget... Office of Management and Budget (OMB) for review and approval. The information collection request (ICR...
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Gas hydrate potential of the mid Atlantic outer continental shelf
Shedd, William W.; Hutchinson, Deborah R.
2006-01-01
For the last two years, the Minerals Management Service (MMS) has been studying the resource potential of gas hydrates in federal offshore lands of the Outer Continental Shelf (OCS) off the Atlantic, Gulf of Mexico, Pacific, and Alaska in collaboration with the U.S. Geological Survey (USGS), the Department of Energy (DOE), the National Oceanic and Atmospheric Administration (NOAA), the Naval Research Lab (NRL) and academia. Utilizing its extensive seismic, well, and geochemical databases, the MMS will be reporting the in-place resource numbers within the next few months. Though the methodology of the study was not prospect oriented, discrete prospects have been recognized.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-12
... on location in order to drill exploratory wells at various prospects located in the Chukchi and Beaufort Sea Outer Continental Shelf, Alaska, during the 2010 drilling season. The purpose of the temporary... allisions, oil spills, and releases of natural gas, and thereby protect the safety of life, property, and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-23
... 211111, Crude Petroleum and Natural Gas Extraction and 213111, Drilling Oil and Gas Wells. For these... identify measures necessary to improve the safety of oil and gas exploration and development on the Outer Continental Shelf in light of the Deepwater Horizon event on April 20, 2010, and resulting oil spill. To...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-06
...] Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf Offshore... governments, offshore wind energy developers, and the public in the Department of the Interior's (DOI) ``Smart from the Start'' wind energy initiative offshore Massachusetts. The purpose of the ``Smart from the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-05
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] Outer Continental Shelf...: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Notice of Intent; Notice of Scoping Meetings... 70123-2394, telephone (504) 736-3233. For information on the National Marine Fisheries Service (NMFS...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-18
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official Protraction Diagram (OPDs) AGENCY... OPDs. SUMMARY: Notice is hereby given that effective with this publication two NAD 83-based OCS...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-17
... No. BOEM-2010-0063] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore..., Regulation and Enforcement (BOEMRE), Interior. ACTION: Request for Interest (RFI) in Commercial Wind Energy... (BOEMRE) is reopening the comment period on the RFI in Commercial Wind Energy Leasing Offshore...
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An oilspill risk analysis for the Mid-Atlantic Outer Continental Shelf lease area
Smith, Richard Allmon; Slack, James Richard; Davis, Robert K.
1976-01-01
An oilspill risk analysis was conducted to determine relative environmental impacts of developing oil in different regions of the Mid-Atlantic Outer Continental Shelf lease area. The study analyzed probability of spills, likely path of pollutants from spills, and locations in space and time of recreational and biological resources likely to be vulnerable. These results are combined to yield estimates of the overall oilspill risk associated with development of the lease area. (Woodard-USGS)
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-30
...; MMAA104000] Research Lease on the Outer Continental Shelf (OCS) Offshore Virginia, Request for Competitive... Unsolicited Request for an OCS Research Lease; Request for Competitive Interest (RFCI); and Request for Public... for wind energy research activities; (2) solicit indications of interest in a renewable energy lease...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
Federal responsibility for oil and gas development on the U.S. outer continental shelf (OCS) resides with the Minerals Management Service (MMS) of the U.S. Department of the Interior (DOI). The DOI's Environmental Studies Program (ESP) is the program through which MMS conducts environmental studies on the OCS and collects information to prepare environmental impact statements (EISs). It appeared to MMS in 1986 that the time was ripe to assess the status of the present program and to explore the needs for future studies. MMS requested an evaluation of the adequacy and applicability of ESP studies, a review of the generalmore » state of knowledge in the appropriate disciplines, and recommendations for future studies. Three panels were established, one of which, the Physical Oceanography Panel, investigated the physical oceanographic aspects of the ESP, the subject of the report, which is the first of three in a series. In reviewing the ESP's physical oceanography program, the panel evaluated the quality and relevance of studies carried out in waters under federal control, which extend from the limits of state jurisdictions (3-12 miles offshore) and include the central and outer continental shelf waters and the continental slope.« less
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Revised oil-spill risk analysis: Beaufort Sea outer continental shelf lease sale 170. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, C.; Johnson, W.; Marshall, C.
1997-11-01
The Federal Government has proposed to offer Outer Continental Shelf lands in the Beaufort Sea for oil and gas leasing. Because oil spills may occur from activities associated with offshore oil production, the Minerals Management Service conducts a formal risk assessment. This report summarizes results of oil-spill risk analysis conducted for the proposed Beaufort Sea lease sale.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-05
...] Commercial Wind Leasing and Site Assessment Activities on the Atlantic Outer Continental Shelf (OCS) Offshore... Assessment (EA) for Commercial Wind Leasing and Site Assessment Activities on the OCS Offshore North Carolina... INFORMATION: Background: On December 13, 2012, BOEM published the Notice in the Federal Register (77 FR 74218...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-14
... Policy Leasing for Renewable Energy Data Collection Facility on the Outer Continental Shelf off the Coast..., tribes, local governments, and the public in the preparation of an EA. The EA will consider the environmental consequences associated with issuing a lease for an offshore data collection facility located on...
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Very large dune formation along the Ebro outer continental shelf (Western Mediterranean)
NASA Astrophysics Data System (ADS)
Lo Iacono, Claudio; Guillén, Jorge; Puig, Pere; Ribó, Marta; Ballesteros, Maria; Palanques, Albert; Farrán, Marcelli; Acosta, Juan
2010-05-01
Large and very large subaqueous dunes have been observed in a number of outer shelf regions around the world, tipically developing on fossil sand bodies and ridges. Dunes observed on outer shelves usually display large dimensions with maximum wavelength reaching up to 500 m and heights up to 20 m. Forcing mechanisms able to induce their formation have been described as strong bottom currents related to tidal variations and water masses flowing under geostrophic conditions, generally controlled and enhanced by local geomorphologic configurations. In this study, such bed features have been recognized, mapped and measured around the Columbretes Islands (Ebro continental shelf - Western Mediterranean) with the aim to reconstruct which are the potential forcing processes that could generate them in relation to the local settings of the area. Swath-bathymetry around the Columbretes Islands was collected using 30 kHz and 180 kHz Multi Beam echo-sounders for a 50-400 m water depth range. Bathymetric data revealed the presence of three main relict sand bodies along the outer shelf, for a 80-116 m depth range, above which asymmetrical, slightly asymmetrical and symmetrical large and very large 2D and 3D subaqueous dunes were observed. Dunes range from 150 to 760 m in wavelength and from tens of cm to 6 m in height. These bedforms are composed of sandy sediments, presumably coming from the degraded relict sand bodies on which they developed, mixed to the fine fractions coming from the recent draping holocenic sediments. The orientation of the dunes is SSW and progressively turns to W directions moving towards the southernmost sector of the area, following the trend of the shelf-edge. Observed dunes display a strong asymmetric profile for those occurring along the shelf-edge (Symmetry Index (SI): 2.6) and lose progressively their asymmetry towards the inner portion of the shelf (SI: 0.5), being 0.6 the minimum SI value to classify the dunes as asymmetric. The subaqueous dunes
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76 FR 20367 - Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Off Delaware...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-12
... No. BOEM-2011-0008] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Off... determination that no competitive interest exists in acquiring a commercial wind lease in the area offshore... a Request for Interest (RFI) in the Federal Register on April 26, 2010 (75 FR 21653). Bluewater Wind...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-09
...-0045] RIN 1010-AD79 Renewable Energy Alternate Uses of Existing Facilities on the Outer Continental... rule related to acquiring a lease non-competitively for offshore renewable energy projects. DATES... or Timothy Redding, Renewable Energy, BOEM, at (703) 787-1219 or email [email protected
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-01
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement 30 CFR Part 250 [Docket ID: BOEM-2010-0076] Oil and Gas and Sulphur Operations in the Outer Continental Shelf--Safety and Environmental Management Systems; Public Workshop AGENCY: Bureau of Ocean Energy Management...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-27
... Outer Continental Shelf Air Regulations to the Delaware Department of Natural Resources and.... SUMMARY: On July 21, 2010, EPA sent the Delaware Department of Natural Resources and Environmental Control... of Natural Resources and Environmental Control, 89 Kings Highway, P.O. Box 1401, Dover, Delaware. FOR...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The final report for the project is presented in five volumes. The project sought to determine the impact of Outer Continental Shelf development on recreation and tourism in California. This volume is the User's Guide. It includes the following topics: Introduction and Summary Guide; Input Data Files; Gravity Model Programs; Economic Effects Model Programs; Consumer Surplus Model Programs; References; and Appendices.
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Karl, Herman A.; Carlson, P.R.
1987-01-01
Samples of total suspended matter (TSM) were collected at the surface over the northern outer continental margin of the Bering Sea during the summers of 1980 and 1981. Volume concentrations of surface TSM averaged 0.6 and 1.1 mg l-1 for 1980 and 1981, respectively. Organic matter, largely plankton, made up about 65% of the near-surface TSM for both years. Distributions of TSM suggested that shelf circulation patterns were characterized either by meso- and large- scale eddies or by cross-shelf components of flow superimposed on a general northwesterly net drift. These patterns may be caused by large submarine canyons which dominate the physiography of this part of the Bering Sea continental margin. ?? 1987.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-23
...-AA00 Safety Zone; KULLUK, Outer Continental Shelf Mobile Offshore Drilling Unit (MODU), Beaufort Sea... on location in order to drill exploratory wells at various prospects located in the Beaufort Sea... in order to drill exploratory wells in several prospects located in the Beaufort Sea during the 2012...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-09
... will use responses to this RFI to enable BOEMRE to gauge specific interest in commercial development of... BOEMRE Maryland Renewable Energy Task Force. A detailed description of the RFI area is found later in... Energy and Alternate Uses of Existing Facilities on the Outer Continental Shelf (REAU) rule. If...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-05
...] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore North Carolina--Call for... Commercial Leasing for Wind Power Offshore North Carolina (Call), published on December 13, 2012 (77 FR 7204). DATES: BOEM must receive your nomination describing your interest in obtaining a commercial wind lease...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The final report for the project is presented in five volumes. This volume is the Programmer's Manual. It covers: a system overview, attractiveness component of gravity model, trip-distribution component of gravity model, economic-effects model, and the consumer-surplus model. The project sought to determine the impact of Outer Continental Shelf development on recreation and tourism.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-15
... Environmental Impact Statement (Multisale FEIS). Authority: This NOA is published pursuant to the regulations... NEPA process. The Multisale FEIS evaluated the environmental and socioeconomic impacts for WPA Lease... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Gulf of Mexico, Outer Continental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-12
... (BOEMRE), Interior. ACTION: Notice of Availability (NOA) of a Final Supplemental Environmental Impact... sale's incremental contribution to the cumulative impacts on environmental and socioeconomic resources... Mexico (GOM), Outer Continental Shelf (OCS), Western Planning Area (WPA), Oil and Gas Lease Sale for the...
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Steiner, C.K.; Causley, M.C.; Yocke, M.A.
1994-04-01
The 1990 Clean Air Act Amendments require the Minerals Management Service (MMS) to conduct a research study to assess the potential onshore air quality impact from the development of outer continental shelf (OCS) petroleum resources in the Gulf of Mexico. The need for this study arises from concern about the cumulative impacts of current and future OCS emissions on ozone concentrations on nonattainment areas, particularly in Texas and Louisiana. To make quantitative assessments of these impacts, MMS has commissioned an air quality study which includes as a major component the development of a comprehensive emission inventory for photochemical grid modeling.more » The emission inventories prepared in this study include both onshore and offshore emissions. All relevant emissions from anthropogenic and biogenic sources are considered, with special attention focused on offshore anthropogenic sources, including OCS oil and gas production facilities, crew and supply vessels and helicopters serving OCS facilities, commercial shipping and fishing, recreational boating, intercoastal barge traffic and other sources located in the adjacent state waters. This document describes the database created during this study that contains the activity information collected for the development of the OCS platform, and crew/supply vessel and helicopter emission inventories.« less
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-10
... Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Offshore Maine; Request for Interest... Request for a Commercial OCS Wind Lease, Request for Interest, and Request for Public Comment SUMMARY: The... (Statoil NA) to acquire an OCS wind lease; (2) solicit public input regarding the proposal, its potential...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-26
... No. BOEM-2010-0075] Commercial Leasing for Wind Power on the Outer Continental Shelf (OCS) Off... commercial wind development on the OCS off Delaware and requests submission of indications of competitive... received two nominations of proposed lease areas: One from Bluewater Wind Delaware LLC (Bluewater) and...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-11
... Environmental Impact Statement (Multisale FEIS). Authority: This NOA is published pursuant to the regulations... the NEPA process. The Multisale FEIS evaluated the environmental and socioeconomic impacts for CPA... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Gulf of Mexico, Outer Continental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-15
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Outer Continental Shelf (OCS), Central and Western Gulf of Mexico, Oil and Gas Lease Sales for Years 2012-2017 AGENCY: Bureau of Ocean... 229, Western GOM 2012 Sale 227, Central GOM 2013 Sale 233, Western GOM 2013 Sale 231, Central GOM 2014...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-05
... environmental assessment (EA) for proposed Gulf of Mexico Outer Continental Shelf (OCS) oil and gas Lease Sale... Environmental Impact Statement; Volumes I and II (Multisale EIS, OCS EIS/EA MMS 2007-018) and in the Gulf of...; Western Planning Area Sales 210, 215, and 218--Final Supplemental Environmental Impact Statement...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-18
...: Nameplate capacity is the maximum rated electric output, expressed in MW, which the turbines of the wind facility under commercial operations can produce at their rated wind speed as designated by the turbine's...; MMAA104000] Atlantic Wind Lease Sale 3 (ATLW3) Commercial Leasing for Wind Power on the Outer Continental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-05
... Notice of Sale (NOS) for Outer Continental Shelf (OCS) Oil and Gas Lease Sale 215 in the Western Planning... matter of information to the public. With regard to oil and gas leasing on the OCS, the Secretary of the... NOS for Sale 215 and a ``Proposed Notice of Sale Package'' containing information essential to...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-22
... Availability of the Proposed Notice of Sale (NOS) for Outer Continental Shelf (OCS) Oil and Gas Lease Sale 218... matter of information to the public. With regard to oil and gas leasing on the OCS, the Secretary of the... NOS for Sale 218 and a ``Proposed Notice of Sale Package'' containing information essential to...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-27
... Proposed Notice of Sale for Outer Continental Shelf (OCS) Oil and Gas Lease Sale 216/222 in the Central...: Notice of Availability of the Proposed Notice of Sale for Proposed Sale 216/222. SUMMARY: BOEM announces the availability of the proposed Notice of Sale (NOS) for proposed Sale 216/222 in the CPA. This...
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Di Tullio, Juliana Couto; Gandra, Tiago B R; Zerbini, Alexandre N; Secchi, Eduardo R
2016-01-01
Temporal and spatial patterns of cetacean diversity and distribution were investigated through eight ship-based surveys carried out during spring and autumn between 2009 and 2014 on the outer continental shelf (~150m) and slope (1500m) off southeastern and southern Brazil (~23°S to ~34°S). The survey area was divided into southeast and south areas according to their oceanographic characteristics. Twenty-one species were observed in 503 sightings. The overall number of species was similar between the two areas, though it was higher in the spring in the south area. Five species were dominant and diversity varied more seasonally than spatially. ANOVA and kernel analyses showed that overall cetacean densities were higher in spring compared to autumn. Physeter macrocephalus, the most frequent species, concentrated throughout the south area at depths over 1000m in both seasons. Despite the overlapped occurrence at a broader scale, small delphinids presented latitudinal and in-offshore gradients as well as seasonal variation in distribution patterns, which could indicate habitat partitioning between some species. Delphinus delphis was only recorded in the south and its density decreased in areas where the presence of Stenella frontalis increased, mainly beyond the 250m isobath. Densities of S. longirostris and S. attenuata increased in lower latitudes and beyond the shelf break. The large delphinids Tursiops truncatus and Globicephala melas formed mixed groups in many occasions and were observed along the study area around depths of 500m. Grampus griseus was twice as frequent in the south area and densities increased in waters deeper than 600m. As expected, densities of both small and large migratory whales were higher during spring, over the continental slope, in the southeast area. The results presented here provided strong evidence on the importance of the outer continental shelf and slope to a diverse community of cetaceans occurring in the subtropical Southwestern
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-24
... Proposed Notice of Sale for Outer Continental Shelf (OCS) Oil and Gas Lease Sale 229 in the Western...: Notice of Availability of the Proposed Notice of Sale for Proposed Sale 229. SUMMARY: BOEM announces the availability of the Proposed Notice of Sale (NOS) for proposed Sale 229 in the WPA. This sale will be the first...
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Oil-spill risk analysis: Outer continental shelf lease sale 144, Beaufort Sea. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, C.M.; Johnson, W.R.; Marshall, C.F.
1995-08-01
The Federal Government has proposed to offer Outer Continental Shelf lands in the Beaufort Sea for oil and gas leasing. Because oil spills may occur from activities associated with offshore oil production, the Minerals Management Service conducts a formal risk assessment. In evaluating the significance of accidental oil spills, it is important to remember that the occurrence of such spills is fundamentally probabilistic. This report summarizes results of an oil-spill risk analysis conducted for OCS Lease Sale 144, Beaufort Sea. The objective of this analysis was to estimate relative risks associated with oil and gas production for the proposed leasemore » sale.« less
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, C.M.; Johnson, W.R.; Marshall, C.F.
1995-01-01
The Federal Government has proposed to offer Outer Continental Shelf lands in the Gulf of Alaska/Yakutat for oil and gas leasing. Because oil spills may occur from activities associated with offshore oil production, the Minerals Management Service conducts a formal risk assessment. The report summarizes results of an oil-spill risk analysis conducted for OCS Lease Sale 158, Gulf of Alaska/Yakutat. The objective of this analysis was to estimate relative risks associated with oil and gas production for the proposed lease sale.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-25
... of Sand and Gravel Activities on the Outer Continental Shelf AGENCY: Minerals Management Service... Environmental Policy Act (NEPA), the Council on Environmental Quality regulations (40 CFR parts 1500-1508), and... Impact (FONSI) prepared and/or adopted by the MMS for three sand and gravel activities proposed on the...
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Sedimentology and geochemistry of surface sediments, outer continental shelf, southern Bering Sea
Gardner, J.V.; Dean, W.E.; Vallier, T.L.
1980-01-01
Present-day sediment dynamics, combined with lowerings of sea level during the Pleistocene, have created a mixture of sediments on the outer continental shelf of the southern Bering Sea that was derived from the Alaskan Mainland, the Aleutian Islands, and the Pribilof ridge. Concentrations of finer-grained, higher-organic sediments in the region of the St. George basin have further modified regional distribution patterns of sediment composition. Q-mode factor analysis of 58 variables related to sediment size and composition - including content of major, minor, and trace elements, heavy and light minerals, and clay minerals - reveals three dominant associations of sediment: 1. (1) The most significant contribution, forming a coarse-grained sediment scattered over most of the shelf consists of felsic sediment derived from the generally quartz-rich rocks of the Alaskan mainland. This sediment contains relatively high concentrations of Si, Ba, Rb, quartz, garnet, epidote, metamorphic rock fragments, potassium feldspar, and illite. 2. (2) The next most important group, superimposed on the felsic group consists of andesitic sediment derived from the Aleutian Islands. This more mafic sediment contains relatively high concentrations of Na, Ca, Ti, Sr, V, Mn, Cu, Fe, Al, Co, Zn, Y, Yb, Ga, volcanic rock fragments, glass, clinopyroxene, smectite, and vermiculite. 3. (3) A local group of basaltic sediment, derived from rocks of the Pribilof Islands, is a subgroup of the Aleutian andesite group. Accumulation of fine-grained sediment in St. George basin has created a sediment group containing relatively high concentrations of C, S, U, Li, B, Zr, Ga, Hg, silt, and clay. Sediment of the Aleutian andesite group exhibits a strong gradient, or "plume", with concentrations decreasing away from Unimak Pass and toward St. George basin. The absence of present-day currents sufficient to move even clay-size material as well as the presence of Bering submarine canyon between the Aleutian
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Di Tullio, Juliana Couto; Gandra, Tiago B. R.; Zerbini, Alexandre N.; Secchi, Eduardo R.
2016-01-01
Temporal and spatial patterns of cetacean diversity and distribution were investigated through eight ship-based surveys carried out during spring and autumn between 2009 and 2014 on the outer continental shelf (~150m) and slope (1500m) off southeastern and southern Brazil (~23°S to ~34°S). The survey area was divided into southeast and south areas according to their oceanographic characteristics. Twenty-one species were observed in 503 sightings. The overall number of species was similar between the two areas, though it was higher in the spring in the south area. Five species were dominant and diversity varied more seasonally than spatially. ANOVA and kernel analyses showed that overall cetacean densities were higher in spring compared to autumn. Physeter macrocephalus, the most frequent species, concentrated throughout the south area at depths over 1000m in both seasons. Despite the overlapped occurrence at a broader scale, small delphinids presented latitudinal and in-offshore gradients as well as seasonal variation in distribution patterns, which could indicate habitat partitioning between some species. Delphinus delphis was only recorded in the south and its density decreased in areas where the presence of Stenella frontalis increased, mainly beyond the 250m isobath. Densities of S. longirostris and S. attenuata increased in lower latitudes and beyond the shelf break. The large delphinids Tursiops truncatus and Globicephala melas formed mixed groups in many occasions and were observed along the study area around depths of 500m. Grampus griseus was twice as frequent in the south area and densities increased in waters deeper than 600m. As expected, densities of both small and large migratory whales were higher during spring, over the continental slope, in the southeast area. The results presented here provided strong evidence on the importance of the outer continental shelf and slope to a diverse community of cetaceans occurring in the subtropical Southwestern
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The report describes the process of developing and conducting two series of workshops on 'Onshore Impact of Outer Continental Shelf Oil and Gas Development'. The purpose of this report is to evaluate the workshops from the standpoint of their objectives, content, teaching methods...
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Notices of Intent (NOIs) submitted to EPA for coverage under the NPDES general permit for discharges from oil and gas exploration facilities on the outer continental shelf in the Chukchi Sea off Alaska.
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Depositional history of Louisiana-Mississippi outer continental shelf
Kindinger, J.L.; Miller, R.J.; Stelting, C.E.
1982-01-01
A geological study was undertaken in 1981 in the Louisiana-Mississippi outer continental shelf for the Bureau of Land Management. The study included a high-resolution seismic reflection survey, surficial sediment sampling and surface current drifter sampling. Approximately 7100 sq km of the Louisiana-Mississippi shelf and upper slope were surveyed. The sea floor of the entire area is relatively smooth except for occasional areas of uplift produced by diapiric intrusion along the upper slope. Characteristics of the topography and subsurface shelf sediments are the result of depositional sequences due to delta outbuilding over transgressive sediments with intervening periods of erosion during low sea level stands. Little evidence of structural deformation such as faults, diapirs, and shallow gas is present on the shelf and only a few minor faults and scarps are found on the slope. Minisparker seismic records in combination with air gun (40 and 5 cu in) and 3.5-kHz subbottom profile records reveal that seven major stages of shelf development have occurred since the middle Pleistocene. The shelf development has been controlled by the rise and fall of sea level. These stages are defined by four major unconformities, several depositions of transgressive sediments, sequences of river channeling and progradational delta deposits. Surficial sediment sample and seismic records indicate tat the last major depositional event was the progradation of the St. Bernard Delta lobe. This delta lobe covered the northwestern and central regions. Surficial sediments in most of the study area are the product of the reworking of the San Bernard Delta lobe and previous progradations.
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Continental Margins of the Arctic Ocean: Implications for Law of the Sea
NASA Astrophysics Data System (ADS)
Mosher, David
2016-04-01
A coastal State must define the outer edge of its continental margin in order to be entitled to extend the outer limits of its continental shelf beyond 200 M, according to article 76 of the UN Convention on the Law of the Sea. The article prescribes the methods with which to make this definition and includes such metrics as water depth, seafloor gradient and thickness of sediment. Note the distinction between the "outer edge of the continental margin", which is the extent of the margin after application of the formula of article 76, and the "outer limit of the continental shelf", which is the limit after constraint criteria of article 76 are applied. For a relatively small ocean basin, the Arctic Ocean reveals a plethora of continental margin types reflecting both its complex tectonic origins and its diverse sedimentation history. These factors play important roles in determining the extended continental shelves of Arctic coastal States. This study highlights the critical factors that might determine the outer edge of continental margins in the Arctic Ocean as prescribed by article 76. Norway is the only Arctic coastal State that has had recommendations rendered by the Commission on the Limits of the Continental Shelf (CLCS). Russia and Denmark (Greenland) have made submissions to the CLCS to support their extended continental shelves in the Arctic and are awaiting recommendations. Canada has yet to make its submission and the US has not yet ratified the Convention. The various criteria that each coastal State has utilized or potentially can utilize to determine the outer edge of the continental margin are considered. Important criteria in the Arctic include, 1) morphological continuity of undersea features, such as the various ridges and spurs, with the landmass, 2) the tectonic origins and geologic affinities with the adjacent land masses of the margins and various ridges, 3) sedimentary processes, particularly along continental slopes, and 4) thickness and
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, S.Y.; Watkins, J.S.
Mapping of Miocene stratigraphy and structure of the Sabine Pass, West Cameron, and East Cameron areas of the western Louisiana outer continental shelf - based on over 1300 mi of seismic data on a 4-mi grid, paleotops from 60 wells, and logs from 35 wells - resulted in time-structure and isochron maps at six intervals from the upper Pliocene to lower Miocene. The most pronounced structural features are the fault systems, which trend east-northeast to east along the Miocene stratigraphic trend. Isolated normal faults with small displacements characterize the inner inner shelf, whereas interconnected faults with greater displacements characterize themore » outer inner shelf. The inner inner shelf faults exhibit little growth, but expansion across the interconnected outer inner shelf fault ranges up to 1 sec two-way traveltime. The interconnected faults belong to two structurally independent fault families. The innermost shelf faults appear to root in the sediment column. A third set of faults located in the Sabine Pass area trends north-south. This fault set is thought to be related to basement movement and/or basement structure. Very little salt is evident in the area. A single diapir is located in West Cameron Block 110 and vicinity. There is little evidence of deep salt. Overall sediment thickness probably exceeds 20,000 ft, with the middle Miocene accounting for 8000 ft.« less
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,
1975-01-01
The area designated for possible oil and gas lease sale in Bureau of Land Management memorandum 3310 #43 (722) and referred to therein as part of the United States South Atlantic Outer Continental Shelf (OCS) contains about 98,000 square kilometres of the continental margin seaward of the 3 mile offshore limit and within the 600 metre isobath. The designated area, offshore of North Carolina, South Carolina, Georgia, and Florida, encompasses parts of three physiographic provinces: the Continental Shelf, the Florida-Hatteras Slope, and the Blake Plateau. The structural framework of the U.3. South Atlantic region is dominated by the Southeast Georgia Embayment --an east-plunging depression recessed into the Atlantic Coastal Plain and shelf between Cape Fear, North Carolina and Jacksonville, Florida. The embayment is bounded to the north by the Cape Fear Arch and to southeast by the Peninsular Arch. Refraction data indicate a minor basement(?) ridge beneath the outer shelf between 30? and 32?N at 80?W. Drill hole data also suggest a gentle fold or accretionary structure (reef?) off the east coast of Florida. Several other structural features have been identified by refraction and reflection techniques and drilling. These are the Yamacraw Uplift, Burton High, Stone Arch, and the Suwannee Channel. Gravity and magnetic anomalies within the area probably result from emplacement of magma bodies along linear features representing fundamental crustal boundaries. Of these anomalies, the most prominent, is a segment of the East Coast Magnetic Anomaly which crosses the coast at Brunswick, Georgia. This anomaly has been interpreted as representing an ancient continental boundary where two formerly separate continental plates collided and were welded together. There may be as much as 5,000 m of sedimentary rocks in the Southeast Georgia Embayment out to the 600 m isobath. Basement rocks beneath the Southeast Georgia Embayment are expected to be similar to those exposed in the
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Popenoe, Peter; Popenoe, Peter
1981-01-01
This report is a summary of the second year of marine environmental research activities by the U.S. Geological Survey (USGS) on the southeaster U.S. Atlantic Continental Margin, in accordance with with Memorandum of Understanding (MOU) AA551-MU8-13 between the USGS and the Bureau of Land Management (BLM). The report covers studies whose fieldwork was conducted during the period from 1 October 1977 to 30 September 1978. The results of the first year of study are reported in Popenoe (1978a and b) and as U.S. Department of Commerce NTIS report PB 300-820. The purpose of these investigations is to provide basic geologic and oceanographic data to the BLM Outer Continental Shelf (OCS) Marine Environmental Studies Program in support of management decisions which relate to possible development of oil and gas resources of the continental shelf. The objectives of the USGS-BLM geologic research program for fiscal year 1978 (FY-78) were 1) to determine the sedimentation rates and processes on the upper slope and inner Blake Plateau; 2) to determine the distribution, areal extent, and vertical characteristics of geological features supportive of biological communities; 3) to monitor the transport of bottom sediment across the OCS, evaluate its possible effect on pollutant transfer along the seabed and the potential of sediment as a pollutant sink, determine the implications of erosion/deposition on pipeline emplacement, and aid the interpretation of chemical, biological, and physical data; 4) to determine the concentration levels of chosen trace metals and silica in three chemically defined fractions of the suspended particulate matter (seston); 5) to study the shelf edge and slope near areas of oil and gas interest, and the northern portion of the Blake Plateau for evidence of slope instability and other geologic hazards, and 6) to determine the depth and rate of sediment mixing caused by large storms and/or by benthic organisms and where possible to estimate the rate of
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The final report for the project is presented in five volumes. This volume, Detailed Methodology Review, presents a discussion of the methods considered and used to estimate the impacts of Outer Continental Shelf (OCS) oil and gas development on coastal recreation in California. The purpose is to provide the Minerals Management Service with data and methods to improve their ability to analyze the socio-economic impacts of OCS development. Chapter II provides a review of previous attempts to evaluate the effects of OCS development and of oil spills on coastal recreation. The review also discusses the strengths and weaknesses of differentmore » approaches and presents the rationale for the methodology selection made. Chapter III presents a detailed discussion of the methods actually used in the study. The volume contains the bibliography for the entire study.« less
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NASA Astrophysics Data System (ADS)
2002-09-01
The Federal Government plans to offer U.S. Outer Continental Shelf (OCS) lands in the Eastern Planning Area of the Gulf of Mexico (GOM) for oil and gas leasing. This report summarizes results of that analysis, the objective of which was to estimate the risk of oil-spill contact to sensitive offshore and onshore environmental resources and socioeconomic features from oil spills accidentally occurring from the OCS activities.
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NASA Astrophysics Data System (ADS)
Vang Heinesen, Martin; Mørk, Finn
2017-04-01
documentation to the CLCS of the outer limits of the continental shelf to the north of the Faroe Islands.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
The study was intended to provide the Mineral Management Service (MMS) with an analytical tool to evaluate possible economic impacts from Outer Continental Shelf (OCS) development. In particular, the study was designed to provide MMS staff who work on lease sale Energy Impact Statements with an objective technique for estimating the impacts to coastal communities from events that might occur as a result of lease sales: oil spills, onshore construction, and construction of platforms offshore. The project had several specific objectives: (1) provide profiles of 1982 socio-economic conditions in coastal communities, including an analysis of the relative importance of themore » tourist industry in each coastal county; (2) develop a methodology for determining the effects of OCS development on coastal recreation; and recommend mitigation measure that may reduce the negative effect of OCS development on coastal recreation using gravity and economic effects models.« less
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Gardner, James V.; Hughes-Clarke, John E.; Meyer, Larry A.
2002-01-01
The mid to outer continental shelf off Mississippi-Alabama and off northwest Florida were the focus of US Geological Survey (USGS) multibeam echosounder (MBES) mapping cruises in 2000 and 2001, respectively. These areas were mapped to investigate the extent of "deep-water reefs" first suggested by Ludwick and Walton (1957). The reefs off Mississippi and Alabama were initially described in water depths of 60 to 120 m (Ludwick and Walton, 1957) but the 2000 mapping found reef and hardgrounds to be much more extensive than previously thought (Gardner et al., 2001). The persistent trend of reef-like features along the outer shelf of Mississippi-Alabama suggested the trend might continue along the northwest Florida mid and outer shelf so a MBES-mapping effort was mounted in 2001 to test this suggestion. It is critical to determine the accurate location, geomorphology, and types of the ridges and reefs that occur in this region to understand the Quaternary history of the area and to assess their importance as benthic habitats for fisheries. The 2001 survey found a series of shelf-depth platforms with ridges (possibly reefs) constructed on their surfaces (Gardner et al., 2002). The area known as the "head of De Soto Canyon" is the large unmapped region between the 2000 and 2001 mapped areas. The head of De Soto Canyon is an outer shelf zone with a relatively steep western wall and a much gentler eastern wall. It was unknown prior to this cruise whether the reefs of the Mississippi-Alabama shelf continue eastward into the head of De Soto Canyon and connect with the ridges and reefs mapped on the northwest Florida outer shelf. The existence of carbonate-cemented latest Quaternary to Holocene sandstones along the western wall of the head of De Soto Canyon (Shipp and Hopkins, 1978; Benson et al., 1997; W.W. Schroeder, personnel comm., 2002) is of interest because of the potential benthic habitats they may represent. Precisely georeferenced high-resolution mapping of
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Do Continental Shelves Act as an Atmospheric CO2 Sink?
NASA Astrophysics Data System (ADS)
Cai, W.
2003-12-01
Recent air-to-sea CO2 flux measurements at several major continental shelves (European Atlantic Shelves, East China Sea and U.S. Middle Atlantic Bight) suggest that shelves may act as a one-way pump and absorb atmospheric CO2 into the ocean. These observations also favor the argument that continental shelves are autotrophic (i.e., net production of organic carbon, OC). The U.S. South Atlantic Bight (SAB) contrasts these findings in that it acts as a strong source of CO2 to the atmosphere while simultaneously exporting dissolved inorganic carbon (DIC) to the open ocean. We report pCO2, DIC, and alkalinity data from the SAB collected in 8 cruises along a transect from the shore to the shelf break in the central SAB. The shelf-wide net heterotrophy and carbon exports in the SAB are subsidized by the export of OC from the abundant intertidal marshes, which are a sink for atmospheric CO2. It is proposed here that the SAB represents a marsh-dominated heterotrophic ocean margin as opposed to river-dominated autotrophic margins. To further investigate why margins may behave differently in term of CO2 sink/source, the physical and biological conditions of several western boundary current margins are compared. Based on this and other studies, DIC export flux from margins to the open ocean must be significant in the overall global ocean carbon budget.
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Robb, James M.
1983-01-01
Because of the need for knowledge of an offshore area that is undergoing exploration for oil and gas resources, since 1975 the U.S. Bureau of Land Management (BLM) has funded studies of the environmental characteristics of the Mid-Atlantic Outer Continental Shelf. This volume briefly summarizes a final report to the BLM on the results of U.S. Geological Survey investigations stemming from data acquired during 1978 and 1979. The parent final report contains complete accounts of those investigations. The subjects of the studies range from the geologic effects of water currents and their capabilities of erosion and transportation, to delineation of potentially hazardous geologic characteristics of the area. Nine specific studies address the complexities of water currents, the nature of materials suspended in the sea waters, rates of mixing-in of material deposited on the bottom, and the sites of probable deposition of such materials, as well as sites and mechanisms of possible submarine landsliding or unstable bottom (engineering characteristics) of the Continental Slope and shelf.
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Wyant, Timothy; Slack, James R.
1978-01-01
An oilspill risk analysis was conducted to determine the relative environmental hazards of developing oil in different regions of the Eastern Gulf of Mexico Outer Continental Shelf lease area. The study analyzed the probability of spill occurrence, likely paths of the spills, and locations in space and time of such objects as recreational and biological resources likely to be vulnerable. These results combined to yield estimates of the overall oilspill risk associated with development of the proposed lease area. This risk is compared to the existing oilspill risk from existing leases in the area. The analysis implicitly includes estimates of weathering rates and slick dispersion and an indication of the possible mitigating effects of cleanups.
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Outer Continental Shelf Lands Act Amendments Act of 2010
Sen. Whitehouse, Sheldon [D-RI
2010-05-11
Senate - 05/25/2010 Committee on Energy and Natural Resources. Hearings held. Hearings printed: S.Hrg. 111-679, pt. 3. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:
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NASA Astrophysics Data System (ADS)
Somoza, Luis; Medialdea, Teresa; Vázquez, Juan T.; González, Francisco J.; León, Ricardo; Palomino, Desiree; Fernández-Salas, Luis M.; Rengel, Juan
2017-04-01
Spain presented on 11 May 2009 a partial submission for delimiting the extended Continental Shelf in respect to the area of Galicia to the Commission on the Limits of the Continental Shelf (CLCS). The Galicia margin represents an example of the transition between two different types of continental margins (CM): a western hyperpextended margin and a northern convergent margin in the Bay of Biscay. The western Galicia Margin (wGM 41° to 43° N) corresponds to a hyper-extended rifted margin as result of the poly-phase development of the Iberian-Newfoundland conjugate margin during the Mesozoic. Otherwise, the north Galicia Margin (nGM) is the western end of the Cenozoic subduction of the Bay of Biscay along the north Iberian Margin (NIM) linked to the Pyrenean-Mediterranean collisional belt Following the procedure established by the CLCS Scientific and Technical Guidelines (CLCS/11), the points of the Foot of Slope (FoS) has to be determined as the points of maximum change in gradient in the region defined as the Base of the continental Slope (BoS). Moreover, the CLCS guidelines specify that the BoS should be contained within the continental margin (CM). In this way, a full-coverage multibeam bathymetry and an extensive dataset of up 4,736 km of multichannel seismic profiles were expressly obtained during two oceanographic surveys (Breogham-2005 and Espor-2008), aboard the Spanish research vessel Hespérides, to map the outer limit of the CM.In order to follow the criteria of the CLCS guidelines, two types of models reported in the CLCS Guidelines were applied to the Galicia Margin. In passive margins, the Commission's guidelines establish that the natural prolongation is based on that "the natural process by which a continent breaks up prior to the separation by seafloor spreading involves thinning, extension and rifting of the continental crust…" (para. 7.3, CLCS/11). The seaward extension of the wGM should include crustal continental blocks and the so
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Knebel, H.J.; Folger, D.W.
1976-01-01
New seismic-reflection data show that large sand waves near the head of Wilmington Canyon on the Atlantic Outer Continental Shelf have a spacing of 100-650 m and a relief of 2-9 m. The bedforms trend northwest and are asymmetrical, the steeper slopes being toward the south or west. Vibracore sediments indicate that the waves apparently have formed on a substrate of relict nearshore sediments. Although the age of the original bedforms is unknown, the asymmetry is consistent with the dominant westerly to southerly drift in this area which has been determined by other methods; the asymmetry, therefore, is probably modern. Observations in the sand-wave area from a submersible during August 1975, revealed weak bottom currents, sediment bioturbation, unrippled microtopography, and lack of scour. Thus, the asymmetry may be maintained by periodic water motion, possibly associated with storms or perhaps with flow in the canyon head. ?? 1976.
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Outer Continental Shelf Permit Processing Coordination Act
Sen. Begich, Mark [D-AK
2011-04-14
Senate - 05/17/2011 Committee on Energy and Natural Resources. Hearings held. Hearings printed: S.Hrg. 112-51. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:
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Outer Continental Shelf Reform Act of 2011
Sen. Bingaman, Jeff [D-NM
2011-05-09
Senate - 05/17/2011 Committee on Energy and Natural Resources. Hearings held. Hearings printed: S.Hrg. 112-51. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:
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Outer Continental Shelf Reform Act of 2010
Sen. Bingaman, Jeff [D-NM
2010-06-21
Senate - 07/28/2010 Placed on Senate Legislative Calendar under General Orders. Calendar No. 492. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:
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An oilspill risk analysis of the Mid-Atlantic (Proposed Sale 49) outer continental shelf lease area
Slack, James Richard; Wyant, Timothy
1978-01-01
An oilspill risk analysis was conducted to determine the relative environmental hazards of developing oil in different regions of the mid-Atlantic Outer Continental Shelf lease area. The study analyzed the probability of spill occurrence, likely paths of the spilled oil, and locations in space and time of recreational and biological resources that are likely to be vulnerable. These results are combined to yield estimates of the overall oilspill risk associated with development of the proposed lease area. The analysis implicitly includes estimates of weathering rates and slick dispersion and an indication of the possible mitigating effects of cleanups. Assuming that economically recoverable amounts of petroleum are found in the area, the leasing of the tracts proposed for sale 49 will increase the expected number of spills by about 20-25 percent over the number expected from the existing (sale 40) leases. The probability that an object such as land will be contacted by a spill is increased by at most five percentage points. (Woodard-USGS)
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30 CFR 280.80 - Paperwork Reduction Act statement-information collection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... OFFSHORE PROSPECTING FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR ON THE OUTER CONTINENTAL SHELF... CFR part 280, Prospecting for Minerals other than Oil, Gas, and Sulphur on the Outer Continental Shelf...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas... for oil and gas, and sulphur, in submerged lands of the outer Continental Shelf (OCS). The Act... major oil and gas producers. [64 FR 72795, Dec. 28, 1999] ...
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Volatile components and continental material of planets
NASA Technical Reports Server (NTRS)
Florenskiy, K. P.; Nikolayeva, O. V.
1986-01-01
It is shown that the continental material of the terrestrial planets varies in composition from planet to planet according to the abundances and composition of true volatiles (H20, CO2, etc.) in the outer shells of the planets. The formation of these shells occurs very early in a planet's evolution when the role of endogenous processes is indistinct and continental materials are subject to melting and vaporizing in the absence of an atmosphere. As a result, the chemical properties of continental materials are related not only to fractionation processes but also to meltability and volatility. For planets retaining a certain quantity of true volatile components, the chemical transformation of continental material is characterized by a close interaction between impact melting vaporization and endogeneous geological processes.
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Knebel, Harley J.
1974-01-01
A deductive approach to the problem of determining the movement and effects of spilled oil over the Outer Continental Shelf requires that the potential paths of oil be determined first, in order that critical subareas may be defined for later studies. The paths of spilled oil, in turn, depend primarily on the temporal and spatial variability of four factors: the thermohaline structure of the waters, the circulation of the water, the winds, and the distribution of suspended matter. A review of the existent data concerning these factors for the Baltimore Canyon Trough area (a relatively well studied segment of the Continental Shelf) reveals that the movement and dispersal of potential oil spills cannot be reliably predicted. Variations in the thermohaline structure of waters and in the distribution of suspended matter are adequately known; the uncertainty is due to insufficient wind and storm statistics and to the lack of quantitative understanding of the relationship between the nontidal drift and its basic driving mechanisms. Similar inadequacies should be anticipated for other potentially leasable areas of the shelf because an understanding of the movement of spilled oil has not been the underlying aim of most previous studies.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-13
...BOEM invites the submission of nominations for commercial wind leases that would allow a lessee to propose the construction of a wind energy project on the Outer Continental Shelf (OCS) offshore North Carolina, and to develop the project if approved after further environmental review. Although this announcement is not itself a leasing announcement, the Call Areas described herein, or portions thereof, may be available for future leasing. BOEM will use responses to this Call to gauge specific interest in acquiring commercial wind leases in some or all of the Call Areas, as required by 43 U.S.C. 1337(p)(3). Parties wishing to submit a nomination in response to this Call should submit detailed and specific information in response to the requirements described in the section entitled, ``Required Nomination Information.'' This announcement also requests comments and information from interested and affected parties about site conditions, resources, and multiple uses in close proximity to, or within, the Call Areas that would be relevant to BOEM's review of any nominations submitted and/or to BOEM's subsequent decision to offer all or part of the Call Areas for commercial wind leasing. The information that BOEM is requesting is described in the section of this Call entitled, ``Requested Information from Interested or Affected Parties.'' This Call is published pursuant to subsection 8(p)(3) of the OCS Lands Act, 43 U.S.C. 1337(p)(3), which was added by section 388 of the Energy Policy Act of 2005 (EPAct), as well as the implementing regulations at 30 CFR part 585. The Call Areas described in this notice are located on the OCS offshore North Carolina and are delineated as Wilmington-West, Wilmington-East and Kitty Hawk (formerly referred to as North Carolina Planning Areas 1, 2, and 5, respectively, during BOEM's North Carolina offshore wind planning efforts). The three Call Areas include 195 whole OCS blocks and 60 partial blocks in total and comprise approximately 1
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Outer Continental Shelf Transboundary Hydrocarbon Agreements Authorization Act
Rep. Duncan, Jeff [R-SC-3
2013-04-18
Senate - 10/01/2013 Committee on Energy and Natural Resources. Hearings held. Hearings printed: S.Hrg. 113-104. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:
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Geological and technological assessment of artificial reef sites, Louisiana outer continental shelf
Pope, D.L.; Moslow, T.F.; Wagner, J.B.
1993-01-01
This paper describes the general procedures used to select sites for obsolete oil and gas platforms as artificial reefs on the Louisiana outer continental shelf (OCS). The methods employed incorporate six basic steps designed to resolve multiple-use conflicts that might otherwise arise with daily industry and commercial fishery operations, and to identify and assess both geological and technological constraints that could affect placement of the structures. These steps include: (1) exclusion mapping; (2) establishment of artificial reef planning areas; (3) database compilation; (4) assessment and interpretation of database; (5) mapping of geological and man-made features within each proposed reef site; and (6) site selection. Nautical charts, bathymetric maps, and offshore oil and gas maps were used for exclusion mapping, and to select nine regional planning areas. Pipeline maps were acquired from federal agencies and private industry to determine their general locations within each planning area, and to establish exclusion fairways along each pipeline route. Approximately 1600 line kilometers of high-resolution geophysical data collected by federal agencies and private industry was acquired for the nine planning areas. These data were interpreted to determine the nature and extent of near-surface geologic features that could affect placement of the structures. Seismic reflection patterns were also characterized to evaluate near-bottom sedimentation processes in the vicinity of each reef site. Geotechnical borings were used to determine the lithological and physical properties of the sediment, and for correlation with the geophysical data. Since 1987, five sites containing 10 obsolete production platforms have been selected on the Louisiana OCS using these procedures. Industry participants have realized a total savings of approximately US $1 500 000 in salvaging costs by converting these structures into artificial reefs. ?? 1993.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-27
... Activities; Submission to OMB for Review and Approval; Comment Request; Air Pollution Regulations for Outer... electronic docket, go to www.regulations.gov . Title: Air Pollution Regulations for Outer Continental Shelf... Act gives EPA responsibility for regulating air pollution from outer continental shelf (OCS) sources...
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The Continental Margins of the Western North Atlantic.
ERIC Educational Resources Information Center
Schlee, John S.; And Others
1979-01-01
Presents an interpretation of geological and geophysical data, which provides a summary of the structural and sedimentary history of the United States Atlantic Margin. The importance of an understanding of the development of the outer continental shelf to future hydrocarbon exploration is detailed. (BT)
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-10
...] Information Collection: Renewable Energy and Alternate Uses of Existing Facilities on the Outer Continental... requirements in the regulations under ``Renewable Energy and Alternate Uses of Existing Facilities on the Outer..., transportation, or transmission of energy from sources other than oil and gas (renewable energy). Specifically...
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Oil spills, 1971-75, Gulf of Mexico outer continental shelf
Danenberger, Elmer P.
1976-01-01
Oil spillage connected with federally supervised drilling and production activities has been a matter of wide public concern. In its supervision of mineral-resource development on the Outer Continental Shelf (OCS), the U.S. Geological Survey is responsible for the day-to-day inspection and monitoring of OCS oil and gas operations. During these activities, the U.S. Geological Survey records and investigates hydrocarbon discharges resulting from such operations. Beginning in 1971, all spills have been recorded, and a computer file has been maintained on all spills of 1 barrel or more. The total Gulf of Mexico OCS oil spillage recorded during January 1, 1971-December 31, 1975, amounted to 51,421 barrels. Production during that period amounted to 35,219 barrels per barrel spilled. In all, 5,857 spills were recorded, but 85.5 percent of the total spill volume was contributed by just 5 incidents. The environmental effect of these incidents apparently was minimal and of short duration. No spills of more than 50 barrels resulted from drilling operations during the period. The only spillage resulting from blowouts was caused by nondrilling incidents, including completion, production, and workover. The amount of oil discharged from spills of less than 50 barrels decreased by more than half between 1971 and 1975. The improvement reflects changes in the operating philosophy of the offshore industry, tightening of U.S. Geological Survey operating orders, and substantial increases in the inspection force. Most production-platform spills involve failures in the sump system, the separator system, or other hydrocarbon-handling equipment; improved sump-system designs and better high-low-level controls have reduced both the number and the volume of spills. Pipeline and pump spills also declined significantly, although the decline appears less attributable to revisions in OCS operating requirements. No operator consistently contributed a disproportionate amount of spillage. Most of
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, W.R.; Marshall, C.F.; Anderson, C.M.
