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Papers by Patrick Hart

Research paper thumbnail of Methane-derived authigenic carbonates from the northern Gulf of Mexico--MD02 Cruise

Journal of Geochemical …, 2007

Authigenic carbonates were sampled in piston cores collected from both the Tunica Mound and the M... more Authigenic carbonates were sampled in piston cores collected from both the Tunica Mound and the Mississippi Canyon area on the continental slope of the northern Gulf of Mexico during a Marion Dufresne cruise in July 2002. The carbonates are present as ...

Research paper thumbnail of High-Resolution Chirp and Mini-Sparker Seismic-Reflection Data From the Southern California Continental Shelf - Gaviota to Mugu Canyon

Open-File Report

The US Geological Survey(USGS) collected high-resolution shallow seismic-reflection data in Septe... more The US Geological Survey(USGS) collected high-resolution shallow seismic-reflection data in September, 2007, and June-July, 2008, from the continental shelf offshore of southern California between Gaviota and Mugu Canyon, in support of the California's State Waters ...

Research paper thumbnail of Submarine landslide kinematics derived from high‐resolution imaging in Port Valdez, Alaska

Journal of Geophysical Research: Solid Earth

Submarine landslides caused by strong ground shaking during the M9.2 1964 Great Alaska earthquake... more Submarine landslides caused by strong ground shaking during the M9.2 1964 Great Alaska earthquake generated a tsunami that destroyed much of the old town of Valdez, Alaska, and was responsible for 32 deaths at that location. We explore structural details of the 1964 landslide deposit, as well as landslide deposits from earlier events, in order to characterize kinematics of the landslide process. We present a new high-resolution seismic reflection data set that images the 1964 landslide deposit and six pre-1964 deposits with great detail. These deposits are represented by thick packages (~7-23 m) of debris within >500 m of fjord sedimentation above basement. Internal slide structures are associated with distinctive landslide failure mechanisms, including detailed erosional and depositional features and structures resolved within both landslide blocks and distal debris flow layers. Based on comparisons of deposit volume from subbottom structure and differenced bathymetry, we refine prior interpretations of the source of failed material. New data show evidence for basal erosion and reworking of fjord-floor sedimentation. Additionally, material comprising the 1964 landslide appears to have been translated and deformed by lateral thrusting, rather than having been sourced entirely from upslope evacuation zones. Taking into account these complexities in depositional patterns, we show variations in slide size through Holocene time and relate the history of landslides to the paleoseismic record. Collectively, these new observations demonstrate that Port Valdez has a repeated history of large submarine landslides, which are likely associated with large megathrust earthquakes. Plain Language Summary In Alaska fjords, local tsunamis have caused significant damage and loss of life when they are generated by landslides, often triggered by large earthquakes. In this study, we explore the record of past submarine landslide events in the Port Valdez fjord, which was the location of a deadly tsunami triggered by the 1964 Great Alaska earthquake. New subbottom data are used to characterize the most recent landslide deposit from 1964 that blankets the fjord floor, as well as older landslide deposits below the fjord floor that are likely associated with past earthquake-triggered slide events. Images of these deposits obtained from seismic reflection methods help us to infer the processes of translation and deformation of material that occurred during the landslide, physical properties of the material that failed during the slide, and the size of past events. Characterizing the type of sediment transport processes, as well as the size and source of slides in Port Valdez, is important, as it should help us to better understand the process by which local tsunamis are generated in fjord settings and geohazards in Alaska and along other active margins.

Research paper thumbnail of High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur

Open-File Report

This report consists of high-resolution chirp and single-channel mini-sparker seismic-reflection ... more This report consists of high-resolution chirp and single-channel mini-sparker seismic-reflection profile data from the offshore San Luis Obispo County, California. These data were acquired in 2008 and 2009 using the Research Vessel Parke Snavely (USGS Field Activity IDs: S-6-08-SC, S-6-09-SC). The data are available in binary, TIFF and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser.

Research paper thumbnail of High-resolution marine seismic reflection data from the San Francisco Bay area

Research paper thumbnail of A seismic-reflection investigation of gas hydrates and sea-floor features of the upper continental slope of the Garden Banks and Green Canyon regions, northern Gulf of Mexico: report for cruise G1-99-GM (99002)

Open-File Report

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey e... more This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY formation/distribution on stability of the sea floor. Although seismic data alone cannot be used to identify gas hydrate deposits unequivocally, they are useful in delineating the anomalous subsurface features (e.g., structures, acoustic facies, seismic-attributes, etc.) that are commonly associated with areas where gas hydrates have been recovered in cores. During the cruise, about 1400 km of high resolution multichannel and single-channel seismicreflection data and about 500 km of side-scan and chirp seismic-reflection data were recorded (Figures 1 and 2). The following report describes the field operations and equipment systems employed, gives some examples of ship-board seismic-reflection records, and outlines a few preliminary results.