1994-08-01
This report summarizes results of an oil-spill risk analysis (OSRA) conducted for the proposed lower Cook Inlet Outer Continental Shelf (OCS) Lease Sale 149. The objective of this analysis was to estimate relative oil-spill risks associated with oil and gas production from the leasing alternatives proposed for the lease sale. The Minerals Management Service (MMS) will consider the analysis in the environmental impact statement (EIS) prepared for the lease sale. The analysis for proposed OCS Lease Sale 149 was conducted in three parts corresponding to different aspects of the overall problem. The first part dealt with the probability of oil-spillmore » occurrence. The second dealt with trajectories of oil spills from potential spill sites to various environmental resources or land segments. The third part combined the results of the first two parts to give estimates of the overall oil-spill risk if there is oil production as a result of the lease sale. To aid the analysis, conditional risk contour maps of seasonal conditional probabilities of spill contact were generated for each environmental resource or land segment in the study area (see vol. 2).« less
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75 FR 51968 - Outer Continental Shelf Air Regulations Consistency Update for Massachusetts
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-24
... comments to: Ida McDonnell, Air Permits, Toxics and Indoor Air Unit, Office of Ecosystem Protection, U.S... INFORMATION CONTACT: Ida E. McDonnell, Air Permits, Toxics and Indoor Air Unit, U.S. Environmental Protection... Continental Shelf Air Regulations Consistency Update for Massachusetts AGENCY: Environmental Protection Agency...
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Quaternary seismic stratigraphy and paleoenvironments on the continental shelf of the East China Sea
NASA Astrophysics Data System (ADS)
Liu, Zhen-Xia; Berne, Serge; Saito, Yoshiki; Lericolais, G.; Marsset, T.
2000-08-01
Paleoenvironments and stratigraphy have been interpreted from 4380 km of seismic profiling collected during a geological and geophysical cruise on the continental shelf of the East China Sea (ECS) undertaken in 1996. The geophysical data are correlated with a borehole situated on the outer shelf obtained by Shanghai Marine Geology Bureau, indicating that six seismic units have been preserved since oxygen-isotope stage 6, including four regressive-transgressive cycles. Seismic units U2, U3+U4+U5, U6, and U7 are interpreted to correspond respectively to oxygen-isotope stages 1, 3, 5, and 6, implying that sediment partitioning and sequence architecture in the ECS have been controlled by glacio-eustasy and global climate changes. Alternating continental and marine strata corresponding to glaciation and interglaciation are well preserved on the outer shelf of the ECS. Most of the cold environment strata, which formed on the outer shelf during oxygen-isotope stages 2 and 4, are too thin to be recognized on SIG 600J because of resolution, but corresponding erosion surfaces exist. Seismic unit U7 is widespread over the shelf, extending to the continental edge and showing little variation in thickness, as the regression was pronounced and lasted a long time. Thus, U7 can be used as a marker layer for correlation of Quaternary strata on the shelf of the ECS. Post-glacial transgression is obvious in the ECS. Marine strata with varied thickness were developed in the shallow sea of the inner shelf, thinning toward the outer shelf. The continental shelf of the ECS has been influenced by Pacific tide-wave systems for a long time, forming tidal sand-ridge sequences, developed during transgressions, corresponding to oxygen-isotope stages 7 (or 9), 5, 3 and 1.
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NASA Technical Reports Server (NTRS)
Dyer, M. K.; Little, D. G.; Hoard, E. G.; Taylor, A. C.; Campbell, R.
1972-01-01
An approach that might be used for determining the applicability of NASA management techniques to benefit almost any type of down-to-earth enterprise is presented. A study was made to determine the following: (1) the practicality of adopting NASA contractual quality management techniques to the U.S. Geological Survey Outer Continental Shelf lease management function; (2) the applicability of failure mode effects analysis to the drilling, production, and delivery systems in use offshore; (3) the impact on industrial offshore operations and onshore management operations required to apply recommended NASA techniques; and (4) the probable changes required in laws or regulations in order to implement recommendations. Several management activities that have been applied to space programs are identified, and their institution for improved management of offshore and onshore oil and gas operations is recommended.
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Gardner, James V.; Hughes-Clarke, John E.; Mayer, Larry A.; Dartnell, Peter
2003-01-01
The mid to outer continental shelf off Mississippi-Alabama and off northwest Florida were the focus of U.S. Geological Survey (USGS) multibeam echosounder (MBES) mapping cruises in 2000 and 2001, respectively. These areas were mapped to investigate the extent of "deep-water reefs" first suggested by Ludwig and Walton (1957). The reefs off Mississippi and Alabama were initially described in water depths of 60 to 120 m (Ludwig and Walton, 1957) but the 2000 mapping found reef and hardgrounds to be much more extensive than previously thought (Gardner et al., 2001). The persistent trend of reef-like features along the outer shelf of Mississippi-Alabama suggested the trend might continue along the northwest Florida mid and outer shelf so a MBES-mapping effort was mounted in 2001 to test this suggestion. It is critical to determine the accurate location, geomorphology, and types of the ridges and reefs that occur in this region to understand the Quaternary history of the area and to assess their importance as benthic habitats for fisheries. The area known as the "Head of De Soto Canyon" is the large unmapped region between the 2000 and 2001 mapped areas. It was unknown whether the reefs of the Mississippi-Alabama shelf continue eastward into the head of De Soto Canyon and connect with the ridges and reefs mapped on the northwest Florida outer shelf. The existence of carbonate-cemented Quaternary to Holocene sandstones along the western wall of the head of De Soto Canyon (Shipp and Hopkins, 1978; Benson et al., 1997; W.W. Schroeder, personal commun., 2002) is of interest because of the potential benthic habitats they may represent. In the summer of 2002, the USGS, in cooperation with Minerals Management Service (MMS), the University of New Hampshire, and the University of New Brunswick, conducted a MBES survey of the Head of De Soto Canyon Region connecting the 2000 and 2001 mapped regions.
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NASA Astrophysics Data System (ADS)
Duchemin, Gérald; Jorissen, Frans J.; Le Loc'h, François; Andrieux-Loyer, Françoise; Hily, Christian; Thouzeau, Gérard
2008-08-01
Living benthic foraminiferal faunas of six stations from the continental shelf of the Bay of Biscay have been investigated during three successive seasons (spring, summer and autumn 2002). For the three investigated stations, bottom water oxygen concentration, oxygen penetration into the sediment and sediment organic carbon contents are all relatively similar. Therefore, we think that the density and the composition of the foraminiferal faunas is mainly controlled by the quantity and quality of organic input resulting from a succession of phytoplankton bloom events, occurring from late February to early September. The earliest blooms are positioned at the shelf break, late spring and early summer blooms occur off Brittany, whereas in late summer and early autumn, only coastal blooms appear, often in the vicinity of river outlets. In spring, the benthic foraminiferal faunas of central (B, C and D) and outer (E) continental shelf stations are characterised by strong dominance in the first area and strong presence in the second area of Nonionella iridea. In fact, station E does not serve as a major depocenter for the remains of phytoplankton blooms. If station E is not considered, the densities of this taxon show a clear gradient from the shelf-break, where the species dominates the assemblages, to the coast, where it attains very low densities. We explain this gradient as a response to the presence, in early spring, of an important phytoplankton bloom, mainly composed of coccolithophorids, over the shelf break. This observation is supported by the maximum particles flux values at stations close to the shelf break (18.5 g m - 2 h - 1 ) and lower values in a station closer to the coast (6.8 g m - 2 h - 1 ). In summer, the faunal density is maximum at station A, relatively close to more varied phytoplancton blooms that occur off Brittany until early June. We suggest that the dominant species, Nonion fabum, Cassidulina carinata and Bolivina ex. gr. dilatata respond to
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Geomorphic characterization of the U.S. Atlantic continental margin
Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.
2013-01-01
The increasing volume of multibeam bathymetry data collected along continental margins is providing new opportunities to study the feedbacks between sedimentary and oceanographic processes and seafloor morphology. Attempts to develop simple guidelines that describe the relationships between form and process often overlook the importance of inherited physiography in slope depositional systems. Here, we use multibeam bathymetry data and seismic reflection profiles spanning the U.S. Atlantic outer continental shelf, slope and rise from Cape Hatteras to New England to quantify the broad-scale, across-margin morphological variation. Morphometric analyses suggest the margin can be divided into four basic categories that roughly align with Quaternary sedimentary provinces. Within each category, Quaternary sedimentary processes exerted heavy modification of submarine canyons, landslide complexes and the broad-scale morphology of the continental rise, but they appear to have preserved much of the pre-Quaternary, across-margin shape of the continental slope. Without detailed constraints on the substrate structure, first-order morphological categorization the U.S. Atlantic margin does not provide a reliable framework for predicting relationships between form and process.
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Atlantic continental margin of the United States
Grow, John A.; Sheridan, Robert E.; Palmer, A.R.
1982-01-01
The objective of this Decade of North American Geology (D-NAG) volume will be to focus on the Mesozoic and Cenozoic evolution of the U.S. Atlantic continental margin, including the onshore coastal plain, related onshore Triassic-Jurassic rift grabens, and the offshore basins and platforms. Following multiple compressional tectonic episodes between Africa and North America during the Paleozoic Era that formed the Appalachian Mountains, the Mesozoic and Cenozoic Eras were dominated by tensional tectonic processes that separated Africa and North America. Extensional rifting during Triassic and Early Jurassic times resulted in numerous tensional grabens both onshore and offshore, which filled with nonmarine continental red beds, lacustrine deposits, and volcanic flows and debris. The final stage of this breakup between Africa and North America occurred beneath the present outer continental shelf and continental slope during Early or Middle Jurassic time when sea-floor spreading began to form new oceanic crust and lithosophere between the two continents as they drifted apart. Postrift subsidence of the marginal basins continued in response to cooling of the lithosphere and sedimentary loading.Geophysical surveys and oil-exploration drilling along the U.S. Atlantic continental margin during the past 5 years are beginning to answer many questions concerning its deep structure and stratigraphy and how it evolved during the rifting and early sea-floor-spreading stages of the separation of this region from Africa. Earlier geophysical studies of the U.S. continental margin used marine refraction and submarine gravity measurements. Single-channel seismic-reflection, marine magnetic, aeromagnetic, and continuous gravity measurements became available during the 1960s.
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Booth, James S.; O'Leary, Dennis W.
1992-01-01
An analysis of 179 mass movements on the North American Atlantic continental slope and upper rise shows that slope failures have occurred throughout the geographic extent of the outer margin. Although the slope failures show no striking affinity for a particular depth as an origination level, there is a broad, primary mode centered at about 900 m. The resulting slides terminate at almost all depths and have a primary mode at 1100 m, but the slope/rise boundary (at 2200 m) also is an important mode. Slope failures have occurred at declivities ranging from 1° to 30° (typically, 4°); the resultant mass movement deposits vary in width from 0.2 to 50 km (typically, 1-2 km) and in length from 0.3 to 380 km (typically, 2–4 km), and they have been reported to be as thick as 650 m. On a numeric basis, mass movements are slightly more prevalent on open slopes than in other physiographic settings, and both translational and rotational failure surfaces are common. The typical mass movement is disintegrative in nature. Open slope slides tend to occur at lower slope angles and are larger than canyon slides. Further, large‐scale slides rather than small‐scale slides tend to originate on gentle slopes (≍ 3-4°). Rotational slope failures appear to have a slightly greater chance of occurring in canyons, but there is no analogous bias associated with translational failures. Similarly, disintegrative slides seem more likely to be associated with rotational slope failures than translational ones and are longer than their nondisintegrative counterparts. The occurrence of such a variety of mass movements at low declivities implies that a regional failure mechanism has prevailed. We suggest that earthquakes or, perhaps in some areas, gas hydrates are the most likely cause of the slope failures.
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NASA Astrophysics Data System (ADS)
Campbell, Ian H.; Davies, D. Rhodri
2017-02-01
The changes that occur at the boundary between the Archean and Proterozoic eons are arguably the most fundamental to affect the evolution of Earth's continental crust. The principal component of Archean continental crust is Granite-Greenstone Terranes (GGTs), with granites always dominant. The greenstones consist of a lower sequence of submarine komatiites and basalts, which erupted onto a pre-existing Tonalite-Trondhjemite-Granodiorite (TTG) crust. These basaltic rocks pass upwards initially into evolved volcanic rocks, such as andesites and dacites and, subsequently, into reworked felsic pyroclastic material and immature sediments. This transition coincides with widespread emplacement of granitoids, which stabilised (cratonised) the continental crust. Proterozoic supra-crustal rocks, on the other hand, are dominated by extensive flat-lying platform sequences of mature sediments, which were deposited on stable cratonic basements, with basaltic rocks appreciably less abundant. The siliceous TTGs cannot be produced by direct melting of the mantle, with most hypotheses for their origin requiring them to be underlain by a complimentary dense amphibole-garnet-pyroxenite root, which we suggest acted as ballast to the early continents. Ubiquitous continental pillow basalts in Archean lower greenstone sequences require the early continental crust to have been sub-marine, whereas the appearance of abundant clastic sediments, at higher stratigraphic levels, shows that it had emerged above sea level by the time of sedimentation. We hypothesise that the production of komatiites and associated basalts, the rise of the continental crust, widespread melting of the continental crust, the onset of sedimentation and subsequent cratonisation form a continuum that is the direct result of removal of the continent's dense amphibole-garnet-pyroxenite roots, triggered at a regional scale by the arrival of a mantle plume at the base of the lithosphere. Our idealised calculations suggest
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Johnson, W.R.; Marshall, C.F.; Anderson, C.M.
1994-08-01
The Federal Government has proposed to offer Outer Continental Shelf (OCS) lands in Cook Inlet for oil and gas leasing. Because oil spills may occur from activities associated with offshore oil production, the Minerals Management Service conducts a formal risk assessment. In evaluating the significance of accidental oil spills, it is important to remember that the occurrence of such spills is fundamentally probabilistic. The effects of oil spills that could occur during oil and gas production must be considered. This report summarizes results of an oil-spill risk analysis conducted for the proposed Cook Inlet OCS Lease Sale 149. The objectivemore » of this analysis was to estimate relative risks associated with oil and gas production for the proposed lease sale. To aid the analysis, conditional risk contour maps of seasonal conditional probabilities of spill contact were generated for each environmental resource or land segment in the study area. This aspect is discussed in this volume of the two volume report.« less
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Hutchinson, Deborah R.; Childs, Jonathan R.; Hammar-Klose, Erika; Dadisman, Shawn; Edgar, N. Terrence; Barth, Ginger A.
2004-01-01
Under the provisions of Articles 76 and 77 of the United Nations Convention on the Law of the Sea (UNCLOS), coastal States have sovereign rights over the continental shelf territory beyond 200-nautical mile (nm) from the baseline from which the territorial sea is measured if certain conditions are met regarding the geologic and physiographic character of the legal continental shelf as defined in those articles. These claims to an extended continental shelf must be supported by relevant bathymetric, geophysical and geological data according to guidelines established by the Commission on the Limits of the Continental Shelf (CLCS, 1999). In anticipation of the United States becoming party to UNCLOS, Congress in 2001 directed the Joint Hydrographic Center/Center for Coastal and Ocean Mapping at the University of New Hampshire to conduct a study to evaluate data relevant to establishing the outer limit of the juridical continental shelf beyond 200 nm and to recommend what additional data might be needed to substantiate such an outer limit (Mayer and others, 2002). The resulting report produced an impressive and sophisticated GIS database of data sources. Because of the short time allowed to complete the report, all seismic reflection data were classified together; the authors therefore recommended that USGS perform additional analysis on seismic and related data holdings. The results of this additional analysis are the substance of this report, including the status of geologic framework, sediment isopach research, and resource potential in the eight regions1 identified by Mayer and others (2002) where analysis of seismic data might be crucial for establishing an outer limit . Seismic reflection and refraction data are essential in determining sediment thickness, one of the criteria used in establishing the outer limits of the juridical continental shelf. Accordingly, the initial task has been to inventory public-domain seismic data sources, primarily those regionally
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An oilspill risk analysis for the Mid-Atlantic (proposed sale 76) outer continental shelf lease area
Samuels, W.B.; Hopkins, Dorothy
1982-01-01
An oilspill risk analysis was conducted for the mid-Atlantic (proposed sale 76) Outer Continental Shelf (OCS) lease area. The analysis considered: the probability of spill occurrences based on historical trends; likely movement of oil slicks based on a climatological model; and locations of environmental resources which could be vulnerable to spilled oil. The times between spill occurrence and contact with resources were estimated to aid analysts in estimating slick characteristics. Critical assumptions made for this particular analysis were (1) that oil exists in the lease area, and (2) that 0.879 billion barrels of oil will be found and produced from tracts sold in sale 76. On the basis of this resource estimate, it was calculated that 3 to 4 oilspills of 1,000 barrels or greater will occur over the 30-year production life of the proposed sale 76 lease tracts. The results also depend upon the routes and methods chosen to transport oil from 0CS platforms to shore. Given the above assumptions, the estimated probability that one or more oilspills of 1,000 barrels or larger will occur and contact land after being at sea less than 30 days is 0.36; for spills 10,000 barrels or larger, the probability is 0.22. These probabilities also reflect the following assumptions: oilspills remain intact for up to 30 days, do not weather, and are not cleaned up. It is noteworthy that over 90 percent of the risk from proposed sale 76 is due to transportation rather than production of oil. In addition, the risks from proposed sale 76 are about 1/10 to 1/15 those of existing tanker transportation of crude oil imports and refined products in the mid-Atlantic area.
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Geology of the head of Lydonia Canyon, U.S. Atlantic outer continental shelf
Twichell, David C.
1983-01-01
The geology of the part of Lydonia Canyon shoreward of the continental shelf edge on the southern side of Georges Bank was mapped using high-resolution seismic-reflection and side-scan sonar techniques and surface sediment grab samples. The head of the canyon incises Pleistocene deltaic deposits and Miocene shallow marine strata. Medium sand containing some coarse sand and gravel covers the shelf except for a belt of very fine sand containing no gravel on either side of the canyon in water depths of 125–140 m. Gravel and boulders, presumably ice-rafted debris, cover the rim of the canyon. The canyon floor and canyon wall gullies are covered by coarse silt of Holocene age which is as much as 25 m thick, and Miocene and Pleistocene strata are exposed on the spurs between gullies. The Holocene sediment is restricted to the canyon shoreward of the shelf edge and has been winnowed from the shelf. Furrows cut in the shelf sands and ripples on the shelf and in the canyon suggest that sediment continues to be moved in this area. Sediment distribution, however, is inconsistent with that expected from the inferred westward sediment transport on the shelf. Either the fine-grained deposits on the shelf to either side of the canyon head are relict or there is a significant component of offshore transport around the canyon head.In the head of Oceanographer Canyon, only 40 km west of Lydonia Canyon, present conditions are strikingly different. The floor of Oceanographer Canyon is covered by sand waves, and their presence indicates active reworking of the bottom sediments by strong currents. The close proximity of the two canyons suggests that the relative importance of processes acting in canyons can be variable over short distances.
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Holland-Bartels, Leslie; Pierce, Brenda
2011-01-01
On March 31, 2010, Secretary of the Interior Ken Salazar announced a national strategy for Outer Continental Shelf (OCS) oil and gas development. In that announcement, the Administration outlined a three-pronged approach (U.S. Department of the Interior, 2010a): Development: "...expand development and production throughout the Gulf of Mexico, including resource-rich areas of the Eastern Gulf of Mexico..." Exploration: "...expand oil and gas exploration in frontier areas, such as the Arctic Ocean and areas in the Atlantic Ocean, to gather the information necessary to develop resources in the right places and the right ways." Conservation: "...calls for the protection of special areas like Bristol Bay in Alaska...national treasure[s] that we must protect for future generations." In a companion announcement (U.S. Department of the Interior, 2010b), within the Administration's "Exploration" component, the Secretary asked the U.S. Geological Survey (USGS) to conduct an initial, independent evaluation of the science needs that would inform the Administration's consideration of the right places and the right ways in which to develop oil and gas resources in the Arctic OCS, particularly focused on the Beaufort and Chukchi Seas (fig. 1).
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-25
... Continental Shelf (OCS) Renewable Energy Program Leasing for Marine Hydrokinetic Technology Testing Offshore... found online at: http://www.boem.gov/Renewable-Energy-Program/State-Activities/Florida.aspx . [[Page.... FOR FURTHER INFORMATION CONTACT: Michelle Morin, BOEM Office of Renewable Energy Programs, 381 Elden...
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30 CFR 285.114 - Paperwork Reduction Act statements-information collection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF General... renewable energy applicants, lessees, ROW grant holders, RUE grant holders, Alternate Use RUE grant holders...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-09-18
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region AGENCY: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Notice of the availability of environmental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-11
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region AGENCY: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Notice of the availability of environmental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-13
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region AGENCY: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Notice of the availability of environmental...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-07
... shore protection and beach and coastal restoration, or for use in construction projects funded in whole... Considering the Use of Outer Continental Shelf Sand, Gravel, and Shell Resources for Coastal Restoration and... will submit to BOEMRE to obtain OCS sand, gravel, and shell resources for use in shore protection and...
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Newborns' Face Recognition: Role of Inner and Outer Facial Features
ERIC Educational Resources Information Center
Turati, Chiara; Macchi Cassia, Viola; Simion, Francesca; Leo, Irene
2006-01-01
Existing data indicate that newborns are able to recognize individual faces, but little is known about what perceptual cues drive this ability. The current study showed that either the inner or outer features of the face can act as sufficient cues for newborns' face recognition (Experiment 1), but the outer part of the face enjoys an advantage…
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Samuels, W.B.
1982-01-01
An oilspill risk analysis was conducted for the South Atlantic (proposed sale 78) Outer Continental Shelf (OCS) lease area. The analysis considered the probability of spill occurrences based on historical trends; likely movement of oil slicks based on a climatological model ; and locations of environmental resources which could be vulnerable to spilled oil. The times between spill occurrence and contact with resources were estimated to aid analysts in estimating slick characteristics. Critical assumptions made for this particular analysis were: (1) that oil exists in the lease area, (2) that either 0.228 billion (mean case) or 1.14 billion (high case) barrels of oil will be found and produced from tracts sold in sale 78, and (3) that all the oil will be found either in the northern or the southern portion of the lease area. On the basis of these resource estimates, it was estimated that 1 to 5 oilspills of 1,000 barrels or greater will occur over the 25 to 30-year production life of the proposed sale 78 tracts. The results also depend upon the routes and methods chosen to transport oil from OCS platforms to shore. Given the above assumptions, the estimated probability that one or more oilspills of 1,000 barrels or larger will occur and contact land after being at sea less than 30 days is less than 15 percent for all cases considered; for spills 10,000 barrels or larger, the probability is less than 10 percent. These probabilities also reflect the following assumptions: oilspills remain intact for up to 30 days, do not weather, and are not cleaned up. It is noteworthy that over 80 percent of the risk of oilspill occurrence from proposed sale 78 is due to transportation rather than production of oil. In addition, the risks of oilspill occurrence from proposed sale 78 (mean resource estimate) are less than one-tenth of the risks of existing tanker transportation of crude oil imports and refined products in the South Atlantic area.
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Observed Oceanic Response over the Upper Continental Slope and Outer Shelf during Hurricane Ivan
2007-09-01
the slope and rise. In addition, they were presumed to be along-shelf and cross-shelf components of group veloci- generated by pulsations of the Loop ...hits. Fortunately, all of exchange of mass, momentum, heat , and water proper- the SEED moorings survived this powerful storm and ties across the shelf...15. SUBJECT TERMS SEED, continental shelf, Doppler, waves 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF 18. NUMBER 19a. NAME OF RESPONSIBLE
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NASA Astrophysics Data System (ADS)
Macrì, Patrizia; Sagnotti, Leonardo; Caricchi, Chiara; Colizza, Ester
2016-04-01
We carried out a paleomagnetic and rock magnetic study of 4 gravity cores sampled in the Ross Sea continental slope of the area to the east of Pennell-Iselin banks. The cores (RS14-C1, C2, C3 and ANTA99-C20) consist of hemipelagic fine-grained (silty-clays) sediments with an IRD component. Rock magnetic and paleomagnetic measurements were carried out at 1-cm spacing on u-channel samples. The data indicate that the cored sediments carry a well-defined characteristic remanent magnetization (ChRM) and have a valuable potential to reconstruct dynamics and amplitude of the geomagnetic field variation at high southern latitudes (ca. 75°S) during the Holocene and the late Pleistocene. The paleomagnetic and rock magnetic data are integrated in a multidisciplinary context which includes previous geological, geophysical, oceanographic and morpho-bathimetric data obtained in the same area in the frame of the PNRA/ROSSLOPE (Past and present sedimentary dynamic in the ROSS Sea: a multidisciplinary approach to study the continental slope) Project. The main aim of the project is to investigate the relation between present and past water mass circulation and to provide a basis for paleoceanographic reconstructions and for the development of a depositional model of the modern processes active along the continental slope.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-02
... environmental documents prepared for OCS mineral proposals by the Gulf of Mexico OCS Region. SUMMARY: BOEM, in... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-06
... Environmental Documents Prepared for OCS Mineral Proposals by the Gulf of Mexico OCS Region. SUMMARY: BOEM, in... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-10
... Environmental Documents Prepared for OCS Mineral Proposals by the Gulf of Mexico OCS Region. SUMMARY: BOEM, in... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management MMAA104000 Environmental Documents Prepared for Oil, Gas, and Mineral Operations by the Gulf of Mexico Outer Continental Shelf (OCS) Region...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-29
... ENVIRONMENTAL PROTECTION AGENCY [FRL-9747-5] Reissuance of the NPDES General Permits for Oil and... Sea and on the Outer Continental Shelf in the Chukchi Sea, AK AGENCY: Environmental Protection Agency... draft general permits were also published in the Anchorage Daily News, the Arctic Sounder, and Petroleum...
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Maps showing late Pleistocene and Holocene evolution of the South Texas continental shelf
Pyle, Carroll A.; Berryhill, Henry L.; Trippet, Anita R.
1979-01-01
Interpretation of acoustical profiles has provided insight into the late Quaternary geologic history of the Continental Shelf off South Texas. (See the geographic index map on sheet 1 for location of the area studied.) The profiles reveal the interplay of tectonism, sedimentation, and cyclic fluctuations of sea level in the building and geologic evolution of the continental terrace. The sequence of sediments studied extends to about 200 meters (m) beneath the sea-floor surface. Four seismic-stratigraphic units underlain by four prominent sound reflectors were identified and mapped. This geologic synthesis, for which the research was funded by the U.S. Bureau of Land Management (BLM), is but one aspect of a coordinated, multidisciplinary environmental study of the South Texas Outer Continental Shelf sponsored by BLM (Berryhill, 1976, 1977). The environmental studies are keyed to the leasing of Federal Outer Continental Shelf (OCS) lands for petroleum exploration and production. Their purpose is to provide the data development of petroleum resources on the OCS, as well as to provide the basis for predicting the impact of oil and gas exploration and production on the marine environment. Of primary concern is the recognition of geologic conditions that might be hazardous to structures placed on the sea floor. Geologic hazards relate directly to the potential for significant movement of the sea floor in the future. Judging sea-floor stability and recognizing geologic features that are potentially hazardous require an understanding of the recent geologic history of the area, which, in turn, entails determining the relative rates and interactions of sedimentation and tectonism through time. In addition to the primary objective, the synthesis provides knowledge about the magnitude and extent of sea-level fluctuations in the western Gulf of Mexico, and it provides a depositional facies model of possible use in appraising the resource potential of the more deeply buried
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Bradford, P A; Urban, C; Mariano, N; Projan, S J; Rahal, J J; Bush, K
1997-01-01
Six Escherichia coli and 12 Klebsiella pneumoniae isolates from a single hospital expressed a common beta-lactamase with a pI of approximately 9.0 and were resistant to cefoxitin and cefotetan (MIC ranges, 64 to > 128 and 16 to > 128 micrograms/ml, respectively). Seventeen of the 18 strains produced multiple beta-lactamases. Most significantly, three K. pneumoniae strains were also resistant to imipenem (MICs, 8 to 32 micrograms/ml). Spectrophotometric beta-lactamase assays with purified enzyme indicated hydrolysis of cephamycins, in addition to cephaloridine and benzylpenicillin. The 4ene encoding the pI 9.0 beta-lactamase (designated ACT-1 for AmpC type) was cloned and sequenced, which revealed an ampC-type beta-lactamase gene that originated from Enterobacter cloacae and that had 86% sequence homology to the P99 beta-lactamase and 94% homology to the partial sequence of MIR-1. Southern blotting revealed that the gene encoding ACT-1 was on a large plasmid in some of the K. pneumoniae strains as well as on the chromosomes of all of the strains, suggesting that the gene is located on an easily mobilized element. Outer membrane protein profiles of the K. pneumoniae strains revealed that the three imipenem-resistant strains were lacking a major outer membrane protein of approximately 42 kDa which was present in the imipenem-susceptible strains. ACT-1 is the first plasmid-mediated AmpC-type beta-lactamase derived from Enterobacter which has been completely sequenced. This work demonstrates that in addition to resistance to cephamycins, imipenem resistance can occur in K. pneumoniae when a high level of the ACT-1 beta-lactamase is produced in combination with the loss of a major outer membrane protein. PMID:9055993
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Tectonic elements of the continental margin of East Antarctica, 38-164ºE
O'Brien, P.E.; Stagg, H.M.J.
2007-01-01
The East Antarctic continental margin from 38–164ºE is divided into western and eastern provinces that developed during the separation of India from Australia–Antarctica (Early Cretaceous) and Australia from Antarctica (Late Cretaceous). In the overlap between these provinces the geology is complex and bears the imprint of both extension/spreading episodes, with an overprinting of volcanism. The main rift-bounding faults appear to approximately coincide with the outer edge of the continental shelf. Inboard of these faults, the sedimentary cover thins above shallowing basement towards the coast where crystalline basement generally crops out. The continental slope and the landward flanks of the ocean basins, are blanketed by up to 9–10 km of mainly post-rift sediments in margin-parallel basins, except in the Bruce Rise area. Beneath this blanket, extensive rift basins are identified off Enderby and Wilkes Land/Terre Adélie; however, their extent and detailed structures are difficult to determine.
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An outer arm dynein light chain acts in a conformational switch for flagellar motility
Patel-King, Ramila S.
2009-01-01
A system distinct from the central pair–radial spoke complex was proposed to control outer arm dynein function in response to alterations in the mechanical state of the flagellum. In this study, we examine the role of a Chlamydomonas reinhardtii outer arm dynein light chain that associates with the motor domain of the γ heavy chain (HC). We demonstrate that expression of mutant forms of LC1 yield dominant-negative effects on swimming velocity, as the flagella continually beat out of phase and stall near or at the power/recovery stroke switchpoint. Furthermore, we observed that LC1 interacts directly with tubulin in a nucleotide-independent manner and tethers this motor unit to the A-tubule of the outer doublet microtubules within the axoneme. Therefore, this dynein HC is attached to the same microtubule by two sites: via both the N-terminal region and the motor domain. We propose that this γ HC–LC1–microtubule ternary complex functions as a conformational switch to control outer arm activity. PMID:19620633
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Geological studies of the COST GE-1 well, United States South Atlantic outer continental shelf area
Scholle, Peter A.
1979-01-01
The COST No. GE-1 well is the first deep stratigraphic test to be drilled in the southern part of the U.S. Atlantic Outer Continental Shelf (AOCS) area. The well was drilled within the Southeast Georgia Embayment to a total depth of 13,254 ft (4,040 m). It penetrated a section composed largely of chalky limestones to a depth of about 3,300 ft (1,000 m) below the drill platform. Limestones and calcareous shales with some dolomite predominate between 3,300 and 7,200 ft (1,000 and 2,200 m), whereas interbedded sandstones and shales are dominant from 7,200 to 11,000 ft (2,200 to 3,350 m). From 11,000 ft (3,350 m) to the bottom, the section consists of highly indurated to weakly metamorphosed pelitic sedimentary rocks and meta-igneous flows or intrusives. Biostratigraphic examination has shown that the section down to approximately 3,500 ft (1,060 m) is Tertiary, the interval from 3,500 to 5,900 ft (1,060 to 1,800 m) is Upper Cretaceous, and the section from 5,900 to 11,000 ft (1,800 to 3,350 m) is apparently Lower Cretaceous. The indurated to weakly metamorphosed section below 11,000 ft (3,350 m) is barren of fauna or flora but is presumed to be Paleozoic based on radiometric age determinations. Rocks deposited at upper-slope water depths were encountered in the Upper Cretaceous, Oligocene, and Miocene parts of the section. All other units were deposited in outer-shelf to terrestrial environments. Examination of cores, well cuttings, and electric logs shows that potential hydrocarbon-reservoir units are present within the chalks in the uppermost part of the section as well as in sandstone beds to a depth of at least 10,000 ft (3,000 m). Sandstones below that depth, and the metamorphic section between 11,000 and 13.250 ft (3,350 and 4,040 m) have extremely low permeabilities and are unlikely to contain potential reservoir rock. Studies of organic geochemistry, vitrinite reflectance, and color alteration of visible organic matter indicate that the chalk section down to
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Oceanic-type accretion may begin before complete continental break-up
NASA Astrophysics Data System (ADS)
Geoffroy, L.; Zalan, P. V.; Viana, A. R.
2011-12-01
Oceanic accretion is thought to be the process of oceanic crust (and lithosphere) edification through adiabatic melting of shallow convecting mantle at oceanic spreading ridges. It is usually considered as a post-breakup diagnostic process following continents rupturing. However, this is not always correct. The structure of volcanic passive margins (representing more than 50% of passive continental margins) outlines that the continental lithosphere is progressively changed into oceanic-type lithosphere during the stage of continental extension. This is clear at least, at crustal level. The continental crust is 'changed' from the earliest stages of extension into a typical -however thicker- oceanic crust with the typical oceanic magmatic layers (from top to bottom: lava flows/tuffs, sheeted dyke complexes, dominantly (sill-like) mafic intrusions in the lower crust). The Q-rich continental crust is highly extended and increases in volume (due to the magma) during the extensional process. At the continent-ocean transition there is, finally, no seismic difference between this highly transformed continental crust and the oceanic crust. Using a large range of data (including deep seismic reflection profiles), we discuss the mantle mechanisms that governs the process of mantle-assisted continental extension. We outline the large similarity between those mantle processes and those acting at purely-oceanic spreading axis and discuss the effects of the inherited continental lithosphere in the pattern of new mafic crust edification.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-06
... order to drill exploratory wells at various prospects located in the Chukchi and Beaufort Sea Outer... reduce the threat of allisions, oil spills, and releases of natural gas, and thereby protect the safety... FRONTIER DISCOVERER while anchored on location in order to drill exploratory wells in several prospects...
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NASA Astrophysics Data System (ADS)
Hughes, M.; Harris, S.; Luciano, K. E.; Alexander, C. R., Jr.
2017-12-01
Following the impact of Hurricane Sandy on the U.S. Atlantic coast in 2012 the Bureau of Ocean Energy Management (BOEM), in cooperation with state partners, instituted several regional offshore resource studies for the near outer continental shelf (OCS) on the US East Coast. This study focuses on a portion of this region, offshore of South Carolina and Georgia, with a primary goal of identifying beach renourishment sands and wind-tower placement locations, and creating a conceptual model of the evolution of the shelf in these areas. New and previously collected data are being used to identify sediment distribution patterns, paleolandscapes, sand resources for beach renourishment projects, and feasible locations for offshore wind installations. New chirp subbottom profiler data ( 1000 km), sidescan sonar data ( 7900km2), magnetometer data ( 1700 km), and multibeam bathymetry data ( 430km2) have been processed and interpreted at the University of Charleston using SonarWiz7, QPS-Qimera and QPS-Fledermaus software suites. Areas of focus for the Atlantic Sand Assessment Program (ASAP) data collection along the SC and GA coast are located within the 3 to 8 nautical mile (nm) OCS offshore of (North to South) Little River, Cape Romain, Folly Beach, Hilton Head, Wassaw, Ossabaw, Jekyll, St. Simons, and Cumberland islands. Ravinement, pre-Holocene, and other seismic surfaces, along with internal geometries, were mapped in these distinctly different tidal and wave regimes. Holocene sediment thickness gradually increases to the south with several sediment wedges in excess of 40 meters thickness. Where mapped, subsurface paleochannels/valleys were identified and analyzed for their orientation and complexity, as well as their size and distribution. These paleochannels are more numerous and increasingly complex in the southern survey areas. The channels are possibly related to transgressive channeling, Pleistocene low-stand river channeling, and braided stream formation during
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40 CFR 307.20 - Who may present claims.
Code of Federal Regulations, 2010 CFR
2010-07-01
... conducted under the Outer Continental Shelf Lands Act, as amended (43 U.S.C. 1331 et seq.), or the Deepwater Port Act of 1974, as amended (33 U.S.C. 1501 et seq.); and (5) Recovery is authorized by a treaty or an...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-18
... issued a commercial wind energy lease to Bluewater Wind Delaware LLC (Bluewater) for an area of the Outer... availability of the executed lease. The total acreage of the lease area is approximately 96,430 acres. The lease area comprises 11 full OCS blocks and 95 sub-blocks and lies within Official Protraction Diagram...
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Measurements of storm-generated bottom stresses on the continental shelf.
Cacchione, D.A.; Drake, D.E.
1982-01-01
Large values of bottom friction velocity, u., and roughness length, zo, determined from burst-averaged speed data taken on the continental shelf in outer Norton Sound, Alaska, with the GEOPROBE tripod during a storm are correlated with extremely large values of near-bottom concentration of total suspended particulate matter (TSM). The values obtained from the 'law of the wall' velocity-depth relationship are diminished substantially throughout the storm period when the turbulence-reducing effects of the vertical cncentration gradient of TSM are considered. The values are compared to those obtained from other workers. -from Authors
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Eyles, N.; Daniels, J.; Osterman, L.E.; Januszczak, N.
2001-01-01
Ocean Drilling Program Leg 178 (February-April 1998) drilled two sites (Sites 1097 and 1103) on the outer Antarctic Peninsula Pacific continental shelf. Recovered strata are no older than late Miocene or early Pliocene (<4.6 Ma). Recovery at shallow depths in loosely consolidated and iceberg-turbated bouldery sediment was poor but improved with increasing depth and consolidation to allow description of lithofacies and biofacies and interpretation of depositional environment. Site 1097 lies on the outer shelf within Marguerite Trough which is a major outlet for ice expanding seaward from the Antarctic Peninsula and reached a maximum depth drilled of 436.6 m below the sea floor (mbsf). Seismic stratigraphic data show flat-lying upper strata resting on strata that dip gently seaward. Uppermost strata, to a depth of 150 mbsf, were poorly recovered, but data suggest they consist of diamictites containing reworked and abraded marine microfauna. This interval is interpreted as having been deposited largely as till produced by subglacial cannibalization of marine sediments (deformation till) recording ice sheet expansion across the shelf. Underlying gently dipping strata show massive, stratified and graded diamictite facies with common bioturbation and slump stuctures that are interbedded with laminated and massive mudstones with dropstones. The succession contains a well-preserved in situ marine microfauna typical of open marine and proglacial marine environments. The lower gently dipping succession at Site 1097 is interpreted as a complex of sediment gravity flows formed of poorly sorted glacial debris. Site 1103 was drilled in that part of the continental margin that shows uppermost flat-lying continental shelf topsets overlying steeper dipping slope foresets seaward of a structural mid-shelf high. Drilling reached a depth of 363 mbsf with good recovery in steeply dipping continental slope foreset strata. Foreset strata are dominated by massive and chaotically
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Davey, F.J.; Jacobs, S.S.
2007-01-01
Multibeam sonar bathymetry documents a lack of significant channels crossing outer continental shelf and slope of the western Ross Sea. This indicates that movement of bottom water across the shelf break into the deep ocean in this area is mainly by laminar or sheet flow. Subtle, ~20 m deep and up to 1000 m wide channels extend down the continental slope, into tributary drainage patterns on the upper rise, and then major erosional submarine canyons. These down-slope channels may have been formed by episodic pulses of rapid down slope water flow, some recorded on bottom current meters, or by sub-ice melt water erosion from an icesheet grounded at the margin. Narrow, mostly linear furrows on the continental shelf thought to be caused by iceberg scouring are randomly oriented, have widths generally less than 400 m and depths less than 30m, and extend to water depths in excess of 600 m.
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30 CFR 585.114 - Paperwork Reduction Act statements-information collection.
Code of Federal Regulations, 2013 CFR
2013-07-01
...) Subpart J—RUEs for Energy and Marine-Related Activities Using Existing OCS Facilities To enable BOEM to... collection. 585.114 Section 585.114 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF...
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30 CFR 585.114 - Paperwork Reduction Act statements-information collection.
Code of Federal Regulations, 2012 CFR
2012-07-01
...) Subpart J—RUEs for Energy and Marine-Related Activities Using Existing OCS Facilities To enable BOEM to... collection. 585.114 Section 585.114 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF...
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30 CFR 585.114 - Paperwork Reduction Act statements-information collection.
Code of Federal Regulations, 2014 CFR
2014-07-01
...) Subpart J—RUEs for Energy and Marine-Related Activities Using Existing OCS Facilities To enable BOEM to... collection. 585.114 Section 585.114 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-30
... Continental Shelf (OCS), Western Planning Area (WPA) and Central Planning Area (CPA), Oil and Gas Lease Sales... prepared a Draft EIS on oil and gas lease sales tentatively scheduled in 2012-2017 in the WPA and CPA... scheduled for the WPA and five annual areawide lease sales are scheduled for the CPA. The proposed WPA lease...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-13
.... Abstract: The Outer Continental Shelf (OCS) Lands Act, as amended (43 U.S.C. 1331 et seq. and 43 U.S.C... Independent Offices Appropriations Act (31 U.S.C. 9701), the Omnibus Appropriations Bill (Pub. L. 104-133, 110... respondents considered proprietary under the Freedom of Information Act (5 U.S.C. 552) and its implementing...
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Antarctic glacial history from numerical models and continental margin sediments
Barker, P.F.; Barrett, P.J.; Cooper, A. K.; Huybrechts, P.
1999-01-01
The climate record of glacially transported sediments in prograded wedges around the Antarctic outer continental shelf, and their derivatives in continental rise drifts, may be combined to produce an Antarctic ice sheet history, using numerical models of ice sheet response to temperature and sea-level change. Examination of published models suggests several preliminary conclusions about ice sheet history. The ice sheet's present high sensitivity to sea-level change at short (orbital) periods was developed gradually as its size increased, replacing a declining sensitivity to temperature. Models suggest that the ice sheet grew abruptly to 40% (or possibly more) of its present size at the Eocene-Oligocene boundary, mainly as a result of its own temperature sensitivity. A large but more gradual middle Miocene change was externally driven, probably by development of the Antarctic Circumpolar Current (ACC) and Polar Front, provided that a few million years' delay can be explained. The Oligocene ice sheet varied considerably in size and areal extent, but the late Miocene ice sheet was more stable, though significantly warmer than today's. This difference probably relates to the confining effect of the Antarctic continental margin. Present-day numerical models of ice sheet development are sufficient to guide current sampling plans, but sea-ice formation, polar wander, basal topography and ice streaming can be identified as factors meriting additional modelling effort in the future.
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30 CFR 291.110 - Who may MMS require to produce information?
Code of Federal Regulations, 2010 CFR
2010-07-01
... OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT... make a decision on whether open access or nondiscriminatory access was denied. (b) If you are a party...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 281.2 Authority. The Act authorizes the Secretary to grant leases for any mineral other than oil, gas...
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28 CFR 0.40 - General functions.
Code of Federal Regulations, 2010 CFR
2010-07-01
...)), furnishing advice regarding the proposed disposition of surplus Government property required by the Federal... deepwater port licenses under the Deepwater Port Act of 1974 (33 U.S.C. 1506), furnishing advice and reports...)), furnishing advice on oil and gas leasing under the Outer Continental Shelf Lands Act Amendments of 1978 (43 U...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-29
... Beaufort Seas, Alaska (See Table 1). Table 1--Prospect Locations Prospect Well Area Block Lease No... requirements. The planned exploration drilling in the identified lease blocks will be conducted with the NOBLE... outer boundaries of the safety zone to include the anchor chain extending from the OCS facilities; one...
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Samuels, W.B.; Hopkins, Dorothy; Lanfear, K.J.
1981-01-01
An oilspill risk analysis was conducted to determine the relative environmental hazards of developing oil in different regions of the Beaufort Sea, Alaska, (Proposed Sale 71) Outer Continental Shelf (OCS) lease area. The probability of spill occurrences, likely movement of oil slicks, and locations of resources vulnerable to spilled oil were analyzed. The model predicted movement of the center of spill mass and estimated the times between spill occurrence and contact with various resources, to allow a qualitative assessment of oil characteristics at the time of contact; no direct computation was made of weathering and cleanup. The model also assumed that any oil spilled under ice would remain in place, unchanged, until spring breakup. Ice movements, or travel of oil under ice, if occurring, would affect the results in a manner not directly predictable at this time. The combined results of spill occurrence and spill movement predictions yielded estimates of the overall risks associated with development of the proposed lease area. Assuming that oil exists in the lease area (a 99.3-percent chance) it is estimated that the leasing of the tracts proposed for OCS Sale 71 will result in an expected 9.2 oilspills (of 1,000 barrels or larger) over the lease lifetime of 25 years. This estimate is based on historic oilspill accident data for platforms and pipelines on the U.S. OCS (Gulf of Mexico and California). The estimated probability that land will be contacted by one or more oilspills (of 1,000 barrels or larger) that have been at sea less than 30 days (not counting any time trapped under ice) is greater than 99.5 percent. If oilspill accident data for Prudhoe Bay, Alaska, is used in the analysis, it is estimated that 5.6 oilspills (1,000 barrels or larger) will occur over the lease lifetime. The estimated probability that one or more oilspills (1,000 barrels or larger)will occur and contact land is99 percent. The results of a recent experimental cleanup operation for
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NASA Astrophysics Data System (ADS)
Li, Fucheng; Sun, Zhen; Zhang, Jiangyang
2018-06-01
Although the presence of low-viscosity middle crustal layer in the continental crust has been detected by both geophysical and geochemical studies, its influence on the deformation behavior of continental crust during subduction remains poorly investigated. To illustrate the crustal deformation associated with layered crust during continental subduction, we conducted a suite of 2-D thermo-mechanical numerical studies with visco-brittle/plastic rheology based on finite-differences and marker-in-cell techniques. In the experiments, we established a three-layer crustal model with a quartz-rich middle crustal layer embedded between the upper and lower continental crust. Results show that the middle crustal layer determines the amount of the accreted upper crust, maximum subduction depth, and exhumation path of the subducted upper crust. By varying the initial effective viscosity and thickness of the middle crustal layer, the further effects can be summarized as: (1) a rheologically weaker and/or thicker middle crustal layer results in a larger percentage of the upper crust detaching from the underlying slab and accreting at the trench zone, thereby leading to more serious crustal deformation. The rest of the upper crust only subducts into the depths of high pressure (HP) conditions, causing the absence of ultra-high pressure (UHP) metamorphic rocks; (2) a rheologically stronger and/or thinner middle crustal layer favors the stable subduction of the continental crust, dragging the upper crust to a maximum depth of ∼100 km and forming UHP rocks; (3) the middle crustal layer flows in a ductile way and acts as an exhumation channel for the HP-UHP rocks in both situations. In addition, the higher convergence velocity decreases the amount of subducted upper crust. A detailed comparison of our modeling results with the Himalayan collisional belt are conducted. Our work suggests that the presence of low-viscosity middle crustal layer may be another possible mechanism for
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Fischer, Wolfgang; Buhrdorf, Renate; Gerland, Elke; Haas, Rainer
2001-01-01
Helicobacter pylori produces a number of proteins associated with the outer membrane, including adhesins and the vacuolating cytotoxin. These proteins are supposed to integrate into the outer membrane by β-barrel structures, characteristic of the family of autotransporter proteins. By using the SOMPES (shuttle vector-based outer membrane protein expression) system for outer membrane protein production, we were able to functionally express in H. pylori the cholera toxin B subunit genetically fused to the C-terminal VacA domain. We demonstrate that the fusion protein is translocated to the H. pylori outer membrane and that the CtxB domain is exposed on the H. pylori surface. Thus, we provide the first experimental evidence that the C-terminal β-domain of VacA can transport a foreign passenger protein to the H. pylori surface and hence acts as a functional autotransporter. PMID:11598049
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Lateral release of proteins from the TOM complex into the outer membrane of mitochondria.
Harner, Max; Neupert, Walter; Deponte, Marcel
2011-07-15
The TOM complex of the outer membrane of mitochondria is the entry gate for the vast majority of precursor proteins that are imported into the mitochondria. It is made up by receptors and a protein conducting channel. Although precursor proteins of all subcompartments of mitochondria use the TOM complex, it is not known whether its channel can only mediate passage across the outer membrane or also lateral release into the outer membrane. To study this, we have generated fusion proteins of GFP and Tim23 which are inserted into the inner membrane and, at the same time, are spanning either the TOM complex or are integrated into the outer membrane. Our results demonstrate that the TOM complex, depending on sequence determinants in the precursors, can act both as a protein conducting pore and as an insertase mediating lateral release into the outer membrane.
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Mapping Mesophotic Reefs Along the Brazilian Continental Margin
NASA Astrophysics Data System (ADS)
Bastos, A.; Moura, R.; Amado Filho, G.; Ferreira, L.; Boni, G.; Vedoato, F.; D'Agostini, D.; Lavagnino, A. C.; Leite, M. D.; Quaresma, V.
2017-12-01
Submerged or drowned reefs constitute an important geological record of sea level variations, forming the substrate for the colonization of modern benthic mesophotic communities. Although mapping mesophotic reefs has increased in the last years, their spatial distribution is poorly known and the worldwide occurrence of this reef habitat maybe underestimated. The importance in recognizing the distribution of mesophotic reefs is that they can act as a refuge for corals during unsuitable environmental conditions and a repository for shallow water corals. Here we present the result of several acoustic surveys that mapped and discovered new mesophotic reefs along the Eastern and Equatorial Brazilian Continental Margin. Seabed mapping was carried out using multibeam and side scan sonars. Ground truthing was obtained using drop camera or scuba diving. Mesophotic reefs were mapped in water depths varying from 30 to 100m and under distinct oceanographic conditions, especially in terms of river load input and shelf width. Reefs showed distinct morphologies, from low relief banks and paleovalleys to shelf edge ridges. Extensive occurrence of low relief banks were mapped along the most important coralline complex province in the South Atlantic, the Abrolhos Shelf. These 30 to 40m deep banks, have no more than 3 meters in height and may represent fringing reefs formed during sea level stabilization. Paleovalleys mapped along the eastern margin showed the occurrence of coralgal ledges along the channel margins. Paleovalleys are usually deeper than 45m and are associated with outer shelf rhodolith beds. Shelf edge ridges (80 to 120m deep) were mapped along both margins and are related to red algal encrusting irregular surfaces that have more than 3m in height, forming a rigid substrate for coral growth. Along the Equatorial Margin, off the Amazon mouth, shelf edge patch reefs and rhodolith beds forming encrusting surfaces and shelf edge ridges were mapped in water depths greater
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77 FR 72744 - Outer Continental Shelf Air Regulations Consistency Update for California
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-06
... County Air Pollution Control District (``Santa Barbara County APCD'' or ``District'') is the designated... 52630), EPA proposed to incorporate various Santa Barbara County APCD air pollution control requirements... the Act requires that EPA establish requirements to control air pollution from OCS sources located...
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A Boundary Delineation System for the Bureau of Ocean Energy Management
NASA Astrophysics Data System (ADS)
Vandegraft, Douglas L.
2018-05-01
Federal government mapping of the offshore areas of the United States in support of the development of oil and gas resources began in 1954. The first mapping system utilized a network of rectangular blocks defined by State Plane coordinates which was later revised to utilize the Universal Transverse Mercator grid. Creation of offshore boundaries directed by the Submerged Lands Act and Outer Continental Shelf Lands Act were mathematically determined using early computer programs that performed the required computations, but required many steps. The Bureau of Ocean Energy Management has revised these antiquated methods using GIS technology which provide the required accuracy and produce the mapping products needed for leasing of energy resources, including renewable energy projects, on the outer continental shelf. (Note: this is an updated version of a paper of the same title written and published in 2015).
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Code of Federal Regulations, 2010 CFR
2010-07-01
... OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 281.2 Authority. The Act authorizes the Secretary to grant leases for any mineral other than oil, gas, and sulphur in any area of the OCS to the...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information General Information § 550.200 Definitions... of Safety and Environmental Enforcement. CID means Conservation Information Document. CZMA means Coastal Zone Management Act. DOCD means Development Operations Coordination Document. DPP means...
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30 CFR 250.915 - What are the CVA's primary responsibilities?
Code of Federal Regulations, 2010 CFR
2010-07-01
... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures... or organizations acting as CVAs must not function in any capacity that would create a conflict of... design, fabrication and installation of the platform. ...
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NRC Continental Margins Workshop
NASA Astrophysics Data System (ADS)
Katsouros, Mary Hope
The Ocean Studies Board of the National Research Council is organizing a workshop, “Continental Margins: Evolution of Passive Continental Margins and Active Marginal Processes,” to stimulate discussion and longterm planning in the scientific community about the evolution of all types of continental margins. We want to coordinate academic, industry, and government agency efforts in this field, and to enhance communication between sea-based and land-based research programs.The continental margins constitute the only available record of the long-term dynamic interaction of oceanic and continental lithosphere. Of great interest are the unique structures and thick sedimentary sequences associated with this interaction. A major focus of the workshop will be to define strategies for exploring and understanding the continental margins in three dimensions and through geologic time. The workshop will be divided into 7 working groups, each concentrating on a major issue in continental margins research. A background document is being prepared summarizing recent research in specific continental margin fields and identifying key scientific and technical issues.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-02
... Continental Shelf (OCS) Oil and Gas Leasing Program for 2007-2012 AGENCY: Minerals Management Service... (MMS) requests comments on the Preliminary Revised 5-Year OCS Oil and Gas Leasing Program for 2007... Elden Street, MS-4010; Herndon, Virginia 20170-4817. Please reference ``Remand of the 2007-2012 OCS Oil...
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-04
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Gulf of Mexico (GOM), Outer...: Bureau of Ocean Energy Management (BOEM), Interior. ACTION: Notice of availability (NOA) of the draft... experts surveyed scientific journals and available scientific data, gathered information, and interviewed...
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76 FR 15898 - Outer Continental Shelf Air Regulations; Consistency Update for California
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-22
... for OCS sources for which the Santa Barbara County Air Pollution Control District (``Santa Barbara...\\ which established requirements to control air pollution from OCS sources in order to attain and maintain... Mexico west of 87.5 degrees longitude. Section 328 of the Act requires that for such sources located...
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76 FR 1389 - Outer Continental Shelf Air Regulations Consistency Update for California
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-10
... for OCS sources for which the Santa Barbara County Air Pollution Control District (``Santa Barbara...\\ which established requirements to control air pollution from OCS sources in order to attain and maintain... Mexico west of 87.5 degrees longitude. Section 328 of the Act requires that for such sources located...
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75 FR 3392 - Outer Continental Shelf Air Regulations Consistency Update for Alaska
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-21
... 40 CFR part 55,\\1\\ which established requirements to control air pollution from OCS sources in order... air pollution from OCS sources located within 25 miles of States' seaward boundaries that are the same... the Act requires that EPA establish requirements to control air pollution from OCS sources located...
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75 FR 51950 - Outer Continental Shelf Air Regulations Consistency Update for Massachusetts
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-24
... 4, 1992, EPA promulgated 40 CFR part 55,\\1\\ which established requirements to control air pollution...) of the Act requires that EPA establish requirements to control air pollution from OCS sources located...: Air Pollution Control, and 310 CMR 8:00: The Prevention and/or Abatement of Air Pollution Episode and...
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Coupling between the continental carbon and water cycles
NASA Astrophysics Data System (ADS)
Gentine, P.; Lemordant, L. A.; Green, J. K.
2017-12-01
The continental carbon adn water cycles are fundamentally coupled through leaf gas exchange at the stomata level. IN this presnetation we will emphasize the importance of this coupling for the future of the water cycle (runoff, evaporation, soil moisture) and in turn the implications for the carbon cycle and the capacity of continents to act as a carbon dioxyde sink in the future. Opprtunites from coupled carbon-water monitoring platforms will be then emphasized.
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NASA Astrophysics Data System (ADS)
Anderson, J. B.; Simkins, L. M.; Prothro, L. O.
2016-12-01
On formerly glaciated Antarctic continental shelves, the crystalline inner shelf is commonly dissected by linked subglacial lake and channel systems; however, signatures of meltwater are rare within subglacial and glacial-marine deposits on the middle to outer continental shelf. Recent observations of ice-marginal landforms incised by meltwater channels in the western Ross Sea indicate pulses of meltwater outbursts at marine-based grounding lines during deglaciation of the continental shelf. Here we present sedimentological evidence of meltwater outbursts and associated plumes from new and legacy cores collected on the continental shelf and slope within the Ross Sea, Amundsen Sea, and Marguerite Bay. Discrete fine-grained silt deposits are found overlying till and within proximal grounding line deposits and open-marine diatomaceous sediments. The deposits are massive to laminated, contain little to no coarser material, moderately sorted and dominated by a 10 μm grain-size mode. Grain-size measurements show no indication of winnowing; therefore, we interpret these deposits as meltwater deposits, transported by subglacial meltwater drainage systems to the grounding line and dispersed further seaward by meltwater plumes. The similarity of the deposits down-core and between shelf and slope sites within the Ross Sea, Amundsen Sea, and Marguerite Bay indicate that sorting and/or production of the fine silts occurs due to subglacial hydrodynamic processes. These distinctive meltwater deposits within the stratigraphic record provide an accessible proxy for identifying meltwater discharge from the Antarctic Ice Sheet and potentially be used to correlate cores on and off the continental shelf. Dating events on the continental shelf is notoriously difficult; therefore, deeper ocean records offer an easier means of bracketing the timing of meltwater discharge events. Longer records of ice dynamics from off the continental shelf are commonly used to reconstruct IRD records
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77 FR 52630 - Outer Continental Shelf Air Regulations Consistency Update for California
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-30
... for OCS sources for which the Santa Barbara County Air Pollution Control District (``Santa Barbara... promulgated 40 CFR part 55,\\1\\ which established requirements to control air pollution from OCS sources in... those located in the Gulf of Mexico west of 87.5 degrees longitude. Section 328 of the Act requires that...
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30 CFR 252.6 - Freedom of Information Act requirements.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Freedom of Information Act requirements. 252.6... CONTINENTAL SHELF (OCS) OIL AND GAS INFORMATION PROGRAM § 252.6 Freedom of Information Act requirements. (a... to the limitations of the Freedom of Information Act (5 U.S.C. 552), the regulations contained in 43...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-15
... Continental Shelf, Alaska OCS Region, Chukchi Sea Planning Area, Oil and Gas Lease Sale 193 AGENCY: Bureau of... development; (2) determine whether missing information identified by BOEMRE in the 193 FEIS was essential or... in the FEIS for Chukchi Sea Lease Sale 193 was essential or relevant under 40 CFR 1502.22; and (3...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-27
... Continental Shelf, Alaska OCS Region, Chukchi Sea Planning Area, Oil and Gas Lease Sale 193 AGENCY: Bureau of...: BOEMRE announces the availability of a Revised Draft SEIS, OCS Oil and Gas Lease Sale 193, Chukchi Sea.... The Revised Draft SEIS augments the analysis of the Final EIS, Oil and Gas Lease Sale 193, Chukchi Sea...
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Data Management Supporting the U.S. Extended Continental Shelf Project
NASA Astrophysics Data System (ADS)
Lim, E.; Henderson, J. F.; Warnken, R.; McLean, S. J.; Varner, J. D.; Mcquinn, E.; LaRocque, J.
2013-12-01
The U.S. Extended Continental Shelf (ECS) Project is a multi-agency collaboration led by the U.S. Department of State whose mission is to establish the full extent of the continental shelf of the United States consistent with international law. Since 2003, the U.S. has been actively collecting bathymetric, seismic, and other geophysical data and geologic samples required to delineate its outer limits in accordance with Article 76 of the UN Convention on the Law of the Sea. In 2007, the U.S. ECS Task Force designated the National Geophysical Data Center (NGDC) to serve as both the Data Management lead and the Data Archive and Integration Center for the U.S. ECS Project. NGDC, one of three National Oceanic and Atmospheric Administration (NOAA) Offices active in the ECS Project, has the primary responsibility to provide a common infrastructure and a means to integrate the data supporting, and products resulting from ECS analysis. One of the key challenges in the ECS project is the requirement to track the provenance of data and derived products. Final ECS analyses may result in hundreds of points that define a new maritime boundary that is our extended continental shelf. These points will be developed in a rigorous process of analysis encompassing potentially thousands of raw datasets and derived products. NGDC has spent the past two years planning, designing, and partially implementing the Information Management System (IMS), a highly functional, interactive software system that serves as the master database for the ECS Project. The purpose of this geospatial database is to archive, access, and manage the primary data, derivative data and products, associated metadata, information and decisions that will form the U.S. submission. The IMS enables team members to manage ECS data in a consistent way while maintaining institutional memory and the rationale behind decisions. The IMS contains two major components: First, a catalog that acts as the interface to the IMS by
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Doyle, Larry J.
1983-01-01
An 1800-joule sparker survey of the West Florida continental slope between about 26?N and 29?15?N showed a top bed of Pleistocene age forming an irregular drape over a surface that is probably Pliocene. The contact between the top two layers is unconformable in the south and, in some places, shows karst collapse and solution features. Karst topography grades into a more hummocky erosional surface to the north, which in turn smoothes out; the contact become conformable still further north. A period of folding, which is widespread over the outer portion of the study area and which may be related to large scale mass wasting, occurred at about the same time represented by the unconformity. Significant subsidence has occurred as late as Pleistocene. The surface layer thins to a minimum (0 in the south) at about 525-meters water depth and then thickens again dramatically to the west, downslope. This thinning is interpreted to be due to the Loop Current, which flows from north to south in the area and which acts to block deposition and scour the bottom. Despite the fact that the margin is dominated by carbonates, usually associated with low sedimentation rates, there is widespread evidence of mass wasting affecting ancient and surficial deposits on the outer part of the upper slope. Three potential groups of geohazards identified are: 1. Potential bottom failure in areas where a thin top layer overlies the karst surface. 2. Potential for sliding and slumping. 3. Scour due to currents which could also affect drilling and engineering activities.
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-24
... the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), at Mississippi Canyon 252, in the Outer... the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), which is currently set to expire on... response to the sinking of the DEEPWATER HORIZON, a Mobile Offshore Drilling Unit (MODU), near Mississippi...
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The Project for the Extension of the Continental Shelf - the Portuguese experience
NASA Astrophysics Data System (ADS)
Madureira, Pedro; Ribeiro, Luísa P.; Roque, Cristina; Henriques, Guida; Brandão, Filipe; Dias, Frederico; Simões, Maria; Neves, Mariana; Conceição, Patricia; Botelho Leal, Isabel; Emepc, Equipa
2017-04-01
Under the United Nations Convention on the Law of the Sea (UNCLOS), the continental shelf is a juridical term used to define a submarine area that extends throughout the natural prolongation of a land territory, where the coastal State exercises sovereign rights for the purpose of exploring it and exploiting its natural resources. Article 76 provides a methodology for determining the outer edge of the continental margin and to delineate the outer limits of the continental shelf. The task of preparing the Portuguese submission to the Commission on the Limits of the Continental Shelf was committed to the Task Group for the Extension of the Continental Shelf (EMEPC), which formally began its activity in January 2005. At that time, the existing national capacity to conduct such a task was very limited in its hydrographic, geological and geophysical components. A great effort has been made by Portugal to overcome these weaknesses and develop a strategy to submit the proposal for the extension of the continental shelf beyond 200 nautical miles on 11th May of 2009. The execution of the project involved the implementation of several complementary strategies including: 1) intensive bathymetric, geophysical and, locally, geological data acquisition; 2) acquisition/development of new stand-alone and ship mounted equipment; 3) interactions with universities and research institutes, with emphasis in R&D initiatives; 4) creation of critical mass in deep-sea research by promoting advanced studies on: International Law, Geophysics, Geology, Hydrography, Biology, amongst others; 5) promotion of the sea as a major national goal, coupled with an outreach strategy. Until now, more than 1050 days of surveying have resulted in a large scale seafloor mapping using two EM120 and one EM710 multibeam echosounders from Kongsberg mounted on two hydrographic vessels. The surveys follow IHO Order 2 Standard (SP44, 5th Edition) and cover an area over 2.6 million km2. A multichannel reflection
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Competition and performance in OCS oil and gas lease sales and lease development, 1954-1969
Mead, Walter J.; Sorensen, Philip Edward
1980-01-01
The oil and gas resources of the Outer Continental Shelf represent one of America's largest publicly-owned assets. Through 1978, OCS oil and gas leases had yielded \\$40.5 billion in gross production value and produced over \\$28.3 billion in direct revenue to the federal government.Policies and procedures for managing the oil and gas resources of the OCS were established by Congress in the Outer Continental Shelf Lands Act of 1953. The Department of Interior was given the central responsibility for carrying out this management role in the 1953 Act; this responsibility has been re-established in the 1978 Amendments to the OCS Lands Act. As stated in the 1978 legislation, the goals of OCS management are to:...preserve, protect and develop oil and natural gas resources in a manner which is consistent with the need (A) to make such resources available to meet the Nation's energy needs as rapidly as possible... (C) to insure the public a fair and equitable return on the resources of the Outer Continental Shelf, and (D) to preserve and maintain free enterprise competition.As part of its continuing effort to monitor the effectiveness of federal policies relating to OCS oil and gas resources, the Conservation Division of U.S. Geological Survey, Department of Interior, has sponsored the research which is the basis for the present report. The objectives of the research have been to determine the extent to which the historical policies of OCS management have resulted in achievement of the goals set forth by Congress in the section quoted above.
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ARM - Midlatitude Continental Convective Clouds (jensen-sonde)
Jensen, Mike; Comstock, Jennifer; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos
2012-01-19
A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment.
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Thurman, Paul E.; McBride, Richard S.; Sulak, Kenneth J.; Dennis, George D.
2004-01-01
Specimens of the four study species were collected during cruises to outer-continental shelf reefs of the northeastern Gulf of Mexico. Age was estimated for all serranid species using whole otoliths and C. enchrysurus ages were determined from transverse sections of sagittal otoliths. Ring structure observed on otoliths was validated as having an annual periodicity for P. martinicensis using marginal increment analysis. Ring structure on remaining species was assumed to correspond to age (years). Pronotogrammus martinicensis, H. vivanus, S. phoebe, and C. enchrysurus exhibited maximum ages of 9, 8, 5, and 11, respectively. Spatial variations in size-at-age were observed in P. martinicensis populations. Individuals inhabiting reefs in the Madison-Swanson Reserve area on the West Florida Shelf edge exhibited the fastest growth rates, while the slowest growing P. martinicensis were collected from the Alabama Alps Reef, the farthest west study reef. Pronotogrammus martinicensis and H. vivanus are both protogynous hermaphrodites. Evidence of active spawning was observed in the months from February through July for P. martinicensis, and March and May for H. vivanus. Serranus phoebe was observed to be a simultaneous hermaphroditic capable of spawning year-round. Batch fecundity estimates for P. martinicensis ranged from 149-394 oocytes per fish. Size selectivity was evident in our primary sampling method, hook and line using small tandem bait hooks. Smaller size-classes of all species examined were under-represented in our samples, hindering accurate growth modeling. Due to the protogynous nature of P. martinicensis and H. vivanus, hook and line sampling also tended to select for males. Future descriptions of the reproductive biology of both protogynous species would be more complete if less selective sampling methods could be successfully employed. The data presented here contribute to a better assessment of the fish community of the northeastern Gulf of Mexico. Little
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-26
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management, Regulation and Enforcement Outer... Ocean Energy Management, Regulation and Enforcement, Interior. ACTION: Notice of Availability of a Final Supplemental Environmental Impact Statement SUMMARY: The Bureau of Ocean Energy Management, Regulation and...
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Antarctic new particle formation from continental biogenic precursors
NASA Astrophysics Data System (ADS)
Kyrö, E.-M.; Kerminen, V.-M.; Virkkula, A.; Dal Maso, M.; Parshintsev, J.; Ruíz-Jimenez, J.; Forsström, L.; Manninen, H. E.; Riekkola, M.-L.; Heinonen, P.; Kulmala, M.
2012-12-01
Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in the continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN). The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher) communities of local ponds. This is the first time when freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.
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Antarctic new particle formation from continental biogenic precursors
NASA Astrophysics Data System (ADS)
Kyrö, E.-M.; Kerminen, V.-M.; Virkkula, A.; Dal Maso, M.; Parshintsev, J.; Ruíz-Jimenez, J.; Forsström, L.; Manninen, H. E.; Riekkola, M.-L.; Heinonen, P.; Kulmala, M.
2013-04-01
Over Antarctica, aerosol particles originate almost entirely from marine areas, with minor contribution from long-range transported dust or anthropogenic material. The Antarctic continent itself, unlike all other continental areas, has been thought to be practically free of aerosol sources. Here we present evidence of local aerosol production associated with melt-water ponds in continental Antarctica. We show that in air masses passing such ponds, new aerosol particles are efficiently formed and these particles grow up to sizes where they may act as cloud condensation nuclei (CCN). The precursor vapours responsible for aerosol formation and growth originate very likely from highly abundant cyanobacteria Nostoc commune (Vaucher) communities of local ponds. This is the first time freshwater vegetation has been identified as an aerosol precursor source. The influence of the new source on clouds and climate may increase in future Antarctica, and possibly elsewhere undergoing accelerating summer melting of semi-permanent snow cover.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
1986-01-01
The Senate Committee on Energy and Natural Resources report on S. 1026 recommends without amendment the bill which directs the Secretaries of the Interior and the National Science Foundation to cooperate in implementing the Continental Scientific Drilling Program (CSDP). The purpose of the CSDP is to enhance the knowledge and understanding of the composition, structure, dynamics, and evolution of the continental crust, including how such processes affect natural phenomena. The report includes background and the need for the legislation and summarizes the four sections.
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Code of Federal Regulations, 2011 CFR
2011-07-01
... Information Document CZMA means Coastal Zone Management Act DOCD means Development Operations Coordination... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information General Information § 250.200 Definitions. Acronyms and terms used in this subpart have the following meanings: (a...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF General... the Energy Policy Act of 2005 (EPAct) (Pub. L. 109-58). The Secretary of the Interior delegated to the...
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-31
.... BOEM-2011-0068; OMB Number 1014-0003] Information Collection Activities: Oil and Gas Production Safety... requirements in the regulations under Subpart H, ``Oil and Gas Production Safety Systems.'' This notice also... Gas Production Safety Systems. Abstract: The Outer Continental Shelf (OCS) Lands Act, as amended (43 U...
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33 CFR 142.4 - Duties of lessees, permittees, and persons responsible for actual operations.
Code of Federal Regulations, 2010 CFR
2010-07-01
... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE... operations. (a) Each holder of a lease or permit under the Act shall ensure that all places of employment... with workplace safety and health regulations of this part and, in addition, free from recognized...
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26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.
Code of Federal Regulations, 2014 CFR
2014-04-01
... obligations of the Fund, the Secretary shall issue to the Secretary of the Treasury notes or other obligations... and conditions as may be prescribed by the Secretary of the Treasury. Redemption of such notes or other obligations shall be made by the Secretary from moneys in the Fund. Such notes or other...
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26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.
Code of Federal Regulations, 2012 CFR
2012-04-01
... obligations of the Fund, the Secretary shall issue to the Secretary of the Treasury notes or other obligations... and conditions as may be prescribed by the Secretary of the Treasury. Redemption of such notes or other obligations shall be made by the Secretary from moneys in the Fund. Such notes or other...
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26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.
Code of Federal Regulations, 2013 CFR
2013-04-01
... obligations of the Fund, the Secretary shall issue to the Secretary of the Treasury notes or other obligations... and conditions as may be prescribed by the Secretary of the Treasury. Redemption of such notes or other obligations shall be made by the Secretary from moneys in the Fund. Such notes or other...
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26 CFR 301.9001 - Statutory provisions; Outer Continental Shelf Lands Act Amendments of 1978.
Code of Federal Regulations, 2010 CFR
2010-04-01
... obligations of the Fund, the Secretary shall issue to the Secretary of the Treasury notes or other obligations... and conditions as may be prescribed by the Secretary of the Treasury. Redemption of such notes or other obligations shall be made by the Secretary from moneys in the Fund. Such notes or other...
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Hydrates of natural gas in continental margins
Kvenvolden, K.A.; Barnard, L.A.
1982-01-01
Natural gas hydrates in continental margin sediment can be inferred from the widespread occurrence of an anomalous seismic reflector which coincides with the predicted transition boundary at the base of the gas hydrate zone. Direct evidence of gas hydrates is provided by visual observations of sediments from the landward wall of the Mid-America Trench off Mexico and Guatemala, from the Blake Outer Ridge off the southeastern United States, and from the Black Sea in the U.S.S.R. Where solid gas hydrates have been sampled, the gas is composed mainly of methane accompanied by CO2 and low concentrations of ethane and hydrocarbons of higher molecular weight. The molecular and isotopic composition of hydrocarbons indicates that most of the methane is of biolog cal origin. The gas was probably produced by the bacterial alteration of organic matter buried in the sediment. Organic carbon contents of the sediment containing sampled gas hydrates are higher than the average organic carbon content of marine sediments. The main economic importance of gas hydrates may reside in their ability to serve as a cap under which free gas can collect. To be producible, however, such trapped gas must occur in porous and permeable reservoirs. Although gas hydrates are common along continental margins, the degree to which they are associated with significant reservoirs remains to be investigated.
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Evidence of post-Pleistocene faults on New Jersey Atlantic outer continental shelf
Sheridan, R.E.; Knebel, H.J.
1976-01-01
Recently obtained high-resolution seismic profiles (400-4,000-Hz band) show evidence of faults in shallow sedimentary strata near the edge of the Atlantic continental shelf off New Jersey. Apparent normal faults having a throw of about 1.5 m displace sediments to within 7 m of the sea floor. The faults appear to be overlain by undeformed horizontal beds of relatively recent age. Several faults 1 to 2 km apart strike approximately N70°E and dip northwest. The data suggest that the faults are upthrown on the southeast.Projection of the faults on the high-resolution profiles to a nearby multichannel seismic-reflection profile indicates that these shallow faults might be the near-surface expression of a more fundamental deep-seated fault. Several prominent reflectors in the multichannel records are offset by a high-angle normal fault reaching depths of 4.0 to 5.0 sec (6.0 to 6.5 km). The deep fault on the multichannel line also is upthrown on the southeast. Throws of as much as 90 m are apparent at depth, but offsets of as much as 10 m could be present in the shallower parts of the section that may not be resolved in the multichannel data.The position and strike of these faults coincide with and parallel the East Coast magnetic anomaly interpreted as the fundamental seaward basement boundary of the Baltimore Canyon trough. Recurring movements along such boundary faults are expected theoretically if the marginal basins are subsiding in response to the plate rotation of North America and seafloor spreading in the Atlantic.
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Ebert, Todd A [West Palm Beach, FL; Carella, John A [Jupiter, FL
2012-03-13
A triple acting radial seal used as an interstage seal assembly in a gas turbine engine, where the seal assembly includes an interstage seal support extending from a stationary inner shroud of a vane ring, the interstage seal support includes a larger annular radial inward facing groove in which an outer annular floating seal assembly is secured for radial displacement, and the outer annular floating seal assembly includes a smaller annular radial inward facing groove in which an inner annular floating seal assembly is secured also for radial displacement. A compliant seal is secured to the inner annular floating seal assembly. The outer annular floating seal assembly encapsulates the inner annular floating seal assembly which is made from a very low alpha material in order to reduce thermal stress.
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NASA Astrophysics Data System (ADS)
Cukur, Deniz; Um, In-Kwon; Chun, Jong-Hwa; Kim, So-Ra; Lee, Gwang-Soo; Kim, Yuri; Kong, Gee-Soo; Horozal, Senay; Kim, Seong-Pil
2018-04-01
This study investigates sediment transport and depositional processes from a newly collected dataset comprising sub-bottom chirp profiles, multibeam bathymetry, and sediment cores from the northeastern continental margin of Korea in the East Sea (Japan Sea). Twelve echo-types and eleven sedimentary facies have been defined and interpreted as deposits formed by shallow-marine, hemipelagic sedimentation, bottom current, and mass-movement processes. Hemipelagic sedimentation, which is acoustically characterized by undisturbed layered sediments, appears to have been the primary sedimentary process throughout the study area. The inner and outer continental shelf (<150 m water depth) have been influenced by shallow-marine sedimentary processes. Two slope-parallel canyons, 0.2-2 km wide and up to 30 km long, appear to have acted as possible conduits for turbidity currents from the shallower shelf into the deep basins. Bottom current deposits, expressed as erosional moats immediately below topographic highs, are prevalent on the southern lower slope at water depths of 400-450 m. Mass-movements (i.e., slides/slumps, debris flow deposits) consisting of chaotic facies characterize the lower slope and represent one of the most important sedimentary processes in the study area. Piston cores confirm the presence of mass-transport deposits (MTDs) that are characterized by mud clasts of variable size, shape, and color. Multibeam bathymetry shows that large-scale MTDs are chiefly initiated on the lower slope (400-600 m) with gradients up to 3° and where they produce scarps on the order of 100 m in height. Sandy MTDs also occur on the upper continental slope adjacent to the seaward edge of the shelf terrace. Earthquakes associated with tectonic activity and the development of fluid overpressure is considered as the main conditioning factor for destabilizing the slope sediments. Overall, the sedimentary processes show typical characteristics of a fine-grained clastic slope apron and
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Continental collision slowing due to viscous mantle lithosphere rather than topography.
Clark, Marin Kristen
2012-02-29
Because the inertia of tectonic plates is negligible, plate velocities result from the balance of forces acting at plate margins and along their base. Observations of past plate motion derived from marine magnetic anomalies provide evidence of how continental deformation may contribute to plate driving forces. A decrease in convergence rate at the inception of continental collision is expected because of the greater buoyancy of continental than oceanic lithosphere, but post-collisional rates are less well understood. Slowing of convergence has generally been attributed to the development of high topography that further resists convergent motion; however, the role of deforming continental mantle lithosphere on plate motions has not previously been considered. Here I show that the rate of India's penetration into Eurasia has decreased exponentially since their collision. The exponential decrease in convergence rate suggests that contractional strain across Tibet has been constant throughout the collision at a rate of 7.03 × 10(-16) s(-1), which matches the current rate. A constant bulk strain rate of the orogen suggests that convergent motion is resisted by constant average stress (constant force) applied to a relatively uniform layer or interface at depth. This finding follows new evidence that the mantle lithosphere beneath Tibet is intact, which supports the interpretation that the long-term strain history of Tibet reflects deformation of the mantle lithosphere. Under conditions of constant stress and strength, the deforming continental lithosphere creates a type of viscous resistance that affects plate motion irrespective of how topography evolved.
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LaBelle, R.P.
1982-01-01
An oilspill risk analysis was conducted for the Gulf of Mexico Outer Continental Shelf (OCS)lease area region. Results of the analysis can be used to determine relative risks associated with oil production in different regions to be offered in OCS Lease Sales 72, 74, and 79. The analysis considered the probability of spill occurrences based on historical trends; likely movement of oil slicks based on a climatological model; and locations of major environmental resources which could be vulnerable to spilled oil. The times between spill occurrence and contact with resources were estimated to aid in estimating slick characteristics. Critical assumptions made for this particular analysis were (1) that oil exists in the lease area, and (2) that oil will be, found and produced from tracts sold in sales 72, 74, and 79. On the basis of a most likely resource estimate of 241 million barrels of oil to be produced over an 18-year production life from sales to be held in 1983 (sales 72, 74, 79), it was calculated that approximately one oilspill of 1,000 barrels or larger will occur. The estimated probability that one or more oilspills of 1,000 barrels or larger will occur and contact land after being at sea less than 30 days is 41-percent. For a high resource estimate case of sales to be held in 1983, 717 million barrels are estimated to be produced over an 18-year production life with an 83-percent chance of one or more spills of 1,000 barrels or larger occurring and contacting land within 30 days. These results depend upon the routes and methods chosen to transport oil from OCS platforms to shore. Given a total development scenario in which 5.6 billion barrels of oil are estimated to be present and produced, it was calculated that 18 oilspills of 1,000 barrels or larger will occur over the 40-year production life of the proposed lease area. The estimated probability that one or more oilspills of 1,000 barrels or larger will occur and contact land after being at sea less than
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30 CFR 291.115 - How do I exhaust administrative remedies?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I exhaust administrative remedies? 291.115 Section 291.115 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT...
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Code of Federal Regulations, 2010 CFR
2010-07-01
... decision on whether a grantee or transporter has provided open and nondiscriminatory access? 291.112 Section 291.112 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.112 What process...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... resolve an allegation that open and nondiscriminatory access was denied? 291.102 Section 291.102 Mineral... OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT... allegation concerning open and nondiscriminatory access by calling the toll-free MMS Hotline at 1-888-232...
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30 CFR 220.003 - Information collection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT ACCOUNTING PROCEDURES FOR DETERMINING NET PROFIT SHARE PAYMENT FOR OUTER CONTINENTAL SHELF OIL AND GAS LEASES... accordance with the Federal Oil and Gas Royalty Management Act of 1982, 30 U.S.C. 1701 et seq. (b) Public...
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30 CFR 256.0 - Authority for information collection.
Code of Federal Regulations, 2010 CFR
2010-07-01
... OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and... part 256, Leasing of Sulphur or Oil and Gas in the Outer Continental Shelf.” (b) MMS collects this...
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Holland-Bartels, Leslie; Pierce, Brenda
2011-01-01
The U. S. Geological Survey (USGS) was asked to conduct an initial, independent evaluation of the science needs that would inform the Administration's consideration of the right places and the right ways in which to develop oil and gas resources in the Arctic Outer Continental Shelf (OCS), particularly focused on the Beaufort and Chukchi Seas. Oil and gas potential is significant in Arctic Alaska. Beyond petroleum potential, this region supports unique fish and wildlife resources and ecosystems, and indigenous people who rely on these resources for subsistence. This report summarizes key existing scientific information and provides initial guidance of what new and (or) continued research could inform decision making. This report is presented in a series of topical chapters and various appendixes each written by a subset of the USGS OCS Team based on their areas of expertise. Three chapters (Chapters 2, 3, and 4) provide foundational information on geology; ecology and subsistence; and climate settings important to understanding the conditions pertinent to development in the Arctic OCS. These chapters are followed by three chapters that examine the scientific understanding, science gaps, and science sufficiency questions regarding oil-spill risk, response, and impact (Chapter 5), marine mammals and anthropogenic noise (Chapter 6), and cumulative impacts (Chapter 7). Lessons learned from the 1989 Exxon Valdez Oil Spill are included to identify valuable "pre-positioned" science and scientific approaches to improved response and reduced uncertainty in damage assessment and restoration efforts (appendix D). An appendix on Structured Decision Making (appendix C) is included to illustrate the value of such tools that go beyond, but incorporate, science in looking at what can/should be done about policy and implementation of Arctic development. The report provides a series of findings and recommendations for consideration developed during the independent examination of
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Code of Federal Regulations, 2014 CFR
2014-07-01
... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... program to control air pollution from outer continental shelf sources, under section 328 of the Act; (12... other functionally-equivalent opening. General permit means a part 70 permit that meets the requirements of § 70.6(d). Major source means any stationary source (or any group of stationary sources that are...
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30 CFR 281.1 - Purpose and applicability.
Code of Federal Regulations, 2010 CFR
2010-07-01
... OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 281.1 Purpose and... than oil, gas, and sulphur in the OCS. The rules in this part apply exclusively to leasing activities for minerals other than oil, gas, and sulphur in the OCS pursuant to the Act. ...
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30 CFR 291.105 - What must a complaint contain?
Code of Federal Regulations, 2010 CFR
2010-07-01
... legal and factual basis for the allegation that a shipper was denied open and nondiscriminatory access... 291.105 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.105 What must a...
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30 CFR 291.100 - What is the purpose of this part?
Code of Federal Regulations, 2010 CFR
2010-07-01
... from the OCS open and nondiscriminatory access to a pipeline; (b) Explains the procedures MMS will... Section 291.100 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.100 What is the...
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30 CFR 291.1 - What is MMS's authority to collect information?
Code of Federal Regulations, 2010 CFR
2010-07-01
... nondiscriminatory access to Outer Continental Shelf (OCS) pipelines as sections of 5(e) and (f) of the OCS Lands Act (OCSLA) require. (d) Respondents are companies that ship or transport oil and gas production across the... proprietary under applicable law. (e) Send comments regarding any aspect of the collection of information...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-28
... Environmental Policy Act (NEPA) policies, practices, and procedures for the Minerals Management Service (MMS... applies NEPA in its management of Outer Continental Shelf oil and gas exploration and development and make recommendations for revisions. The scope of the review is intended to be holistic, i.e. from leasing decisions to...
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NASA Astrophysics Data System (ADS)
Durán, Ruth; Canals, Miquel; Lastras, Galderic; Micallef, Aaron; Amblas, David; Pedrosa-Pàmies, Rut; Sanz, José Luis
2013-11-01
The Blanes submarine canyon (BC) deeply incises the Catalan continental shelf in the NW Mediterranean Sea. As a consequence of the closeness (only 4 km) of its head to the coastline and the mouth of the Tordera River, the canyon has a direct influence on the shelf dispersal system as it collects large amounts of sediment, mainly during high-energy events. Multibeam bathymetry, backscatter imagery and very-high resolution seismic reflection profiles have allowed characterizing the morphology of the continental shelf around the canyon head, also identifying sediment sources and transport pathways into the canyon. The morphological data have also been used to reconstruct the evolution of the continental shelf during the last sea-level transgression so that the current understanding of shelf-to-canyon sediment exchanges through time could be improved. The continental shelf surrounding the BC consists of both depositional and erosional or non-depositional areas. Depositional areas display prominent sediment bodies, a generally smooth bathymetry and variable backscatter. These include: (i) an area of modern coarse-grained sediment accumulation that comprises the inner shelf; (ii) a modern fine-grained sedimentation area on the middle shelf offshore Tossa de Mar; and (iii) a modern sediment depleted area that covers most of the middle and outer shelf to the west of the canyon head. Erosional and non-depositional areas display a rough topography and high backscatter, and occur primarily to the east of the canyon head, where the arrival of river-fed inputs is very small. In agreement with this pattern, the continental shelf north and west of the canyon head likely is the main source of shelf sediment into the canyon. To the north, a pattern of very high backscatter extends from the coastline to the canyon head, suggesting the remobilization and off-shelf export of fines. Additionally, relict near-shore sand bodies developed over the Barcelona shelf that extend to the canyon
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The Escherichia coli Phospholipase PldA Regulates Outer Membrane Homeostasis via Lipid Signaling.
May, Kerrie L; Silhavy, Thomas J
2018-03-20
The outer membrane (OM) bilayer of Gram-negative bacteria is biologically unique in its asymmetrical organization of lipids, with an inner leaflet composed of glycerophospholipids (PLs) and a surface-exposed outer leaflet composed of lipopolysaccharide (LPS). This lipid organization is integral to the OM's barrier properties. Perturbations of the outer leaflet by antimicrobial peptides or defects in LPS biosynthesis or transport to the OM cause a compensatory flipping of PLs to the outer leaflet. As a result, lipid asymmetry is disrupted and OM integrity is compromised. Recently, we identified an Escherichia coli mutant that exhibits aberrant accumulation of surface PLs accompanied by a cellular increase in LPS production. Remarkably, the observed hyperproduction of LPS is PldA dependent. Here we provide evidence that the fatty acids generated by PldA at the OM are transported into the cytoplasm and simultaneously activated by thioesterification to coenzyme A (CoA) by FadD. The acyl-CoAs produced ultimately inhibit LpxC degradation by FtsH. The increased levels of LpxC, the enzyme that catalyzes the first committed step in LPS biosynthesis, increases the amount of LPS produced. Our data suggest that PldA acts as a sensor for lipid asymmetry in the OM. PldA protects the OM barrier by both degrading mislocalized PLs and generating lipid second messengers that enable long-distance signaling that prompts the cell to restore homeostasis at a distant organelle. IMPORTANCE The outer membrane of Gram-negative bacteria is an effective permeability barrier that protects the cell from toxic agents, including antibiotics. Barrier defects are often manifested by phospholipids present in the outer leaflet of this membrane that take up space normally occupied by lipopolysaccharide. We have discovered a signaling mechanism that operates across the entire cell envelope used by the cell to detect these outer membrane defects. A phospholipase, PldA, that functions to degrade these
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Deep sea sedimentation processes and geomorphology: Northwest Atlantic continental margin
NASA Astrophysics Data System (ADS)
Mosher, David; Campbell, Calvin; Gardner, Jim; Chaytor, Jason; Piper, David; Rebesco, Michele
2017-04-01
Deep-sea sedimentation processes impart a fundamental control on the morphology of the western North Atlantic continental margin from Blake Spur to Hudson Strait. This fact is illustrated by the variable patterns of cross-margin gradients that are based on extensive new multibeam echo-sounder data informed by subbottom profiler and seismic reflection data. Erosion by off-shelf sediment transport in turbidity currents creates gullies, canyons and channels and a steep upper slope. Amalgamation of these conduits produces singular channels and turbidite fan complexes on the lower slope, flattening slope-profile gradients. The effect is an exponentially decaying "graded" slope profile. Comparatively, sediment mass failure produces steeper upper slopes due to head scarp development and a wedging architecture to the lower slope as deposits thin in the downslope direction. This process results in either a "stepped" slope, and/or a significant downslope gradient change where MTDs pinch out. Large drift deposits created by geostrophic currents are developed all along the margin. Blake Ridge, Sackville Spur, and Hamilton Spur are large detached drifts on disparate parts of the margin. They form a linear "above grade" profile along their crests from the shelf to abyssal plain. Deeper portions of the US continental margin are dominated by the Chesapeake Drift and Hatteras Outer Ridge; both plastered elongate mounded drifts. Farther north, particularly on the Grand Banks margin, are plastered and separated drifts. These drifts form "stepped" slope profiles, where they onlap the margin. Trough-mouth fan complexes become more common along the margin with increasing latitude. Sediment deposition and retention, particularly those dominated by glacigenic debris flows, characterize these segments producing an "above grade" slope profile. Understanding these geomorphological consequences of deep sea sedimentation processes is important to extended continental shelf mapping in which
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Structure of Rotavirus Outer-Layer Protein VP7 Bound with a Neutralizing Fab
DOE Office of Scientific and Technical Information (OSTI.GOV)
Aoki, Scott T.; Settembre, Ethan C.; Trask, Shane D.
2009-06-17
Rotavirus outer-layer protein VP7 is a principal target of protective antibodies. Removal of free calcium ions (Ca{sup 2+}) dissociates VP7 trimers into monomers, releasing VP7 from the virion, and initiates penetration-inducing conformational changes in the other outer-layer protein, VP4. We report the crystal structure at 3.4 angstrom resolution of VP7 bound with the Fab fragment of a neutralizing monoclonal antibody. The Fab binds across the outer surface of the intersubunit contact, which contains two Ca{sup 2+} sites. Mutations that escape neutralization by other antibodies suggest that the same region bears the epitopes of most neutralizing antibodies. The monovalent Fab ismore » sufficient to neutralize infectivity. We propose that neutralizing antibodies against VP7 act by stabilizing the trimer, thereby inhibiting the uncoating trigger for VP4 rearrangement. A disulfide-linked trimer is a potential subunit immunogen.« less
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NASA Astrophysics Data System (ADS)
DuVal, C.; Carton, G.; Trembanis, A. C.; Edwards, M.; Miller, J. K.
2017-12-01
Munitions and explosives of concern (MEC) are present in U.S. waters as a result of past and ongoing live-fire testing and training, combat operations, and sea disposal. To identify MEC that may pose a risk to human safety during development of offshore wind facilities on the Atlantic Outer Continental Shelf (OCS), the Bureau of Ocean Energy Management (BOEM) is preparing to develop guidance on risk analysis and selection processes for methods and technologies to identify MEC in Wind Energy Areas (WEA). This study developed a process for selecting appropriate technologies and methodologies for MEC detection using a synthesis of historical research, physical site characterization, remote sensing technology review, and in-field trials. Personnel were tasked with seeding a portion of the Delaware WEA with munitions surrogates, while a second group of researchers not privy to the surrogate locations tested and optimized the selected methodology to find and identify the placed targets. This in-field trial, conducted in July 2016, emphasized the use of multiple sensors for MEC detection, and led to further guidance for future MEC detection efforts on the Atlantic OCS. An April 2017 follow on study determined the fate of the munitions surrogates after the Atlantic storm season had passed. Using regional hydrodynamic models and incorporating the recommendations from the 2016 field trial, the follow on study examined the fate of the MEC and compared the findings to existing research on munitions mobility, as well as models developed as part of the Office of Naval Research Mine-Burial Program. Focus was given to characterizing the influence of sediment type on surrogate munitions behavior and the influence of mophodynamics and object burial on MEC detection. Supporting Mine-Burial models, ripple bedforms were observed to impede surrogate scour and burial in coarse sediments, while surrogate burial was both predicted and observed in finer sediments. Further, incorporation of
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Modelling the bathymetry of the Antarctic continental shelf
ten Brink, Uri S.; Rogers, William P.; Kirkham, R.M.
1992-01-01
Continental shelves are typically covered by relatively shallow waters (<200 m) which deepen gradually from the coast to the shelf edge. The continental shelf around Antarctica is deeper than normal (400-700m) and is characterized in many areas by a nearshore trough (up to 1 km deep) that gradually shallows toward the shelf edge. We examine the cause for the unusual shelf bathymetry of Antarctica by 2-D numerical models that simulate the bathymetry along seismic line ODP-119 in Prydz Bay. Line ODP-119 was chosen because it is tied to to 5 ODP boreholes, and because the margin underwent little recent tectonic activity or changes in the glacial drainage pattern. The numerical models incorporate several factors that are likely to influence the bathymetry, such as the load of the ice cap, the isostatic response of the lithosphere, thermal and tectnoic subsidence of the margin, sea level changes, and the patterns of erosion and sedimentation across the margin. The models show that the observed bathymetry can be produced almost entirely by the sum of the outer-shelf sediment loading and inner-shelf unloading and by the load of the slope sediments. A simple statistical mdoel demonstrates that this distribution pattern of erosion and deposition can be generated by multiple cycles of ice sheet advances across the shelf, whereby in each cycle a thin (a few tens of meters) uniform layer of sediments is eroded from under the ice sheet and is redeposited seaward of the grounding line.
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30 CFR 581.8 - Rights to minerals.
Code of Federal Regulations, 2013 CFR
2013-07-01
... THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 581.8 Rights to minerals. (a... leases; (2) Oil; (3) Gas; (4) Sulphur; (5) Minerals produced in direct association with oil, gas, or... essential to production of fissionable materials which are reserved pursuant to section 12(a) of the Act. (b...
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30 CFR 581.8 - Rights to minerals.
Code of Federal Regulations, 2012 CFR
2012-07-01
... THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 581.8 Rights to minerals. (a... leases; (2) Oil; (3) Gas; (4) Sulphur; (5) Minerals produced in direct association with oil, gas, or... essential to production of fissionable materials which are reserved pursuant to section 12(a) of the Act. (b...
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30 CFR 581.8 - Rights to minerals.
Code of Federal Regulations, 2014 CFR
2014-07-01
... THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF General § 581.8 Rights to minerals. (a... leases; (2) Oil; (3) Gas; (4) Sulphur; (5) Minerals produced in direct association with oil, gas, or... essential to production of fissionable materials which are reserved pursuant to section 12(a) of the Act. (b...
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30 CFR 291.106 - How do I file a complaint?
Code of Federal Regulations, 2010 CFR
2010-07-01
....106 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.106 How do I... later than two (2) years from the time of the alleged access denial. If the complaint is filed later...
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28 CFR 0.40 - General functions.
Code of Federal Regulations, 2013 CFR
2013-07-01
... proposed acquisitions under the Savings and Loan Holding Company Amendments of 1967 (12 U.S.C. 1730a(e...)), furnishing advice on oil and gas leasing under the Outer Continental Shelf Lands Act Amendments of 1978 (43 U... programs or agreements and small business production or raw material pools, the national defense program...
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28 CFR 0.40 - General functions.
Code of Federal Regulations, 2014 CFR
2014-07-01
... proposed acquisitions under the Savings and Loan Holding Company Amendments of 1967 (12 U.S.C. 1730a(e...)), furnishing advice on oil and gas leasing under the Outer Continental Shelf Lands Act Amendments of 1978 (43 U... programs or agreements and small business production or raw material pools, the national defense program...
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28 CFR 0.40 - General functions.
Code of Federal Regulations, 2011 CFR
2011-07-01
... proposed acquisitions under the Savings and Loan Holding Company Amendments of 1967 (12 U.S.C. 1730a(e...)), furnishing advice on oil and gas leasing under the Outer Continental Shelf Lands Act Amendments of 1978 (43 U... programs or agreements and small business production or raw material pools, the national defense program...
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28 CFR 0.40 - General functions.
Code of Federal Regulations, 2012 CFR
2012-07-01
... proposed acquisitions under the Savings and Loan Holding Company Amendments of 1967 (12 U.S.C. 1730a(e...)), furnishing advice on oil and gas leasing under the Outer Continental Shelf Lands Act Amendments of 1978 (43 U... programs or agreements and small business production or raw material pools, the national defense program...
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NASA Astrophysics Data System (ADS)
Santín, Andreu; Grinyó, Jordi; Ambroso, Stefano; Uriz, Maria J.; Gori, Andrea; Dominguez-Carrió, Carlos; Gili, Josep-Maria
2018-01-01
Sponge assemblages on continental shelves and slopes around the world have been known about for centuries. However, due to limitations of the traditional sampling systems, data about individual sponge species rather than assemblages have been reported. This study characterizes sponge assemblages over a wide bathymetric range ( 50-350 m depth) and covering the entire continental shelf and the upper slope of the Menorca Channel, an area soon to be declared a Marine Protected Area (MPA) as part of the Natura 2000 Network. Quantitative analysis of 85 video-transects (a total linear distance of 75 km), together with representative collections to confirm species identifications, allowed us to discriminate six major assemblages. Differences in the assemblages mainly corresponded to differences in substrate type and depth. On the inner continental shelf, a semi-sciaphilous Axinellid assemblage dominated the rocky outcrops. Maërl beds on the inner continental shelf were dominated by Haliclona (Reniera) mediterranea, whereas the horny sponge Aplysina cavernicola and several other haliclonids mostly dominated maërl beds and rocky substrates of the outer shelf. Soft sediments on the shelf break hosted a monospecific Thenea muricata assemblage, whereas rocky substrates of the shelf break were characterized by a mixture of encrusting, columnar and fan-shaped sponges. Finally, the upper slope was dominated by Hamacantha (Vomerula) falcula and the hexactinellid Tretodictyum reiswigi. Overall, sponge diversity showed its highest values above the shelf break, plummeting severely on the upper slope. Despite this diversity decrease, we found very high densities (> 70 ind./m2) of sponges over vast areas of both the shelf break and the upper slope.