Research paper thumbnail of Cruise report for a seismic investigation of gas hydrates in the Mississippi Canyon region, northern Gulf of Mexico; cruise M1-98-GM

Open-File Report

The equipment systems used during the cruise are listed in Table 1. Most equipment was provided b... more The equipment systems used during the cruise are listed in Table 1. Most equipment was provided by USGS, with exception of the SeaScope recording system and 15 in 3 water gun, which were furnished by MMTC. Technical specification for the Ocean Bottom Seismometer (OBS) experiment are given in Table 2, and an operations log showing the amounts of data recorded with these systems is outlined in Table 3. Appendix A gives a detailed list of trackline data collected, and Appendix B gives a detailed list of OBS operations. Survey speeds ranged from 2.5 to 4 knots. Seismic systems were fired at different energy levels and rates, as noted. The seismic data were sampled at fast rates (4 kHz to 200 kHz) at or near the

Research paper thumbnail of Cruise report for A1-00-SC southern California earthquake hazards project, part A

Open-File Report

assisted Todd Chandler as marine mammal observers on the survey. Lisa Schlender computer coded th... more assisted Todd Chandler as marine mammal observers on the survey. Lisa Schlender computer coded the data gathered in the field. Support for the marine mammal observations was provided by the US Geological Survey. The National Marine Fisheries Service provided a permit for the research. Our thanks to the USGS personnel who assisted including Chris Gutmacher, Jon Childs, Bill Normark, and Mike Fisher. We thank the crew of the Auriga for their help.

Research paper thumbnail of GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey

Open-File Report

David C Twichell, VeeAnn A Cross, Valerie F Paskevich, Deborah R Hutchinson, William J Winters, P... more David C Twichell, VeeAnn A Cross, Valerie F Paskevich, Deborah R Hutchinson, William J Winters, Patrick E Hart Open-File Report. ... with the publication, include digital sidescan sonar imagery, digital seismic-reflection data, and descriptions and analyses of piston and gravity ...

Research paper thumbnail of Cruise Report for G1-03-GM, USGS Gas Hydrates Cruise, R/V Gyre, 1-14 May 2003, Northern Gulf of Mexico

Open-File Report

This report gives a summary of the field program and instrumentation used on the R/V Gyre in the ... more This report gives a summary of the field program and instrumentation used on the R/V Gyre in the Gulf of Mexico in May, 2003 to collect multichannel seismic data in support of USGS and Department of Energy gas hydrate studies. Tabulated statistics, metadata, figures and maps are included to show the breadth of data collected and preliminary interpretations made during the field program. Geophysical data collected during this cruise will be released in a separate report. At the start of the cruise, three test lines were run to compare different source configurations in order to optimize data quality for the objectives of the cruise. The source chosen was the 13/13 in 3 Generator-Injector (GI) Gun. Following these tests, a total of 101 lines (approximately 1033 km) of 24-channel high-resolution seismic reflection data were collected in the northern Gulf of Mexico. 59 lines (about 600 km) were collected in and around lease block Keathley Canyon 195. An additional 4 lines (85 km) provided a seismic tie between the Keathley Canyon data and USGS multichannel data collected in 1999. About 253 km of data were collected along 35 short lines in and around lease block Atwater Valley 14 on the floor of the Mississippi Canyon. Three lines (53 km) completed the cruise and provided a seismic tie to USGS multichannel data collected in 1998. Two on-board trained marine-mammal observers fulfilled the requirements determined by NOAA/National Marine Fisheries Service to avoid incidental harassment of marine mammals as established in the Marine Mammal Protection Act (MMPA). A total of three species of dolphins were observed during the cruise and one basking shark. No sperm whales were sighted. During the cruise, seismic operations were not delayed or terminated because of marine mammal activity.

Research paper thumbnail of High-resolution chirp seismic reflection data acquired from the Cap de Creus shelf and canyon area, Gulf of Lions, Spain in 2004

Open-File Report

This report consists of high-resolution chirp seismic reflection profile data from the northern G... more This report consists of high-resolution chirp seismic reflection profile data from the northern Gulf of Lions, Spain. These data were acquired in 2004 using the Research Vessel Oceanus (USGS Cruise ID: O-1-04-MS). The data are available in binary and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser.

Research paper thumbnail of Geophysical Surveys of the San Andreas and Crystal Springs Reservoir System Including Seismic-Reflection Profiles and Swath Bathymetry, San Mateo County, California

Research paper thumbnail of High-resolution multichannel seismic-reflection data acquired in the northern Gulf of Mexico, 2003

Open-File Report

This report consists of two-dimensional marine seismic reflection profile data from the northern ... more This report consists of two-dimensional marine seismic reflection profile data from the northern Gulf of Mexico. These data were acquired in 1998 and 1999 with the Research Vessels Tommy Munro (M1-98-GM) and Gyre (G1-99-GM). The data are available in binary and GIF image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and GIF images of the profiles may be viewed with your Web browser.