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Generation of Continental Rifts, Basins and Swells by Lithosphere Instabilities
NASA Astrophysics Data System (ADS)
Milelli, L.; Fourel, L.; Jaupart, C. P.
2012-12-01
blocks of finite size that became unstable due to cooling from above and describe the peculiar horizontal planform that developed. Dynamical behaviour depends on three dimensionless numbers, a Rayleigh number for the unstable block, a buoyancy number that scales the intrinsic density contrast to the thermal one and the aspect ratio of the block. Within the block, instability develops in two different ways in an outer annulus and in an inner region. In the outer annulus, upwellings and downwellings take the form of radial rolls spaced regularly. In the interior region, the planform adopts the more familiar form of polygonal cells. Translated to geological conditions, such instabilities should manifest themselves as linear rifts striking at a right angle to the continent-ocean boundary and an array of domal uplifts, volcanic swells and basins in the continental interior. The laboratory data lead to simple scaling laws for the dimensions and spacings of the convective structures. For the sub-continental lithospheric mantle, these dimensions and distances take values in the 500-1000 km range, close to geological examples. The large intrinsic buoyancy of Archean lithospheric roots prevents this type of instability, which explains why the widespread volcanic activity that currently affects Western Africa is confined to post-Archean domains.
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The effects of trawling, dredging and ocean dumping on the eastern Canadian continental shelf seabed
NASA Astrophysics Data System (ADS)
Messieh, S. N.; Rowell, T. W.; Peer, D. L.; Cranford, P. J.
1991-08-01
This paper presents an overview of current knowledge on the effects of trawling, dredging and ocean dumping on the eastern Canadian continental shelf seabed. The impact of trawling and dredging for fish and shellfish on marine habitats has recently attracted international attention among fisheries and environmental scientists. In Atlantic Canada, trawling and dredging are the principal methods of harvesting groundfish and scallops and ocean clams, respectively. It is estimated that fish trawlers and scallop dredges have swept tracks, cris-crossing the Canadian continental shelf, approximately 4.3 million km in length in 1985. In the past few years several studies were carried out by scientists from Canada, the United States and Europe to assess the impacts of trawling and dredging but results were inconclusive. Some studies showed physical damage as well as biological effects, whereas others indicated that the adverse effects were not considered to be serious. Fishermen are not the only potential users of the resources of the continental shelf. There is an increasing demand for good-quality sand and gravel aggregate and the ocean seabed is being seen as a possible source. The eastern Canadian continental shelf also exhibits hydrocarbon potential and operational and accidental discharges are an environmental concern. Increased marine transportation and expansion of the fishing fleet have resulted in a greater need for harbour dredging. Dredging and dredge spoil disposal were controlled by the Ocean Dumping Control Act and now the Canadian Environmental Protection Act which places restrictions on the composition of material that can be disposed of in the sea. Nevertheless some harbours contain contaminant concentrations exceeding the maximum allowable limits. It is concluded that the impacts of human activities on the continental shelf seabed environment are inevitable and the long-term effects, while difficult to determine, must be assessed. The sub-lethal effects
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30 CFR 291.114 - How do I appeal to the IBLA?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I appeal to the IBLA? 291.114 Section 291.114 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.114 How do I...
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30 CFR 291.107 - How do I answer a complaint?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I answer a complaint? 291.107 Section 291.107 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR APPEALS OPEN AND NONDISCRIMINATORY ACCESS TO OIL AND GAS PIPELINES UNDER THE OUTER CONTINENTAL SHELF LANDS ACT § 291.107 How do I...
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Turbine airfoil with outer wall thickness indicators
Marra, John J; James, Allister W; Merrill, Gary B
2013-08-06
A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.
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Chronobiology of deep-water decapod crustaceans on continental margins.
Aguzzi, Jacopo; Company, Joan B
2010-01-01
Species have evolved biological rhythms in behaviour and physiology with a 24-h periodicity in order to increase their fitness, anticipating the onset of unfavourable habitat conditions. In marine organisms inhabiting deep-water continental margins (i.e. the submerged outer edges of continents), day-night activity rhythms are often referred to in three ways: vertical water column migrations (i.e. pelagic), horizontal displacements within benthic boundary layer of the continental margin, along bathymetric gradients (i.e. nektobenthic), and endobenthic movements (i.e. rhythmic emergence from the substrate). Many studies have been conducted on crustacean decapods that migrate vertically in the water column, but much less information is available for other endobenthic and nektobenthic species. Also, the types of displacement and major life habits of most marine species are still largely unknown, especially in deep-water continental margins, where steep clines in habitat factors (i.e. light intensity and its spectral quality, sediment characteristics, and hydrography) take place. This is the result of technical difficulties in performing temporally scheduled sampling and laboratory testing on living specimens. According to this scenario, there are several major issues that still need extensive research in deep-water crustacean decapods. First, the regulation of their behaviour and physiology by a biological clock is almost unknown compared to data for coastal species that are easily accessible to direct observation and sampling. Second, biological rhythms may change at different life stages (i.e. size-related variations) or at different moments of the reproductive cycle (e.g. at egg-bearing) based on different intra- and interspecific interactions. Third, there is still a major lack of knowledge on the links that exist among the observed bathymetric distributions of species and selected autoecological traits that are controlled by their biological clock, such as the
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Strategy for outer planets exploration
NASA Technical Reports Server (NTRS)
1975-01-01
NASA's Planetary Programs Office formed a number of scientific working groups to study in depth the potential scientific return from the various candidate missions to the outer solar system. The results of these working group studies were brought together in a series of symposia to evaluate the potential outer planet missions and to discuss strategies for exploration of the outer solar system that were consistent with fiscal constraints and with anticipated spacecraft and launch vehicle capabilities. A logical, scientifically sound, and cost effective approach to exploration of the outer solar system is presented.
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Seabed fluid expulsion along the upper slope and outer shelf of the U.S. Atlantic continental margin
Brothers, D.S.; Ruppel, C.; Kluesner, J.W.; ten Brink, Uri S.; Chaytor, J.D.; Hill, J.C.; Andrews, B.D.; Flores, C.
2014-01-01
Identifying the spatial distribution of seabed fluid expulsion features is crucial for understanding the substrate plumbing system of any continental margin. A 1100 km stretch of the U.S. Atlantic margin contains more than 5000 pockmarks at water depths of 120 m (shelf edge) to 700 m (upper slope), mostly updip of the contemporary gas hydrate stability zone (GHSZ). Advanced attribute analyses of high-resolution multichannel seismic reflection data reveal gas-charged sediment and probable fluid chimneys beneath pockmark fields. A series of enhanced reflectors, inferred to represent hydrate-bearing sediments, occur within the GHSZ. Differential sediment loading at the shelf edge and warming-induced gas hydrate dissociation along the upper slope are the proposed mechanisms that led to transient changes in substrate pore fluid overpressure, vertical fluid/gas migration, and pockmark formation.
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Turbine airfoil with a compliant outer wall
Campbell, Christian X [Oviedo, FL; Morrison, Jay A [Oviedo, FL
2012-04-03
A turbine airfoil usable in a turbine engine with a cooling system and a compliant dual wall configuration configured to enable thermal expansion between inner and outer layers while eliminating stress formation in the outer layer is disclosed. The compliant dual wall configuration may be formed a dual wall formed from inner and outer layers separated by a support structure. The outer layer may be a compliant layer configured such that the outer layer may thermally expand and thereby reduce the stress within the outer layer. The outer layer may be formed from a nonplanar surface configured to thermally expand. In another embodiment, the outer layer may be planar and include a plurality of slots enabling unrestricted thermal expansion in a direction aligned with the outer layer.
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NASA Astrophysics Data System (ADS)
Johnson, Christopher Daniel
2018-01-01
Negotiated at the United Nations and in force since 1967, the Outer Space Treaty has been ratified by over 100 countries and is the most important and foundational source of space law. The treaty, whose full title is "Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies," governs all of humankind's activities in outer space, including activities on other celestial bodies and many activities on Earth related to outer space. All space exploration and human spaceflight, planetary sciences, and commercial uses of space—such as the global telecommunications industry and the use of space technologies such as position, navigation, and timing (PNT), take place against the backdrop of the general regulatory framework established in the Outer Space Treaty. A treaty is an international legal instrument which balances rights and obligations between states, and exists as a kind of mutual contract of shared understandings, rights, and responsibilities between them. Negotiated and drafted during the Cold War era of heightened political tensions, the Outer Space Treaty is largely the product of efforts by the United States and the USSR to agree on certain minimum standards and obligations to govern their competition in "conquering" space. Additionally, the Outer Space Treaty is similar to other treaties, including treaties governing the high seas, international airspace, and the Antarctic, all of which govern the behavior of states outside of their national borders. The treaty is brief in nature and only contains 17 articles, and is not comprehensive in addressing and regulating every possible scenario. The negotiating states knew that the Outer Space Treaty could only establish certain foundational concepts such as freedom of access, state responsibility and liability, non-weaponization of space, the treatment of astronauts in distress, and the prohibition of non-appropriation of
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30 CFR 256.0 - Authority for information collection.
Code of Federal Regulations, 2011 CFR
2011-07-01
... OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.0 Authority for information collection. (a... information collection is “30 CFR part 256, Leasing of Sulphur or Oil and Gas in the Outer Continental Shelf...
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Beaudoin, Jonathan D.; Gardner, James V.; Clarke, John E. Hughes
2002-01-01
Following the publication of high-resolution multibeam echosounder (MBES) images and data of the Flower Gardens area of the northwest Gulf of Mexico outer continental shelf (Gardner et al., 1998), the Flower Gardens Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the US Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico in 2002. The areas were chosen by personnel of the FGBNMS and the choice of MBES was made by the USGS. MMS and FGBNMS funded the mapping and the USGS organized the ship and multibeam systems through a Cooperative Agreement between the USGS and the University of New Brunswick. The University of New Brunswick (UNB) contracted the RV Ocean Surveyor and the EM1000 MBES system from C&C Technologies, Inc., Lafayette, LA. C&C personnel oversaw data collection whereas UNB personnel conducted the cruise and processed all the data. USGS personnel were responsible for the overall cruise including the final data processing and digital map products.
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NASA Astrophysics Data System (ADS)
Durán, Ruth; Canals, Miquel; Sanz, José Luis; Lastras, Galderic; Amblas, David; Micallef, Aaron
2014-01-01
The northern Catalan continental shelf, in the northwestern Mediterranean Sea, extends along 200 km from the Cap de Creus submarine canyon to the Llobregat Delta, in the vicinity of the city of Barcelona. In this paper we present the results of a systematic investigation of this area by means of very high-resolution multibeam bathymetry to fully assess its morphological variability. The causative factors and processes determining such variability are subsequently interpreted. The shelf is divided in three segments by two prominent submarine canyons: the northernmost Roses Shelf is separated from the intermediate La Planassa Shelf by the La Fonera Canyon, while the boundary between the La Planassa Shelf and the southernmost Barcelona Shelf is marked by the Blanes Canyon. These two canyons are deeply incised in the continental margin, with their heads located at only 0.8 and 5 km from the shore, respectively. The seafloor character reflects the influence of external controlling factors on the geomorphology and sediment dynamics of the northern continental shelf of Catalonia. These factors are the geological setting, the volume and nature of sediment input, and the type and characteristics of processes leading to sediment redistribution, such as dense shelf water cascading (DSWC) and eastern storms. The interaction of all these factors determines sediment dynamics and allows subdividing the northern Catalan continental shelf into three segments: the erosional-depositional Roses Shelf to the north, the non-depositional La Planassa Shelf in the middle, and the depositional Barcelona Shelf to the south. Erosional features off the Cap de Creus Peninsula and an along-shelf subdued channel in the outer shelf illustrate prevailing sediment dynamics in the Roses segment, which is dominated by erosional processes, local sediment accumulations and the southward bypass of sediment. The rocky character of the seafloor immediately north of the Blanes Canyon head demonstrates that
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Continental underplating after slab break-off
NASA Astrophysics Data System (ADS)
Magni, V.; Allen, M. B.; van Hunen, J.; Bouilhol, P.
2017-09-01
We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900 °C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India-Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.
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Misra, Rajeev; Morrison, Keith D; Cho, Hyun Jae; Khuu, Thanh
2015-08-01
The constitutively expressed AcrAB multidrug efflux system of Escherichia coli shows a high degree of homology with the normally silent AcrEF system. Exposure of a strain with acrAB deleted to antibiotic selection pressure frequently leads to the insertion sequence-mediated activation of the homologous AcrEF system. In this study, we used strains constitutively expressing either AcrAB or AcrEF from their normal chromosomal locations to resolve a controversy about whether phenylalanylarginine β-naphthylamide (PAβN) inhibits the activities of AcrAB and AcrEF and/or acts synergistically with antibiotics by destabilizing the outer membrane permeability barrier. Real-time efflux assays allowed a clear distinction between the efflux pump-inhibiting activity of PAβN and the outer membrane-destabilizing action of polymyxin B nonapeptide (PMXBN). When added in equal amounts, PAβN, but not PMXBN, strongly inhibited the efflux activities of both AcrAB and AcrEF pumps. In contrast, when outer membrane destabilization was assessed by the nitrocefin hydrolysis assay, PMXBN exerted a much greater damaging effect than PAβN. Strong action of PAβN in inhibiting efflux activity compared to its weak action in destabilizing the outer membrane permeability barrier suggests that PAβN acts mainly by inhibiting efflux pumps. We concluded that at low concentrations, PAβN acts specifically as an inhibitor of both AcrAB and AcrEF efflux pumps; however, at high concentrations, PAβN in the efflux-proficient background not only inhibits efflux pump activity but also destabilizes the membrane. The effects of PAβN on membrane integrity are compounded in cells unable to extrude PAβN. The increase in multidrug-resistant bacterial pathogens at an alarming rate has accelerated the need for implementation of better antimicrobial stewardship, discovery of new antibiotics, and deeper understanding of the mechanism of drug resistance. The work carried out in this study highlights the importance
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-19
...), Interior. ACTION: Notice of the availability of Environmental Assessment (EA) and Finding of No Significant... that implement the National Environmental Policy Act (NEPA), announces the availability of two... 2010 open-water period. Shell's proposal includes suspending all operations and removal of the drill...
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Continental Affinities of the Alpha Ridge
NASA Astrophysics Data System (ADS)
Jackson, H. Ruth; Li, Qingmou; Shimeld, John; Chian, Deping
2017-04-01
Identifying the crustal attributes of the Alpha Ridge (AR) part of the High Arctic Large Igneous Province and tracing the spreading centre across the Amerasia Basin plays a key role in understanding the opening history of the Arctic Ocean. In this approach, we report the evidence for a continental influence on the development of the AR and reduced ocean crust in the Amerasia Basin. These points are inferred from a documented continental sedimentation source in the Amerasia Basin and calculated diagnostic compressional and shear refraction waves, and from the tracing of the distinct spreading centre using the potential field data. (1) The circum-Arctic geology of the small polar ocean provides compelling evidence of a long-lived continental landmass north of the Sverdrup Basin in the Canadian Arctic Islands and north of the Barents Sea continental margin. Based on sediment distribution patterns in the Sverdrup Basin a continental source is required from the Triassic to mid Jurassic. In addition, an extensive continental sediment source to the north of the Barents Sea is required until the Barremian. (2) Offshore data suggest a portion of continental crust in the Alpha and Mendeleev ridges including measured shear wave velocities, similarity of compressional wave velocities with large igneous province with continental fragments and magnetic patterns. Ocean bottom seismometers recorded shear waves velocities that are sensitive to the quartz content of rocks across the Chukchi Borderland and the Mendeleev Ridge that are diagnostic of both an upper and lower continental crust. On the Nautilus Spur of the Alpha Ridge expendable sonobuoys recorded clear converted shear waves also consistent with continental crust. The magnetic patterns (amplitude, frequency, and textures) on the Northwind Ridge and the Nautilus Spur also have similarities. In fact only limited portions of the deepest water portions of the Canada Basin and the Makarov Basin have typical oceanic layer 2 and
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Cheriton, Olivia M.; McPhee-Shaw, Erika E.; Storlazzi, Curt D.; Rosenberger, Kurt J.; Shaw, William J.; Raanan, Ben Y.
2014-01-01
Several sequential upwelling events were observed in fall 2012, using measurements from the outer half of the continental shelf in Monterey Bay, during which the infiltration of dense water onto the shelf created a secondary, near-bottom pycnocline. This deep pycnocline existed in concert with the near-surface pycnocline and enabled the propagation of near-bottom, cold, semidiurnal internal tidal bores, as well as energetic, high-frequency, nonlinear internal waves of elevation (IWOE). The IWOE occurred within 20 m of the bottom, had amplitudes of 8–24 m, periods of 6–45 min, and depth-integrated energy fluxes up to 200 W m−1. Iribarren numbers (<0.03) indicate that these IWOE were nonbreaking in this region of the shelf. These observations further demonstrate how regional upwelling dynamics and the resulting bulk, cross-margin hydrography is a first-order control on the ability of internal waves, at tidal and higher frequencies, to propagate through continental shelf waters.
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Deep continental margin reflectors
Ewing, J.; Heirtzler, J.; Purdy, M.; Klitgord, Kim D.
1985-01-01
In contrast to the rarity of such observations a decade ago, seismic reflecting and refracting horizons are now being observed to Moho depths under continental shelves in a number of places. These observations provide knowledge of the entire crustal thickness from the shoreline to the oceanic crust on passive margins and supplement Consortium for Continental Reflection Profiling (COCORP)-type measurements on land.
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NASA Technical Reports Server (NTRS)
Schardt, A. W.; Behannon, K. W.; Carbary, J. F.; Eviatar, A.; Lepping, R. P.; Siscoe, G. L.
1983-01-01
Similarities between the Saturnian and terrestrial outer magnetosphere are examined. Saturn, like Earth, has a fully developed magnetic tail, 80 to 100 RS in diameter. One major difference between the two outer magnetospheres is the hydrogen and nitrogen torus produced by Titan. This plasma is, in general, convected in the corotation direction at nearly the rigid corotation speed. Energies of magnetospheric particles extend to above 500 keV. In contrast, interplanetary protons and ions above 2 MeV have free access to the outer magnetosphere to distances well below the Stormer cutoff. This access presumably occurs through the magnetotail. In addition to the H+, H2+, and H3+ ions primarily of local origin, energetic He, C, N, and O ions are found with solar composition. Their flux can be substantially enhanced over that of interplanetary ions at energies of 0.2 to 0.4 MeV/nuc.
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ERIC Educational Resources Information Center
Tyler, Barbara R.; Biesekerski, Joan
The Quinmester course "The Outer Limits" involves an exploration of unknown worlds, mental and physical, through fiction and nonfiction. Its purpose is to focus attention on the ongoing conquest of the frontiers of the mind, the physical world, and outer space. The subject matter includes identification and investigation of unknown…
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Grantz, Arthur; Eittreim, Stephen L.; Whitney, O.T.
1979-01-01
The continental margin north of Alaska is of Atlantic type. It began to form probably in Early Jurassic time but possibly in middle Early Cretaceous time, when the oceanic Canada Basin of the Arctic Ocean is thought to have opened by rifting about a pole of rotation near the Mackenzie Delta. Offsets of the rift along two fracture zones are thought to have divided the Alaskan margin into three sectors of contrasting structure and stratigraphy. In the Barter Island sector on the east and the Chukchi sector on the west the rift was closer to the present northern Alaska mainland than in the Barrow sector, which lies between them. In the Barter Island and Chukchi sectors the continental shelf is underlain by prisms of clastic sedimentary rocks that are inferred to include thick sections of Jurassic and Neocomian (lower Lower Cretaceous) strata of southern provenance. In the intervening Barrow sector the shelf is underlain by relatively thin sections of Jurassic and Neocomian strata derived from northern sources that now lie beneath the outer continental shelf. The rifted continental margin is overlain by a prograded prism of Albian (upper Lower Cretaceous) to Tertiary clastic sedimentary rocks that comprises the continental terrace of the western Beaufort and northern Chukchi Seas. On the south the prism is bounded by Barrow arch, which is a hingeline between the northward-tilted basement surface beneath the continental shelf of the western Beaufort Sea and the southward-tilted Arctic Platform of northern Alaska. The Arctic platform is overlain by shelf clastic and carbonate strata of Mississippian to Cretaceous age, and by Jurassic and Cretaceous clastic strata of the Colville foredeep. Both the Arctic platform and Colville foredeep sequences extend from northern Alaska beneath the northern Chukchi Sea. At Herald fault zone in the central Chukchi Sea they are overthrust by more strongly deformed Cretaceous to Paleozoic sedimentary rocks of Herald arch, which trends
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NASA Astrophysics Data System (ADS)
Tymms, V. J.; Kusznir, N. J.
2004-12-01
The effect of temperature dependent rheology has been examined for a model of continental lithosphere thinning by an upwelling divergent flow field within continental lithosphere and asthenosphere leading to continental breakup and rifted continental margin formation. The model uses a coupled FE fluid flow and thermal solution and is kinematically driven using a half divergence rate Vx and upwelling velocity Vz. Viscosity structure is modified by the evolving temperature field of the model through the temperature dependent Newtonian rheology. Continental lithosphere and asthenosphere material are advected by the fluid-flow field in order to predict crustal and mantle lithosphere thinning leading to rifted continental margin formation. The results of the temperature dependent rheology model are compared with those of a simple isoviscous model. The temperature dependent rheology model predicts continental lithosphere thinning and depth dependent stretching, similar to that predicted by the uniform viscosity model. However compared with the uniform viscosity model the temperature dependent rheology predicts greater amounts of thinning of the continental crust and lithospheric mantle than the isoviscous solutions. An important parameter within the kinematic model of continental lithosphere breakup and rifted continental margin development is the velocity ratio Vz/Vx. For non-volcanic margins, Vz/Vx is thought to be around unity. Applying a velocity ratio Vz/Vx of unity gives a diffuse ocean-continent transition and exhumation of continental lithospheric mantle. For volcanic margins, Vz/Vx is of order 10, falling to unity with a half-life of order 10 Ma, leading to a more sharply defined ocean-continent transition. While Vx during continental breakup may be estimated, Vz can only be inferred. FE fluid flow solutions, in which Vz is not imposed and without an initial buoyancy driven flow component, predict a velocity ratio Vz/Vx of around unity for both temperature
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Ludt, William B.; Bernal, Moisés A.; Bowen, Brian W.; Rocha, Luiz A.
2012-01-01
Sea level fluctuations during glacial cycles affect the distribution of shallow marine biota, exposing the continental shelf on a global scale, and displacing coral reef habitat to steep slopes on oceanic islands. In these circumstances we expect that species inhabiting lagoons should show shallow genetic architecture relative to species inhabiting more stable outer reefs. Here we test this expectation on an ocean-basin scale with four wrasses (genus Halichoeres): H. claudia (N = 194, with ocean-wide distribution) and H. ornatissimus (N = 346, a Hawaiian endemic) inhabit seaward reef slopes, whereas H. trimaculatus (N = 239) and H. margaritaceus (N = 118) inhabit lagoons and shallow habitats throughout the Pacific. Two mitochondrial markers (cytochrome oxidase I and control region) were sequenced to resolve population structure and history of each species. Haplotype and nucleotide diversity were similar among all four species. The outer reef species showed significantly less population structure, consistent with longer pelagic larval durations. Mismatch distributions and significant negative Fu’s F values indicate Pleistocene population expansion for all species, and (contrary to expectations) shallower histories in the outer slope species. We conclude that lagoonal wrasses may persist through glacial habitat disruptions, but are restricted to refugia during lower sea level stands. In contrast, outer reef slope species have homogeneous and well-connected populations through their entire ranges regardless of sea level fluctuations. These findings contradict the hypothesis that shallow species are less genetically diverse as a consequence of glacial cycles. PMID:22701597
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27 CFR 9.207 - Outer Coastal Plain.
Code of Federal Regulations, 2010 CFR
2010-04-01
... Outer Coastal Plain. (a) Name. The name of the viticultural area described in this section is “Outer...,000 scale. (c) Boundary. The Outer Coastal Plain viticultural area includes all of Cumberland, Cape... Counties in the State of New Jersey. The boundary of the Outer Coastal Plain viticultural area is as...
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Continental Scientific Drilling Program.
1979-01-01
Institute of Technology ALBERT W. BALLY, Shell Oil Company, Houston HUBERT L. BARNES, Pennsylvania State University ARTHUR L. BOETTCHER, University of...San Marcos arch near Victoria, Texas. Information from a hole would answer fundamental questions about ancient continental margins and would complement...did the uplift begin in this area? Is the crust continental or oceanic? Area 3 (Figure A-7), positioned upon the San Marcos arch to avoid the thick
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Robb, James M.
1980-01-01
High-resolution seismic-reflection profiles were collected by the U.S. Geological Survey (USGS) aboard R/V COLUMBUS ISELIN, cruise 7807-1, from 18 August to 4 September 1978 over the Continental Slope of the Eastern United States between Wilmington and Hudson Canyons. These data were acquired as part of a study to determine potential geologic hazards to petroleum development of the Baltimore Canyon trough area. On this cruise, the Continental Slope between Lindenkohl and Carteret Canyons was surveyed along lines spaced one-half nautical mile apart to study the size and distribution of mass-wasting features as a guide to assess the importance of mass wasting processes on the Continental Slope. The seismic-reflection profiles were placed to complement other data gathered previously by the USGS.Track-line distances totaled 2,050 km of 40-in3 air-gun (with wave shaper) profiles, 2,100 km of 800-J sparker data, and 2,100 km of 3 .5-kHz data. The air-gun and sparker profiles are of high quality, but the 3.5-kHz system did not function well and achieved no subbottom penetration. The side-scan sonar system was operated along the uppermost Continental Slope to investigate its potential for use in this environment. Data were acquired over 22 km of ship's track.Navigation was by Loran-C (5-minute fix interval).The original records can be examined at the U.S. Geological Survey offices in Woods Hole, Massachusetts 02543. Microfilm copies of the data are available for purchase from the National Geophysical and Solar-Terrestrial Data Center (NGSDC), Boulder, Colorado 80303.
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Brazilian continental cretaceous
NASA Astrophysics Data System (ADS)
Petri, Setembrino; Campanha, Vilma A.
1981-04-01
Cretaceous deposits in Brazil are very well developed, chiefly in continental facies and in thick sequences. Sedimentation occurred essentially in rift-valleys inland and along the coast. Three different sequences can be distinguished: (1) a lower clastic non-marine section, (2) a middle evaporitic section, (3) an upper marine section with non-marine regressive lithosomes. Continental deposits have been laid down chiefly between the latest Jurassic and Albian. The lower lithostratigraphic unit is represented by red shales with occasional evaporites and fresh-water limestones, dated by ostracods. A series of thick sandstone lithosomes accumulated in the inland rift-valleys. In the coastal basins these sequences are often incompletely preserved. Uplift in the beginning of the Aptian produced a widespread unconformity. In many of the inland rift-valleys sedimentation ceased at that time. A later transgression penetrated far into northeastern Brazil, but shortly after continental sedimentation continued, with the deposition of fluvial sandstones which once covered large areas of the country and which have been preserved in many places. The continental Cretaceous sediments have been laid down in fluvial and lacustrine environments, under warm climatic conditions which were dry from time to time. The fossil record is fairly rich, including besides plants and invertebrates, also reptiles and fishes. As faulting tectonism was rather strong, chiefly during the beginning of the Cretaceous, intercalations of igneous rocks are frequent in some places. Irregular uplift and erosion caused sediments belonging to the remainder of this period to be preserved only in tectonic basins scattered across the country.
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Mean Lagrangian drift in continental shelf waves
NASA Astrophysics Data System (ADS)
Drivdal, M.; Weber, J. E. H.
2012-04-01
The time- and depth-averaged mean drift induced by barotropic continental shelf waves (CSW's) is studied theoretically for idealized shelf topography by calculating the mean volume fluxes to second order in wave amplitude. The waves suffer weak spatial damping due to bottom friction, which leads to radiation stress forcing of the mean fluxes. In terms of the total wave energy density E¯ over the shelf region, the radiation stress tensor component S¯11 for CSW's is found to be different from that of shallow water surface waves in a non-rotating ocean. For CSW's, the ratio ¯S11/¯E depends strongly on the wave number. The mean Lagrangian flow forced by the radiation stress can be subdivided into a Stokes drift and a mean Eulerian drift current. The magnitude of the latter depends on the ratio between the radiation stress and the bottom stress acting on the mean flow. When the effect of bottom friction acts equally strong on the waves and the mean current, calculations for short CSW's show that the Stokes drift and the friction-dependent wave-induced mean Eulerian current varies approximately in anti-phase over the shelf, and that the latter is numerically the largest. For long CSW's they are approximately in phase. In both cases the mean Lagrangian current, which is responsible for the net particle drift, has its largest numerical value at the coast on the shallow part of the shelf. Enhancing the effect of bottom friction on the Eulerian mean flow, results in a general current speed reduction, as well as a change in spatial structure for long waves. Applying realistic physical parameters for the continental shelf west of Norway, calculations yield along-shelf mean drift velocities for short CSW's that may be important for the transport of biological material, neutral tracers, and underwater plumes of dissolved oil from deep water drilling accidents.
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How Continental Bank outsourced its "crown jewels.".
Huber, R L
1993-01-01
No industry relies more on information than banking does, yet Continental, one of America's largest banks, outsources its information technology. Why? Because that's the best way to service the customers that form the core of the bank's business, says vice chairman Dick Huber. In the late 1970s and early 1980s, Continental participated heavily with Penn Square Bank in energy investments. When falling energy prices burst Penn Square's bubble in 1982, Continental was stuck with more than $1 billion in bad loans. Eight years later when Dick Huber came on board, Continental was working hard to restore its once solid reputation. Executives had made many tough decisions already, altering the bank's focus from retail to business banking and laying off thousands of employees. Yet management still needed to cut costs and improve services to stay afloat. Regulators, investors, and analysts were watching every step. Continental executives, eager to focus on the bank's core mission of serving business customers, decided to outsource one after another in-house service--from cafeteria services to information technology. While conventional wisdom holds that banks must retain complete internal control of IT, Continental bucked this argument when it entered into a ten-year, multimillion-dollar contract with Integrated Systems Solutions Corporation. Continental is already reaping benefits from outsourcing IT. Most important, Continental staffers today focus on their true core competencies: intimate knowledge of customers' needs and relationships with customers.
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Nineteenth-century collapse of a benthic marine ecosystem on the open continental shelf
Tomašových, Adam; Kidwell, Susan M.
2017-01-01
The soft-sediment seafloor of the open continental shelf is among the least-known biomes on Earth, despite its high diversity and importance to fisheries and biogeochemical cycling. Abundant dead shells of epifaunal suspension-feeding terebratulid brachiopods (Laqueus) and scallops on the now-muddy mainland continental shelf of southern California reveal the recent, previously unsuspected extirpation of an extensive offshore shell-gravel ecosystem, evidently driven by anthropogenic siltation. Living populations of attached epifauna, which formerly existed in a middle- and outer-shelf mosaic with patches of trophically diverse muds, are restricted today to rocky seafloor along the shelf edge and to the sandier shelves of offshore islands. Geological age-dating of 190 dead brachiopod shells shows that (i) no shells have been produced on the mainland shelf within the last 100 years, (ii) their shell production declined steeply during the nineteenth century, and (iii) they had formerly been present continuously for at least 4 kyr. This loss, sufficiently rapid (less than or equal to 100 years) and thorough to represent an ecosystem collapse, coincides with intensification of alluvial-plain land use in the nineteenth century, particularly livestock grazing. Extirpation was complete by the start of twentieth-century urbanization, warming, bottom fishing and scientific surveys. The loss of this filter-feeding fauna and the new spatial homogeneity and dominance of deposit- and detritus-feeders would have altered ecosystem functioning by reducing habitat heterogeneity and seawater filtering. This discovery, attesting to the power of this geological approach to recent ecological transitions, also strongly increases the spatial scope attributable to the negative effects of siltation, and suggests that it has been under-recognized on continental shelves elsewhere as a legacy of coastal land use. PMID:28592668
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Nineteenth-century collapse of a benthic marine ecosystem on the open continental shelf.
Tomašových, Adam; Kidwell, Susan M
2017-06-14
The soft-sediment seafloor of the open continental shelf is among the least-known biomes on Earth, despite its high diversity and importance to fisheries and biogeochemical cycling. Abundant dead shells of epifaunal suspension-feeding terebratulid brachiopods ( Laqueus ) and scallops on the now-muddy mainland continental shelf of southern California reveal the recent, previously unsuspected extirpation of an extensive offshore shell-gravel ecosystem, evidently driven by anthropogenic siltation. Living populations of attached epifauna, which formerly existed in a middle- and outer-shelf mosaic with patches of trophically diverse muds, are restricted today to rocky seafloor along the shelf edge and to the sandier shelves of offshore islands. Geological age-dating of 190 dead brachiopod shells shows that (i) no shells have been produced on the mainland shelf within the last 100 years, (ii) their shell production declined steeply during the nineteenth century, and (iii) they had formerly been present continuously for at least 4 kyr. This loss, sufficiently rapid (less than or equal to 100 years) and thorough to represent an ecosystem collapse, coincides with intensification of alluvial-plain land use in the nineteenth century, particularly livestock grazing. Extirpation was complete by the start of twentieth-century urbanization, warming, bottom fishing and scientific surveys. The loss of this filter-feeding fauna and the new spatial homogeneity and dominance of deposit- and detritus-feeders would have altered ecosystem functioning by reducing habitat heterogeneity and seawater filtering. This discovery, attesting to the power of this geological approach to recent ecological transitions, also strongly increases the spatial scope attributable to the negative effects of siltation, and suggests that it has been under-recognized on continental shelves elsewhere as a legacy of coastal land use. © 2017 The Author(s).
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Continental fragmentation and the strontium isotopic evolution of seawater.
NASA Astrophysics Data System (ADS)
Eric, H.; Jean Pascal, C.
2008-12-01
The time evolution of the strontium isotopic composition of seawater over the last 600 million years has the form of an asymmetric trough. The values are highest in the Cambrian and recent and lowest in the Jurassic. Superimposed on this trend are a number of smaller oscillations. The mechanisms responsible for these global isotopic fluctuations are subject to much debates. In order to get a quantitative picture of the changing paleogeography, we have characterized land-ocean distributions over Late Proterozoic to Phanerozoic times from measurement of perimeters and areas of continental fragments, based on paleomagnetic reconstructions. These measurements served to calculate geophysically constrainted breakup and scatter indexes of continental land masses from 0 to 1100 Ma (Cogne and Humler, 2008). Both parameters (strontium isotopic ratios of seawater and continental fragmentation indexes) are obviously highly correlated during the last 600 Ma. Low continental dispersion (that is large continental land masses) are associated with low seawater strontium isotopic ratios (that is when the continental inputs to oceans are minimum) and high continental dispersion (that is relatively small and widely distributed continents) with high seawater strontium isotopic ratios (that is when the continental input to ocean is maximum). Importantly, this first order evolution appears to conflict with the common idea of mountains erosion as a source for radiogenic strontium to oceans because high strontium isotopic ratios in seawater correspond to period of maximum dispersion of continents and not with period of general collisions. At first glance, it would seem that continental erosion increases with the degree of continental dispersion. Models showing that continental precipitation increases when continental masses are smaller and more widely dispersed and/or the length of continental margins available for rivers to carry continental material to oceans are thus favoured in order
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Subduction-driven recycling of continental margin lithosphere.
Levander, A; Bezada, M J; Niu, F; Humphreys, E D; Palomeras, I; Thurner, S M; Masy, J; Schmitz, M; Gallart, J; Carbonell, R; Miller, M S
2014-11-13
Whereas subduction recycling of oceanic lithosphere is one of the central themes of plate tectonics, the recycling of continental lithosphere appears to be far more complicated and less well understood. Delamination and convective downwelling are two widely recognized processes invoked to explain the removal of lithospheric mantle under or adjacent to orogenic belts. Here we relate oceanic plate subduction to removal of adjacent continental lithosphere in certain plate tectonic settings. We have developed teleseismic body wave images from dense broadband seismic experiments that show higher than expected volumes of anomalously fast mantle associated with the subducted Atlantic slab under northeastern South America and the Alboran slab beneath the Gibraltar arc region; the anomalies are under, and are aligned with, the continental margins at depths greater than 200 kilometres. Rayleigh wave analysis finds that the lithospheric mantle under the continental margins is significantly thinner than expected, and that thin lithosphere extends from the orogens adjacent to the subduction zones inland to the edges of nearby cratonic cores. Taking these data together, here we describe a process that can lead to the loss of continental lithosphere adjacent to a subduction zone. Subducting oceanic plates can viscously entrain and remove the bottom of the continental thermal boundary layer lithosphere from adjacent continental margins. This drives surface tectonics and pre-conditions the margins for further deformation by creating topography along the lithosphere-asthenosphere boundary. This can lead to development of secondary downwellings under the continental interior, probably under both South America and the Gibraltar arc, and to delamination of the entire lithospheric mantle, as around the Gibraltar arc. This process reconciles numerous, sometimes mutually exclusive, geodynamic models proposed to explain the complex oceanic-continental tectonics of these subduction zones.
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Processes in continental collision zones: Preface
NASA Astrophysics Data System (ADS)
Zheng, Yong-Fei; Zhang, Lifei; McClelland, William C.; Cuthbert, Simon
2012-04-01
Formation and exhumation of high-pressure (HP) to ultrahigh-pressure (UHP) metamorphic rocks in continental subduction zones are the two fundamental geodynamic aspects of collisional orogensis. This volume is based on the Session 08c titled "Geochemical processes in continental collision zones" at Goldschmidt 2010 in Knoxville, USA. It focuses on micro- to macro-scale processes that are temporally and spatially linked to different depths of crustal subduction/exhumation and associated mineralogical changes. They are a key to understanding a wide spectrum of phenomena, involving HP/UHP metamorphism and syn-/post-collisional magmatism. Papers in this volume report progresses in petrological, geochronological and geochemical studies of UHP metamorphic rocks and their derivatives in China, with tectonic settings varying from arc-continent collision to continent-continent collision. Microbeam in-situ analyses of metamorphic and magmatic minerals are successfully utilized to solve various problems in the study of continental deep subduction and UHP metamorphism. In addition to their geochronological applications to dating of HP to UHP metamorphic events during continental collision, microbeam techniques have also served as an efficient means to recognize different generations of mineral growth during continental subduction-zone metamorphism. Furthermore, metamorphic dehydration and partial melting of UHP metamorphic rocks during subduction and exhumation are highlighted with respect to their effects on fluid action and element mobilization. These have provided new insights into chemical geodynamics in continental subduction zones.
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Rapid hydrogen ion uptake of rod outer segments and rhodopsin solutions on illumination
Falk, G.; Fatt, P.
1966-01-01
1. Flash illumination of a suspension of frog rod outer segments or rhodopsin solution in contact with a platinum electrode produces a rapidly developing negative displacement of potential of the electrode (with respect to a reversible electrode). 2. The amplitude of the potential change varies inversely with the H+ buffering capacity of the medium. It is inferred that the response is due to an uptake of H+ by the rod outer segments or rhodopsin, with the platinum surface acting as a pH electrode. 3. Determination of the action spectrum shows that the response depends on the absorption of light by rhodopsin. 4. In frog rods one acid-binding group with a pK of about 7·9 is produced for each molecule of rhodopsin bleached, consistent with a rhodopsin concentration in frog rods of 1·7 mM. 5. It is suggested that the time course of the response with rhodopsin solutions reflects the kinetics of the conversion of metarhodopsin I to metarhodopsin II. 6. A slower time course of voltage change observed for suspensions of outer segments is attributable to the time required for the diffusion of H+ buffer out of the rods. PMID:5945249
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Seismic probing of continental subduction zones
NASA Astrophysics Data System (ADS)
Zhao, Liang; Xu, Xiaobing; Malusà, Marco G.
2017-09-01
High-resolution images of Earth's interior provide pivotal information for the understanding of a range of geodynamic processes, including continental subduction and exhumation of ultrahigh-pressure (UHP) metamorphic rocks. Here we present a synthesis of available global seismic observations on continental subduction zones, and selected examples of seismic probing from the European Alps, the Himalaya-Tibet and the Qinling-Dabie orogenic belts. Our synthesis and examples show that slabs recognized beneath exhumed continental UHP terranes generally have shallow dip angles (<45°) at depths <100 km, to become much steeper at depths >100 km. Slabs underlined by a clear high velocity anomaly from Earth's surface to the mantle are generally Cenozoic in age. Some of these slabs are continuous, whereas other continental subduction zones are located above discontinuous high velocity anomalies possibly suggesting slab breakoff. The density of seismic stations and the quality of recordings are of primary importance to get high-resolution images of the upper mantle to be used as a starting point to provide reliable geodynamic interpretations. In some cases, areas previously indicated as possible site of slab breakoff, such as the European Alps, have been later proven to be located above a continuous slab by using higher quality travel time data from denser seismic arrays. Discriminating between oceanic and continental slabs can be challenging, but valuable information can be provided by combining teleseismic tomography and receiver function analysis. The upper mantle beneath most continental UHP terranes generally shows complex seismic anisotropy patterns that are potentially preserved even in pre-Cenozoic subduction zones. These patterns can be used to provide information on continental slabs that are no longer highlighted by a clear high-velocity anomaly.
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The Continental Margins Program in Georgia
Cocker, M.D.; Shapiro, E.A.
1999-01-01
From 1984 to 1993, the Georgia Geologic Survey (GGS) participated in the Minerals Management Service-funded Continental Margins Program. Geological and geophysical data acquisition focused on offshore stratigraphic framework studies, phosphate-bearing Miocene-age strata, distribution of heavy minerals, near-surface alternative sources of groundwater, and development of a PC-based Coastal Geographic Information System (GIS). Seven GGS publications document results of those investigations. In addition to those publications, direct benefits of the GGS's participation include an impetus to the GGS's investigations of economic minerals on the Georgia coast, establishment of a GIS that includes computer hardware and software, and seeds for additional investigations through the information and training acquired as a result of the Continental Margins Program. These addtional investigations are quite varied in scope, and many were made possible because of GIS expertise gained as a result of the Continental Margins Program. Future investigations will also reap the benefits of the Continental Margins Program.From 1984 to 1993, the Georgia Geologic Survey (GGS) participated in the Minerals Management Service-funded Continental Margins Program. Geological and geophysical data acquisition focused on offshore stratigraphic framework studies, phosphate-bearing Miocene-age strata, distribution of heavy minerals, near-surface alternative sources of groundwater, and development of a PC-based Coastal Geographic Information System (GIS). Seven GGS publications document results of those investigations. In addition to those publications, direct benefits of the GGS's participation include an impetus to the GGS's investigations of economic minerals on the Georgia coast, establishment of a GIS that includes computer hardware and software, and seeds for additional investigations through the information and training acquired as a result of the Continental Margins Program. These additional
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,
1975-01-01
The area designated for possible oil and gas lease sale as modified from BLM memorandum 3310 #42 (722) and referred to therein as the North Atlantic Outer Continental Shelf (OCS) contains about 58,300 sq km of shelf beneath water depths of less than 200 m and lies chiefly within the Georges Bank basin. The oldest sediments drilled or dredged on the bordering Continental Slope are sandstone, clay, and silt of Upper Cretaceous age. In Upper Cretaceous exposures, on Marthas Vineyard and nearby New England islands, the predominant lithology appears to be clay. About 125 km northeast of the eastern tip of Georges Bank, the Shell B-93 well penetrated clays and silts of Upper and Lower Cretaceous age above dense Jurassic carbonate rocks which overlie a basement of lower Paleozoic slate, schist, quartzite, and granite. Structurally, the Georges Bank basin is a westerly trending trough which opens to the west-southwest. Post-Paleozoic sediments are more than 8 km thick in parts of the basin. Major structural features appear to be directly related to basement structures. Local anticlines, probably caused by differential compaction over basement flexures and horst blocks or by later uplift along basement faults are reflected principally in Lower Cretaceous and older sediments, though some of these features continue upward to within 0.7 of a second (about 650 m) of the seafloor. Tertiary deposits in the Georges Bank basin are probably up to a kilometre thick and are made up of poorly consolidated sand, silt, and clay. The Cretaceous section is inferred to be up to 3.5 km thick and to be mainly clastics -- shale, siltstone, calcareous shale, changing to limestone in the lowest part of the system. Jurassic rocks in the deepest part of the basin appear to be about 3.6 to 4.0 km thick and probably consist mainly of dense carbonates. Potential source rocks in the Georges Bank basin may include organic-rich Cretaceous shale and carbonaceous Jurassic limestone. By analogy with the
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-10
... locate it on the Internet at http://www.boem.gov/5-year/2012-2017 or you may contact Mr. James F. Bennett... prepared. Dated: October 26, 2011. Rodney Cluck, Acting Chief Environmental Officer, Bureau of Ocean Energy...
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Continental rifts and mineral resources
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burke, K.
1992-01-01
Continental rifts are widespread and range in age from the present to 3 b.y. Individual rifts may form parts of complex systems as in E. Africa and the Basin and Range. Rifts have originated in diverse environments such as arc-crests, sites of continental collision, collapsing mountain belts and on continents at rest over the mantle circulation pattern. Continental rift resources can be classified by depth of origin: For example, in the Great Dike, Norilsk and Mwadui magma from the mantle is the host. At shallower depths continental crust partly melted above mafic magma hosts ore (Climax, Henderson). Rift volcanics aremore » linked to local hydrothermal systems and to extensive zeolite deposits (Basin and Range, East Africa). Copper (Zambia, Belt), zinc (Red Dog) and lead ores (Benue) are related to hydrothermal systems which involve hot rock and water flow through both pre-rift basement and sedimentary and volcanic rift fill. Economically significant sediments in rifts include coals (the Gondwana of Inida), marine evaporites (Lou Ann of the Gulf of Mexico) and non-marine evaporites (East Africa). Oil and gas in rifts relate to a variety of source, reservoir and trap relations (North Sea, Libya), but rift-lake sediment sources are important (Sung Liao, Bo Hai, Mina, Cabinda). Some ancient iron ores (Hammersley) may have formed in rift lakes but Algoman ores and greenstone belt mineral deposits in general are linked to oceanic and island arc environments. To the extent that continental environments are represented in such areas as the Archean of the Superior and Slave they are Andean Arc environments which today have locally rifted crests (Ecuador, N. Peru). The Pongola, on Kaapvaal craton may, on the other hand represent the world's oldest preserved, little deformed, continental rift.« less
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NASA Astrophysics Data System (ADS)
Lyakhovsky, V.; Segev, A.; Schattner, U.; Weinberger, R.
2012-01-01
We study the propagation of a continental rift and its interaction with a continental margin utilizing a 3-D lithospheric model with a seismogenic crust governed by a damage rheology. A long-standing problem in rift-mechanics, known as thetectonic force paradox, is that the magnitude of the tectonic forces required for rifting are not large enough in the absence of basaltic magmatism. Our modeling results demonstrate that under moderate rift-driving tectonic forces the rift propagation is feasible even in the absence of magmatism. This is due to gradual weakening and "long-term memory" of fractured rocks that lead to a significantly lower yielding stress than that of the surrounding intact rocks. We show that the style, rate and the associated seismicity pattern of the rift zone formation in the continental lithosphere depend not only on the applied tectonic forces, but also on the rate of healing. Accounting for the memory effect provides a feasible solution for thetectonic force paradox. Our modeling results also demonstrate how the lithosphere structure affects the geometry of the propagating rift system toward a continental margin. Thinning of the crystalline crust leads to a decrease in the propagation rate and possibly to rift termination across the margin. In such a case, a new fault system is created perpendicular to the direction of the rift propagation. These results reveal that the local lithosphere structure is one of the key factors controlling the geometry of the evolving rift system and seismicity pattern.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Williams, Kathryn A.; Stenhouse, Iain J.; Johnson, Sarah M.
The Mid-Atlantic Baseline Studies Project helped address environmental barriers to offshore wind energy development in the mid-Atlantic region by providing regulators, developers, and other stakeholders with comprehensive baseline ecological data and analyses. Project funders and collaborators from a range of academic institutions, non-governmental organizations, federal agencies, foundations, and private companies came together to study bird, sea turtle, and marine mammal distributions, densities, and movements on the mid-Atlantic Outer Continental Shelf between 2012 and 2014. Specific project activities and goals included the following: (1) Conduct standardized surveys to quantify bird, sea turtle, and marine mammal densities seasonally and annually throughout themore » study region and identify important habitat use or aggregation areas. (2) Develop statistical models to help understand the drivers of wildlife distribution and abundance patterns. (3) Use individual tracking data for several focal bird species to provide information on population connectivity and individual movements that is complementary to survey data. (4) Identify species that are likely to be exposed to offshore wind energy development activities in the mid-Atlantic study area. (5) Develop U.S.-based technological resources and assessment methods for future monitoring efforts, including a comparison of high resolution digital video aerial surveys to boat-based surveys. (6) Help meet data needs associated with National Environmental Policy Act (NEPA), Marine Mammal Protection Act, and Endangered Species Act requirements, by contributing several years of data and analysis towards future Environmental Impact Statements. This report consists of six parts: Project overview (executive summary and Chapters 1-2); Examining wildlife distributions and relative abundance from a digital video aerial survey platform (Chapters 3-6); Examining wildlife distributions and abundance using boat-based surveys
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Geology of continental margins
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
With continued high interest in offshore petroleum exploration, the 1977 AAPG Short Course presents the latest interpretations of new data bearing on the geology and geophysics of continental margins. Seven well-known earth scientists have organized an integrated program covering major topics involved in the development of ocean basins and continental margins with emphasis on the slopes and rises. The discussion of plate tectonics and evolution of continental margins is followed by presentations on the stratigraphy and structure of pull-apart and compressional margins. Prospective petroleum source rocks, their organic content, rate of burial, and distribution on slopes and rises of differentmore » margin types is covered. Prospective reservoir rock patterns are related to depositional processes and to the sedimentary and structural histories for different types of continental margins. Finally, the seismic recognition of depositional facies on slopes and rises for different margin types with varying rates of sediment supply during eustatic sea-level changes are discussed. The course with this syllabus offers an invaluable opportunity for explorationists to refresh their understanding of the geology associated with an important petroleum frontier. In addition, the course sets forth a technical frame of reference for the case-histoy papers to be presented later in the AAPG Research Symposium on the Petroleum Potential of Slopes, Rises, and Plateaus.« less
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Map of Distribution of Bottom Sediments on the Continental Shelf, Gulf of Alaska
Evans, Kevin R.; Carlson, Paul R.; Hampton, Monty A.; Marlow, Michael S.; Barnes, Peter W.
2000-01-01
floor structures. Sea-floor sediment on shallow banks is eroded by seasonal wave-generated currents. The winnowing action of the large storm waves results in concentrations of gravel over broad segments of the Kodiak shelf. Northeastern Gulf of Alaska -- Tectonic framework studies demonstrate that rocks of distant origin (Yakutat terrane) are currently attached to and moving with the Pacific Plate, as it collides with and is subducted beneath southern Alaska. This collision process has led to pronounced structural deformation of the continental margin and adjacent southern Alaska. Consequences include rapidly rising mountains and high fluvial and glacial sedimentation rates on the adjacent margin and ocean floor. The northeastern Gulf of Alaska shelf also has concentrations of winnowed (lag) gravel on Tarr Bank and on the outer shelf southeast of Yakutat Bay. Between Kayak Island and Yakutat Bay the outer shelf consists of pebbly mud (diamict). This diamict is a product of glacial marine sedimentation during the Pleistocene and is present today as a relict sediment. A prograding wedge of Holocene sediment consisting of nearshore sand grading seaward into clayey silt and silty clay covers the relict pebbly mud to mid-shelf and beyond. Shelf and slope channel systems transport glacially derived sediment across the continental margin into Surveyor Channel, an abyssal fan and channel system that reaches over 1,000 km to the Aleutian Trench.
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Radiation stress and mean drift in continental shelf waves
NASA Astrophysics Data System (ADS)
Weber, Jan Erik H.; Drivdal, Magnus
2012-03-01
The time- and depth-averaged mean drift induced by barotropic continental shelf waves (CSW's) is studied theoretically for idealized shelf topography by calculating the mean volume fluxes to second order in wave amplitude. The waves suffer weak spatial damping due to bottom friction, which leads to radiation stress forcing of the mean fluxes. In terms of the total wave energy density E̅̅ over the shelf region, the radiation stress tensor component S̅11 for CSW's is found to be different from that of shallow water surface waves in a non-rotating ocean. For CSW's, the ratio S̅11/E̅ depends strongly on the wave number. The mean Lagrangian flow forced by the radiation stress can be subdivided into a Stokes drift and a mean Eulerian drift current. The magnitude of latter depends on ratio between the radiation stress and the bottom stress acting on the mean flow. When the effect of bottom friction acts equally strong on the waves and the mean current, calculations for short CSW's show that the Stokes drift and the friction-dependent wave-induced mean Eulerian current varies approximately in anti-phase over the shelf, and that the latter is numerically the largest. For long CSW's they are approximately in phase. In both cases the mean Lagrangian current, which is responsible for the net particle drift, has its largest numerical value at the coast on the shallow part of the shelf. Enhancing the effect of bottom friction on the Eulerian mean flow, results in a general current speed reduction, as well as a change in spatial structure for long waves. Applying realistic physical parameters for the continental shelf west of Norway, calculations yield along-shelf mean drift velocities for short CSW's that may be important for the transport of biological material, neutral tracers, and underwater plumes of dissolved oil from deepwater drilling accidents.
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NASA Astrophysics Data System (ADS)
do Nascimento Silva, Luzia Liniane; Gomes, Moab Praxedes; Vital, Helenice
2018-05-01
Submerged reefs, referred to as the Açu Reefs, have been newly observed on both sides of the Açu Incised Valley on the northeastern equatorial Brazilian outer shelf. This study aims to understand the roles of shelf physiography, its antecedent morphologies, and its inter reef sedimentation on the different development stages of the biogenic reef during last deglacial sea-level rise. The data sets consist of side-scan sonar imagery, one sparker seismic profile, 76 sediment samples, and underwater photography. Seven backscatter patterns (P1 to P7) were identified and associated with eleven sedimentary carbonate and siliciclastic facies. The inherited relief, the mouth of the paleo incised valley, and the interreef sediment distribution play major controls on the deglacial reef evolution. The reefs occur in a depth-limited 25-55 m water depth range and in a 6 km wide narrow zone of the outer shelf. The reefs crop out in a surface area over 100 km2 and occur as a series of NW-SE preferentially orientated ridges composed of three parallel ridge sets at 45, 35, and 25 m of water depth. The reefs form a series of individual, roughly linear ridges, tens of km in length, acting as barriers in addition to scattered reef mounds or knolls, averaging 4 m in height and grouped in small patches and aggregates. The reefs, currently limited at the transition between the photic and mesophotic zones, are thinly covered by red algae and scattered coral heads and sponges. Taking into account the established sea-level curves from the equatorial Brazilian northeastern shelf / Rochas Atoll and Barbados, the shelf physiography, and the shallow bedrock, the optimal conditions for reef development had to occur during a time interval (11-9 kyr BP) characterized by a slowdown of the outer shelf flooding, immediately following Meltwater Pulse-1B. This 2 kyr short interval provided unique conditions for remarkable reef backstepping into distinct parallel ridge sets. Furthermore, the Açu Reefs
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NASA Astrophysics Data System (ADS)
Kosuge, Toshio
2002-01-01
" P e aceful use of outer space of outer space.....Principles of exploitation of outer space was passed in the Japanese Diet. It clearly mentioned that any activity of launching space object into outer space and developing launching rocket should be exclusively for peaceful purpose. NASDA was also established based upon the same principles of the public law. Japanese interpretation of Space Treaty and other related international agreements has been more strict on peaceful use of outer space, like non-military use rather than non-aggressive, because of influence of Japanese Constitution. Treaty and other agreements is analyzed through rapid development of its space activities, technologies and international cooperation with other space powers. Through more than thirty years experiences in space activities in public and private sectors, Japanese domestic laws and policies have not been changed in relation with basic principles. and laws relating to space activities in order to develop new space law and more international cooperation for space utilization rather than military use in new century.
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33 CFR 106.260 - Security measures for access control.
Code of Federal Regulations, 2013 CFR
2013-07-01
... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental... unattended spaces that adjoin areas to which OCS facility personnel and visitors have access; (9) Ensure OCS...
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33 CFR 106.260 - Security measures for access control.
Code of Federal Regulations, 2012 CFR
2012-07-01
... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental... unattended spaces that adjoin areas to which OCS facility personnel and visitors have access; (9) Ensure OCS...
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33 CFR 106.260 - Security measures for access control.
Code of Federal Regulations, 2011 CFR
2011-07-01
... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental... unattended spaces that adjoin areas to which OCS facility personnel and visitors have access; (9) Ensure OCS...
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33 CFR 106.260 - Security measures for access control.
Code of Federal Regulations, 2014 CFR
2014-07-01
... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental... unattended spaces that adjoin areas to which OCS facility personnel and visitors have access; (9) Ensure OCS...
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33 CFR 106.260 - Security measures for access control.
Code of Federal Regulations, 2010 CFR
2010-07-01
... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental... unattended spaces that adjoin areas to which OCS facility personnel and visitors have access; (9) Ensure OCS...
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Thermoelectric Outer Planets Spacecraft (TOPS)
NASA Technical Reports Server (NTRS)
1973-01-01
The research and advanced development work is reported on a ballistic-mode, outer planet spacecraft using radioisotope thermoelectric generator (RTG) power. The Thermoelectric Outer Planet Spacecraft (TOPS) project was established to provide the advanced systems technology that would allow the realistic estimates of performance, cost, reliability, and scheduling that are required for an actual flight mission. A system design of the complete RTG-powered outer planet spacecraft was made; major technical innovations of certain hardware elements were designed, developed, and tested; and reliability and quality assurance concepts were developed for long-life requirements. At the conclusion of its active phase, the TOPS Project reached its principal objectives: a development and experience base was established for project definition, and for estimating cost, performance, and reliability; an understanding of system and subsystem capabilities for successful outer planets missions was achieved. The system design answered long-life requirements with massive redundancy, controlled by on-board analysis of spacecraft performance data.
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The extent of continental crust beneath the Seychelles
NASA Astrophysics Data System (ADS)
Hammond, J. O. S.; Kendall, J.-M.; Collier, J. S.; Rümpker, G.
2013-11-01
The granitic islands of the Seychelles Plateau have long been recognised to overlie continental crust, isolated from Madagascar and India during the formation of the Indian Ocean. However, to date the extent of continental crust beneath the Seychelles region remains unknown. This is particularly true beneath the Mascarene Basin between the Seychelles Plateau and Madagascar and beneath the Amirante Arc. Constraining the size and shape of the Seychelles continental fragment is needed for accurate plate reconstructions of the breakup of Gondwana and has implications for the processes of continental breakup in general. Here we present new estimates of crustal thickness and VP/VS from H-κ stacking of receiver functions from a year long deployment of seismic stations across the Seychelles covering the topographic plateau, the Amirante Ridge and the northern Mascarene Basin. These results, combined with gravity modelling of historical ship track data, confirm that continental crust is present beneath the Seychelles Plateau. This is ˜30-33 km thick, but with a relatively high velocity lower crustal layer. This layer thins southwards from ˜10 km to ˜1 km over a distance of ˜50 km, which is consistent with the Seychelles being at the edge of the Deccan plume prior to its separation from India. In contrast, the majority of the Seychelles Islands away from the topographic plateau show no direct evidence for continental crust. The exception to this is the island of Desroche on the northern Amirante Ridge, where thicker low density crust, consistent with a block of continental material is present. We suggest that the northern Amirantes are likely continental in nature and that small fragments of continental material are a common feature of plume affected continental breakup.
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Poppe, L.J.; Poag, C.W.; Stanton, R.W.
1992-01-01
The Mobil 312-1 hydrocarbon exploratory well, southeastern Georges Bank Basin penetrated a section entirely composed of sedimentary rocks that range from Middle to Pliocene age. Carbonates are the dominant lithologies in the intervals at 6096-3444 m, 2560-2096 m and 1067-887 m; siliciclastics make up most of the remaining section. Although inferred paleoenvironments range primarily from supratidal to outer neritic, thin lignitic coal beds at 2204-2195 m and 1929-1920 m record brief periods of nonmarine sedimentation. Middle and Upper Jurassic calcarenites, the drilling targets of the well, have little or no visible porosity and underwent at least three episodes of cementation.
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Estimation of continental precipitation recycling
NASA Technical Reports Server (NTRS)
Brubaker, Kaye L.; Entekhabi, Dara; Eagleson, P. S.
1993-01-01
The total amount of water that precipitates on large continental regions is supplied by two mechanisms: 1) advection from the surrounding areas external to the region and 2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the continental area. The degree to which regional precipitation is supplied by recycled moisture is a potentially significant climate feedback mechanism and land surface-atmosphere interaction, which may contribute to the persistence and intensification of droughts. Gridded data on observed wind and humidity in the global atmosphere are used to determine the convergence of atmospheric water vapor over continental regions. A simplified model of the atmospheric moisture over continents and simultaneous estimates of regional precipitation are employed to estimate, for several large continental regions, the fraction of precipitation that is locally derived. The results indicate that the contribution of regional evaporation to regional precipitation varies substantially with location and season. For the regions studied, the ratio of locally contributed to total monthly precipitation generally lies between 0. 10 and 0.30 but is as high as 0.40 in several cases.
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NASA Astrophysics Data System (ADS)
Breivik, Asbjørn Johan; Faleide, Jan Inge; Mjelde, Rolf; Flueh, Ernst R.; Murai, Yoshio
2017-10-01
The Early Eocene continental breakup was magma-rich and formed part of the North Atlantic Igneous Province. Extrusive and intrusive magmatism was abundant on the continental side, and a thick oceanic crust was produced up to a few m.y. after breakup. However, the extensive magmatism at the Vøring Plateau off mid-Norway died down rapidly northeastwards towards the Lofoten/Vesterålen Margin. In 2003 an Ocean Bottom Seismometer profile was collected from mainland Norway, across Lofoten, and into the deep ocean. Forward/inverse velocity modeling by raytracing reveals a continental margin transitional between magma-rich and magma-poor rifting. For the first time a distinct lower-crustal body typical for volcanic margins has been identified at this outer margin segment, up to 3.5 km thick and ∼50 km wide. On the other hand, expected extrusive magmatism could not be clearly identified here. Strong reflections earlier interpreted as the top of extensive lavas may at least partly represent high-velocity sediments derived from the shelf, and/or fault surfaces. Early post-breakup oceanic crust is moderately thickened (∼8 km), but is reduced to 6 km after 1 m.y. The adjacent continental crystalline crust is extended down to a minimum of 4.5 km thickness. Early plate spreading rates derived from the Norway Basin and the northern Vøring Plateau were used to calculate synthetic magnetic seafloor anomalies, and compared to our ship magnetic profile. It appears that continental breakup took place at ∼53.1 Ma, ∼1 m.y. later than on the Vøring Plateau, consistent with late strong crustal extension. The low interaction between extension and magmatism indicates that mantle plume material was not present at the Lofoten Margin during initial rifting, and that the observed excess magmatism was created by late lateral transport from a nearby pool of plume material into the lithospheric rift zone at breakup time.
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Chlamydomonas Outer Arm Dynein Alters Conformation in Response to Ca2+
Sakato, Miho; Sakakibara, Hitoshi
2007-01-01
We have previously shown that Ca2+ directly activates ATP-sensitive microtubule binding by a Chlamydomonas outer arm dynein subparticle containing the β and γ heavy chains (HCs). The γ HC–associated LC4 light chain is a member of the calmodulin family and binds 1-2 Ca2+ with KCa = 3 × 10−5 M in vitro, suggesting it may act as a Ca2+ sensor for outer arm dynein. Here we investigate interactions between the LC4 light chain and γ HC. Two IQ consensus motifs for binding calmodulin-like proteins are located within the stem domain of the γ heavy chain. In vitro experiments indicate that LC4 undergoes a Ca2+-dependent interaction with the IQ motif domain while remaining tethered to the HC. LC4 also moves into close proximity of the intermediate chain IC1 in the presence of Ca2+. The sedimentation profile of the γ HC subunit changed subtly upon Ca2+ addition, suggesting that the entire complex had become more compact, and electron microscopy of the isolated γ subunit revealed a distinct alteration in conformation of the N-terminal stem in response to Ca2+ addition. We propose that Ca2+-dependent conformational change of LC4 has a direct effect on the stem domain of the γ HC, which eventually leads to alterations in mechanochemical interactions between microtubules and the motor domain(s) of the outer dynein arm. PMID:17634291
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30 CFR 256.10 - Information to States.
Code of Federal Regulations, 2011 CFR
2011-07-01
... INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.10 Information to States. (a) The information covered...
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Macpherson, George S.; Bernstein, Janis
1980-01-01
Outer Continental Shelf (OCS) oil and gas exploration and development have been under way in the Pacific (Southern California) Region since 1966. During that time, there have been four Federal lease sales: in 1966, 1968, 1975 (Sale 35), and 1979 (Sale 48). Oil and gas production from three leases has been going on since 1968. It peaked in 1971 and now averages around 31,400 barrels of oil and 15.4 million cubic feet of gas per day. Discoveries on areas leased in the 1968 and 1975 sales have led to plans for eight new platforms to begin production in the early 1980's. Five platforms are in the eastern end of Santa Barbara Channel, one is in the western Channel, and two are in San Pedro Bay, south of Long Beach. Three rigs are doing exploratory drilling in the Region. The most recent estimates by the U.S. Geological Survey of remaining reserves for all identified fields in the Southern California Region are 695 million barrels of oil and 1,575 billion cubic feet of gas (January 1979). The USGS has also made risked estimates of economically recoverable oil and gas resources for all the leased tracts in the Region (March 1980). These risked estimates of economically recoverable resources are 394 billion barrels of oil and 1,295 billion cubic feet of gas. The USGS estimates of undiscovered recoverable resources for the entire Southern California OCS Region (January 1980) are 3,200 million barrels of oil and 3,400 billion cubic feet of gas. Because of the long history of oil and gas production in Southern California from wells onshore and in State waters, there are many existing facilities for the transportation, processing, and refining of oil and gas. Some of the expected new OCS production can be accommodated in these facilities. Four new onshore projects will be required. Two of these are under construction: (1) a 9.6-km (6-mi) onshore oil pipeline (capacity: 60,000 bpd) between Carpinteria (Santa Barbara County) and the existing Mobil-Rincon separation and treatment
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30 CFR 256.12 - Supplemental sales.
Code of Federal Regulations, 2011 CFR
2011-07-01
... INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.12 Supplemental sales. (a) The Secretary may conduct a...
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NASA Astrophysics Data System (ADS)
Cao, W.; Lee, C. T.
2016-12-01
Continental arc volcanoes have been suggested to release more CO2 than island arc volcanoes due to decarbonation of wallrock carbonates in the continental upper plate through which the magmas traverse (Lee et al., 2013). Continental arcs may thus play an important role in long-term climate. To test this hypothesis, we compiled geological maps to reconstruct the surface distribution of granitoid plutons and the lengths of ancient continental arcs. These results were then compiled into a GIS framework and incorporated into GPlates plate reconstructions. Our results show an episodic nature of global continental arc activity since 720 Ma. The lengths of continental arcs were at minimums during most of the Cryogenian ( 720-670 Ma), the middle Paleozoic ( 460-300 Ma) and the Cenozoic ( 50-0 Ma). Arc lengths were highest during the Ediacaran ( 640-570 Ma), the early Paleozoic ( 550-430 Ma) and the entire Mesozoic with peaks in the Early Triassic ( 250-240 Ma), Late Jurassic-Early Cretaceous ( 160-130 Ma), and Late Cretaceous ( 90-65 Ma). The extensive continental arcs in the Ediacaran and early Paleozoic reflect the Pan-African events and circum-Gondwana subduction during the assembly of the Gondwana supercontinent. The Early Triassic peak is coincident with the final closure of the paleo-Asian oceans and the onset of circum-Pacific subduction associated with the assembly of the Pangea supercontinent. The Jurassic-Cretaceous peaks reflect the extensive continental arcs established in the western Pacific, North and South American Cordillera, coincident with the initial dispersal of the Pangea. Continental arcs are favored during the final assembly and the early-stage dispersal of a supercontinent. Our compilation shows a temporal match between continental arc activity and long-term climate at least since 720 Ma. For example, continental arc activity was reduced during the Cryogenian icehouse event, and enhanced during the Early Paleozoic and Jurassic-Cretaceous greenhouse
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Code of Federal Regulations, 2011 CFR
2011-07-01
... LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and... administer a leasing program for oil, gas and sulphur. The procedures under which the Secretary will exercise...
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Uncovering the glacial history of the Irish continental shelf (Invited)
NASA Astrophysics Data System (ADS)
Dunlop, P.; Benetti, S.; OCofaigh, C.
2013-12-01
In 1999 the Irish Government initiated a €32 million survey of its territorial waters known as the Irish National Seabed Survey (INSS). The INSS is amongst the largest marine mapping programmes ever undertaken anywhere in the world and provides high-resolution multibeam, backscatter and seismic data of the seabed around Ireland. These data have been used to provide the first clear evidence for extensive glaciation of the continental shelf west and northwest of Ireland. Streamlined drumlins on the mid to outer shelf record former offshore-directed ice flow towards the shelf edge and show that the ice sheet was grounded in a zone of confluence where ice flowing onto the shelf from northwest Ireland merged with ice flowing across the Malin Shelf from southwest Scotland. The major glacial features on the shelf are well developed nested arcuate moraine systems that mark the position of the ice sheet margin and confirm that the former British Irish Ice Sheet was grounded as far as the shelf edge around 100 km offshore of west Donegal at the last glacial maximum. Distal to the moraines, on the outermost shelf, prominent zones of iceberg plough marks give way to the Barra/Donegal fan and a well developed system of gullies and canyons which incise the continental slope. Since 2008 several scientific cruises have retrieved cores from the shelf and slope to help build a more detailed understanding of glacial events in this region. This presentation will provide an overview of the glacial history of the Irish shelf and will discuss ongoing research programmes that are building on the initial research findings to produce a better understanding of the nature and timing of ice sheet events in this region.
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30 CFR 256.8 - Leasing maps and diagrams.
Code of Federal Regulations, 2011 CFR
2011-07-01
... INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.8 Leasing maps and diagrams. (a) Any area of the OCS...
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Regional magnetic anomaly constraints on continental breakup
DOE Office of Scientific and Technical Information (OSTI.GOV)
von Frese, R.R.B.; Hinze, W.J.; Olivier, R.
1986-01-01
Continental lithosphere magnetic anomalies mapped by the Magsat satellite are related to tectonic features associated with regional compositional variations of the crust and upper mantle and crustal thickness and thermal perturbations. These continental-scale anomaly patterns when corrected for varying observation elevation and the global change in the direction and intensity of the geomagnetic field show remarkable correlation of regional lithospheric magnetic sources across rifted continental margins when plotted on a reconstruction of Pangea. Accordingly, these anomalies provide new and fundamental constraints on the geologic evolution and dynamics of the continents and oceans.
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Drift of continental rafts with asymmetric heating.
Knopoff, L; Poehls, K A; Smith, R C
1972-06-02
A laboratory model of a lithospheric raft is propelled through a viscous asthenospheric layer with constant velocity of scaled magnitude appropriate to continental drift. The propulsion is due to differential heat concentration in the model oceanic and continental crusts.
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Prevention of the Outer Space Weaponization
NASA Astrophysics Data System (ADS)
Zhukov, Gennady P.
2002-01-01
9 states. The satellites of various functions (early warning, communication, data acquisition, reconnaissance and navigation) were actively used and continue to be used with the purposes of raising efficiency of ground armed forces, especially in fight against international terrorism. At the same time such satellites are not a weapon in the sense of that word since they do not create the threats of armed attack in outer space or from outer space. Moreover, they promote maintaining of stability in the international relations. For this reason the reconnaissance and data acquisition satellites used for the verification of observance by States of the arms limitation agreements are under international protection as national technical means of the control. Similar protection is enjoyed by the early warning satellites. With the help of space communication facilities the more reliable operative connection of the statesmen is organized in the strained situations. By this way the probability of making of the incorrect retaliatory decisions in critical political situations is reduced. At the same time it's necessary to take into consideration that the activities of such satellite systems are tightly connected with ground armed forces of the states. the earth, what from the point of view of international law may be qualified as establishing a partial demilitarization regime in outer space. After the prohibition of anti-satellite weapons (ASAT) and anti-satellite (ASAT) weapons it will be possible to speak about establishing of an international legal regime of complete demilitarization in outer space eliminating any kinds of weapon from outer space. in a peaceful time. weaponization.The main task of this paper is to analyze and to discuss the present binding regime of the outer space deweaponization and particular measures on consolidation and strengthening of this regime. agreements of the Russian Federation and the USA into multilateral Treaties. Such "immunity" would cover
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Robb, James M.
1980-01-01
High-resolution seismic-reflection profiles were collected by the U.S. Geological Survey (USGS) aboard R/V JAMES M. GILLIS (cruise GS 7903-4) from 27 June to 11 July 1979 over the Continental Slope of the Eastern United States between Lindenkohl and Hudson Canyons. These data were acquired as part of a study to determine potential geologic hazards to petroleum development of the Baltimore Canyon trough area. On this cruise, the Continental Slope between Carteret and South Toms Canyons was surveyed along lines spaced one-half nautical mile apart to study the size and distribution of mass-wasting features as a guide to assess the importance of mass-wasting processes on the Continental Slope. The seimsic-reflection profiles were placed to complement other data gathered previously by the USGS and to continue a survey grid begun in 1978 aboard the R/V COLUMBUS !SELIN, cruise CI 7807-1.Track-line distances totaled 1,555 km of 40-in3 air-gun (with wave shaper) profiles, 1, 750 km of 800-J sparker data, and 1,780 km of 3 .5-kHz data. All data are of high quality. A side-scan sonar system was operated briefly along the uppermost Continental Slope to acquire data over 70 km of ship's track. In addition, experimental profiling data were collected from a hydrophone towed at depth over the midslope on the end of the side-scan cable; the surface-towed sparker was used as a sound source. High-resolution profiles were collected by this method over 105 km of track.Navigation was by Loran-C (5-minute fix interval) and satellite.The original data may be inspected at the offices of the U.S. Geological Survey in Woods Hole, Massachusetts 02543. Microfilm copies of the data from this cruise are available for purchase from the National Geophysical and Solar-Terrestrial Data Center (NGSDC), Boulder, Colorado 80303.
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NASA Astrophysics Data System (ADS)
Höning, D.; Spohn, T.
2016-12-01
The evolution of Earth is charcterized by intertwined feedback cycles. We focus on two feedback cycles that include the mantle water budget and the continental crust and study possible effects of the Earth's biosphere. The first feedback loop includes cycling of water into the mantle at subduction zones and outgassing at volcanic chains and mid-ocean ridges. Water will reduce the viscosity of mantle rock, and therefore the speed of mantle convection and plate subduction will increase with the mantle water concentration, eventually enhancing the rates of mantle water regassing and outgassing. A second feedback loop includes the production and erosion of continental crust. Continents grow by volcanism above subduction zones, whose total length is determined by the total area of the continents. Furthermore, the erosion rate of the continents is proportional to the total surface area of continental crust. The rate of sediment subduction affects the rate of transport of water to the mantle and the production rate of new continental crust. We present a model that includes both cycles and show how the system develops stable and unstable fixed points in a plane defined by mantle water concentration and surface are of continents. The stable points represent either an Earth mostly covered by continents and a wet mantle or an Earth mostly covered by oceans with a dry mantle. The presently observed Earth is inbetween these extreme states but the state is intrinsically unstable. We couple the feedback model to a parameterized thermal evolution model. We show how Earth evolved towards its present unstable state. We argue that other feedback cycles such as the carbonate silicate cycle may act to stabilize the present state, however. By enhancing continental weathering and erosion, and eventually the sediment transport into subduction zones, the biosphere impacts both feedback cycles and might play a crucial role in regulating Earth's system and keep continental crust coverage and
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Depletion of the Outer Asteroid Belt
Liou; Malhotra
1997-01-17
During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.
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Depletion of the Outer Asteroid Belt
NASA Technical Reports Server (NTRS)
Liou, Jer-Chyi; Malhotra, Renu
1997-01-01
During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.
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NASA Astrophysics Data System (ADS)
Mosher, D. C.; Campbell, C.; Piper, D.; Chaytor, J. D.; Gardner, J. V.; Rebesco, M.
2016-12-01
Deep-sea sedimentation processes impart a fundamental control on the morphology of the western North Atlantic continental margin from Blake Spur to Hudson Strait. This fact is illustrated by the variable patterns of cross-margin gradients that are based on extensive new multibeam echo-sounder data in concert with subbottom profiler and seismic reflection data. Most of the continental margin has a steep (>3o) upper slope down to 1500 to 2500 m and then a gradual middle and lower slope with a general concave upward shape There is a constant interplay of deep sea sedimentation processes, but the general morphology is dictated by the dominant one. Erosion by off-shelf sediment transport in turbidity currents creating channels, gullies and canyons creates the steep upper slope. These gullies and canyons amalgamate to form singular channels that are conduits to the abyssal plain. This process results in a general seaward flattening of gradients, producing an exponentially decaying slope profile. Comparatively, sediment mass failure produces steeper upper slopes due to head scarp development and a wedging architecture to the lower slope as deposits thin in the downslope direction. This process results in either a two-segment slope, and/or a significant downslope gradient change where MTDs pinch out. Large sediment bodies deposited by contour-following currents are developed all along the margin. Blake Ridge, Sackville Spur, and Hamilton Spur are large detached drifts on disparate parts of the margin. Along their crests, they form a linear profile from the shelf to abyssal plain. Deeper portions of the US continental margin are dominated by the Chesapeake Drift and Hatteras Outer Ridge; both plastered elongate mounded drifts. Farther north, particularly on the Grand Banks margin, are plastered and separated drifts. These drifts tend to form bathymetric steps in profile, where they onlap the margin. Stacked drifts create several steps. Turbidites of the abyssal plain onlap
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Review of the outer scale of the atmospheric turbulence
NASA Astrophysics Data System (ADS)
Ziad, Aziz
2016-07-01
Outer scale is a relevant parameter for the experimental performance evaluation of large telescopes. Different techniques have been used for the outer scale estimation. In situ measurements with radiosounding balloons have given very small values of outer scale. This latter has also been estimated directly at the ground level from the wavefront analysis with High Angular Resolution (HAR) techniques using interferometric or Shack-Hartmann or more generally AO systems data. Dedicated instruments have been also developed for the outer scale monitoring such as the Generalized Seeing Monitor (GSM) and the Monitor of Outer Scale Profile (MOSP). The measured values of outer scale from HAR techniques, GSM and MOSP are somewhat coherent and are larger than the in situ results. The main explanation of this difference comes from the definition of the outer scale itself. This paper aims to give a review in a non-exhaustive way of different techniques and instruments for the measurement of the outer scale. Comparisons of outer scale measurements will be discussed in the light of the different definitions of this parameter, the associated observable quantities and the atmospheric turbulence model as well.
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Continental Basalts and Mantle Xenoliths
NASA Astrophysics Data System (ADS)
Zartman, Robert E.
In this decade of the International Lithosphere Program, much scientific attention is being directed toward the deep continental crust and subadjacent mantle. The petrologic, geochemical, and isotopic signatures of basaltic magmas, which transect much of the lithosphere as they ascend from their site of melting, and of contained cognate and accidental xenoliths, which are found along the path of ascent, give us, perhaps, the best clues to composition and structure in the third dimension. Continental Basalts and Mantle Xenoliths provides an opportunity to sample the British school of thought on subjects such as differences between oceanic and continental basalts, effects of mantle metasomatism, and relationships between events in the subcontinental mantle and those in the overlying crust. This volume is recommended by the publisher as being of interest to senior undergraduates and postgraduate researchers; I would extend that readership to all scientists who seek access to a potpourri of recent findings and current ideas in a rapidly evolving field of research.
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Outer Retinal Tubulation in Degenerative Retinal Disorders
Goldberg, Naomi R.; Greenberg, Jonathan P.; Laud, Ketan; Tsang, Stephen; Freund, K. Bailey
2013-01-01
Objective To demonstrate outer retinal tubulation (ORT) in various degenerative retinal disorders. Methods This was a retrospective review of the multimodal imaging of 29 eyes of 15 patients with various retinal dystrophies and inflammatory maculopathies manifesting ORT. The morphologic features of ORT and its evolution over time were analyzed using spectral-domain optical coherence tomography (SD-OCT) data. Results Outer retinal tubulation was identified as round or ovoid structures with hyper-reflective borders in pattern dystrophy (6 eyes), acute zonal occult outer retinopathy (5 eyes), retinitis pigmentosa (4 eyes), Stargardt disease (4 eyes), gyrate atrophy (2 eyes), choroideremia (2 eyes), and various other degenerative conditions. These structures appeared to develop from the invagination of photoreceptors at the junction of intact and atrophic outer retina. During follow-up, the number and distribution of ORT largely remained stable. As zones of atrophy enlarged, the frequency of ORT appeared to increase. The ORT structures were found in fewer than 10% of patients with retinitis pigmentosa, Stargardt, or pattern dystrophy. Conclusion Outer retinal tubulation is found in various degenerative retinal disorders that share in common damage to the outer retina and/or retinal pigment epithelium. The presence of ORT may be in an indicator of underlying disease stage and severity. PMID:23676993
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Plasmas in the outer heliosphere
NASA Technical Reports Server (NTRS)
Belcher, J. W.; Richardson, J. D.; Lazarus, A. J.; Gazis, P. R.; Barnes, A.
1995-01-01
We review the observed properties of the solar wind in the outer heliosphere, including observations from Voyager and the Pioneers, as well as from inner heliospheric probes as appropriate. These observations are crucial to modeling of the heliosphere and its interactions with the interstellar medium, since the wind ram pressure and its temporal variations are important in understanding the distance to the termination shock and heliopause and how those boundaries might vary in time. We focus on results since Solar Wind 7. Among the issues we will discuss are: (1) the time scales for and statistical properties of variations in the ram pressure in the outer heliosphere, and how those variations might affect the morphology of the heliospheric/interstellar medium interface; (2) the question of possible solar wind slowing in the outer heliosphere due to the pick-up of interstellar ions; (3) the issue of whether there is bulk heating of the solar wind associated either with interstellar ion pick-up or with continued heating due to stream-stream interactions; (4) evidence for latitudinal variations in solar wind properties; and (5) the 1.3 year periodicities apparent in the outer heliosphere, and the close correspondence with similar variations seen with inner heliospheric probes.
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NASA Technical Reports Server (NTRS)
Holman, Matthew J.; Lindstrom, David (Technical Monitor)
2005-01-01
Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; ( 2 ) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; ( 5 ) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.
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30 CFR 250.1405 - When is a case file developed?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 250.1405 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf (OCS) Civil... Officer may administer oaths and issue subpoenas requiring witnesses to attend meetings, submit...
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Continental volume and freeboard through geological time
NASA Technical Reports Server (NTRS)
Schubert, G.; Reymer, A. P. S.
1985-01-01
The consequences of approximately constant freeboard for continental growth are explored using a model that relates the volumes of isostatically compensated continents and oceans to the secular decline in terrestrial heat flow. It is found that a post-Archean increase in freeboard by 200 m requires continental growth of only 10 percent, while a decrease in freeboard by 200 m during this same period necessitates a crustal growth of 40 percent. Shrinkage of the continental crust since the end of the Archean can be ruled out. Changes of more than 10 percent in post-Archean crustal thickness are highly unlikely.
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Atmospheric entry probes for outer planet exploration. Outer planet entry probe technical summary
NASA Technical Reports Server (NTRS)
1974-01-01
The use of unmanned space probes for investigating the conditions existing on and around the outer planets of the solar system is discussed. The subjects included in the report are: (1) the design of a common entry probe for outer planet missions, (2) the significant trades related to the development of a common probe design, (3) the impact of bus selection on probe design, (4) the impact of probe requirements on bus modifications, and (5) the key technology elements recommended for advanced development. Drawings and illustrations of typical probes are included to show the components and systems used in the space probes.
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NASA Astrophysics Data System (ADS)
Morrill, P. L.; Rietze, A.; Kohl, L.; Miles, S.; Kavanagh, H.; Cox, A.; Brazelton, W. J.; Ishii, S.; Sherwood Lollar, B.; Schrenk, M. O.; Nealson, K. H.; Ziegler, S. E.; Ono, S.; Wang, D. T.; Lang, S. Q.; Cumming, E.
2014-12-01
Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface ultramafic environment rich in hydrogen and methane gases. Field data and results from substrate addition microcosm experiments will be presented from two contrasting continental sites of serpentinization: the Tablelands, NL, CAN and The Cedars, CA, USA both Phanerozoic in age. These continental sites share geochemical characteristics that make these environments challenging for life, such as high pH, low Eh, scarce electron acceptors, and limited dissolved inorganic carbon for autotrophic growth. However, microbiological analyses have demonstrated that life does indeed exist in these environments. While environmental genomic studies indicated the potential metabolic capabilities of microorganisms in the sites, actual microbial metabolic activities in these environments remain unknown. To expand the understanding of biogeochemistry of the sites, we are conducting studies focusing on chemical and isotopic measurements, carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms. Thus far, in situ geochemical data suggests that the methane from the Tablelands is primarily non-microbial, while the methane from The Cedars likely has some microbial contributions. To date, substrate addition microcosm experiments show no microbial production of methane from Tablelands' water and sediments. However, microbial carbon monoxide utilization has been observed in Tableland microcosms, but not in The Cedars microcosms. These results demonstrate how geochemistry and substrate addition experiments can be complementary for the determination of the processes favored at these continental sites of serpentinization.
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A Facies Model for Temperate Continental Glaciers.
ERIC Educational Resources Information Center
Ashley, Gail Mowry
1987-01-01
Discusses the presence and dynamics of continental glaciers in the domination of the physical processes of erosion and deposition in the mid-latitudes during the Pleistocene period. Describes the use of a sedimentary facies model as a guide to recognizing ancient temperate continental glacial deposits. (TW)
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Corrugated outer sheath gas-insulated transmission line
Kemeny, George A.; Cookson, Alan H.
1981-01-01
A gas-insulated transmission line includes two transmission line sections each of which are formed of a corrugated outer housing enclosing an inner high-voltage conductor disposed therein, with insulating support means supporting the inner conductor within the outer housing and an insulating gas providing electrical insulation therebetween. The outer housings in each section have smooth end sections at the longitudinal ends thereof which are joined together by joining means which provide for a sealing fixed joint.
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Controls on continental strain partitioning above an oblique subduction zone, Northern Andes
NASA Astrophysics Data System (ADS)
Schütt, Jorina M.; Whipp, David M., Jr.
2016-04-01
Strain partitioning is a common process at obliquely convergent plate margins dividing oblique convergence into margin-normal slip on the plate-bounding fault and horizontal shearing on a strike-slip system parallel to the subduction margin. In subduction zones, strain partitioning in the upper continental plate is mainly controlled by the shear forces acting on the plate interface and the strength of the continental crust. The plate interface forces are influenced by the subducting plate dip angle and the obliquity angle between the normal to the plate margin and the convergence velocity vector, and the crustal strength of the continent is strongly affected by the presence or absence of a volcanic arc, with the presence of the volcanic arcs being common at steep subduction zones. Along the ˜7000 km western margin of South America the convergence obliquity, subduction dip angles and presence of a volcanic arc all vary, but strain partitioning is only observed along parts of it. This raises the questions, to what extent do subduction zone characteristics control strain partitioning in the overriding continental plate, and which factors have the largest influence? We address these questions using lithospheric-scale 3D numerical geodynamic experiments to investigate the influence of subduction dip angle, convergence obliquity, and weaknesses in the crust owing to the volcanic arc on strain partitioning behavior. We base the model design on the Northern Volcanic Zone of the Andes (5° N - 2° S), characterized by steep subduction (˜ 35°), a convergence obliquity between 31° -45° and extensive arc volcanism, and where strain partitioning is observed. The numerical modelling software (DOUAR) solves the Stokes flow and heat transfer equations for a viscous-plastic creeping flow to calculate velocity fields, thermal evolution, rock uplift and strain rates in a 1600 km x 1600 km box with depth 160 km. Subduction geometry and material properties are based on a
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NASA Technical Reports Server (NTRS)
Parks, R. J.
1979-01-01
Initial, current and planned United States projects for the spacecraft exploration of the outer planets of the solar system are presented. Initial plans were developed in the mid-1960's for the exploration of the outer planets by utilizing the gravity-assist technique during a fortuitous alignment of the outer planets in the Grand Tour Project, however although state-of-the-art space technology could have supported the project, it was considered too expensive, therefore politically infeasible. Subsequently, the Pioneer Project was undertaken to explore the asteroid belt and the environment around Jupiter and the Voyager Project was undertaken to send two spacecraft to fly by Jupiter and utilize its gravity assist to reach Saturn. The successful Pioneer 10 and 11 missions have provided important information on the effects of the asteroid belt and the severe radiation environment around Jupiter, and Voyager 1 has collected information about Jupiter, its magnetic fields and radiation zones, and its satellites. Project Galileo is intended to be launched in January 1982 to conduct an intensive investigation of Jupiter, its satellites and immediate environment and a Saturn Orbiter dual probe mission and a Uranus orbiter are also under consideration.
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33 CFR 106.305 - Facility Security Assessment (FSA) requirements.
Code of Federal Regulations, 2013 CFR
2013-07-01
..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...
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33 CFR 106.305 - Facility Security Assessment (FSA) requirements.
Code of Federal Regulations, 2011 CFR
2011-07-01
..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...
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Code of Federal Regulations, 2014 CFR
2014-07-01
... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental Shelf (OCS) Facility Security Assessment (FSA) § 106.300 General. (a) The Facility Security Assessment (FSA) is a written document that is...
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Code of Federal Regulations, 2012 CFR
2012-07-01
... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental Shelf (OCS) Facility Security Assessment (FSA) § 106.300 General. (a) The Facility Security Assessment (FSA) is a written document that is...
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Code of Federal Regulations, 2013 CFR
2013-07-01
... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental Shelf (OCS) Facility Security Assessment (FSA) § 106.300 General. (a) The Facility Security Assessment (FSA) is a written document that is...
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33 CFR 106.305 - Facility Security Assessment (FSA) requirements.
Code of Federal Regulations, 2014 CFR
2014-07-01
..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...
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33 CFR 106.305 - Facility Security Assessment (FSA) requirements.
Code of Federal Regulations, 2012 CFR
2012-07-01
..., including computer systems and networks; (vi) Existing agreements with private security companies; (vii) Any... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Facility Security Assessment (FSA... SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental Shelf (OCS) Facility Security Assessment (FSA) § 106.300 General. (a) The Facility Security Assessment (FSA) is a written document that is...
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Late Pleistocene and Holocene sedimentary facies on the Ebro continental shelf
Diaz, J.; Nelson, C.H.; Barber, J.H.; Giro, S.
1990-01-01
Late Pleistocene-Holocene history of the Ebro continental shelf of northeastern Spain is recorded in two main sedimentary units: (1) a lower, transgressive unit that covers the shelf and is exposed on the outer shelf south of 40??40???N, and (2) an upper, progradational, prodeltaic unit that borders the Ebro Delta and extends southward along the inner shelf. The lower transgressive unit includes a large linear shoal found at a water depth of 90 m and hardground mounds at water depths of 70-80 m. Some patches of earlier Pleistocene prodelta mud remain also, exposed or covered by a thin veneer of transgressive sand on the northern outer shelf. This relict sand sheet is 2-3 m thick and contains 9000-12,500 yr old oyster and other shells at water depths of 78-88 m. The upper prodelta unit covers most of the inner shelf from water depths of 20-80 m and extends from the present Ebro River Delta to an area to the southwest where the unit progressively thins and narrows. Interpretation of high-resolution seismic reflection data shows the following facies occurring progressively offshore: (1) a thick stratified facies with thin progradational "foresets beds", (2) a faintly laminated facies with sparse reflectors of low continuity, and (3) a thin transparent bottomset facies underlain by a prominent flat-lying reflector. Deposition in the northern half of the prodelta began as soon as the shoreline transgressed over the mid-shelf, but progradation of the southern half did not begin until about 1000-3000 yrs after the transgression. A classic deltaic progradational sequence is shown in the Ebro prodelta mud by (1) gradation of seismic facies away from the delta, (2) coarsening-upward sequences near the delta and fining-upward sequences in the distal mud belt deposits, and (3) thin storm-sand layers and shell lags in the nearshore stratified facies. The boundaries of the prodeltaic unit are controlled by increased current speeds on the outer shelf (where the shelf narrows) and
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OUTER RADIATION BELT AND AURORAS
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gorchakov, E.V.
1961-01-01
Data obtained from Sputnik IH were used to determine the high-latitude boundary of the outer radiation belt and to interpret the nature of auroras. At the heights at which the auroras were observed, the outer boundary of the belt (69 deg north geomagnetic latitude) practically coincides with the auroral zone maximum (70 deg north geomagnetic latitude), while the maximum intensity of the outer belt near the earth lies at about 55 deg north geomagnetic latitude, i.e., at latitudes 15 deg below the auroral maximum. Consequently, auroras near the zone of maximum cannot be caused by the penetration into the atmospheremore » of electrons from the outer belt with energies on the order of 0.1 Mev (the mean energy of electrons in the outer belt). Other investigators have reported the detection of lowenergy streams at 55,000 to 75,000 km from the center of the earth in the equatorial plane. Moving toward the surface of the earth along the force lines of the magnetic field, electron streams of this type will reach the earth precisely in the region of the auroral zone maximum. It is considered possible that the electron streams are trapped at these distances from the earth and are at least partially responsible for auroras in the region of maximum. The existence of two maxima in the latitudinal distribution of auroral frequency, which attests to differert mechanisms of aurora formation, favors this hypothesis. In the region of the basic auroral maximum (70 deg north geomagnetic latitude) the auroras are the result of the invasion of belt particles, while in the region of the additional maximum (about 80 deg north geomagnetic latitude) they are caused by the direct penetration of corpuscular streams into the atmosphere. (OTS)« less
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46 CFR 154.170 - Outer hull steel plating.
Code of Federal Regulations, 2014 CFR
2014-10-01
... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2014-10-01 2014-10-01 false Outer hull steel plating. 154.170 Section 154.170...
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46 CFR 154.170 - Outer hull steel plating.
Code of Federal Regulations, 2012 CFR
2012-10-01
... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2012-10-01 2012-10-01 false Outer hull steel plating. 154.170 Section 154.170...
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46 CFR 154.170 - Outer hull steel plating.
Code of Federal Regulations, 2013 CFR
2013-10-01
... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2013-10-01 2013-10-01 false Outer hull steel plating. 154.170 Section 154.170...
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A geodynamic constraint on Archean continental geotherms
NASA Astrophysics Data System (ADS)
Bailey, R. C.
2003-04-01
Dewey (1988) observed that gravitational collapse appears to currently limit the altitudes of large plateaus on Earth to about 3 to 5 km above sea level. Arndt (1999) summarized the evidence for the failure of large parts of the continental crust to reach even sea-level during the Archean. If this property of Archean continental elevations was also enforced by gravitational collapse, it permits an estimation of the geothermal gradient in Archean continental crust. If extensional (collapse) tectonics is primarily a balance between gravitational power and the power consumed by extensional (normal) faulting in the upper brittle crust, as analysed by Bailey (1999), then it occurs when continental elevations above ocean bottoms exceed about 0.4 times the thickness of the brittle crust (Bailey, 2000). Assuming an Archean oceanic depth of about 5 km, it follows that that the typical thickness of Archean continental brittle crustal must have been less than about 12 km. Assuming the brittle-ductile transition to occur at about 350 degrees Celsius, this suggests a steep geothermal gradient of at least 30 degrees Celsius per kilometer for Archean continents, during that part of the Archean when continents were primarily submarine. This result does not help resolve the Archean thermal paradox (England and Bickle, 1984) whereby the high global heat flow of the Archean conflicts with the rather shallow crustal Archean geotherms inferred from geobarometry. In fact, the low elevation of Archean continental platforms raises another paradox, a barometric one: that continents were significantly below sea-level implies, by isostasy, that continental crustal thicknesses were significantly less than 30 km, yet the geobarometric data utilized by England and Bickle indicated burial pressures of Archean continental material of up to 10 kb. One resolution of both paradoxes (as discussed by England and Bickle) would be to interpret such deep burials as transient crustal thickening events of
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Heat flow and continental breakup: The Gulf of Elat (Aqaba)
NASA Technical Reports Server (NTRS)
Ben-Avraham, Z.; Vonherzen, R. P.
1985-01-01
Heat flow measurements were made in the major basins of the Gulf of Elat (Aqaba), northern Red Sea. The gulf is located at the southern portion of the Dead Sea rift which is a transform plate boundary. Gradient measurements at each site were made with a probe which allows multiple penetration of the bottom during a single deployment of the instrument. Thermal conductivity was determined by needle probe measurements on sedimentary cores. The mean heat flux, about 80 mWm(-2), is significantly above the continental mean, and probably also above that from the adjacent Sinai and Arabian continental blocks. The heat flow appears to increase from north to south. Such an increase may be related to the more advanced rifting stage of the Red Sea immediately to the south, which presently includes creation of an oceanic crust. This trend also corresponds to the general trend of the deep crustal structure in the gulf. Evidence from various geophysical fields suggest a gradual thinning of the crust towards the direction of the Red Sea where a normal oceanic crust exists. The heat flow data, together with other geophysical data, indicate a propagation of mature rifting activity from the Red Sea into the Gulf of Elat. This process is acting simultaneously with the transform motion along the Dead Sea rift.
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MHD processes in the outer heliosphere
NASA Technical Reports Server (NTRS)
Burlaga, L. F.
1984-01-01
The magnetic field measurements from Voyager and the magnetohydrodynamic (MHD) processes in the outer heliosphere are reviewed. A bibliography of the experimental and theoretical work concerning magnetic fields and plasmas observed in the outer heliosphere is given. Emphasis in this review is on basic concepts and dynamical processes involving the magnetic field. The theory that serves to explain and unify the interplanetary magnetic field and plasma observations is magnetohydrodynamics. Basic physical processes and observations that relate directly to solutions of the MHD equations are emphasized, but obtaining solutions of this complex system of equations involves various assumptions and approximations. The spatial and temporal complexity of the outer heliosphere and some approaches for dealing with this complexity are discussed.
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Seafloor geology of the Monterey Bay area continental shelf
Eittreim, S.L.; Anima, R.J.; Stevenson, A.J.
2002-01-01
Acoustic swath-mapping of the greater Monterey Bay area continental shelf from Point An??o Nuevo to Point Sur reveals complex patterns of rock outcrops on the shelf, and coarse-sand bodies that occur in distinct depressions on the inner and mid-shelves. Most of the rock outcrops are erosional cuestas of dipping Tertiary rocks that make up the bedrock of the surrounding lands. A mid-shelf mud belt of Holocene sediment buries the Tertiary rocks in a continuous, 6-km-wide zone on the northern Monterey Bay shelf. Rock exposures occur on the inner shelf, near tectonically uplifting highlands, and on the outer shelf, beyond the reach of the mud depositing on the mid-shelf since the Holocene sea-level rise. The sediment-starved shelf off the Monterey Peninsula and south to Point Sur has a very thin cover of Holocene sediment, and bedrock outcrops occur across the whole shelf, with Salinian granite outcrops surrounding the Monterey Peninsula. Coarse-sand deposits occur both bounded within low-relief rippled scour depressions, and in broad sheets in areas like the Sur Platform where fine sediment sources are limited. The greatest concentrations of coarse-sand deposits occur on the southern Monterey Bay shelf and the Sur shelf. ?? 2002 Elsevier Science B.V. All rights reserved.
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30 CFR 285.101 - What is the purpose of this part?
Code of Federal Regulations, 2010 CFR
2010-07-01
... RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF General Provisions...) grants for renewable energy production on the Outer Continental Shelf (OCS) and RUEs for the alternate... obligations when you undertake activities authorized in this part; and (c) Ensure that renewable energy...
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NASA Astrophysics Data System (ADS)
Fewings, M. R.; Washburn, L.; Ohlmann, C.; Blanchette, C.; Caselle, J.; Gotschalk, C.
2008-12-01
We use seven-year time series of wind stress, water velocity, and temperature in 15-18 m water depth to describe the circulation and water temperature over the inner continental shelves of the Channel Islands and California mainland in the Santa Barbara Basin. This area is strongly influenced by the California Current upwelling system. In turn, the water circulation in the Santa Barbara Basin influences the local marine ecosystem by affecting the water temperature and the supply of nutrients and larval fish and invertebrates. Larvae and nutrients traveling from the coast to the open ocean and back again must somehow pass through the inner shelf. The water circulation over the inner continental shelf of the Northern Channel Islands has not been described. Due to the shallowness of the water, an inner shelf has different physical dynamics than either the surfzone or the middle and outer continental shelf. We discuss the relative importance of upwelling- favorable along-shelf winds and of cross-shelf winds as forcing mechanisms for coastal upwelling circulations over the inner shelf; test whether the cross-shelf wind stress and surface gravity waves are important for cross-shelf circulation in the Santa Barbara Basin; and describe the subtidal patterns of water temperature, stratification, and velocity around the Channel Islands and their relation to observed larval settlement patterns. Cross-shelf circulation and the movement of water masses into and out of the Basin have implications for settlement and recruitment of many coastal species, including the economically important kelp rockfish, kelp bass, and sea urchin. Understanding the circulation of the Santa Barbara Basin and its inner shelves is a precursor to determining the source locations of the planktonic larvae. That information on source locations is essential for the design, siting, and assessment of existing and future marine protected areas in California and elsewhere.
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Waldrop, Mark P.; Holloway, JoAnn M.; Smith, David; Goldhaber, Martin B.; Drenovsky, R.E.; Scow, K.M.; Dick, R.; Howard, Daniel M.; Wylie, Bruce K.; Grace, James B.
2017-01-01
Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of hypotheses about the direct and indirect effects of climatic, biotic, and edaphic variables on microbial communities across the continental United States. The primary goals of this work were to test our current understanding of the interactions among climate, soils, and plants in affecting microbial community composition, and to examine whether variation in the composition of the microbial community affects potential rates of soil enzymatic activities. A model of interacting factors created through SEM shows several expected patterns. Distal factors such as climate had indirect effects on microbial communities by influencing plant productivity, soil mineralogy, and soil pH, but factors related to soil organic matter chemistry had the most direct influence on community composition. We observed that both plant productivity and soil mineral composition were important indirect influences on community composition at the continental scale, both interacting to affect organic matter content and microbial biomass and ultimately community composition. Although soil hydrolytic enzymes were related to the moisture regime and soil carbon, oxidative enzymes were also affected by community composition, reflected in the abundance of soil fungi. These results highlight
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Mantle plumes and continental tectonics.
Hill, R I; Campbell, I H; Davies, G F; Griffiths, R W
1992-04-10
Mantle plumes and plate tectonics, the result of two distinct modes of convection within the Earth, operate largely independently. Although plumes are secondary in terms of heat transport, they have probably played an important role in continental geology. A new plume starts with a large spherical head that can cause uplift and flood basalt volcanism, and may be responsible for regional-scale metamorphism or crustal melting and varying amounts of crustal extension. Plume heads are followed by narrow tails that give rise to the familiar hot-spot tracks. The cumulative effect of processes associated with tail volcanism may also significantly affect continental crust.
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Marginally outer trapped surfaces and symmetries
NASA Astrophysics Data System (ADS)
Carrasco, Alberto; Mars, Marc
2009-05-01
We study properties of outermost marginally outer trapped surfaces in slices of space-times possessing certain symmetries, like isometries, homotheties or conformal Killings. In particular, we find restrictions on these surfaces for the vector field generating the symmetry. As an application we give a result of non-existence of outermost marginally outer trapped surfaces in accelerated Friedmann-Lemaître-Roberson-Walker spacetimes.
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Design Of Robots For Outer Space
NASA Technical Reports Server (NTRS)
Roston, Gerald P.
1990-01-01
Report discusses design of robots for use in zero gravity and vacuum, with attention to differences between requirements imposed on designs by outer space and by terrestrial applications. Terrestrial robots designed for multiple purposes and for minimal cost. Outer-space robots designed specialized to one task where cost has relatively low priority. Design optimal in one environment unlikely optimal in another.
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Storlazzi, Curt D.; Reid, Jane A.
2010-01-01
Ocean surface waves are the dominant temporally and spatially variable process influencing sea floor sediment resuspension along most continental shelves. Wave-induced sediment mobility on the continental shelf and upper continental slope off central California for different phases of El Niño-Southern Oscillation (ENSO) events was modeled using monthly statistics derived from more than 14 years of concurrent hourly oceanographic and meteorologic data as boundary input for the Delft SWAN wave model, gridded sea floor grain-size data from the usSEABED database, and regional bathymetry. Differences as small as 0.5 m in wave height, 1 s in wave period, and 10° in wave direction, in conjunction with the spatially heterogeneous unconsolidated sea-floor sedimentary cover, result in significant changes in the predicted mobility of continental shelf surficial sediment in the study area. El Niño events result in more frequent mobilization on the inner shelf in the summer and winter than during La Niña events and on the outer shelf and upper slope in the winter months, while La Niña events result in more frequent mobilization on the mid-shelf during spring and summer months than during El Niño events. The timing and patterns of seabed mobility are addressed in context of geologic and biologic processes. By understanding the spatial and temporal variability in the disturbance of the sea floor, scientists can better interpret sedimentary patterns and ecosystem structure, while providing managers and planners an understanding of natural impacts when considering the permitting of offshore activities that disturb the sea floor such as trawling, dredging, and the emplacement of sea-floor engineering structures.
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78 FR 32184 - Importation of Fresh Apricots From Continental Spain
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-29
.... APHIS-2011-0132] RIN 0579-AD62 Importation of Fresh Apricots From Continental Spain AGENCY: Animal and... United States of fresh apricots from continental Spain. This action will allow interested persons... importation of fruits and vegetables to allow the importation of fresh apricots from continental Spain into...
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MULTIPLE CURRENT SHEET SYSTEMS IN THE OUTER HELIOSPHERE: ENERGY RELEASE AND TURBULENCE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burgess, D.; Gingell, P. W.; Matteini, L.
2016-05-01
In the outer heliosphere, beyond the solar wind termination shock, it is expected that the warped heliospheric current sheet forms a region of closely packed, multiple, thin current sheets. Such a system may be subject to the ion-kinetic tearing instability, and hence may generate magnetic islands and hot populations of ions associated with magnetic reconnection. Reconnection processes in this environment have important implications for local particle transport, and for particle acceleration at reconnection sites and in turbulence. We study this complex environment by means of three-dimensional hybrid simulations over long timescales, in order to capture the evolution from linear growthmore » of the tearing instability to a fully developed turbulent state at late times. The final state develops from the highly ordered initial state via both forward and inverse cascades. Component and spectral anisotropy in the magnetic fluctuations is present when a guide field is included. The inclusion of a population of newborn interstellar pickup protons does not strongly affect these results. Finally, we conclude that reconnection between multiple current sheets can act as an important source of turbulence in the outer heliosphere, with implications for energetic particle acceleration and propagation.« less
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Larval Transport on the Atlantic Continental Shelf of North America: a Review
NASA Astrophysics Data System (ADS)
Epifanio, C. E.; Garvine, R. W.
2001-01-01
This review considers transport of larval fish and crustaceans on the continental shelf. Previous reviews have contained only limited treatments of the physical processes involved. The present paper provides a physical background that is considerably more comprehensive. It includes a discussion of three principal forcing agents: (1) wind stress; (2) tides propagating from the deep ocean; and (3) differences in density associated with the buoyant outflow of estuaries, surface heat flux, or the interaction of coastal and oceanic water masses at the seaward margin of the shelf. The authors discuss the effects of these forcing agents on transport of larvae in the Middle Atlantic and South Atlantic Bights along the east coast of North America. The discussion concentrates on three species (blue crab, menhaden, bluefish) that have been the subject of a very recent multi-disciplinary study. Taken as a whole, the reproductive activities of these three species span the entire year and utilize the entire shelf, from the most seaward margin to the estuarine nursery. The blue crab is representative of species affected by physical processes occurring during summer and early autumn on the inner and mid-shelf. Menhaden are impacted by processes occurring in winter on the outer and mid-shelf. Bluefish are influenced primarily by processes occurring during early spring at the outer shelf margin near the western boundary current. The authors conclude that alongshore wind stress and density differences, i.e. buoyancy-driven flow, are the primary agents of larval transport in the region. Circulation associated with the western boundary current is only important at the shelf margin and tidally driven processes are generally inconsequential.
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A numerical investigation of continental collision styles
NASA Astrophysics Data System (ADS)
Ghazian, Reza Khabbaz; Buiter, Susanne J. H.
2013-06-01
Continental collision after closure of an ocean can lead to different deformation styles: subduction of continental crust and lithosphere, lithospheric thickening, folding of the unsubducted continents, Rayleigh-Taylor (RT) instabilities and/or slab break-off. We use 2-D thermomechanical models of oceanic subduction followed by continental collision to investigate the sensitivity of these collision styles to driving velocity, crustal and lithospheric temperature, continental rheology and the initial density difference between the oceanic lithosphere and the asthenosphere. We find that these parameters influence the collision system, but that driving velocity, rheology and lithospheric (rather than Moho and mantle) temperature can be classified as important controls, whereas reasonable variations in the initial density contrast between oceanic lithosphere and asthenosphere are not necessarily important. Stable continental subduction occurs over a relatively large range of values of driving velocity and lithospheric temperature. Fast and cold systems are more likely to show folding, whereas slow and warm systems can experience RT-type dripping. Our results show that a continent with a strong upper crust can experience subduction of the entire crust and is more likely to fold. Accretion of the upper crust at the trench is feasible when the upper crust has a moderate to weak strength, whereas the entire crust can be scraped-off in the case of a weak lower crust. We also illustrate that weakening of the lithospheric mantle promotes RT-type of dripping in a collision system. We use a dynamic collision model, in which collision is driven by slab pull only, to illustrate that adjacent plates can play an important role in continental collision systems. In dynamic collision models, exhumation of subducted continental material and sediments is triggered by slab retreat and opening of a subduction channel, which allows upward flow of buoyant materials. Exhumation continues
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Functional Architecture of the Outer Arm Dynein Conformational Switch*
King, Stephen M.; Patel-King, Ramila S.
2012-01-01
Dynein light chain 1 (LC1/DNAL1) is one of the most highly conserved components of ciliary axonemal outer arm dyneins, and it associates with both a heavy chain motor unit and tubulin located within the A-tubule of the axonemal outer doublet microtubules. In a variety of model systems, lack of LC1 or expression of mutant forms leads to profound defects in ciliary motility, including the failure of the hydrodynamic coupling needed for ciliary metachronal synchrony, random stalling during the power/recovery stroke transition, an aberrant response to imposed viscous load, and in some cases partial failure of motor assembly. These phenotypes have led to the proposal that LC1 acts as part of a mechanical switch to control motor function in response to alterations in axonemal curvature. Here we have used NMR chemical shift mapping to define the regions perturbed by a series of mutations in the C-terminal domain that yield a range of phenotypic effects on motility. In addition, we have identified the subdomain of LC1 involved in binding microtubules and characterized the consequences of an Asn → Ser alteration within the terminal leucine-rich repeat that in humans causes primary ciliary dyskinesia. Together, these data define a series of functional subdomains within LC1 and allow us to propose a structural model for the organization of the dynein heavy chain-LC1-microtubule ternary complex that is required for the coordinated activity of dynein motors in cilia. PMID:22157010
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NASA Astrophysics Data System (ADS)
Saito, S.; Hackney, R. I.; Bryan, S. E.; Kimura, J. I.; Müller, D.; Arculus, R. J.; Mortimer, N. N.; Collot, J.; Tamura, Y.; Yamada, Y.
2016-12-01
Plate tectonics and resulting changes in crustal architecture profoundly influence global climate, oceanic circulation, and the origin, distribution and sustainability of life. Ribbons of continental crust rifted from continental margins are one product of plate tectonics that can influence the Earth system. Yet we have been unable to fully resolve the tectonic setting and evolution of huge, thinned, submerged, and relatively inaccessible continental ribbons like the Lord Howe Rise (LHR), which formed during Cretaceous fragmentation of eastern Gondwana. Thinned continental ribbons like the LHR are not easily explained or predicted by plate-tectonic theory. However, because Cretaceous rift basins on the LHR preserve the stratigraphy of an un-accreted and intact continental ribbon, they can help to determine whether plate motion is self-organised—passively driven by the pull of negatively-buoyant subducting slabs—or actively driven by convective flow in the mantle. In a self-organising scenario, the LHR formed in response to ocean-ward retreat of the long-lived eastern Gondwana subduction zone and linked upper-plate extension. In the mantle-driven scenario, the LHR resulted from rifting near the eastern edge of Gondwana that was triggered by processes linked to emplacement of a silicic Large Igneous Province. These scenarios can be distinguished using the ribbon's extensional history and the composition and tectonic affinity of igneous rocks within rift basins. However, current knowledge of LHR rift basins is based on widely-distributed marine and satellite geophysical data, limited dredge samples, and sparse shallow drilling (<600 m below-seafloor). This limits our ability to understand the evolution of extended continental ribbons, but a recent deep crustal seismic survey across the LHR and a proposed IODP deep stratigraphic well through a LHR rift basin provide new opportunities to explore the drivers behind rifting, continental ribboning and plate tectonics.
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Tectonic escape in the evolution of the continental crust
NASA Technical Reports Server (NTRS)
Burke, K.; Sengor, C.
1986-01-01
The continental crust originated by processes similar to those operating today and continents consist of material most of which originated long ago in arc-systems that have later been modified, especially at Andean margins and in continental collisions where crustal thickening is common. Collision-related strike-slip motion is a general process in continental evolution. Because buoyant continental (or arc) material generally moves during collision toward a nearby oceanic margin where less buoyant lithosphere crops out, the process of major strike-slip dominated motion toward a 'free-face' is called 'tectonic escape'. Tectonic escape is and has been an element in continental evolution throughout recorded earth-history. It promotes: (1) rifting and the formation of rift-basins with thinning of thickened crust; (2) pervasive strike-slip faulting late in orogenic history which breaks up mountain belts across strike and may juxtapose unrelated sectors in cross-section; (3) localized compressional mountains and related foreland-trough basins.
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Constraints on continental accretion from sedimentation
NASA Technical Reports Server (NTRS)
Abbott, Dallas
1988-01-01
Heat loss in the ancient Earth was discussed assuming that classical sea floor spreading was the only mechanism. This may be expressed as faster spreading or longer total ridge length. These have important implications as to the size and number of cratonic plates in the distant past, the degree to which they are flooded, the kinds of sediments and volcanics that would be expected, and the amount of recycling of continental material taking place. The higher proportion of marine sedimentary rocks and oceanic volcanics in the Archean, and the relative paucity of evaporites and continental volcanics may in part be due to smaller cratonic blocks. A model was developed of the percentage of continental flooding which utilizes round continents and a constant width of the zone of flooding. This model produces a reasonable good fit to the percentage of flooding on the present day continents.
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Will Outer Tropical Cyclone Size Change due to Anthropogenic Warming?
NASA Astrophysics Data System (ADS)
Schenkel, B. A.; Lin, N.; Chavas, D. R.; Vecchi, G. A.; Knutson, T. R.; Oppenheimer, M.
2017-12-01
Prior research has shown significant interbasin and intrabasin variability in outer tropical cyclone (TC) size. Moreover, outer TC size has even been shown to vary substantially over the lifetime of the majority of TCs. However, the factors responsible for both setting initial outer TC size and determining its evolution throughout the TC lifetime remain uncertain. Given these gaps in our physical understanding, there remains uncertainty in how outer TC size will change, if at all, due to anthropogenic warming. The present study seeks to quantify whether outer TC size will change significantly in response to anthropogenic warming using data from a high-resolution global climate model and a regional hurricane model. Similar to prior work, the outer TC size metric used in this study is the radius in which the azimuthal-mean surface azimuthal wind equals 8 m/s. The initial results from the high-resolution global climate model data suggest that the distribution of outer TC size shifts significantly towards larger values in each global TC basin during future climates, as revealed by 1) statistically significant increase of the median outer TC size by 5-10% (p<0.05) according to a 1,000-sample bootstrap resampling approach with replacement and 2) statistically significant differences between distributions of outer TC size from current and future climate simulations as shown using two-sample Kolmogorov Smirnov testing (p<<0.01). Additional analysis of the high-resolution global climate model data reveals that outer TC size does not uniformly increase within each basin in future climates, but rather shows substantial locational dependence. Future work will incorporate the regional mesoscale hurricane model data to help focus on identifying the source of the spatial variability in outer TC size increases within each basin during future climates and, more importantly, why outer TC size changes in response to anthropogenic warming.
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Basins in ARC-continental collisions
Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio
2012-01-01
Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from
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Code of Federal Regulations, 2010 CFR
2010-07-01
... MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.1... Secretary of the Interior (Secretary) will exercise the authority to administer a leasing program for oil...
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Code of Federal Regulations, 2010 CFR
2010-07-01
... Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General... Secretary of the Interior to issue, on a competitive basis, leases for oil and gas, and sulphur, in...
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30 CFR 256.12 - Supplemental sales.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Supplemental sales. 256.12 Section 256.12 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management...
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30 CFR 256.10 - Information to States.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Information to States. 256.10 Section 256.10 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management...
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Structure of the North American Atlantic Continental Margin.
ERIC Educational Resources Information Center
Klitgord, K. K.; Schlee, J. S.
1986-01-01
Offers explanations on the origin of the North American Atlantic continental margin. Provides an analysis and illustrations of structural and strategraphic elements of cross sections of the Atlantic continental margin. Also explains the operations and applications of seismic-relection profiles in studying ocean areas. (ML)
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Thermal regime of the continental lithosphere
NASA Technical Reports Server (NTRS)
Morgan, P.; Sass, J. H.
1984-01-01
From studies of the global heat flow data set, it has been generalized, with respect to the continental lithosphere, that there is a negative correlation between heat flow and the lithosphere's tectonic edge, and that the lithosphere's thermal evolution is similar to that of the ocean basins, resulting in a 'stable geotherm' in both environments. It is presently noted that a regional study perspective for heat flow data leads to doubts concerning the general applicability of either statement. Rao et al. (1982) have demonstrated that the data are not normally distributed, and that it is not possible to establish a negative correlation between heat flow and age in a rigorous statistical fashion. While some sites of stable continental blocks may have a geotherm that is by chance similar to that for old ocean basins, this need not hold true generally, and many stable continental terranes will be characterized by geotherms very different from those for old ocean basins.
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Continental shelf landscapes of the southeastern United States since the last interglacial
NASA Astrophysics Data System (ADS)
Harris, M. Scott; Sautter, Leslie Reynolds; Johnson, Kacey L.; Luciano, Katherine E.; Sedberry, George R.; Wright, Eric E.; Siuda, Amy N. S.
2013-12-01
The wide, sediment-starved continental shelf and modern coastal areas of the southeastern United States retain well-preserved but scattered remnants of a submerged paleolandscape. This paper presents a conceptual model of stratigraphic deposition and landscape formation since the last interglacial on the continental shelf of South Carolina, with portions of North Carolina, Georgia, and Florida (USA). Data for this study include multibeam bathymetry surveys, sidescan sonar mosaics, high-resolution subbottom profiles, and ground-truth surveys from - 250 m to the modern tidewater region. Four bathymetric zones are recognized with eleven landforms and landform indicators. The described zones range in depths from the modern shoreline, across the shelf, and over the shelf edge to - 250 m MSL. Relative sea level curves are presented for the area and discussed in conjunction with cultural and climatic events. The potential for preservation of Paleoamerican sites is high at the shelf edge between - 130 m and - 45 m, with Archaic and later occupations likely in depths of less than - 25 m. Prominent vantage points for Paleoamericans (> 11 kya) would have existed at the shelf edge, and tidewater resources would have been available nearby for a period of almost 6 ka. Rapid transgression rates (> 60 km/ka) after the sea level rose over the shelf edge make preservation of tidewater sites less likely on the outer and middle shelf. Searches for the earliest Paleoamericans should focus on promontories at the edge of the shelf and along future discoveries of paleoincisions on the shelf. Mapping and delineating this paleolandscape and associated unconsolidated sedimentary deposits interspersed with rocky plains and ledges will continue to be a priority to marine archeologists, coastal managers, fishery scientists, and marine spatial planners over the next several decades.
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Scholle, Peter A.; Wenkam, Chiye R.
1982-01-01
The COST Nos. G-1 and G-2 wells (fig. 1) are the second and third deep stratigraphic test wells drilled in the North Atlantic Outer Continental Shelf of the United States. COST No. G-1 was drilled in the Georges Bank basin to a total depth of 16,071 ft (4,898 m). G-1 bottomed in phyllite, slate, and metaquartzite overlain by weakly metamorphosed dolomite, all of Cambrian age. From approximately 15,600 to 12,400 ft (4,755 to 3,780 m) the strata are Upper Triassic(?), Lower Jurassic(?), and Middle Jurassic, predominantly red shales, sandstones, and conglomerates. Thin, gray Middle Jurassic beds of shale, sandstone, limestone, and dolomite occur from 12,400 to 9,900 ft (3,780 to 3,018 m). From 9,900 to 1,030 ft (3,018 to 314 m) are coarse-grained unconsolidated sands and loosely cemented sandstones, with beds of gray shale, lignite, and coal. The microfossils indicate the rocks are Upper Jurassic from 10,100 ft (3,078 m) up to 5,400 ft (1,646 m) and Cretaceous from that depth to 1,030 ft (314 m). No younger or shallower rocks were recovered in the drilling at the COST No. G-1 site, but an Eocene limestone is inferred to be disconformable over Santonian strata. The Jurassic strata of the COST No. G-1 well were deposited in shallow marine, marginal marine, and nonmarine environments, which changed to a dominantly shallow marine but still nearshore environment in the Cretaceous. The COST No. G-2 well was drilled 42 statute miles {68 km) east of the G-1 site, still within the Georges Bank basin, to a depth of 21,874 ft (6,667 m). The bottom 40 ft (12 m) of salt and anhydrite is overlain by approximately 7,000 ft {2,134 m) of Upper Triassic{?), Lower Jurassic{?) and Middle Jurassic dolomite, limestone, and interbedded anhydrite from 21,830 to 13,615 ft (6,654 to 4,153 m). From 13,500 to 9,700 ft (4,115 to 2,957 m) are Middle Jurassic limestones with interbedded sandstone. From 9,700 to 4,000 ft (2,957 to 1,219 m) are Upper Jurassic and Cretaceous interbedded sandstones and
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30 CFR 256.8 - Leasing maps and diagrams.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Leasing maps and diagrams. 256.8 Section 256.8 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management...
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Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Policy. 256.2 Section 256.2 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and...
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USArray Imaging of North American Continental Crust
NASA Astrophysics Data System (ADS)
Ma, Xiaofei
The layered structure and bulk composition of continental crust contains important clues about its history of mountain-building, about its magmatic evolution, and about dynamical processes that continue to happen now. Geophysical and geological features such as gravity anomalies, surface topography, lithospheric strength and the deformation that drives the earthquake cycle are all directly related to deep crustal chemistry and the movement of materials through the crust that alter that chemistry. The North American continental crust records billions of years of history of tectonic and dynamical changes. The western U.S. is currently experiencing a diverse array of dynamical processes including modification by the Yellowstone hotspot, shortening and extension related to Pacific coast subduction and transform boundary shear, and plate interior seismicity driven by flow of the lower crust and upper mantle. The midcontinent and eastern U.S. is mostly stable but records a history of ancient continental collision and rifting. EarthScope's USArray seismic deployment has collected massive amounts of data across the entire United States that illuminates the deep continental crust, lithosphere and deeper mantle. This study uses EarthScope data to investigate the thickness and composition of the continental crust, including properties of its upper and lower layers. One-layer and two-layer models of crustal properties exhibit interesting relationships to the history of North American continental formation and recent tectonic activities that promise to significantly improve our understanding of the deep processes that shape the Earth's surface. Model results show that seismic velocity ratios are unusually low in the lower crust under the western U.S. Cordillera. Further modeling of how chemistry affects the seismic velocity ratio at temperatures and pressures found in the lower crust suggests that low seismic velocity ratios occur when water is mixed into the mineral matrix
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Roier, Sandro; Leitner, Deborah R.; Iwashkiw, Jeremy; Schild-Prüfert, Kristina; Feldman, Mario F.; Krohne, Georg; Reidl, Joachim; Schild, Stefan
2012-01-01
Abstract Haemophilus influenzae is a Gram-negative human-restricted bacterium that can act as a commensal and a pathogen of the respiratory tract. Especially nontypeable H. influenzae (NTHi) is a major threat to public health and is responsible for several infectious diseases in humans, such as pneumonia, sinusitis, and otitis media. Additionally, NTHi strains are highly associated with exacerbations in patients suffering from chronic obstructive pulmonary disease. Currently, there is no licensed vaccine against NTHi commercially available. Thus, this study investigated the utilization of outer membrane vesicles (OMVs) as a potential vaccine candidate against NTHi infections. We analyzed the immunogenic and protective properties of OMVs derived from various NTHi strains by means of nasopharyngeal immunization and colonization studies with BALB/c mice. The results presented herein demonstrate that an intranasal immunization with NTHi OMVs results in a robust and complex humoral and mucosal immune response. Immunoprecipitation revealed the most important immunogenic proteins, such as the heme utilization protein, protective surface antigen D15, heme binding protein A, and the outer membrane proteins P1, P2, P5 and P6. The induced immune response conferred not only protection against colonization with a homologous NTHi strain, which served as an OMV donor for the immunization mixtures, but also against a heterologous NTHi strain, whose OMVs were not part of the immunization mixtures. These findings indicate that OMVs derived from NTHi strains have a high potential to act as a vaccine against NTHi infections. PMID:22880074
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Galveston Symposium: Physical Oceanography of the Louisiana/Texas Continental Shelf
NASA Astrophysics Data System (ADS)
Mitchell, Thomas M.; Brown, Murray
The Minerals Management Service (MMS), Gulf of Mexico Outer Continental Shelf (OCS) Region sponsored a symposium on the Physical Oceanography of the Louisiana/Texas (LA/TX) Shelf in Galveston, Texas, on May 24-26, 1988. The symposium brought together a number of physical oceanographers, meteorologists, and ecologists to discuss the state of knowledge and to begin the planning process for a long-term study of shelf circulation covering the region from the mouth of the Mississippi River to approximately 24° latitude along the Mexican coast and from the shore out to a depth of approximately 500 m. The proposed study, to be a component of the ongoing MMS Environmental Studies Program, is expected to take place during the period 1989-1991. It is anticipated that the work will be done principally through contracts after a competitive procurement process. Specific charges to the participants were as follows:to assess the current state of knowledge concerning the circulation on the LA/TX shelfto identify significant gaps in that knowledgeto recommend a field measurement program to address these gapsto recommend a circulation modeling program for the LA/TX shelf that will improve MMS' oil spill risk assessmentsto identify and initiate coordination mechanisms and data-sharing arrangements with other proposed research efforts
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Molecular basis for photoreceptor outer segment architecture
Goldberg, Andrew F. X.; Moritz, Orson L.; Williams, David S.
2016-01-01
To serve vision, vertebrate rod and cone photoreceptors must detect photons, convert the light stimuli into cellular signals, and then convey the encoded information to downstream neurons. Rods and cones are sensory neurons that each rely on specialized ciliary organelles to detect light. These organelles, called outer segments, possess elaborate architectures that include many hundreds of light-sensitive membranous disks arrayed one atop another in precise register. These stacked disks capture light and initiate the chain of molecular and cellular events that underlie normal vision. Outer segment organization is challenged by an inherently dynamic nature; these organelles are subject to a renewal process that replaces a significant fraction of their disks (up to ~10%) on a daily basis. In addition, a broad range of environmental and genetic insults can disrupt outer segment morphology to impair photoreceptor function and viability. In this chapter, we survey the major progress that has been made for understanding the molecular basis of outer segment architecture. We also discuss key aspects of organelle lipid and protein composition, and highlight distributions, interactions, and potential structural functions of key OS-resident molecules, including: kinesin-2, actin, RP1, prominin-1, protocadherin 21, peripherin-2/rds, rom-1, glutamic acid-rich proteins, and rhodopsin. Finally, we identify key knowledge gaps and challenges that remain for understanding how normal outer segment architecture is established and maintained. PMID:27260426
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Continental drift before 1900.
Rupke, N A
1970-07-25
The idea that Francis Bacon and other seventeenth and eighteenth century thinkers first conceived the notion of continental drift does not stand up to close scrutiny. The few authors who expressed the idea viewed the process as a catastrophic event.
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Impacts of continental arcs on global carbon cycling and climate
NASA Astrophysics Data System (ADS)
Lee, C. T.; Jiang, H.; Carter, L.; Dasgupta, R.; Cao, W.; Lackey, J. S.; Lenardic, A.; Barnes, J.; McKenzie, R.
2017-12-01
On myr timescales, climatic variability is tied to variations in atmospheric CO2, which in turn is driven by geologic sources of CO2 and modulated by the efficiency of chemical weathering and carbonate precipitation (sinks). Long-term variability in CO2 has largely been attributed to changes in mid-ocean ridge inputs or the efficiency of global weathering. For example, the Cretaceous greenhouse is thought to be related to enhanced oceanic crust production, while the late Cenozoic icehouse is attributed to enhanced chemical weathering associated with the Himalayan orogeny. Here, we show that continental arcs may play a more important role in controlling climate, both in terms of sources and sinks. Continental arcs differ from island arcs and mid-ocean ridges in that the continental plate through which arc magmas pass may contain large amounts of sedimentary carbonate, accumulated over the history of the continent. Interaction of arc magmas with crustal carbonates via assimilation, reaction or heating can significantly add to the mantle-sourced CO2 flux. Detrital zircons and global mapping of basement rocks shows that the length of continental arcs in the Cretaceous was more than twice that in the mid-Cenozoic; maps also show many of these arcs intersected crustal carbonates. The increased length of continental arc magmatism coincided with increased oceanic spreading rates, placing convergent margins into compression, which favors continental arcs. Around 50 Ma, however, nearly all the continental arcs in Eurasia and North America terminated as India collided with Eurasia and the western Pacific rolled back, initiating the Marianas-Tonga-Kermadec intra-oceanic subduction complex and possibly leading to a decrease in global CO2 production. Meanwhile, extinct continental arcs continued to erode, resulting in regionally enhanced chemical weathering unsupported by magmatic fluxes of CO2. Continental arcs, during their magmatic lifetimes, are thus a source of CO2, driving
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Radioisotope Electric Propulsion for Fast Outer Planetary Orbiters
NASA Technical Reports Server (NTRS)
Oleson, Steven; Benson, Scott; Gefert, Leon; Patterson, Michael; Schreiber, Jeffrey
2002-01-01
Recent interest in outer planetary targets by the Office of Space Science has spurred the search for technology options to enable relatively quick missions to outer planetary targets. Several options are being explored including solar electric propelled stages combined with aerocapture at the target and nuclear electric propulsion. Another option uses radioisotope powered electric thrusters to reach the outer planets. Past work looked at using this technology to provide faster flybys. A better use for this technology is for outer planet orbiters. Combined with medium class launch vehicles and a new direct trajectory these small, sub-kilowatt ion thrusters and Stirling radioisotope generators were found to allow missions as fast as 5 to 12 years for objects from Saturn to Pluto, respectively. Key to the development is light spacecraft and science payload technologies.
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MAGSAT anomaly map and continental drift
NASA Technical Reports Server (NTRS)
Lemouel, J. L. (Principal Investigator); Galdeano, A.; Ducruix, J.
1981-01-01
Anomaly maps of high quality are needed to display unambiguously the so called long wave length anomalies. The anomalies were analyzed in terms of continental drift and the nature of their sources is discussed. The map presented confirms the thinness of the oceanic magnetized layer. Continental magnetic anomalies are characterized by elongated structures generally of east-west trend. Paleomagnetic reconstruction shows that the anomalies found in India, Australia, and Antarctic exhibit a fair consistency with the African anomalies. It is also shown that anomalies are locked under the continents and have a fixed geometry.
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NASA Astrophysics Data System (ADS)
Chalmers, James
2014-05-01
There are mountain ranges up to more than 2 km high along many passive continental margins (e.g. Norway, eastern Australia, eastern Brazil, SE and SW Africa, east and west Greenland etc.), dubbed Elevated Passive Continental Margins (EPCMs). EPCMs contain several features in common and observations indicate that uplift of these margins took place after continental break-up. There are many explanations for their formation but none that satisfy all the observations. Lack of a geodynamical mechanism has meant that there has been difficulty in getting the community to accept the observational evidence. Formation of a passive continental margin must take place under conditions of tension. After rifting ceases, however, the margin can come under compression from forces originating elsewhere on or below its plate, e.g. orogeny elsewhere in the plate or sub-lithospheric drag. The World Stress Map (www.world-stress-mp.org) shows that, where data exists, all EPCMs are currently under compression. Under sufficient compression, crust and/or lithosphere can fold, and Cloetingh & Burov (2010) showed that many continental areas may have folded in this way. The wavelengths of folding observed by Cloetingh & Burov (2010) imply that the lower crust is likely to be of intermediate composition; granitic lower crust would fold with a shorter wavelength and basic lower crust would mean that the whole lithosphere would have to fold as a unit resulting in a much longer wavelength. Continental crust more than 20 km thick would be separated from the mantle by a weak layer. However, crust less thick than that would contain no weak layers would become effectively annealed to the underlying strong mantle. Under sufficient horizontal compression stress, material can flow in the lower weak layer towards a continental margin from the continental side. The annealed extended crust and mantle under the rift means, however, that flow cannot continue towards the ocean. Mid- and lower crustal material
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Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Policy. 256.2 Section 256.2 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Oil, Gas, and Sulphur Management, General § 256.2 Policy...
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30 CFR 250.1401 - Index table.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Index table. 250.1401 Section 250.1401 Mineral... OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf (OCS) Civil Penalties § 250.1401 Index table. The following table is an index of the sections in this subpart: § 250.1401Table Definitions...
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33 CFR 106.415 - Amendment and audit.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Amendment and audit. 106.415 Section 106.415 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MARITIME SECURITY MARINE SECURITY: OUTER CONTINENTAL SHELF (OCS) FACILITIES Outer Continental Shelf (OCS) Facility Security Plan (FSP) § 106.415 Amendment and...
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NASA Astrophysics Data System (ADS)
Amodeo, K.; Rathnayaka, S.; Weeraratne, D. S.; Kohler, M. D.
2016-12-01
Continental and oceanic lithosphere, which form in different tectonic environments, are studied in a single amphibious seismic array across the Southern California continental margin. This provides a unique opportunity to directly compare oceanic and continental lithosphere, asthenosphere, and the LAB (Lithosphere-Asthenosphere Boundary) in a single data set. The complex history of the region, including spreading center subduction, block rotation, and Borderland extension, allows us to study limits in the rigidity and strength of the lithosphere. We study Rayleigh wave phase velocities obtained from the ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) offshore seismic array project and invert for shear wave velocity structure as a function of depth. We divide the study area into several regions: continent, inner Borderland, outer Borderland, and oceanic seafloor categorized by age. A unique starting Vs model is used for each case including layer thicknesses, densities, and P and S velocities which predicts Rayleigh phase velocities and are compared to observed phase velocities in each region. We solve for shear wave velocities with the best fit between observed and predicted phase velocity data in a least square sense. Preliminary results indicate that lithospheric velocities in the oceanic mantle are higher than the continental region by at least 2%. The LAB is observed at 50 ± 20 km beneath 15-35 Ma oceanic seafloor. Asthenospheric low velocities reach a minimum of 4.2 km/s in all regions, but have a steeper positive velocity gradient at the base of the oceanic asthenosphere compared to the continent. Seismic tomography images in two and three dimensions will be presented from each study region.
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NASA Technical Reports Server (NTRS)
Morrison, D.
1983-01-01
The present investigation takes into account the published literature on outer planet satellites for 1979-1982. It is pointed out that all but three (the moon and the two Martian satellites) of the known planetary satellites are found in the outer solar system. Most of these are associated with the three regular satellite systems of Jupiter, Saturn, and Uranus. The largest satellites are Titan in the Saturn system and Ganymede and Callisto in the Jupiter system. Intermediate in size between Mercury and Mars, each has a diameter of about 5000 km. Presumably each has an internal composition about 60 percent rock and 40 ice, and each is differentiated with a dense core extending out about 75 percent of the distance to the surface, with a mantle of high-pressure ice and a crust of ordinary ice perhaps 100 km thick. Attention is also given to Io, Europa, the icy satellites of Saturn, the satellites of Uranus, the small satellites of Jupiter and Saturn, Triton and the Pluto system, and plans for future studies.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Rybin, V.O.; Gureeva, A.A.
1986-05-10
The action of cholera toxin, capable of ADP-ribosylation of the activator N/sub s/ protein, and pertussis toxin, capable of ADP-ribosylation of the inhibitor N/sub i/ protein of the adenylate cyclase complex, on transducin, the GTP-binding protein of the rod outer segments of the retina, was investigated. It was shown that under the action of pertussis and cholera toxins, the GTPase activity of transducin is inhibited. Pertussin toxin inhibits the GTPase of native retinal rod outer segments by 30-40%, while GTPase of homogeneous transducin produces a 70-80% inhibition. The action of toxins on transducin depends on the presence and nature ofmore » the guanylic nucleotide with which incubation is performed. On the basis of the data obtained it is suggested that pertussis toxin interacts with pretransducin and with the transducin-GDP complex, while cholera toxin ADP-ribosylates the transducin-GTP complex and does not act on transducin lacking GTP.« less
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NASA Astrophysics Data System (ADS)
Triezenberg, P. J.; Hart, P. E.; Childs, J. R.
2014-12-01
The National Archive of Marine Seismic Surveys (NAMSS) was established by the USGS in 2004 in an effort to rescue marine seismic reflection profile data acquired largely by the oil exploration industry throughout the US outer continental shelf (OCS). It features a Web interface for easy on-line geographic search and download. The commercial value of these data had decreased significantly because of drilling moratoria and newer acquisition technology, and large quantities were at risk of disposal. But, the data still had tremendous value for scientific research and education purposes, and an effort was undertaken to ensure that the data were preserved and publicly available. More recently, the USGS and Bureau of Ocean Energy Management (BOEM) have developed a partnership to make similarly available a much larger quantity of 2D and 3D seismic data acquired by the U.S. government for assessment of resources in the OCS. Under Federal regulation, BOEM is required to publicly release all processed geophysical data, including seismic profiles, acquired under an exploration permit, purchased and retained by BOEM, no sooner than 25 years after issuance of the permit. Data acquired prior to 1989 are now eligible for release. Currently these data are distributed on CD or DVD, but data discovery can be tedious. Inclusion of these data within NAMSS vastly increases the amount of seismic data available for research purposes. A new NAMSS geographical interface provides easy and intuitive access to the data library. The interface utilizes OpenLayers, Mapnik, and the Django web framework. In addition, metadata capabilities have been greatly increased using a PostgresSQL/PostGIS database incorporating a community-developed ISO-compliant XML template. The NAMSS database currently contains 452 2D seismic surveys comprising 1,645,956 line km and nine 3D seismic surveys covering 9,385 square km. The 2D data holdings consist of stack, migrated and depth sections, most in SEG-Y format.
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NASA Astrophysics Data System (ADS)
Gomez, C. D.; Escobar, L., Sr.; Rathnayaka, S.; Weeraratne, D. S.; Kohler, M. D.
2016-12-01
The California continental margin, a major transform plate boundary in continental North America, is the locus of complex tectonic stress fields that are important in interpreting both remnant and ongoing deformational strain. Ancient subduction of the East Pacific Rise spreading center, the rotation and translation of tectonic blocks and inception of the San Andreas fault all contribute to the dynamic stress fields located both onshore and offshore southern California. Data obtained by the ALBACORE (Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment) and the CISN (California Integrated Seismic Network) seismic array are analyzed for azimuthal anisotropy of Rayleigh waves from 80 teleseismic events at periods 16 - 78 s. Here we invert Rayleigh wave data for shear wave velocity structure and three-dimensional seismic anisotropy in the thee regions designated within the continental margin including the continent, seafloor and California Borderlands. Preliminary results show that seismic anisotropy is resolved in multiple layers and can be used to determine the lithosphere-asthenosphere boundary (LAB) in offshore and continental regions. The oldest seafloor in our study at age 25-35 Ma indicates that the anisotropic transition across the LAB occurs at 73 km +/- 25 km with the lithospheric fast direction oriented WNW-ESE, consistent with current Pacific plate motion direction. The continent region west of the San Andreas indicates similar WNW-ESE anisotropy and LAB depth. Regions east of the San Andreas fault indicate NW-SE anisotropy transitioning to a N-S alignment at 80 km depth north of the Garlock fault. The youngest seafloor (15 - 25 Ma) and outer Borderlands indicate a more complex three layer fabric where shallow lithospheric NE-SW fast directions are perpendicular with ancient Farallon subduction arc, a mid-layer with E-W fast directions are perpendicular to remnant fossil fabric, and the deepest layer
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Autofluorescence from the outer retina and subretinal space: hypothesis and review.
Spaide, Richard
2008-01-01
To review the pathophysiologic principles underlying increased autofluorescence from the outer retina and subretinal space using selected diseases as examples. The ocular imaging information and histopathologic features, when known, were integrated for diseases causing increased autofluorescence from the outer retina and subretinal space. Inferences were taken from this information and used to create a classification scheme. These diseases are principally those that cause separation of the outer retina from the retinal pigment epithelium, thereby preventing proper phagocytosis of photoreceptor outer segments. The separation can arise from increased exudation into the subretinal space or inadequate removal of fluid from the subretinal space. Lack of normal outer segment processing initially leads to increased accumulation of outer segments on the outer retina and subretinal space. Over time, this material is visible as an increasingly thick coating on the outer retina, is yellow, and is autofluorescent. Over time, atrophy develops with thinning of the deposited material and decreasing autofluorescence. The accumulated material is ultimately capable of inducing damage to the retinal pigment epithelium. Diseases causing accumulation of the material include central serous chorioretinopathy, vitelliform macular dystrophy, acute exudative polymorphous vitelliform maculopathy, choroidal tumors, and vitreomacular traction syndrome. The physical separation of the retinal outer segments from the retinal pigment epithelium hinders proper phagocytosis of the outer segments. Accumulation of the shed but not phagocytized outer segments plays a role in disease manifestations for a number of macular diseases.
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Evaluation of inner-outer space distinction and verbal hallucinations in schizophrenia.
Stephane, Massoud; Kuskowski, Michael; McClannahan, Kate; Surerus, Christa; Nelson, Katie
2010-09-01
Verbal hallucinations could result from attributing one's own inner speech to another. Inner speech is usually experienced in inner space, whereas hallucinations are often experienced in outer space. To clarify this paradox, we investigated schizophrenia patients' ability to distinguish between speech experienced in inner space, and speech experienced in outer space. 32 schizophrenia patients and 26 matched healthy controls underwent a two-stage experiment. First, they read sentences aloud or silently. Afterwards, they were required to distinguish between the sentences read aloud (experienced in outer space), the sentences read silently (experienced in inner space), and new sentences not previously read (no space coding). The sentences were in the first, second, or third person in equal proportions. Linear mixed models were used to investigate the effects of group, sentence location, pronoun, and hallucinations status. Schizophrenia patients were similar to controls in recognition capacity of sentences without space coding. They exhibited both inner-outer and outer-inner space confusion (they confused silently read sentences for sentences read aloud, and vice versa). Patients who experienced hallucinations inside their head were more likely to have outer-inner space bias. For speech generated by one's own brain, schizophrenia patients have bidirectional failure of inner-outer space distinction (inner-outer and outer-inner space biases); this might explain why hallucinations (abnormal inner speech) could be experienced in outer space. Furthermore, the direction of inner-outer space indistinction could determine the spatial location of the experienced hallucinations (inside or outside the head).
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Urfer, Matthias; Bogdanovic, Jasmina; Lo Monte, Fabio; Moehle, Kerstin; Zerbe, Katja; Omasits, Ulrich; Ahrens, Christian H.; Pessi, Gabriella; Eberl, Leo; Robinson, John A.
2016-01-01
Increasing antibacterial resistance presents a major challenge in antibiotic discovery. One attractive target in Gram-negative bacteria is the unique asymmetric outer membrane (OM), which acts as a permeability barrier that protects the cell from external stresses, such as the presence of antibiotics. We describe a novel β-hairpin macrocyclic peptide JB-95 with potent antimicrobial activity against Escherichia coli. This peptide exhibits no cellular lytic activity, but electron microscopy and fluorescence studies reveal an ability to selectively disrupt the OM but not the inner membrane of E. coli. The selective targeting of the OM probably occurs through interactions of JB-95 with selected β-barrel OM proteins, including BamA and LptD as shown by photolabeling experiments. Membrane proteomic studies reveal rapid depletion of many β-barrel OM proteins from JB-95-treated E. coli, consistent with induction of a membrane stress response and/or direct inhibition of the Bam folding machine. The results suggest that lethal disruption of the OM by JB-95 occurs through a novel mechanism of action at key interaction sites within clusters of β-barrel proteins in the OM. These findings open new avenues for developing antibiotics that specifically target β-barrel proteins and the integrity of the Gram-negative OM. PMID:26627837
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-24
... Western Gulf of Mexico Planning Areas, Oil and Gas Lease Sales for Years 2012-2017 (Sales 229, 227, 233... Register (76 FR 70748) correcting the sale numbers that were identified in the Call. This document... them with: 1. Whole blocks and portions of blocks deferred by the Gulf of Mexico Energy Security Act of...
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The membrane current of single rod outer segments.
Baylor, D A; Lamb, T D; Yau, K W
1979-03-01
1. Outer segments of individual rods in the retina of the toad, Bufo marinus, were drawn into a glass pipette to record the membrane current. 2. Light flashes evoked transient outward currents. The peak response amplitude was related to flash intensity by a Michaelis equation with half-saturating intensity about 1 photon mum-2. 3. The saturating response amplitude ranged up to 27 pA and corresponded closely to complete suppression of the steady inward current present in darkness. 4. For a given cell the saturating response amplitude varied linearly with the length of outer segment within the pipette. This is consistent with a uniform density of light-sensitive channels and negligible gradient of membrane potential along the outer segment. 5. Responses to bright flashes never showed the relaxation from an initial peak seen previously in intracellular voltage recordings, suggesting that the conductance change responsible for the relaxation does not occur in the outer segment. 6. Responses to local illumination of only the recorded outer segment were very similar to those obtained with diffuse light at the same intensity, indicating that peripheral rods made little contribution to the responses. 7. The spectral sensitivity of 'red' rods was consistent with a retinal1-based pigment with lambda max = 498 +/- 2 nm. 8. The kinetics of the response were consistent with four stages of delay affecting action of the internal transmitter. Responses were faster at the basal end of the outer segment than at the distal tip. 9. Background light reduced the sensitivity to a superposed dim test flash and shortened the time course of the response, indicating that adapting light modifies the kinetics and gain of the transduction mechanism within the outer segment. 10. Responses to dim lights exhibited pronounced fluctuations which are attributed in the succeeding paper (Baylor, Lamb & Yau, 1979) to the quantal nature of light.
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Temporal change in fragmentation of continental US forests
James D. Wickham; Kurt H. Riitters; Timothy G. Wade; Collin Homer
2008-01-01
Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US....
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The initiation of segmented buoyancy-driven melting during continental breakup
Gallacher, Ryan J.; Keir, Derek; Harmon, Nicholas; Stuart, Graham; Leroy, Sylvie; Hammond, James O. S.; Kendall, J-Michael; Ayele, Atalay; Goitom, Berhe; Ogubazghi, Ghebrebrhan; Ahmed, Abdulhakim
2016-01-01
Melting of the mantle during continental breakup leads to magmatic intrusion and volcanism, yet our understanding of the location and dominant mechanisms of melt generation in rifting environments is impeded by a paucity of direct observations of mantle melting. It is unclear when during the rifting process the segmented nature of magma supply typical of seafloor spreading initiates. Here, we use Rayleigh-wave tomography to construct a high-resolution absolute three-dimensional shear-wave velocity model of the upper 250 km beneath the Afar triple junction, imaging the mantle response during progressive continental breakup. Our model suggests melt production is highest and melting depths deepest early during continental breakup. Elevated melt production during continental rifting is likely due to localized thinning and melt focusing when the rift is narrow. In addition, we interpret segmented zones of melt supply beneath the rift, suggesting that buoyancy-driven active upwelling of the mantle initiates early during continental rifting. PMID:27752044
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30 CFR 250.1497 - When will BOEMRE monitor my financial solvency?
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 2 2011-07-01 2011-07-01 false When will BOEMRE monitor my financial solvency? 250.1497 Section 250.1497 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Outer Continental Shelf Civil Penaltie...
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NASA Astrophysics Data System (ADS)
Chassefiere, Bernard
1990-09-01
Mass-physical properties of the surficial (upper 5 m) sediments on the Gulf of Lions continental margin were analysed, from more than 100 short (1 m) and longer (5 m) cores obtained during several cruises. Data include water content, unit weight, Atterberg limits (liquid limit, plastic limit, plasticity index), shear strength and compression index, and are used to determine: first, the mass property distribution, according to the main parameters influencing mass-physical properties; the relationships between these properties and the nepheloid layer on the shelf. The shoreline (lagoons) and inner shelf are characterized by low density and shear strength and high water content deposits, due to electrochemical flocculation of the sediment. The outer shelf is blanketed by higher density and shear strength and lower water content deposits generated by normal settling of suspended particles. On the inner shelf, during river peak discharges, a short-term thin bottom layer of "yogurt-like" [ FASS (1985) Geomarine Letters, 4, 147-152; FASS (1986) Continental Shelf Research, 6, 189-208] fluid-mud (unit weight lower than 1.3 mg m -3) is supplied, by a bottom nepheloid layer. During stormy periods, this "yogurt-like" layer (about 10 cm thick) partly disappears by resuspension of suspended particulate matter; this is advected, in the bottom nepheloid layer, over the shelf and the canyons within the upper slope.
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Cold-seep carbonates of the middle and lower continental slope, northern Gulf of Mexico
NASA Astrophysics Data System (ADS)
Roberts, Harry H.; Feng, Dong; Joye, Samantha B.
2010-11-01
of the GOM do not appear to be substantially different from those found on the upper slope (<1000-m water depth). The highly variable fluids and gases that leave their geochemical imprints on seep carbonate of the middle and lower continental slope are similar to their outer shelf and upper slope counterparts.
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Geomorphology of the Iberian Continental Margin
NASA Astrophysics Data System (ADS)
Maestro, Adolfo; López-Martínez, Jerónimo; Llave, Estefanía; Bohoyo, Fernando; Acosta, Juan; Hernández-Molina, F. Javier; Muñoz, Araceli; Jané, Gloria
2013-08-01
The submarine features and processes around the Iberian Peninsula are the result of a complex and diverse geological and oceanographical setting. This paper presents an overview of the seafloor geomorphology of the Iberian Continental Margin and the adjacent abyssal plains. The study covers an area of approximately 2.3 million km2, including a 50 to 400 km wide band adjacent to the coastline. The main morphological characteristics of the seafloor features on the Iberian continental shelf, continental slope, continental rise and the surrounding abyssal plains are described. Individual seafloor features existing on the Iberian Margin have been classified into three main groups according to their origin: tectonic and/or volcanic, depositional and erosional. Major depositional and erosional features around the Iberian Margin developed in late Pleistocene-Holocene times and have been controlled by tectonic movements and eustatic fluctuations. The distribution of the geomorphological features is discussed in relation to their genetic processes and the evolution of the margin. The prevalence of one or several specific processes in certain areas reflects the dominant morphotectonic and oceanographic controlling factors. Sedimentary processes and the resulting depositional products are dominant on the Valencia-Catalán Margin and in the northern part of the Balearic Promontory. Strong tectonic control is observed in the geomorphology of the Betic and the Gulf of Cádiz margins. The role of bottom currents is especially evident throughout the Iberian Margin. The Galicia, Portuguese and Cantabrian margins show a predominance of erosional features and tectonically-controlled linear features related to faults.
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Kahnt, Jörg; Aguiluz, Kryssia; Koch, Jürgen; Treuner-Lange, Anke; Konovalova, Anna; Huntley, Stuart; Hoppert, Michael; Søgaard-Andersen, Lotte; Hedderich, Reiner
2010-10-01
Social behavior in the bacterium Myxococcus xanthus relies on contact-dependent activities involving cell-cell and cell-substratum interactions. To identify outer membrane proteins that have a role in these activities, we profiled the outer membrane proteome of growing and starving cells using two strategies. First, outer membrane proteins were enriched by biotinylation of intact cells using the reagent NHS (N-hydroxysuccinimide)-PEO(12) (polyethylene oxide)-biotin with subsequent membrane solubilization and affinity chromatography. Second, the proteome of outer membrane vesicles (OMV) was determined. Comparisons of detected proteins show that these methods have different detection profiles and together provide a comprehensive view of the outer membrane proteome. From 362 proteins identified, 274 (76%) were cell envelope proteins including 64 integral outer membrane proteins and 85 lipoproteins. The majority of these proteins were of unknown function. Among integral outer membrane proteins with homologues of known function, TonB-dependent transporters comprise the largest group. Our data suggest novel functions for these transporters. Among lipoproteins with homologues of known function, proteins with hydrolytic functions comprise the largest group. The luminal load of OMV was enriched for proteins with hydrolytic functions. Our data suggest that OMV have functions in predation and possibly in transfer of intercellular signaling molecules between cells.
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Long-Lived Glass Mirrors For Outer Space
NASA Technical Reports Server (NTRS)
Bouquet, Frank L.; Maag, Carl R.; Heggen, Philip M.
1988-01-01
Paper summarizes available knowledge about glass mirrors for use in outer space. Strengths and weaknesses of various types of first and second reflective surfaces identified. Second-surface glass mirrors used in outer space designed to different criteria more stringent for terrestrial mirrors. Protons, electrons, cosmic rays, meteorites, and orbiting space debris affect longevities of components. Contamination also factor in space.
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Do the pyramids show continental drift?
Pawley, G S; Abrahamsen, N
1973-03-02
The mystery of the orientation of the Great Pyramids of Giza has remained unexplained for many decades. The general alignment is 4 minutes west of north. It is argued that this is not a builders' error but is caused by movement over the centuries. Modern theories of continental drift do not predict quite such large movements, but other causes of polar wandering give even smaller shifts. Thus, continental drift is the most likely explanation, although somewhat implausible, especially as relevant measurements have been made over a 50-year period, whereas geophysical measurements of sea-floor spreading relate to million-year time scales.
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16 CFR 1611.36 - Application of act to particular types of products.
Code of Federal Regulations, 2012 CFR
2012-01-01
... ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF VINYL PLASTIC FILM Rules and Regulations § 1611.36...) Multilayer fabric and wearing apparel with a film or coating on the uncovered or exposed surface. Plastic film or plastic-coated fabric used, or intended for use, as the outer layer of disposable diapers is...
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16 CFR 1611.36 - Application of act to particular types of products.
Code of Federal Regulations, 2014 CFR
2014-01-01
... ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF VINYL PLASTIC FILM Rules and Regulations § 1611.36...) Multilayer fabric and wearing apparel with a film or coating on the uncovered or exposed surface. Plastic film or plastic-coated fabric used, or intended for use, as the outer layer of disposable diapers is...
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16 CFR 1611.36 - Application of act to particular types of products.
Code of Federal Regulations, 2011 CFR
2011-01-01
... ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF VINYL PLASTIC FILM Rules and Regulations § 1611.36...) Multilayer fabric and wearing apparel with a film or coating on the uncovered or exposed surface. Plastic film or plastic-coated fabric used, or intended for use, as the outer layer of disposable diapers is...
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NASA Technical Reports Server (NTRS)
Holman, Matthew J.; Boyce, J. (Technical Monitor)
2003-01-01
We feel that at the present moment the available theoretical models of the Kuiper belt are still in advance of the data, and thus our main task has been to conduct observational work guided by theoretical motivations. Our efforts over the past year can be divided into four categories: A) Wide-field Searches for Kuiper Belt Objects; B) Pencil-beam Searches for Kuiper Belt Objects; C) Wide-field Searches for Moons of the Outer Planets; D) Pencil-beam Searches for Faint Uranian and Neptunian Moons; E) Recovery Observations. As of April 2002, we have conducted several searches for Kuiper belt objects using large-format mosaic CCD camera on 4-meter class telescopes. In May 1999, we used the Kitt Peak 4-meter with the NOAO Mosaic camera we attempted a search for KBOs at a range of ecliptic latitudes. In addition to our wide-field searches, we have conducted three 'pencil-beam' searches in the past year. In a pencil-beam search we take repeated integrations of the same field throughout a night. After preprocessing the resulting images we shift and recombine them along a range of rates and directions consistent with the motion of KBOs. Stationary objects then smear out, while objects moving at near the shift rate appear as point sources. In addition to our searches for Kuiper belt objects, we are completing the inventory of the outer solar system by search for faint satellites of the outer planets. In August 2001 we conducted pencil beam searches for faint Uranian and Neptunian satellites at CFHT and CTIO. These searches resulted in the discover of two Neptunian and four Uranian satellite candidates. The discovery of Kuiper belt objects and outer planet satellites is of little use if the discoveries are not followed by systematic, repeated astrometric observations that permit reliable estimates of their orbits.
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Ground Based Studies of the Outer Planets
NASA Technical Reports Server (NTRS)
Trafton, Laurence M.
2005-01-01
This report covers progress to date under this grant on our continuing program to conduct ground based studies of the outer solar system planets and satellites, with emphasis on spectroscopy and atmospheric phenomena. The research continues under our new PAST grant, NNG04G131G beginning 5/1/2004. The original period of performance of the subject grant was 3/1/2001 to 2/28/2004, but was extended one year at no cost. Although there is some overlap in the scientific projects conducted during the extended year with those of the new grant, this report is confined to the portion of the work funded under NAG5-10435. The primary goals for this grant period were a comparative study of outer planet thermospheres/ionospheres near solar maximum, extended to the mid-IR, and the investigation of molecular dimers in outer solar system atmospheres. This project supports NASA's planned space missions, Jupiter Polar Orbiter, outer Planet Microprobes, and the recent Cassini flyby of Jupiter. It also supports the OSS strategic plan themes, The Exploration of the Solar System and The Sun-Earth Connection/ Understanding comparative planetary space environments.
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Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-12
.... 080219213-3470-01] RIN 0648-AT31 Atlantic Coastal Fisheries Cooperative Management Act Provisions; American... lobster trap fishery in Lobster Conservation Management Area 2 (Federal nearshore waters in Southern New England; Area 2), and in the Outer Cape Cod Lobster Conservation Management Area (Federal nearshore waters...
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Propagation of Interplanetary Disturbances in the Outer Heliosphere
NASA Technical Reports Server (NTRS)
Wang, Chi
2002-01-01
Work finished during 2002 included: (1) Finished a multi-fluid solar wind model; (2) Determined the solar wind slowdown and interstellar neutral density; (3) Studied shock propagation and evolution in the outer heliosphere; (4) Investigated statistical properties of the solar wind in the outer heliosphere.
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2013-01-01
Background Population stratification is a systematic difference in allele frequencies between subpopulations. This can lead to spurious association findings in the case–control genome wide association studies (GWASs) used to identify single nucleotide polymorphisms (SNPs) associated with disease-linked phenotypes. Methods such as self-declared ancestry, ancestry informative markers, genomic control, structured association, and principal component analysis are used to assess and correct population stratification but each has limitations. We provide an alternative technique to address population stratification. Results We propose a novel machine learning method, ETHNOPRED, which uses the genotype and ethnicity data from the HapMap project to learn ensembles of disjoint decision trees, capable of accurately predicting an individual’s continental and sub-continental ancestry. To predict an individual’s continental ancestry, ETHNOPRED produced an ensemble of 3 decision trees involving a total of 10 SNPs, with 10-fold cross validation accuracy of 100% using HapMap II dataset. We extended this model to involve 29 disjoint decision trees over 149 SNPs, and showed that this ensemble has an accuracy of ≥ 99.9%, even if some of those 149 SNP values were missing. On an independent dataset, predominantly of Caucasian origin, our continental classifier showed 96.8% accuracy and improved genomic control’s λ from 1.22 to 1.11. We next used the HapMap III dataset to learn classifiers to distinguish European subpopulations (North-Western vs. Southern), East Asian subpopulations (Chinese vs. Japanese), African subpopulations (Eastern vs. Western), North American subpopulations (European vs. Chinese vs. African vs. Mexican vs. Indian), and Kenyan subpopulations (Luhya vs. Maasai). In these cases, ETHNOPRED produced ensembles of 3, 39, 21, 11, and 25 disjoint decision trees, respectively involving 31, 502, 526, 242 and 271 SNPs, with 10-fold cross validation accuracy of
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Hajiloo, Mohsen; Sapkota, Yadav; Mackey, John R; Robson, Paula; Greiner, Russell; Damaraju, Sambasivarao
2013-02-22
Population stratification is a systematic difference in allele frequencies between subpopulations. This can lead to spurious association findings in the case-control genome wide association studies (GWASs) used to identify single nucleotide polymorphisms (SNPs) associated with disease-linked phenotypes. Methods such as self-declared ancestry, ancestry informative markers, genomic control, structured association, and principal component analysis are used to assess and correct population stratification but each has limitations. We provide an alternative technique to address population stratification. We propose a novel machine learning method, ETHNOPRED, which uses the genotype and ethnicity data from the HapMap project to learn ensembles of disjoint decision trees, capable of accurately predicting an individual's continental and sub-continental ancestry. To predict an individual's continental ancestry, ETHNOPRED produced an ensemble of 3 decision trees involving a total of 10 SNPs, with 10-fold cross validation accuracy of 100% using HapMap II dataset. We extended this model to involve 29 disjoint decision trees over 149 SNPs, and showed that this ensemble has an accuracy of ≥ 99.9%, even if some of those 149 SNP values were missing. On an independent dataset, predominantly of Caucasian origin, our continental classifier showed 96.8% accuracy and improved genomic control's λ from 1.22 to 1.11. We next used the HapMap III dataset to learn classifiers to distinguish European subpopulations (North-Western vs. Southern), East Asian subpopulations (Chinese vs. Japanese), African subpopulations (Eastern vs. Western), North American subpopulations (European vs. Chinese vs. African vs. Mexican vs. Indian), and Kenyan subpopulations (Luhya vs. Maasai). In these cases, ETHNOPRED produced ensembles of 3, 39, 21, 11, and 25 disjoint decision trees, respectively involving 31, 502, 526, 242 and 271 SNPs, with 10-fold cross validation accuracy of 86.5% ± 2.4%, 95.6% ± 3
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Structure of the North American Atlantic Continental Margin
Schlee, J.S.; Klitgord, K.K.
1986-01-01
Off E N America, where the structure of the continental margin is essentially constructional, seismic profiles have approximated geologic cross sections up to 10-15km below the sea floor and revealed major structural and stratigraphic features that have regional hydrocarbon potential. These features include a) a block-faulted basement hinge zone; b) a deep, broad, rifted basement filled with clastic sediment and salt; and c) a buried paleoshelf-edge complex that has many forms. The mapping of seismostratigraphic units over the continental shelf, slope, and rise has shown that the margin's developmental state included infilling of a rifted margin, buildup of a carbonate platform, and construction of an onlapping continental-rise wedge that was accompanied by erosion of the slope. -from Authors
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Continental crust beneath southeast Iceland.
Torsvik, Trond H; Amundsen, Hans E F; Trønnes, Reidar G; Doubrovine, Pavel V; Gaina, Carmen; Kusznir, Nick J; Steinberger, Bernhard; Corfu, Fernando; Ashwal, Lewis D; Griffin, William L; Werner, Stephanie C; Jamtveit, Bjørn
2015-04-14
The magmatic activity (0-16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Iceland--and especially the Öræfajökull volcano--is characterized by a unique enriched-mantle component (EM2-like) with elevated (87)Sr/(86)Sr and (207)Pb/(204)Pb. Here, we demonstrate through modeling of Sr-Nd-Pb abundances and isotope ratios that the primitive Öræfajökull melts could have assimilated 2-6% of underlying continental crust before differentiating to more evolved melts. From inversion of gravity anomaly data (crustal thickness), analysis of regional magnetic data, and plate reconstructions, we propose that continental crust beneath southeast Iceland is part of ∼350-km-long and 70-km-wide extension of the Jan Mayen Microcontinent (JMM). The extended JMM was marginal to East Greenland but detached in the Early Eocene (between 52 and 47 Mya); by the Oligocene (27 Mya), all parts of the JMM permanently became part of the Eurasian plate following a westward ridge jump in the direction of the Iceland plume.
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Continental crust beneath southeast Iceland
Torsvik, Trond H.; Amundsen, Hans E. F.; Trønnes, Reidar G.; Doubrovine, Pavel V.; Gaina, Carmen; Kusznir, Nick J.; Steinberger, Bernhard; Corfu, Fernando; Ashwal, Lewis D.; Griffin, William L.; Werner, Stephanie C.; Jamtveit, Bjørn
2015-01-01
The magmatic activity (0–16 Ma) in Iceland is linked to a deep mantle plume that has been active for the past 62 My. Icelandic and northeast Atlantic basalts contain variable proportions of two enriched components, interpreted as recycled oceanic crust supplied by the plume, and subcontinental lithospheric mantle derived from the nearby continental margins. A restricted area in southeast Iceland—and especially the Öræfajökull volcano—is characterized by a unique enriched-mantle component (EM2-like) with elevated 87Sr/86Sr and 207Pb/204Pb. Here, we demonstrate through modeling of Sr–Nd–Pb abundances and isotope ratios that the primitive Öræfajökull melts could have assimilated 2–6% of underlying continental crust before differentiating to more evolved melts. From inversion of gravity anomaly data (crustal thickness), analysis of regional magnetic data, and plate reconstructions, we propose that continental crust beneath southeast Iceland is part of ∼350-km-long and 70-km-wide extension of the Jan Mayen Microcontinent (JMM). The extended JMM was marginal to East Greenland but detached in the Early Eocene (between 52 and 47 Mya); by the Oligocene (27 Mya), all parts of the JMM permanently became part of the Eurasian plate following a westward ridge jump in the direction of the Iceland plume. PMID:25825769
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Formation of an Oceanic Transform Fault During Continental Rifting
NASA Astrophysics Data System (ADS)
Illsley-Kemp, F.; Bull, J. M.; Keir, D.; Gerya, T.; Pagli, C.; Gernon, T.; Ayele, A.; Goitom, B.; Hammond, J. O. S.; Kendall, J. M.
2017-12-01
We integrate evidence from surface faults, geodetic measurements, local seismicity, and 3D numerical modelling of the subaerial Afar continental rift to show that an oceanic-style transform fault is forming during the final stages of continental breakup. Transform faults are a fundamental tenet of plate tectonics, connecting offset extensional segments of mid-ocean ridges, and are vital in palaeotectonic reconstructions of passive margins. The current consensus is that transform faults initiate after the onset of seafloor spreading. However this inference has been difficult to test given the lack of observations of transform fault formation. We present the first direct observation of transform fault initiation, and shed unprecedented light on their formation mechanisms. We demonstrate that they originate during late-stage continental rifting, earlier in the rifting cycle than previously thought. Our results have important implications for reconstructing the breakup history of the continents. Palaeotectonic reconstructions that use transform fault terminations as an indicator of the continent-ocean boundary may have placed the continent-ocean boundary landward of its true location. This will have led to an overestimation of the age of continental breakup of between 8-18 Myr. Our results therefore have significant implications for studies that rely on accurate dating of continental breakup events.
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Acute Zonal Cone Photoreceptor Outer Segment Loss.
Aleman, Tomas S; Sandhu, Harpal S; Serrano, Leona W; Traband, Anastasia; Lau, Marisa K; Adamus, Grazyna; Avery, Robert A
2017-05-01
The diagnostic path presented narrows down the cause of acute vision loss to the cone photoreceptor outer segment and will refocus the search for the cause of similar currently idiopathic conditions. To describe the structural and functional associations found in a patient with acute zonal occult photoreceptor loss. A case report of an adolescent boy with acute visual field loss despite a normal fundus examination performed at a university teaching hospital. Results of a complete ophthalmic examination, full-field flash electroretinography (ERG) and multifocal ERG, light-adapted achromatic and 2-color dark-adapted perimetry, and microperimetry. Imaging was performed with spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) and short-wavelength (SW) fundus autofluorescence (FAF), and NIR reflectance (REF). The patient was evaluated within a week of the onset of a scotoma in the nasal field of his left eye. Visual acuity was 20/20 OU, and color vision was normal in both eyes. Results of the fundus examination and of SW-FAF and NIR-FAF imaging were normal in both eyes, whereas NIR-REF imaging showed a region of hyporeflectance temporal to the fovea that corresponded with a dense relative scotoma noted on light-adapted static perimetry in the left eye. Loss in the photoreceptor outer segment detected by SD-OCT co-localized with an area of dense cone dysfunction detected on light-adapted perimetry and multifocal ERG but with near-normal rod-mediated vision according to results of 2-color dark-adapted perimetry. Full-field flash ERG findings were normal in both eyes. The outer nuclear layer and inner retinal thicknesses were normal. Localized, isolated cone dysfunction may represent the earliest photoreceptor abnormality or a distinct entity within the acute zonal occult outer retinopathy complex. Acute zonal occult outer retinopathy should be considered in patients with acute vision loss and abnormalities on NIR-REF imaging, especially if
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Self-Consistent Generation of Continental Crust in Global Mantle Convection Models
NASA Astrophysics Data System (ADS)
Jain, C.; Rozel, A. B.; Tackley, P.
2016-12-01
Numerical modelling commonly shows that mantle convection and continents have strong feedbacks on each other (Philips and Coltice, JGR 2010; Heron and Lowman, JGR 2014), but the continents are always inserted a priori while basaltic (oceanic) crust is generated self-consistently in such models (Rolf et al., EPSL 2012). We aim to implement self-consistent generation of continental crust in global models of mantle convection using StagYY (Tackley, PEPI 2008). The silica-rich continental crust appears to have been formed by fractional melting and crystallization in episodes of relatively rapid growth from late Archaean to late Proterozoic eras (3-1 Ga) (Hawkesworth & Kemp, Nature 2006). It takes several stages of differentiation to generate continental crust. First, the basaltic magma is extracted from the pyrolitic mantle. Second, it goes through eclogitic transformation and then partially melts to form Na-rich Tonalite-Trondhjemite-Granodiorite (TTG) which rise to form proto-continents (Rudnick, Nature 1995; Herzberg & Rudnick, Lithos 2012). TTGs dominate the grey gneiss complexes which make up most of the continental crust. Based on the melting conditions proposed by Moyen (Lithos, 2011), we parameterize TTG formation and henceforth, the continental crust. Continental crust can also be destroyed by subduction or delamination. We will investigate continental growth and destruction history in the models spanning the age of the Earth.
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Self-consistent generation of continental crust in global mantle convection models
NASA Astrophysics Data System (ADS)
Jain, Charitra; Rozel, Antoine; Tackley, Paul
2017-04-01
Numerical modeling commonly shows that mantle convection and continents have strong feedbacks on each other (Philips and Coltice, JGR 2010; Heron and Lowman, JGR 2014), but the continents are always inserted a priori while basaltic (oceanic) crust is generated self-consistently in such models (Rolf et al., EPSL 2012). We aim to implement self-consistent generation of continental crust in global models of mantle convection using StagYY (Tackley, PEPI 2008). The silica-rich continental crust appears to have been formed by fractional melting and crystallization in episodes of relatively rapid growth from late Archean to late Proterozoic eras (3-1 Ga) (Hawkesworth & Kemp, Nature 2006). It takes several stages of differentiation to generate continental crust. First, the basaltic magma is extracted from the pyrolitic mantle. Second, it goes through eclogitic transformation and then partially melts to form Na-rich Tonalite-Trondhjemite-Granodiorite (TTG) which rise to form proto-continents (Rudnick, Nature 1995; Herzberg & Rudnick, Lithos 2012). TTGs dominate the grey gneiss complexes which make up most of the continental crust. Based on the melting conditions proposed by Moyen (Lithos, 2011), we parameterize TTG formation and henceforth, the continental crust. Continental crust can also be destroyed by subduction or delamination. We will investigate continental growth and destruction history in the models spanning the age of the Earth.
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NASA Astrophysics Data System (ADS)
Davy, R. G.; Morgan, J. V.; Minshull, T. A.; Bayrakci, G.; Bull, J. M.; Klaeschen, D.; Reston, T. J.; Sawyer, D. S.; Lymer, G.; Cresswell, D.
2018-01-01
Continental hyperextension during magma-poor rifting at the Deep Galicia Margin is characterized by a complex pattern of faulting, thin continental fault blocks and the serpentinization, with local exhumation, of mantle peridotites along the S-reflector, interpreted as a detachment surface. In order to understand fully the evolution of these features, it is important to image seismically the structure and to model the velocity structure to the greatest resolution possible. Traveltime tomography models have revealed the long-wavelength velocity structure of this hyperextended domain, but are often insufficient to match accurately the short-wavelength structure observed in reflection seismic imaging. Here, we demonstrate the application of 2-D time-domain acoustic full-waveform inversion (FWI) to deep-water seismic data collected at the Deep Galicia Margin, in order to attain a high-resolution velocity model of continental hyperextension. We have used several quality assurance procedures to assess the velocity model, including comparison of the observed and modeled waveforms, checkerboard tests, testing of parameter and inversion strategy and comparison with the migrated reflection image. Our final model exhibits an increase in the resolution of subsurface velocities, with particular improvement observed in the westernmost continental fault blocks, with a clear rotation of the velocity field to match steeply dipping reflectors. Across the S-reflector, there is a sharpening in the velocity contrast, with lower velocities beneath S indicative of preferential mantle serpentinization. This study supports the hypothesis that normal faulting acts to hydrate the upper-mantle peridotite, observed as a systematic decrease in seismic velocities, consistent with increased serpentinization. Our results confirm the feasibility of applying the FWI method to sparse, deep-water crustal data sets.
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In vivo evidence of TonB shuttling between the cytoplasmic and outer membrane in Escherichia coli.
Larsen, Ray A; Letain, Tracy E; Postle, Kathleen
2003-07-01
Gram-negative bacteria are able to convert potential energy inherent in the proton gradient of the cytoplasmic membrane into active nutrient transport across the outer membrane. The transduction of energy is mediated by TonB protein. Previous studies suggest a model in which TonB makes sequential and cyclic contact with proteins in each membrane, a process called shuttling. A key feature of shuttling is that the amino-terminal signal anchor must quit its association with the cytoplasmic membrane, and TonB becomes associated solely with the outer membrane. However, the initial studies did not exclude the possibility that TonB was artifactually pulled from the cytoplasmic membrane by the fractionation process. To resolve this ambiguity, we devised a method to test whether the extreme TonB amino-terminus, located in the cytoplasm, ever became accessible to the cys-specific, cytoplasmic membrane-impermeant molecule, Oregon Green(R) 488 maleimide (OGM) in vivo. A full-length TonB and a truncated TonB were modified to carry a sole cysteine at position 3. Both full-length TonB and truncated TonB (consisting of the amino-terminal two-thirds) achieved identical conformations in the cytoplasmic membrane, as determined by their abilities to cross-link to the cytoplasmic membrane protein ExbB and their abilities to respond conformationally to the presence or absence of proton motive force. Full-length TonB could be amino-terminally labelled in vivo, suggesting that it was periplasmically exposed. In contrast, truncated TonB, which did not associate with the outer membrane, was not specifically labelled in vivo. The truncated TonB also acted as a control for leakage of OGM across the cytoplasmic membrane. Further, the extent of labelling for full-length TonB correlated roughly with the proportion of TonB found at the outer membrane. These findings suggest that TonB does indeed disengage from the cytoplasmic membrane during energy transduction and shuttle to the outer membrane.
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NASA Astrophysics Data System (ADS)
Haskell, Brian J.; Johnson, Thomas C.
1993-01-01
Two transects of box core, hydrographic and photographic stations were made along the Blake Outer Ridge on the southeastern U.S. continental rise to study how circulation patterns affect surface sediment properties. Circulation is strongest at 4200 m on the flanks of the ridge and is reflected in the suspended particulate distribution. A second turbidity maximum at 3600 m suggests that there may be a second axis of circulation at this depth. The intense circulation on the flanks of the ridge has resulted in winnowing of the sediment revealed by coarsening and flattening of the grain size distribution in the detrital silt fraction, and concentration of carbonate by the formation of a foraminiferal lag deposit. The mean grain size of the detrital silt fraction on the crest of the ridge decreases southeastwards with increasing distance from upstream sediment sources. Shifts in the position and strength of the Western Boundary Undercurrent affect the distance that relatively coarse silt is transported. Downcore changes in grain size can therefore be used as paleoceanographic proxy for changes in deepwater circulation.
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The Outer Banks of North Carolina
Dolan, Robert; Lins, Harry F.; Smith, Jodi Jones
2016-12-27
The Outer Banks of North Carolina are excellent examples of the nearly 300 barrier islands rimming the Atlantic and Gulf coasts of the United States. These low, sandy islands are among the most dynamic natural landscapes occupied by man. Beach sands move offshore, onshore, and along the shore in the direction of the prevailing longshore currents. In this way, sandy coasts continuously adjust to different tide, wave, and current conditions and to rising sea level that causes the islands to migrate landward.Despite such changes, barrier islands are of considerable environmental importance. The Outer Banks are home to diverse natural ecosystems that are adapted to the harsh coastal environment. Native species tend to be robust and many are specifically adapted to withstand salt spray, periodic saltwater flooding, and the islands’ well-drained sandy soil. The Outer Banks provide an important stopover for birds on the Atlantic flyway, and many species inhabit the islands year round. In addition, Outer Banks beaches provide an important nesting habitat for five endangered or threatened sea turtle species.European explorers discovered North Carolina’s barrier islands in the 16th century, although the islands were not permanently settled until the middle 17th century. By the early 19th century, shipbuilding and lumber industries were among the most successful, until forest resources were depleted. Commercial fishing eventually followed, and it expanded considerably after the Civil War. By the Great Depression, however, little industry existed on the Outer Banks. In response to the effects of a severe hurricane in 1933, the National Park Service and the Civilian Conservation Corps proposed a massive sand-fixation program to stabilize the moving sand and prevent storm waves from sweeping across the entire width of some sections of the islands. Between 1933 and 1940, this program constructed sand fencing on 185 kilometers (115 miles) of beach and planted grass seedlings
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78 FR 32183 - Importation of Avocados From Continental Spain
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-29
.... APHIS-2012-0002] RIN 0579-AD63 Importation of Avocados From Continental Spain AGENCY: Animal and Plant... reopening the comment period for our proposed rule that would allow the importation of avocados from... avocados from continental Spain (excluding the Balearic Islands and Canary Islands) into the United States...
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31 CFR 515.321 - United States; continental United States.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...
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31 CFR 535.321 - United States; continental United States.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...
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31 CFR 535.321 - United States; continental United States.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...
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31 CFR 535.321 - United States; continental United States.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...
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31 CFR 515.321 - United States; continental United States.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...
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31 CFR 515.321 - United States; continental United States.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...
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31 CFR 500.321 - United States; continental United States.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false United States; continental United... General Definitions § 500.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including U.S. trust territories...
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31 CFR 515.321 - United States; continental United States.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...
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31 CFR 535.321 - United States; continental United States.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...
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31 CFR 535.321 - United States; continental United States.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false United States; continental United... General Definitions § 535.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof including the Trust Territory of...
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31 CFR 515.321 - United States; continental United States.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false United States; continental United... General Definitions § 515.321 United States; continental United States. The term United States means the United States and all areas under the jurisdiction or authority thereof, including the Trust Territory of...
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ERIC Educational Resources Information Center
Schmidt, William G.
1997-01-01
Provides an overview of the current practice and fascinating future of legal issues involved in outer space exploration and colonization. Current space law, by necessity, addresses broad principles rather than specific incidents. Nonetheless, it covers a variety of issues including commercial development, rescue agreements, object registration,…
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NASA Astrophysics Data System (ADS)
Perek, Lubos
1993-10-01
Various aspects of space-environment management are discussed. Attention is called to the fact that, while space radio communications are already under an adequate management by the International Communications Union, the use of nuclear power sources is regulated by the recently adopted set of principles, and space debris will be discussed in the near future at the UN COPUOS, other aspects of management of outer space received little or no attention of the international community. These include the competency of crews and technical equipment of spacecraft launched by newcomers to space exploration; monitoring of locations and motions of space objects (now in national hands), with relevant data made accessible through a computer network; and the requirement to use space only for beneficial purposes and not for promoting narrow and debatable interests damaging the outer space environment and impeding on astronomical observations. It is suggested that some of these tasks would be best performed by an international space agency within the UN system of organizations.
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Xie, Fang; Li, Gang; Zhang, Wanjiang; Zhang, Yanhe; Zhou, Long; Liu, Shuanghong; Liu, Siguo; Wang, Chunlai
2016-02-01
The outer membrane proteins of Actinobacillus pleuropneumoniae are mediators of infection, acting as targets for the host's defense system. The outer membrane lipoprotein VacJ is involved in serum resistance and intercellular spreading in several pathogenic bacteria. To investigate the role of VacJ in the pathogenicity of Actinobacillus pleuropneumoniae, the vacJ gene-deletion mutant MD12 ΔvacJ was constructed. The increased susceptibility to KCl, SDS plus EDTA, and several antibiotics in the MD12ΔvacJ mutant suggested that the stability of the outer membrane was impaired as a result of the mutation in the vacJ gene. The increased NPN fluorescence and significant cellular morphological variation in the MD12ΔvacJ mutant further demonstrated the crucial role of the VacJ lipoprotein in maintaining the outer membrane integrity of A. pleuropneumoniae. In addition, the MD12ΔvacJ mutant exhibited decreased survival from the serum and complement killing compared to the wild-type strain. Interestingly, the MD12ΔvacJ mutant showed reduced biofilm formation compared to the wild-type strain. To our knowledge, this is the first description of the VacJ lipoprotein contributing to bacterial biofilm formation. The data presented in this study illustrate the important role of the VacJ lipoprotein in the maintenance of cellular integrity, serum resistance, and biofilm formation in A. pleuropneumoniae. Copyright © 2015 Elsevier B.V. All rights reserved.
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46 CFR 154.170 - Outer hull steel plating.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Outer hull steel plating. 154.170 Section 154.170... STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Hull Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the...
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Continental tectonics in the aftermath of plate tectonics
NASA Technical Reports Server (NTRS)
Molnar, Peter
1988-01-01
It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.
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Physical oceanography of continental shelves
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, J.S.; Beardlsey, R.C.; Blanton, J.O.
Knowledge of the physical oceanography of continental shelves has increased tremendously in recent years, primarily as a result of new current and hydrographic measurements made in locations where no comparable measurements existed previously. In general, observations from geographically distinct continental shelves have shown that the nature of the flow may vary considerably from region to region. Although some characteristics, such as the response of currents to wind forcing, are common to many shelves, the relative importance of various physical processes in influencing the shelf flow field frequently is different. In the last several years, the scientific literature on shelf studiesmore » has expanded rapidly, with that for separate regions, to some extent, developing independently because of the variable role played by different physical effects. Consequently, it seems that a simultaneous review of progress in physical oceanographic research in different shelf regions would be especially useful at this time in order to help assess the overall progress in the field. This multi-author report has been compiled as a result. Included are sections on the physical oceanography of continental shelves, in or off of, the eastern Bering Sea, northern Gulf of Alaska, Pacific Northwest, southern California, west Florida, southeastern US, Middle Atlantic Bight, Georges Bank and Peru. These discussions clearly point to the diverse nature of the dominant physics in several of the regions, as well as to some of the dynamical features they share in common. 390 references, 23 figures.« less
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Surficial sediments on the western Canadian continental shelf
NASA Astrophysics Data System (ADS)
Bornhold, Brian D.; Barrie, J. Vaughn
1991-08-01
The active continental margin off western Canada is characterized in the south by convergence between the Explorer and Juan de Fuca Plates and the America Plate, and in the north by transform fault motion between the Pacific and America Plates along the Queen Charlotte Fault. Except in some of the deepest troughs and basins shelf sediments are dominated by immature lithic arenites reflecting this tectonic setting. The Vancouver Island shelf is from 5 to 75 km wide and displays complex topography on the inner shelf and a relatively featureless mid- and outer shelf. An exception is the area off southwestern Vancouver Island where large basins bounded by morainal deposits extend more than two-thirds of the distance across the shelf. The shelf edge varies from 180 to 225 m depth and is indented by numerous canyons. Nearshore sediments consist mainly of gravels and boulders and become finer offshore such that muds are slowly accumulating in depths greater than 100 m. Off northwestern Vancouver Island calcareous sediments are abundant with carbonate values often exceeding 75%. High wave and current energies and efficient sediment trapping in coastal fiords have resulted in low rates of accumulation. Olive, glauconitic, Holocene muds and muddy sands are generally less than 0.3 m thick and accumulate only on the outer shelf over an extensive stiff, gray, glaciomarine sandy mud. Queen Charlotte Sound exhibits three broad, shallow, glacially scoured troughs, filled mainly with clayey silts and fine sands and separated by sand and gravel covered banks. Hecate Strait, between the Queen Charlotte Islands and the mainland, consists of a prominent southward-opening trough along the east side of the Strait bounded by Dogfish and Laskeek Banks on the west adjacent to Graham and Moresby Islands, respectively. The trough below 200 m is filled by silts. The banks are covered by discontinuous sands and gravels of variable calcareous content. The bank edges often display megaripples and
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Li, Lei; Li, Rui-Fang; Ming, Zhen-Hua; Lu, Guang-Tao; Tang, Ji-Liang
2017-01-01
Many bacterial pathogens employ the type III secretion system (T3SS) to translocate effector proteins into eukaryotic cells to overcome host defenses. To date, most of our knowledge about the T3SS molecular architecture comes from the studies on animal pathogens. In plant pathogens, nine Hrc proteins are believed to be structural components of the T3SS, of which HrcC and HrcJ form the outer and inner rings of the T3SS, respectively. Here, we demonstrated that a novel outer membrane-bound protein (HpaM) of Xanthomonas campestris pv. campestris is critical for the type III secretion and is structurally and functionally conserved in phytopathogenic Xanthomonas spp. We showed that the C-terminus of HpaM extends into the periplasm to interact physically with HrcJ and the middle part of HpaM interacts physically with HrcC. It is clear that the outer and inner rings compose the main basal body of the T3SS apparatus in animal pathogens. Therefore, we presume that HpaM may act as a T3SS structural component, or play a role in assisting assembling or affecting the stability of the T3SS apparatus. HpaM is a highly prevalent and specific protein in Xanthomonas spp., suggesting that the T3SS of Xanthomonas is distinctive in some aspects from other pathogens. PMID:28198457
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Self-sterilization of bodies during outer planet entry
NASA Technical Reports Server (NTRS)
Hoffman, A. R.; Jaworski, W.; Taylor, D. M.
1974-01-01
A body encountering the atmosphere of an outer planet is subjected to heat loads which could result in high temperature conditions that render terrestrial organisms on or within the body nonviable. To determine whether an irregularly shaped entering body, consisting of several different materials, would be sterilized during inadvertent entry at high velocity, the thermal response of a typical outer planet spacecraft instrument was studied. The results indicate that the Teflon insulated cable and electronic circuit boards may not experience sterilizing temperatures during a Jupiter, Saturn, or Titan entry. Another conclusion of the study is that small plastic particles entering Saturn from outer space have wider survival corridors than do those at Jupiter.
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Kinetic Assessment of Golf Shoe Outer Sole Design Features
Smith, Neal A.; Dyson, Rosemary J.
2009-01-01
This study assessed human kinetics in relation to golf shoe outer sole design features during the golf swing using a driver club by measuring both within the shoe, and beneath the shoe at the natural grass interface. Three different shoes were assessed: metal 7- spike shoe, alternative 7-spike shoe, and a flat soled shoe. In-shoe plantar pressure data were recorded using Footscan RS International pressure insoles and sampling at 500 Hz. Simultaneously ground reaction force at the shoe outer sole was measured using 2 natural grass covered Kistler force platforms and 1000 Hz data acquisition. Video recording of the 18 right-handed golfers at 200 Hz was undertaken while the golfer performed 5 golf shots with his own driver in each type of shoe. Front foot (nearest to shot direction) maximum vertical force and torque were greater than at the back foot, and there was no significant difference related to the shoe type. Wearing the metal spike shoe when using a driver was associated with more torque generation at the back foot (p < 0. 05) than when the flat soled shoe was worn. Within shoe regional pressures differed significantly with golf shoe outer sole design features (p < 0.05). Comparison of the metal spike and alternative spike shoe results provided indications of the quality of regional traction on the outer sole. Potential golf shoe outer sole design features and traction were presented in relation to phases of the golf swing movement. Application of two kinetic measurement methods identified that moderated (adapted) muscular control of foot and body movement may be induced by golf shoe outer sole design features. Ground reaction force measures inform comparisons of overall shoe functional performance, and insole pressure measurements inform comparisons of the underfoot conditions induced by specific regions of the golf shoe outer sole. Key points Assessments of within golf shoe pressures and beneath shoe forces at the natural grass interface were conducted
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Acute Zonal Cone Photoreceptor Outer Segment Loss
Sandhu, Harpal S.; Serrano, Leona W.; Traband, Anastasia; Lau, Marisa K.; Adamus, Grazyna; Avery, Robert A.
2017-01-01
Importance The diagnostic path presented narrows down the cause of acute vision loss to the cone photoreceptor outer segment and will refocus the search for the cause of similar currently idiopathic conditions. Objective To describe the structural and functional associations found in a patient with acute zonal occult photoreceptor loss. Design, Setting, and Participants A case report of an adolescent boy with acute visual field loss despite a normal fundus examination performed at a university teaching hospital. Main Outcomes and Measures Results of a complete ophthalmic examination, full-field flash electroretinography (ERG) and multifocal ERG, light-adapted achromatic and 2-color dark-adapted perimetry, and microperimetry. Imaging was performed with spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) and short-wavelength (SW) fundus autofluorescence (FAF), and NIR reflectance (REF). Results The patient was evaluated within a week of the onset of a scotoma in the nasal field of his left eye. Visual acuity was 20/20 OU, and color vision was normal in both eyes. Results of the fundus examination and of SW-FAF and NIR-FAF imaging were normal in both eyes, whereas NIR-REF imaging showed a region of hyporeflectance temporal to the fovea that corresponded with a dense relative scotoma noted on light-adapted static perimetry in the left eye. Loss in the photoreceptor outer segment detected by SD-OCT co-localized with an area of dense cone dysfunction detected on light-adapted perimetry and multifocal ERG but with near-normal rod-mediated vision according to results of 2-color dark-adapted perimetry. Full-field flash ERG findings were normal in both eyes. The outer nuclear layer and inner retinal thicknesses were normal. Conclusions and Relevance Localized, isolated cone dysfunction may represent the earliest photoreceptor abnormality or a distinct entity within the acute zonal occult outer retinopathy complex. Acute zonal occult outer retinopathy
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Dissecting Escherichia coli Outer Membrane Biogenesis Using Differential Proteomics
Martorana, Alessandra M.; Motta, Sara; Di Silvestre, Dario; Falchi, Federica; Dehò, Gianni; Mauri, Pierluigi; Sperandeo, Paola; Polissi, Alessandra
2014-01-01
The cell envelope of Gram-negative bacteria is a complex multi-layered structure comprising an inner cytoplasmic membrane and an additional asymmetric lipid bilayer, the outer membrane, which functions as a selective permeability barrier and is essential for viability. Lipopolysaccharide, an essential glycolipid located in the outer leaflet of the outer membrane, greatly contributes to the peculiar properties exhibited by the outer membrane. This complex molecule is transported to the cell surface by a molecular machine composed of seven essential proteins LptABCDEFG that form a transenvelope complex and function as a single device. While advances in understanding the mechanisms that govern the biogenesis of the cell envelope have been recently made, only few studies are available on how bacterial cells respond to severe envelope biogenesis defects on a global scale. Here we report the use of differential proteomics based on Multidimensional Protein Identification Technology (MudPIT) to investigate how Escherichia coli cells respond to a block of lipopolysaccharide transport to the outer membrane. We analysed the envelope proteome of a lptC conditional mutant grown under permissive and non permissive conditions and identified 123 proteins whose level is modulated upon LptC depletion. Most such proteins belong to pathways implicated in cell envelope biogenesis, peptidoglycan remodelling, cell division and protein folding. Overall these data contribute to our understanding on how E. coli cells respond to LPS transport defects to restore outer membrane functionality. PMID:24967819
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Continental drift under the Third Reich.
Buffetaut, Eric
2003-12-01
Contrary to what happened in many other countries in the 1930s and 1940s, Alfred Wegener's theory of continental drift was not generally rejected in Nazi Germany, although several leading German geologists of the time did not accept it. It was actually presented as the modern view of Earth history in books and magazine articles aimed at the general public. Although outlandish geological theories such as Hörbiger's Welteislehre were favoured by some Nazi dignitaries, they were not widely accepted in scientific circles. On the other hand, continental drift received official support under the Third Reich, at a time when it was ignored or ridiculed by most earth scientists outside Germany.
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Inner and Outer Recursive Neural Networks for Chemoinformatics Applications.
Urban, Gregor; Subrahmanya, Niranjan; Baldi, Pierre
2018-02-26
Deep learning methods applied to problems in chemoinformatics often require the use of recursive neural networks to handle data with graphical structure and variable size. We present a useful classification of recursive neural network approaches into two classes, the inner and outer approach. The inner approach uses recursion inside the underlying graph, to essentially "crawl" the edges of the graph, while the outer approach uses recursion outside the underlying graph, to aggregate information over progressively longer distances in an orthogonal direction. We illustrate the inner and outer approaches on several examples. More importantly, we provide open-source implementations [available at www.github.com/Chemoinformatics/InnerOuterRNN and cdb.ics.uci.edu ] for both approaches in Tensorflow which can be used in combination with training data to produce efficient models for predicting the physical, chemical, and biological properties of small molecules.
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Normal Mode Derived Models of the Physical Properties of Earth's Outer Core
NASA Astrophysics Data System (ADS)
Irving, J. C. E.; Cottaar, S.; Lekic, V.; Wu, W.
2017-12-01
Earth's outer core, the largest reservoir of metal in our planet, is comprised of an iron alloy of an uncertain composition. Its dynamical behaviour is responsible for the generation of Earth's magnetic field, with convection driven both by thermal and chemical buoyancy fluxes. Existing models of the seismic velocity and density of the outer core exhibit some variation, and there are only a small number of models which aim to represent the outer core's density.It is therefore important that we develop a better understanding of the physical properties of the outer core. Though most of the outer core is likely to be well mixed, it is possible that the uppermost outer core is stably stratified: it may be enriched in light elements released during the growth of the solid, iron enriched, inner core; by elements dissolved from the mantle into the outer core; or by exsolution of compounds previously dissolved in the liquid metal which will eventually be swept into the mantle. The stratified layer may host MAC or Rossby waves and it could impede communication between the chemically differentiated mantle and outer core, including screening out some of the geodynamo's signal. We use normal mode center frequencies to estimate the physical properties of the outer core in a Bayesian framework. We estimate the mineral physical parameters needed to best produce velocity and density models of the outer core which are consistent with the normal mode observations. We require that our models satisfy realistic physical constraints. We create models of the outer core with and without a distinct uppermost layer and assess the importance of this region.Our normal mode-derived models are compared with observations of body waves which travel through the outer core. In particular, we consider SmKS waves which are especially sensitive to the uppermost outer core and are therefore an important way to understand the robustness of our models.
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16 CFR § 1611.36 - Application of act to particular types of products.
Code of Federal Regulations, 2013 CFR
2013-01-01
... FABRICS ACT REGULATIONS STANDARD FOR THE FLAMMABILITY OF VINYL PLASTIC FILM Rules and Regulations § 1611... inner side. (f) Multilayer fabric and wearing apparel with a film or coating on the uncovered or exposed surface. Plastic film or plastic-coated fabric used, or intended for use, as the outer layer of disposable...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-13
... President and Congress. After a period of at least 60 days from the date it was submitted to the President... (3 areas off Alaska and 3 areas in the Gulf of Mexico (GOM)). Maps A and B show the areas proposed... not under congressional moratorium pursuant to the Gulf of Mexico Energy Security Act of 2006 (GOMESA...
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Atmospheric Residence Times of Continental Aerosols.
NASA Astrophysics Data System (ADS)
Balkanski, Yves Jacques
The global atmospheric distributions of ^{222}Rn and ^{210 }Pb are simulated with a three-dimensional model of atmospheric transport based on the meteorology of the NASA GISS^1>=neral circulation model. The short-lived radioactive gas ^ {222}Rn (half-life = 3.8d) is emitted almost exclusively from land, at a relatively uniform rate; hence it is an excellent tracer of continental influences. Lead -210 is produced by decay of ^{222} Rn and immediately condenses to preexisting aerosol surfaces. It provides an excellent measure of aerosol residence times in the atmosphere because its source is accurately defined by the ^{222} Rn distribution. Results from the three-dimensional model are compared to measurements of ^ {222}Rn and ^{210 }Pb atmospheric concentrations to evaluate model's long-range transport over oceanic regions and to study the deposition mechanisms of atmospheric aerosols. Model results for ^{222} Rn are used to examine the long-range transport of continental air over two selected oceanic regions, the subantartic Indian Ocean and the North Pacific. It is shown that fast transport of air from southern Africa causes substantial continental pollution at southern mid-latitudes, a region usually regarded as pristine. Air over the North Pacific is heavily impacted by continental influences year round, but the altitude at which the transport occurs varies seasonally. Observations of aerosols at island sites, which are commonly used as diagnostics of continental influences, may be misleading because they do not account for influences at high altitude and because aerosols are efficiently scavenged by deposition during transport. The study of ^{210}Pb focuses on defining the residence times of submicron aerosols in the troposphere. Scavenging in wet convective updrafts is found to provide the dominant sink on a global scale. The globally averaged residence time for ^{210 }Pb-containing aerosols in the troposphere is 7 days. The average increase in residence time
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The Impact of Internal Wave Seasonality on the Continental Shelf Energy Budget
NASA Astrophysics Data System (ADS)
Wihsgott, Juliane U.; Sharples, Jonathan; Hopkins, Joanne; Palmer, Matthew R.; Mattias Green, J. A.
2017-04-01
Heating-stirring models are widely used to simulate the timing and strength of stratification in continental shelf environments. Such models are based on bulk potential energy (PE) budgets: the loss of PE due to thermal stratification is balanced by wind and tidal mixing. The model often fails to accurately predict the observed vertical structure, as it only considers forces acting on the surface and bottom boundary of the water column. This highlights the need for additional internal energy sources to close this budget, and produce an accurate seasonal cycle of stratification. We present new results that test the impact of boundary layer and internal wave forcing on stratification and vertical density structure in continental shelves. A new series of continuous measurements of full water depth vertical structure, dynamics and meteorological data spanning 17 months (March'14-July'15) provide unprecedented coverage over a full seasonal cycle at a station 120 km north-east from the continental shelf break. We observe a highly variable but energetic internal wave field from the onset of stratification that suggests a continuous supply of internal PE. The heating-stirring model reproduces bulk characteristics of the seasonal cycle. While it accurately predicts the timing of the onset in spring and peak stratification in late summer there is a persistent 20 J m-3 positive offset between the model and observations throughout this period. By including a source of internal energy in the model we improve the prediction for the strength of stratification and the vertical distribution of heat. Yet a constant source of PE seems to result in a seasonal discrepancy resulting in too little mixing during strong stratification and too much mixing during transient periods. The discrepancy seen in the model is consistent with the seasonality observed in the internal wave field. We will establish the role that changing stratification (N2) exerts on the internal wave field and vice
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NASA Astrophysics Data System (ADS)
Dubinin, Evgeny; Grokholsky, Andrey; Makushkina, Anna
2016-04-01
Complex process of continental lithosphere breakup is often accompanied by full or semi isolation of small continental blocks from the parent continent such as microcontinents or submerged marginal plateaus. We present different types of continental blocks formed in various geodynamic settings. The process depends on thermo-mechanical properties of rifting. 1) The continental blocks fully isolated from the parent continent. This kind of blocks exist in submerged form (Elan Bank, the Jan-Mayen Ridge, Zenith Plateau, Gulden Draak Knoll, Batavia Knoll) and in non-submerged form in case of large block size. Most of listed submerged blocks are formed in proximity of hot-spot or plume. 2) The continental blocks semi-isolated from the parent continent. Exmouth Plateau, Vøring, Agulhas, Naturaliste are submerged continental plateaus of the indicated category; Sri Lanka, Tasmania, Socotra are islands adjacent to continent here. Nowadays illustration of this setting is the Sinai block located between the two continental rifts. 3) The submerged linear continental blocks formed by the continental rifting along margin (the Lomonosov Ridge). Suggested evolution of this paragraph is the rift propagation along existing transtensional (or another type) transform fault. Future example of this type might be the California Peninsula block, detached from the North American plate by the rifting within San-Andreas fault. 4) The submerged continental blocks formed by extensional processes as the result of asthenosphere flow and shear deformations. Examples are submerged blocks in the central and southern Scotia Sea (Terror Bank, Protector Basin, Discovery Bank, Bruce Bank etc.). 5) The continental blocks formed in the transform fault systems originated in setting of contradict rifts propagation in presence of structure barriers, rifts are shifted by several hundreds kilometers from each other. Examples of this geodynamic setting are Equatorial Atlantic at the initial development stage
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Modelling of sea floor spreading initiation and rifted continental margin formation
NASA Astrophysics Data System (ADS)
Tymms, V. J.; Isimm Team
2003-04-01
Recent observations of depth dependent (heterogeneous) stretching where upper crustal extension is much less than that of the lower crust and lithospheric mantle at both non-volcanic and volcanic margins plus the discovery of broad domains of exhumed continental mantle at non-volcanic rifted margins are not predicted by existing quantitative models of rifted margin formation which are usually based on intra-continental rift models subjected to very large stretching factors. New conceptual and quantitative models of rifted margin formation are required. Observations and continuum mechanics suggest that the dominant process responsible for rifted continental margin formation is sea-floor spreading of the young ocean ridge, rather than pre-breakup intra-continental rifting. Simple fluid flow models of ocean ridge processes using analytical iso-viscous corner-flow demonstrate that the divergent motion of the upwelling mantle beneath the ocean ridge, when viewed in the reference frame of the young continental margin, shows oceanward flow of the lower continental crust and lithospheric mantle of the young rifted margin giving rise to depth dependent stretching as observed. Single-phase fluid-models have been developed to model the initiation of sea-floor spreading and the thermal, stretching and thinning evolution of the young rifted continental margin. Finite element fluid-flow modelling incorporating the evolving temperature dependent viscosity field on the fluid flow also show depth dependent stretching of the young continental margin. Two-phase flow models of ocean ridges incorporating the transport of both solid matrix and melt fluid (Spiegelman &Reynolds 1999) predict the divergent motion of the asthenosphere and lithosphere matrix, and the focusing of basaltic melt into the narrow axial zone spreading centre at ocean ridges. We are adapting two-phase flow models for application to the initiation of sea-floor spreading and rifted continental margin formation. i
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Ocean processes at the Antarctic continental slope.
Heywood, Karen J; Schmidtko, Sunke; Heuzé, Céline; Kaiser, Jan; Jickells, Timothy D; Queste, Bastien Y; Stevens, David P; Wadley, Martin; Thompson, Andrew F; Fielding, Sophie; Guihen, Damien; Creed, Elizabeth; Ridley, Jeff K; Smith, Walker
2014-07-13
The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system.
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Ocean processes at the Antarctic continental slope
Heywood, Karen J.; Schmidtko, Sunke; Heuzé, Céline; Kaiser, Jan; Jickells, Timothy D.; Queste, Bastien Y.; Stevens, David P.; Wadley, Martin; Thompson, Andrew F.; Fielding, Sophie; Guihen, Damien; Creed, Elizabeth; Ridley, Jeff K.; Smith, Walker
2014-01-01
The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean–atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system. PMID:24891389
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Continental emergence and growth on a cooling earth
NASA Astrophysics Data System (ADS)
Vlaar, N. J.
2000-07-01
Isostasy considerations are connected to a 1-D model of mantle differentiation due to pressure release partial melting to obtain a model for the evolution of the relative sea level with respect to the continent during the earth secular cooling. In this context, a new mechanism is derived for the selective exhumation of exposed ancient cratons. The model results in a quantitative scenario for sea-level fall due to the changing thicknesses of the oceanic basaltic crust and its harzburgite residual layer as a function of falling mantle temperature. It is also shown that the buoyancy of the harzburgite root of a stabilized continental craton has an important effect on sea-level and on the isostatic readjustment and exhumation of exposed continental surface during the earth's secular cooling. The model does not depend on the usual assumption of constant continental freeboard and crustal thickness and its application is not restricted to the post-Archaean. It predicts large-scale continental emergence near the end of the Archaean and the early Proterozoic. This provides an explanation for reported late Archaean emergence and the subsequent formation of late Archaean cratonic platforms and early Proterozoic sedimentary basins. For a period of secular cooling of 3.8 Ga, corresponding to the length of the geological record, the model predicts a fall of the ocean floor of some 4 km or more. For a constant ocean depth, this implies a sea-level fall of the same magnitude. A formula is derived that allows for an increasing ocean depth due to either the changing ratio of continental with respect to oceanic area, or to a possible increase of the oceanic volume during the geological history. Increasing ocean depth results in a later emergence of submarine ancient geological formations compared to the case when ocean depth is constant. Selective exhumation is studied for the case of constant ocean depth. It is shown that for this case, early exposed continental crust can be exhumed
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Density Sorting During the Evolution of Continental Crust
NASA Astrophysics Data System (ADS)
Kelemen, P. B.; Behn, M. D.; Hacker, B. R.
2015-12-01
We consider two settings - in addition to "delamination" of arc lower crust - in which dense, mafic eclogites founder into the convecting mantle while buoyant, felsic lithologies accumulate at the base of evolving continental crust. Arc processes play a central role in generating continental crust, but it remains uncertain how basaltic arc crust is transformed to andesitic continental crust. Dense, SiO2-poor products of fractionation may founder from the base of arc crust by "delamination", but lower arc crust after delamination has significantly different trace elements compared to lower continental crust (LCC). In an alternative model, buoyant magmatic rocks generated at arcs are first subducted, mainly via subduction erosion. Upon heating, these buoyant lithologies ascend through the mantle wedge or along a subduction channel, and are "relaminated" at the base of overlying crust (e.g., Hacker et al EPSL 11, AREPS 15). Average buoyant lavas and plutons for the Aleutians, Izu-Bonin-Marianas, Kohistan and Talkeetna arcs fall within the range of estimated LCC major and trace elements. Relamination is more efficient in generating continental crust than delamination. Himalayan cross-sections show Indian crust thrust beneath Tibetan crust, with no intervening mantle. There is a horizontal Moho at ca 80 km depth, extending from thickened Indian crust, across the region where Tibetan crust overlies Indian crust, into thickened Tibetan crust. About half the subducted Indian crust is present, whereas the other half is missing. Data (Vp/Vs; Miocene lavas formed by interaction of continental crust with mantle; xenolith thermometry) indicate 1000°C or more from ca 50 km depth to the Moho since the Miocene. We build on earlier studies (LePichon et al Tectonics 92, T'phys 97; Schulte-Pelkum et al Nature 05; Monsalve et al JGR 08) to advance the hypothesis that rapid growth of garnet occurs at 70-80 km and 1000°C within subducting Indian crust. Dense eclogites founder
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Near-bottom currents over the continental slope in the Mid-Atlantic Bight
Csanady, G.T.; Churchill, J.H.; Butman, B.
1988-01-01
From a set of 28 current meter records we have found that near-bottom currents faster than 0.2 m s-1 occur frequently over the outer continental shelf of the Mid-Atlantic Bight (bottom depth <210 m) but very rarely (<1% of the time) between bottom depths of 500 m and 2 km over the slope. The rarity of strong near-bottom flow over the middle and lower slope allows the accumulation of fine-grained sediment and organic carbon in this region. Fast near-bottom currents which do occur over the slope are invariably associated with topographic waves, although it is often superimposed inertial oscillations which increase current speed above the level of 0.2 m s-1. Episodes of intense inertial oscillations occur randomly and last typically for 10-20 days. Their energy source is unknown. Topographic wave energy exhibits a slight, but statistically significant, minimum over the mid-slope. These waves appear irregularly and vary both along isobaths and in time. The irregularity is presumably a consequence of random topographic wave generation by Gulf Stream instability. The current regime within sea-floor depressions in the slope (canyons and gullies) is distinctly different from that of the open slope; most notable is the near absence of topographic wave motion within depressions. ?? 1988.
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Seals map bathymetry of the Antarctic continental shelf
NASA Astrophysics Data System (ADS)
Padman, Laurie; Costa, Daniel P.; Bolmer, S. Thompson; Goebel, Michael E.; Huckstadt, Luis A.; Jenkins, Adrian; McDonald, Birgitte I.; Shoosmith, Deborah R.
2010-11-01
We demonstrate the first use of marine mammal dive-depth data to improve maps of bathymetry in poorly sampled regions of the continental shelf. A group of 57 instrumented elephant seals made on the order of 2 × 105 dives over and near the continental shelf on the western side of the Antarctic Peninsula during five seasons, 2005-2009. Maximum dive depth exceeded 2000 m. For dives made near existing ship tracks with measured water depths H<700 m, ˜30% of dive depths were to the seabed, consistent with expected benthic foraging behavior. By identifying the deepest of multiple dives within small areas as a dive to the seabed, we have developed a map of seal-derived bathymetry. Our map fills in several regions for which trackline data are sparse, significantly improving delineation of troughs crossing the continental shelf of the southern Bellingshausen Sea.
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Why does continental convergence stop
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hynes, A.
1985-01-01
Convergence between India and Asia slowed at 45 Ma when they collided, but continues today. This requires that substantial proportions of the Indian and/or Asian lithospheric mantle are still being subducted. The resulting slab-pull is probably comparable with that from complete lithospheric slabs and may promote continued continental convergence even after collision. Since descending lithospheric slabs are present at all collision zones at the time of collision such continued convergence may be general after continental collisions. It may cease only when there is a major (global) plate reorganization which results in new forces on the convergent continents that may counteractmore » the slab-pull. These inferences may be tested on the late Paleozoic collision between Gondwanaland and Laurasia. This is generally considered to have been complete by mid-Permian time (250 Ma). However, this may be only the time of docking of Gondwanaland with North America, not that of the cessation of convergence. Paleomagnetic polar-wander paths for the Gondwanide continents exhibit consistently greater latitudinal shifts from 250 Ma to 200 Ma than those of Laurasia when corrected for post-Triassic drift, suggesting that convergence continued through late Permian well into the Triassic. It may have been accommodated by crustal thickening under what is now the US Coastal Plain, or by strike-slip faulting. Convergence may have ceased only when Pangea began to fragment again, in which case the cause for its cessation may be related to the cause of continental fragmentation.« less
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Constraints on continental crustal mass loss via chemical weathering using lithium and its isotopes
Liu, Xiao-Ming; Rudnick, Roberta L.
2011-01-01
Chemical weathering, as well as physical erosion, changes the composition and shapes the surface of the continental crust. However, the amount of continental material that has been lost over Earth’s history due to chemical weathering is poorly constrained. Using a mass balance model for lithium inputs and outputs from the continental crust, we find that the mass of continental crust that has been lost due to chemical weathering is at least 15% of the original mass of the juvenile continental crust, and may be as high as 60%, with a best estimate of approximately 45%. Our results suggest that chemical weathering and subsequent subduction of soluble elements have major impacts on both the mass and the compositional evolution of the continental crust. PMID:22184221
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Radioisotope Reduction Using Solar Power for Outer Planetary Missions
NASA Technical Reports Server (NTRS)
Fincannon, James
2008-01-01
Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.
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Continental magnetic anomaly constraints on continental reconstruction
NASA Technical Reports Server (NTRS)
Vonfrese, R. R. B.; Hinze, W. J.; Olivier, R.; Bentley, C. R.
1985-01-01
Crustal magnetic anomalies mapped by the MAGSAT satellite for North and South America, Europe, Africa, India, Australia and Antarctica and adjacent marine areas were adjusted to a common elevation of 400 km and differentially reduced to the radial pole of intensity 60,000 nT. These radially polarized anomalies are normalized for differential inclination, declination and intensity effects of the geomagnetic field, so that in principle they directly reflected the geometric and magnetic polarization attributes of sources which include regional petrologic variations of the crust and upper mantle, and crustal thickness and thermal perturbations. Continental anomalies demonstrate remarkably detailed correlation of regional magnetic sources across rifted margins when plotted on a reconstruction of Pangea. Accordingly, they suggest further fundamental constraints on the geologic evolution of the continents and their reconstructions.
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Aerocapture Technology Development Needs for Outer Planet Exploration
NASA Technical Reports Server (NTRS)
Wercinski, Paul; Munk, Michelle; Powell, Richard; Hall, Jeff; Graves, Claude; Partridge, Harry (Technical Monitor)
2002-01-01
The purpose of this white paper is to identify aerocapture technology and system level development needs to enable NASA future mission planning to support Outer Planet Exploration. Aerocapture is a flight maneuver that takes place at very high speeds within a planet's atmosphere that provides a change in velocity using aerodynamic forces (in contrast to propulsive thrust) for orbit insertion. Aerocapture is very much a system level technology where individual disciplines such as system analysis and integrated vehicle design, aerodynamics, aerothermal environments, thermal protection systems (TPS), guidance, navigation and control (GN&C) instrumentation need to be integrated and optimized to meet mission specific requirements. This paper identifies on-going activities, their relevance and potential benefit to outer planet aerocapture that include New Millennium ST7 Aerocapture concept definition study, Mars Exploration Program aeroassist project level support, and FY01 Aeroassist In-Space Guideline tasks. The challenges of performing aerocapture for outer planet missions such as Titan Explorer or Neptune Orbiter require investments to advance the technology readiness of the aerocapture technology disciplines for the unique application of outer planet aerocapture. This white paper will identify critical technology gaps (with emphasis on aeroshell concepts) and strategies for advancement.
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-08
... Shelf Permits Issued to Shell Offshore, Inc. for the Kulluk Conical Drilling Unit AGENCY: United States... (OCS) permit to construct and Title V air quality operating permit to Shell Offshore, Inc. (``Shell'') for operation of the Kulluk conical drilling unit in the Beaufort Sea off the north coast of Alaska...
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ARM - Midlatitude Continental Convective Clouds Microwave Radiometer Profiler (jensen-mwr)
Jensen, Mike
2012-02-01
A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.
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Crustal volumes of the continents and of oceanic and continental submarine plateaus
NASA Technical Reports Server (NTRS)
Schubert, G.; Sandwell, D.
1989-01-01
Using global topographic data and the assumption of Airy isostasy, it is estimated that the crustal volume of the continents is 7182 X 10 to the 6th cu km. The crustal volumes of the oceanic and continental submarine plateaus are calculated at 369 X 10 to the 6th cu km and 242 X 10 to the 6th cu km, respectively. The total continental crustal volume is found to be 7581 X 10 to the 6th cu km, 3.2 percent of which is comprised of continental submarine plateaus on the seafloor. An upper bound on the contintental crust addition rate by the accretion of oceanic plateaus is set at 3.7 cu km/yr. Subduction of continental submarine plateaus with the oceanic lithosphere on a 100 Myr time scale yields an upper bound to the continental crustal subtraction rate of 2.4 cu km/yr.
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Continental margin sedimentation: From sediment transport to sequence stratigraphy
Nittrouer, Charles A.; Austin, James A.; Field, Michael E.; Kravitz, Joseph H.; Syvitski, James P. M.; Wiberg, Patricia L.
2007-01-01
This volume on continental margin sedimentation brings together an expert editorial and contributor team to create a state-of-the-art resource. Taking a global perspective, the book spans a range of timescales and content, ranging from how oceans transport particles, to how thick rock sequences are formed on continental margins.- Summarizes and integrates our understanding of sedimentary processes and strata associated with fluvial dispersal systems on continental shelves and slopes- Explores timescales ranging from particle transport at one extreme, to deep burial at the other- Insights are presented for margins in general, and with focus on a tectonically active margin (northern California) and a passive margin (New Jersey), enabling detailed examination of the intricate relationships between a wide suite of sedimentary processes and their preserved stratigraphy- Includes observational studies which document the processes and strata found on particular margins, in addition to numerical models and laboratory experimentation, which provide a quantitative basis for extrapolation in time and space of insights about continental-margin sedimentation- Provides a research resource for scientists studying modern and ancient margins, and an educational text for advanced students in sedimentology and stratigraphy
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OUTER LOOP LANDFILL CASE STUDY
This presentation will describe the interim data reaulting from a CRADA between USEPA and Waste Management, Inc. at the outer Loop Landfill Bioreactor research project located in Louisville, KY. Recently updated data will be presented covering landfill solids, gas being collecte...
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Katschke, Kenneth J; Xi, Hongkang; Cox, Christian; Truong, Tom; Malato, Yann; Lee, Wyne P; McKenzie, Brent; Arceo, Rommel; Tao, Jianhua; Rangell, Linda; Reichelt, Mike; Diehl, Lauri; Elstrott, Justin; Weimer, Robby M; Campagne, Menno van Lookeren
2018-05-09
Geographic atrophy (GA), the advanced form of dry age-related macular degeneration (AMD), is characterized by progressive loss of retinal pigment epithelium cells and photoreceptors in the setting of characteristic extracellular deposits and remains a serious unmet medical need. While genetic predisposition to AMD is dominated by polymorphisms in complement genes, it remains unclear how complement activation contributes to retinal atrophy. Here we demonstrate that complement is activated on photoreceptor outer segments (POS) in the retina peripheral to atrophic lesions associated with GA. When exposed to human serum following outer blood-retinal barrier breakdown, POS act as potent activators of the classical and alternative complement pathway. In mouse models of retinal degeneration, classical and alternative pathway complement activation on photoreceptors contributed to the loss of photoreceptor function. This was dependent on C5a-mediated recruitment of peripheral blood monocytes but independent of resident microglia. Genetic or pharmacologic inhibition of both classical and alternative complement C3 and C5 convertases was required to reduce progressive degeneration of photoreceptor rods and cones. Our study implicates systemic classical and alternative complement proteins and peripheral blood monocytes as critical effectors of localized retinal degeneration with potential relevance for the contribution of complement activation to GA.
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Regimes for the ocean, outer space, and weather
NASA Technical Reports Server (NTRS)
Brown, S.; Cornell, N. W.; Fabian, L. L.; Weiss, E. B.
1977-01-01
The allocation of resources among users of the oceans, outer space and the weather is discussed. Attention is given to the international management of maritime navigation, the control of fisheries, offshore oil and gas exploitation, mineral exploitation in the deep seabed (especially the mining of manganese nodules), and the regulation of oceanographic studies. The management of outer space is considered, with special reference to remote sensing by satellites, television broadcasting, the technical requirements of maritime satellites, and problems associated with satellite frequency and orbit allocation. Rainmaking and typhoon modification, as well as the distribution of weather modification capabilities in the world, are also mentioned. The United Nations, international agencies and tribunals, and multi- or bilateral agreements are some of the implements suggested for use in the regulation of the oceans, outer space and the weather.
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Cryovolcanism in the outer solar system
Geissler, Paul E.
2015-01-01
Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout the outer solar system. This chapter examines the mechanisms and manifestations of cryovolcanism, beginning with a review of the materials that make up these unusual ‘‘magmas’’ and the means by which they might erupt and concluding with a volcanologist's tour of the farthest reaches of the solar system.
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Outer-layer manipulators for turbulent drag reduction
NASA Technical Reports Server (NTRS)
Anders, J. B., Jr.
1990-01-01
The last ten years have yielded intriguing research results on aerodynamic boundary outer-layer manipulators as local skin friction reduction devices at low Reynolds numbers; net drag reduction device systems for entire aerodynamic configurations are nevertheless noted to remain elusive. Evidence has emerged for dramatic alterations of the structure of a turbulent boundary layer which persist for long distances downstream and reduce wall shear as a results of any one of several theoretically possible mechanisms. Reduced effectiveness at high Reynolds numbers may, however, limit the applicability of outer-layer manipulators to practical aircraft drag reduction.
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Formation of continental crust by intrusive magmatism
NASA Astrophysics Data System (ADS)
Rozel, A. B.; Golabek, G. J.; Jain, C.; Tackley, P. J.; Gerya, T.
2017-09-01
How were the continents formed in the Earth? No global numerical simulation of our planet ever managed to generate continental material self-consistently. In the present study, we show that the latest developments of the convection code StagYY enable to estimate how to produce the early continents, more than 3 billion years ago. In our models, melting of pyrolitic rocks generates a basaltic melt and leaves behind a depleted solid residue (a harzburgite). The melt generated in the mantle is transported to the surface. Only basaltic rocks melting again can generate continental crust. Should the basaltic melt always reach the open air and cool down? Should the melt be intruded warm in the pre-existing crust? The present study shows that both processes have to be considered to produce continents. Indeed, granitoids can only be created in a tight window of pressure-temperature. If all basalt is quickly cooled by surface volcanism, the lithosphere will be too cold. If all basalt is intruded warm below the crust then the lithosphere will be too warm. The key is to have both volcanism and plutonism (intrusive magmatism) to reach the optimal temperature and form massive volumes of continental material.
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Outer membrane proteins of pathogenic spirochetes
Cullen, Paul A.; Haake, David A.; Adler, Ben
2009-01-01
Pathogenic spirochetes are the causative agents of several important diseases including syphilis, Lyme disease, leptospirosis, swine dysentery, periodontal disease and some forms of relapsing fever. Spirochetal bacteria possess two membranes and the proteins present in the outer membrane are at the site of interaction with host tissue and the immune system. This review describes the current knowledge in the field of spirochetal outer membrane protein (OMP) biology. What is known concerning biogenesis and structure of OMPs, with particular regard to the atypical signal peptide cleavage sites observed amongst the spirochetes, is discussed. We examine the functions that have been determined for several spirochetal OMPs including those that have been demonstrated to function as adhesins, porins or to have roles in complement resistance. A detailed description of the role of spirochetal OMPs in immunity, including those that stimulate protective immunity or that are involved in antigenic variation, is given. A final section is included which covers experimental considerations in spirochetal outer membrane biology. This section covers contentious issues concerning cellular localization of putative OMPs, including determination of surface exposure. A more detailed knowledge of spirochetal OMP biology will hopefully lead to the design of new vaccines and a better understanding of spirochetal pathogenesis. PMID:15449605
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The effect of light on outer segment calcium in salamander rods
Matthews, Hugh R; Fain, Gordon L
2003-01-01
Calcium acts as a second messenger in vertebrate rods, regulating the recovery phase of the light response and modulating sensitivity during light-adaptation. Since light not only decreases the outer segment calcium concentration ([Ca2+]i) by closing cyclic nucleotide-gated channels but can also increase [Ca2+]i by releasing Ca2+ from buffer sites or intracellular stores, we examined in detail the effect of light and circulating current on [Ca2+]i by making simultaneous measurements of suction pipette current and [Ca2+]i from isolated rods of the salamander Ambystoma tigrinum after incorporation of the fluorescent dye fluo-5F. When the release of Ca2+ is measured in 0 Ca2+−0 Na+ solution, minimising fluxes of Ca2+ across the plasma membrane, it is substantial only for light bright enough to bleach a significant fraction of the photopigment and is restricted to the part of the outer segment in which the bleach occurred. It is unlikely, therefore, to make a large contribution to [Ca2+]i for most of the physiological operating range of the rod. Nevertheless, since release is half-maximal for a bleach of less than 10 %, it cannot be produced by a simple mechanism such as a change in the affinity of a binding site on rhodopsin itself but must instead require some more complex interaction. In Ringer solution, the Ca2+ in the light-releasable pool can be discharged merely by the decrease in [Ca2+]i that occurs as the outer segment channels close. In steady background light or after exposure to saturating illumination, the fraction of Ca2+ in the pool decreases essentially in proportion to [Ca2+]i as if Ca2+ were being removed from a buffer site within the cytoplasm. Furthermore, [Ca2+]i itself changes in proportion to the circulating current, with little evidence for a contribution from Ca2+ release or other mechanisms of Ca2+ homeostasis. This indicates that flux of Ca2+ across the plasma membrane is the major determinant of outer segment Ca2+ concentration within the
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NASA Astrophysics Data System (ADS)
Gün, E.; Gogus, O.; Pysklywec, R.; Topuz, G.; Bodur, O. F.
2017-12-01
The Tethyan belt in the eastern Mediterranean region is characterized by the accretion of several micro-continental blocks (e.g. Anatolide-Tauride, Sakarya and Istanbul terranes). The accretion of a micro-continental block to the active continental margin and subsequent initiation of a new subduction are of crucial importance in understanding the geodynamic evolution of the region. Numerical geodynamic experiments are designed to investigate how these micro-continental blocks in the ocean-continent subduction system develops the aforementioned subduction, back-arc extension, surface uplift and the ophiolite emplacement in the eastern Mediterranean since Late Cretaceous. In a series set of experiments, we test various sizes of micro-continental blocks (ranging from 50 to 300 km), different rheological properties (e.g. dry-wet olivine mantle) and imposed plate convergence velocities (0 to 4 cm/year). For a prime present-day analogue to the micro-continental block collision-accretion, model predictions are compared against the collision between Eratosthenes and Cyprus. Preliminary results show that slab break-off occurs directly after the collision when the plate convergence velocities are less than 2 cm/yr and the mantle lithosphere of the continental block has viscoplastic rheology. On the other hand, there is no relationship between convergence rate and break-off event when the lithospheric mantle rheology is chosen to be plastic. Furthermore, the micro-continental block undergoes considerable extension before continental collision due to the slab pull force, if a viscoplastic rheology is assumed for the mantle lithosphere.
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Cockell, Charles S; Rettberg, Petra; Rabbow, Elke; Olsson-Francis, Karen
2011-10-01
An epilithic microbial community was launched into low Earth orbit, and exposed to conditions in outer space for 548 days on the European Space Agency EXPOSE-E facility outside the International Space Station. The natural phototroph biofilm was augmented with akinetes of Anabaena cylindrica and vegetative cells of Nostoc commune and Chroococcidiopsis. In space-exposed dark controls, two algae (Chlorella and Rosenvingiella spp.), a cyanobacterium (Gloeocapsa sp.) and two bacteria associated with the natural community survived. Of the augmented organisms, cells of A. cylindrica and Chroococcidiopsis survived, but no cells of N. commune. Only cells of Chroococcidiopsis were cultured from samples exposed to the unattenuated extraterrestrial ultraviolet (UV) spectrum (>110 nm or 200 nm). Raman spectroscopy and bright-field microscopy showed that under these conditions the surface cells were bleached and their carotenoids were destroyed, although cell morphology was preserved. These experiments demonstrate that outer space can act as a selection pressure on the composition of microbial communities. The results obtained from samples exposed to >200 nm UV (simulating the putative worst-case UV exposure on the early Earth) demonstrate the potential for epilithic colonization of land masses during that time, but that UV radiation on anoxic planets can act as a strong selection pressure on surface-dwelling organisms. Finally, these experiments have yielded new phototrophic organisms of potential use in biomass and oxygen production in space exploration.
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Earth's Outer Core Properties Estimated Using Bayesian Inversion of Normal Mode Eigenfrequencies
NASA Astrophysics Data System (ADS)
Irving, J. C. E.; Cottaar, S.; Lekic, V.
2016-12-01
The outer core is arguably Earth's most dynamic region, and consists of an iron-nickel liquid with an unknown combination of lighter alloying elements. Frequencies of Earth's normal modes provide the strongest constraints on the radial profiles of compressional wavespeed, VΦ, and density, ρ, in the outer core. Recent great earthquakes have yielded new normal mode measurements; however, mineral physics experiments and calculations are often compared to the Preliminary reference Earth model (PREM), which is 35 years old and does not provide uncertainties. Here we investigate the thermo-elastic properties of the outer core using Earth's free oscillations and a Bayesian framework. To estimate radial structure of the outer core and its uncertainties, we choose to exploit recent datasets of normal mode centre frequencies. Under the self-coupling approximation, centre frequencies are unaffected by lateral heterogeneities in the Earth, for example in the mantle. Normal modes are sensitive to both VΦ and ρ in the outer core, with each mode's specific sensitivity depending on its eigenfunctions. We include a priori bounds on outer core models that ensure compatibility with measurements of mass and moment of inertia. We use Bayesian Monte Carlo Markov Chain techniques to explore different choices in parameterizing the outer core, each of which represents different a priori constraints. We test how results vary (1) assuming a smooth polynomial parametrization, (2) allowing for structure close to the outer core's boundaries, (3) assuming an Equation-of-State and adiabaticity and inverting directly for thermo-elastic parameters. In the second approach we recognize that the outer core may have distinct regions close to the core-mantle and inner core boundaries and investigate models which parameterize the well mixed outer core separately from these two layers. In the last approach we seek to map the uncertainties directly into thermo-elastic parameters including the bulk
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Suggestions for Teaching the Principles of Continental Drift in the Elementary School
ERIC Educational Resources Information Center
Glenn, William H.
1977-01-01
Provides a brief overview of current geographic ideas regarding continental drift and plate tectonics and suggests techniques for illustrating continental motions to elementary school pupils. (Author/DB)
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Outer brain barriers in rat and human development.
Brøchner, Christian B; Holst, Camilla B; Møllgård, Kjeld
2015-01-01
Complex barriers at the brain's surface, particularly in development, are poorly defined. In the adult, arachnoid blood-cerebrospinal fluid (CSF) barrier separates the fenestrated dural vessels from the CSF by means of a cell layer joined by tight junctions. Outer CSF-brain barrier provides diffusion restriction between brain and subarachnoid CSF through an initial radial glial end feet layer covered with a pial surface layer. To further characterize these interfaces we examined embryonic rat brains from E10 to P0 and forebrains from human embryos and fetuses (6-21st weeks post-conception) and adults using immunohistochemistry and confocal microscopy. Antibodies against claudin-11, BLBP, collagen 1, SSEA-4, MAP2, YKL-40, and its receptor IL-13Rα2 and EAAT1 were used to describe morphological characteristics and functional aspects of the outer brain barriers. Claudin-11 was a reliable marker of the arachnoid blood-CSF barrier. Collagen 1 delineated the subarachnoid space and stained pial surface layer. BLBP defined radial glial end feet layer and SSEA-4 and YKL-40 were present in both leptomeningeal cells and end feet layer, which transformed into glial limitans. IL-13Rα2 and EAAT1 were present in the end feet layer illustrating transporter/receptor presence in the outer CSF-brain barrier. MAP2 immunostaining in adult brain outlined the lower border of glia limitans; remnants of end feet were YKL-40 positive in some areas. We propose that outer brain barriers are composed of at least 3 interfaces: blood-CSF barrier across arachnoid barrier cell layer, blood-CSF barrier across pial microvessels, and outer CSF-brain barrier comprising glial end feet layer/pial surface layer.
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Louisiana continental slope: geologic and seismic stratigraphic framework
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ray, P.K.; Cooke, D.W.
1987-05-01
The continental slope of Louisiana from Green Canyon to Mississippi Canyon was studied by interpreting seismic CDP data and wells in the area. The slope is characterized by blocked canyon intraslope basins of various dimensions with maximum thickness of sediments in excess of 21,000 ft, rotational slump blocks and large-scale submarine slides. In the subsurface, the outer shelf and upper slope show contrasting character with that of the lower slope, especially below the Sigsbee Scarp. The seismic stratigraphic units established for the deep sea area can be recognized in their entirety up to a water depth of 6000 to 5500more » ft. In shallower water salt tectonics obliterates the sequence. Fragmental records of the sequence, especially the top of Challenger boundary, have been recognized in as shallow as 2000 to 3000 ft of water. The Tertiary units often downlap and onlap directly on the Challenger unit, indicating the progradational nature of the clastic slope. The Sigsbee unit has been traced through the entire slope area and can be divided into five subunits of unique acoustical characteristics. The slope constantly regrades in response to Neogene sea level fluctuations. Loading of the shelf by deltaic deposition contributes to salt sill formation and flowage of salt over deep-water sediments on the slope during high sea level. Regressive sea is represented by slope failure, formation of large-scale submarine slides, filling of blocked canyon intraslope basins which show similar seismic facies to that of Orca and Pigmy basins as reported from DSDP studies, and sporadic uplifting of salt diapirs and massifs and the formation of linear transverse salt ridges.« less
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Powell, Nathaniel J; Jang, Albert; Park, Jang-Yeon; Valette, Julien; Garwood, Michael; Marjańska, Małgorzata
2015-01-01
To introduce a new outer volume suppression (OVS) technique that uses a single pulse and rotating gradients to accomplish frequency-swept excitation. This new technique, which is called gradient rotating outer volume excitation (GROOVE), produces a circular or elliptical suppression band rather than suppressing the entire outer volume. Theoretical and k-space descriptions of GROOVE are provided. The properties of GROOVE were investigated with simulations, phantom, and human experiments performed using a 4T horizontal bore magnet equipped with a TEM coil. Similar suppression performance was obtained in phantom and human brain using GROOVE with circular and elliptical shapes. Simulations indicate that GROOVE requires less SAR and time than traditional OVS schemes, but traditional schemes provide a sharper transition zone and less residual signal. GROOVE represents a new way of performing OVS in which spins are excited temporally in space on a trajectory that can be tailored to fit the shape of the suppression region. In addition, GROOVE is capable of suppressing tailored regions of space with more flexibility and in a shorter period of time than conventional methods. GROOVE provides a fast, low SAR alternative to conventional OVS methods in some applications (e.g., scalp suppression). © 2014 Wiley Periodicals, Inc.
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Protein targeting and integration signal for the chloroplastic outer envelope membrane.
Li, H M; Chen, L J
1996-01-01
Most proteins in chloroplasts are encoded by the nuclear genome and synthesized in the cytosol. With the exception of most quter envelope membrane proteins, nuclear-encoded chloroplastic proteins are synthesized with N-terminal extensions that contain the chloroplast targeting information of these proteins. Most outer membrane proteins, however, are synthesized without extensions in the cytosol. Therefore, it is not clear where the chloroplastic outer membrane targeting information resides within these polypeptides. We have analyzed a chloroplastic outer membrane protein, OEP14 (outer envelope membrane protein of 14 kD, previously named OM14), and localized its outer membrane targeting and integration signal to the first 30 amino acids of the protein. This signal consists of a positively charged N-terminal portion followed by a hydrophobic core, bearing resemblance to the signal peptides of proteins targeted to the endoplasmic reticulum. However, a chimeric protein containing this signal fused to a passenger protein did not integrate into the endoplasmic reticulum membrane. Furthermore, membrane topology analysis indicated that the signal inserts into the chloroplastic outer membrane in an orientation opposite to that predicted by the "positive inside" rule. PMID:8953775
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NASA Astrophysics Data System (ADS)
Cronin, T.; Tziperman, E.; Li, H.
2015-12-01
High latitude continents have warmed much more rapidly in recent decades than the rest of the globe, especially in winter, and the maintenance of warm, frost-free conditions in continental interiors in winter has been a long-standing problem of past equable climates. It has also been found that the high-latitude lapse rate feedback plays an important role in Arctic amplification of climate change in climate model simulations, but we have little understanding of why lapse rates at high latitudes change so strongly with warming. To better understand these problems, we study Arctic air formation - the process by which a high-latitude maritime air mass is advected over a continent during polar night, cooled at the surface by radiation, and transformed into a much colder continental polar air mass - and its sensitivity to climate warming. We use a single-column version of the WRF model to conduct two-week simulations of the cooling process across a wide range of initial temperature profiles and microphysics schemes, and find that a low cloud feedback suppresses Arctic air formation in warmer climates. This cloud feedback consists of an increase in low cloud amount with warming, which shields the surface from radiative cooling, and increases the continental surface air temperature by roughly two degrees for each degree increase of the initial maritime surface air temperature. The time it takes for the surface air temperature to drop below freezing increases nonlinearly to ~10 days for initial maritime surface air temperatures of 20 oC. Given that this is about the time it takes an air mass starting over the Pacific to traverse the north American continent, this suggests that optically thick stratus cloud decks could help to maintain frost-free winter continental interiors in equable climates. We find that CMIP5 climate model runs show large increases in cloud water path and surface cloud longwave forcing in warmer climates, consistent with the proposed low-cloud feedback
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NASA Astrophysics Data System (ADS)
Conrad, Georges; Lappartient, Jean-René
The 'Continental Terminal' in the Senegalo-Mauritanian basin is a Cenozoic and detrital formation, presenting signs of an intense ferralitic alteration with formation of ferruginous concretions and crustings, neo-formation of kaolinite and significant silica movements. Sedimentary structures are generally obliterated by alteration in the formation's summit. However, some fossil layers which have undergone epigenesis by geothite make it possible to establish the sea origin of the eocene and miocene deposits in this 'Continental Terminal'. A better idea of Cenozoic transgressions and regressions can be achieved by a reconstitution of fossil river beds through alterations on the edge of the African continent. The new elements in the 'Continental Terminal' and the Senegalo-Mauritanian Cenozoic paleoclimates are: The 'Continental Terminal' clearly represents an alteration fringe developed at the expense of marine formations (Tessier et al. 1975 Actes 9ème Congr. Int. Sédim., Nice, pp. 207-211), but this concept cannot be generalized to all of the coastal Cenozoic or interior Iullemmeden Nigerian basins. The ferrallitic alterations mostly occurred in the Pliocene period after the sinking of the basin, as in the Miocene margino-littoral facies, and are still highly dominant. The ferruginous crusting can be seen in this period and also during the lower Pleistocene, because of the latitudinal migration of the basin northwards starting from the upper Cretaceous period.
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Geometrical interpretation for the outer SU(3) outer multiplicity label
NASA Technical Reports Server (NTRS)
Draayer, Jerry P.; Troltenier, D.
1995-01-01
A geometrical interpretation for the outer multiplicity rho that occurs in a reduction of the product of two SU(3) representations, (lambda(sub pi), mu(sub pi)) x (lambda(sub nu), mu(sub nu)) approaches sigma(sub rho)(lambda, mu)(sub rho), is introduced. This coupling of proton (pi) and neutron (nu) representations arises, for example, in both boson and fermion descriptions of heavy deformed nuclei. Attributing a geometry to the coupling raises the possibility of introducing a simple interaction that provides a physically meaningful way for distinguishing multiple occurrences of (lambda, mu) values that can arise in such products.
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Outer planet probe cost estimates: First impressions
NASA Technical Reports Server (NTRS)
Niehoff, J.
1974-01-01
An examination was made of early estimates of outer planetary atmospheric probe cost by comparing the estimates with past planetary projects. Of particular interest is identification of project elements which are likely cost drivers for future probe missions. Data are divided into two parts: first, the description of a cost model developed by SAI for the Planetary Programs Office of NASA, and second, use of this model and its data base to evaluate estimates of probe costs. Several observations are offered in conclusion regarding the credibility of current estimates and specific areas of the outer planet probe concept most vulnerable to cost escalation.
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Reconstructing Rodinia by Fitting Neoproterozoic Continental Margins
Stewart, John H.
2009-01-01
Reconstructions of Phanerozoic tectonic plates can be closely constrained by lithologic correlations across conjugate margins by paleontologic information, by correlation of orogenic belts, by paleomagnetic location of continents, and by ocean floor magmatic stripes. In contrast, Proterozoic reconstructions are hindered by the lack of some of these tools or the lack of their precision. To overcome some of these difficulties, this report focuses on a different method of reconstruction, namely the use of the shape of continents to assemble the supercontinent of Rodinia, much like a jigsaw puzzle. Compared to the vast amount of information available for Phanerozoic systems, such a limited approach for Proterozoic rocks, may seem suspect. However, using the assembly of the southern continents (South America, Africa, India, Arabia, Antarctica, and Australia) as an example, a very tight fit of the continents is apparent and illustrates the power of the jigsaw puzzle method. This report focuses on Neoproterozoic rocks, which are shown on two new detailed geologic maps that constitute the backbone of the study. The report also describes the Neoproterozoic, but younger or older rocks are not discussed or not discussed in detail. The Neoproterozoic continents and continental margins are identified based on the distribution of continental-margin sedimentary and magmatic rocks that define the break-up margins of Rodinia. These Neoproterozoic continental exposures, as well as critical Neo- and Meso-Neoproterozoic tectonic features shown on the two new map compilations, are used to reconstruct the Mesoproterozoic supercontinent of Rodinia. This approach differs from the common approach of using fold belts to define structural features deemed important in the Rodinian reconstruction. Fold belts are difficult to date, and many are significantly younger than the time frame considered here (1,200 to 850 Ma). Identifying Neoproterozoic continental margins, which are primarily
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The Continental Plates are Getting Thicker.
ERIC Educational Resources Information Center
Kerr, Richard A.
1986-01-01
Reviews seismological studies that provide evidence of the existence of continental roots beneath the continents. Suggests, that through the collisions of plate tectonics, continents stabilized part of the mobile mantle rock beneath them to form deep roots. (ML)
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NASA Astrophysics Data System (ADS)
Cheriton, Olivia M.; McPhee-Shaw, Erika E.; Shaw, William J.; Stanton, Timothy P.; Bellingham, James G.; Storlazzi, Curt D.
2014-01-01
Physical and optical measurements taken over the mud belt on the southern continental shelf of Monterey Bay, California documented the frequent occurrence of suspended particulate matter features, the majority of which were detached from the seafloor, centered 9-33 m above the bed. In fall 2011, an automated profiling mooring and fixed instrumentation, including a thermistor chain and upward-looking acoustic Doppler current profiler, were deployed at 70 m depth for 5 weeks, and from 12 to 16 October a long-range autonomous underwater vehicle performed across-shelf transects. Individual SPM events were uncorrelated with local bed shear stress caused by surface waves and bottom currents. Nearly half of all observed SPM layers occurred during 1 week of the study, 9-16 October 2011, and were advected past the fixed profiling mooring by the onshore phase of semidiurnal internal tide bottom currents. At the start of the 9-16 October period, we observed intense near-bed vertical velocities capable of lifting particulates into the middle of the water column. This "updraft" event appears to have been associated with nonlinear adjustment of high-amplitude internal tides over the mid and outer shelf. These findings suggest that nonlinear internal tidal motions can erode material over the outer shelf and that, once suspended, this SPM can then be transported shoreward to the middle and shallow sections of the mud belt. This represents a fundamental broadening of our understanding of how shelf mud belts may be built up and sustained.
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Ultrasonic isolation of the outer membrane of Escherichia coli with autodisplayed Z-domains.
Bong, Ji-Hong; Yoo, Gu; Park, Min; Kang, Min-Jung; Jose, Joachim; Pyun, Jae-Chul
2014-11-01
The outer membrane of Escherichia coli was previously isolated as a liposome-like outer membrane particle using an enzymatic treatment for lysozymes; for immunoassays, the particles were subsequently layered on solid supports via hydrophobic interactions. This work presents an enzyme-free isolation method for the E. coli outer membrane with autodisplayed Z-domains using ultrasonication. First, the properties of the outer membrane particle, such as the particle size, zeta potential, and total protein, were compared with the properties of particles obtained using the previous preparation methods. Compared with the conventional isolation method using an enzyme treatment, the ultrasonic method exhibited a higher efficiency at isolating the outer membrane and less contamination by cytosolic proteins. The isolated outer membrane particles were layered on a gold surface, and the roughness and thickness of the layered outer membrane layers were subsequently analyzed using AFM analysis. Finally, the antibody-binding activity of two outer membrane layers with autodisplayed Z-domains created from particles that were isolated using the enzymatic and ultrasonic isolation methods was measured using fluorescein-labeled antibody as a model analyte, and the activity of the outer membrane layer that was isolated from the ultrasonic method was estimated to be more than 20% higher than that from the conventional enzymatic method. Copyright © 2014 Elsevier Inc. All rights reserved.
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The outer magnetosphere. [composition and comparison with earth
NASA Technical Reports Server (NTRS)
Schardt, A. W.; Behannon, K. W.; Lepping, R. P.; Carbary, J. F.; Eviatar, A.; Siscoe, G. L.
1984-01-01
Similarities between the Saturnian and terrestrial outer magnetosphere are examined. Saturn, like earth, has a fully developed magnetic tail, 80 to 100 RS in diameter. One major difference between the two outer magnetospheres is the hydrogen and nitrogen torus produced by Titan. This plasma is, in general, convected in the corotation direction at nearly the rigid corotation speed. Energies of magnetospheric particles extend to above 500 keV. In contrast, interplanetary protons and ions above 2 MeV have free access to the outer magnetosphere to distances well below the Stormer cutoff. This access presumably occurs through the magnetotail. In addition to the H+, H2+, and H3+ ions primarily of local origin, energetic He, C, N, and O ions are found with solar composition. Their flux can be substantially enhanced over that of interplanetary ions at energies of 0.2 to 0.4 MeV/nuc.