Research paper thumbnail of Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska

Open-File Report

Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska" is... more Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska" is based primarily on new bathymetric data acquired during the course of seismic reflection surveys conducted by the U.S. Geological Survey in 1972-74 and 1977-78 and by the Geophysical Corporation of Alaska in 1973 (figs. 1 and 2). The primary data sets provide regional coverage of the shelf, slope, and parts of the continental rise north of Alaska with good position control by satellite or integrated satellite (satellite plug doppler sound) navigation. These data were supplemented in the western half of the map by soundings from the continental slope and rise furnished by R. L. Fisher of the Scripps Institutipn of Oceanography (in part published in Fisher and others, 1958), near the coast by data published by the National Ocean Survey, and on • the lower slope and rise by both published and unpublished soundings from the U.S. Naval Oceanographic Office. Numerous spot soundings obtained during the course of gravity surveys north of Alaska were contributed by Peter Dehlinger of the University• of Connecticut, and a dense network of soundings obtained in the course of gravity surveys north of Canada was contributed by J. R. Tanner of the Earth Physics Branch, Department •of Energy, Mines and Resources, Canada. The supplemental data sets were positioned mainly by radar •and celestial navigation. Except for the data of the Earth Physics Branch, which were positioned by a shore-based Lambda-Decca navigation system, and the nearshore data of the National Ocean Survey, the supplemental data sets provide coverage that is generally less systematic and less closely positioned than the primary sets.

Research paper thumbnail of Missing link between the Hayward and Rodgers Creek faults

Science advances, 2016

The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will m... more The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults. Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery. Detailed subsurface imaging provides definitive evidence of active faulting along the Hayward fault as it traverses San Pablo Bay and bends ~10° to the right toward the Rodgers Creek fault. Integrated geophysical interpretation and kinematic modeling show that the Hayward and Rodgers Creek faults are directly connected at the surface-a geometric relationship that has significant implications for earthquake dynamics and seismic hazard. A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact.

Research paper thumbnail of The Distribution of Subsea Permafrost and Shallow Methane on the Central U.S. Beaufort Inner Shelf from Newly Acquired Geophysical Data

Research paper thumbnail of National Archive of Marine Seismic Surveys (NAMSS): U.S. Geological Survey Program to Provide new Access to Proprietary Data

ABSTRACT During the last four decades, hundreds of thousands of line kilometers of 2D marine seis... more ABSTRACT During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic reflection data have been collected by the hydrocarbon exploration industry within the United States Exclusive Economic Zone. The commercial value of much of these data has decreased significantly because of drilling moratoria and new technology such as 3D acquisition. However, these data still have tremendous value for scientific research and education purposes. The U.S. Geological Survey has recently made agreements with two commercial owners of large data holdings to transfer to the public domain over 250,000 line kilometers of marine data from off the eastern, western, and Alaskan coasts of the United States. In order to provide access to the data, the USGS has developed the National Archive of Marine Seismic Surveys (NAMSS) program. For a small fraction of the money that would be required to collect new data, work is underway to organize and recover digital data currently stored on tens of thousands of 9-track tapes. Even where new data collection efforts could be funded, current environmental restrictions on marine seismic exploration could preclude operations. The NAMSS web site at http://walrus.wr.usgs.gov/NAMSS/ has trackline maps of surveys that are now or will soon be available for downloading in SEG-Y format. As more owners and users become aware of this new data resource, it is hoped that additional partners in will join this data rescue effort.

Research paper thumbnail of A new look at Northwind Ridge: implications for the history of the Canada Basin

Agu Fall Meeting Abstracts, Dec 1, 2010

Researchers from the US and Canada are conducting collaborative seismic, multibeam, and sampling ... more Researchers from the US and Canada are conducting collaborative seismic, multibeam, and sampling studies in the mostly ice-covered regions of the Canada Basin (CB) of the Arctic Ocean. Recently acquired data sets, together with older acoustic and coring data, yield new details about the stratigraphic and structural history of CB, particularly regarding its boundary with Northwind Ridge (NR). As previously

Research paper thumbnail of Degradation of Subsea Permafrost and Associated Gas Hydrates Offshore of Alaska in Response to Climate Change

Research paper thumbnail of National Archive of Marine Seismic Surveys (NAMSS): Status Report on U.S. Geological Survey Program Providing Access to Proprietary Data

During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic refle... more During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic reflection data have been collected by the hydrocarbon exploration industry within the United States Exclusive Economic Zone. The commercial value of much of these data has decreased significantly because of drilling moratoria and new technology such as 3D acquisition. However, these data still have tremendous value for scientific research and education purposes. The U.S. Geological Survey has recently made agreements with two commercial owners of large data holdings to transfer to the public domain over 250,000 line kilometers of marine data from off the eastern, western, and Alaskan coasts of the United States. In order to provide access to the data, the USGS has developed the National Archive of Marine Seismic Surveys (NAMSS) program. For a small fraction of the money that would be required to collect new data, work is underway to organize and recover digital data currently stored on tens ...

Research paper thumbnail of Methane-derived authigenic carbonates from the northern Gulf of Mexico--MD02 Cruise

Journal of Geochemical …, 2007

Authigenic carbonates were sampled in piston cores collected from both the Tunica Mound and the M... more Authigenic carbonates were sampled in piston cores collected from both the Tunica Mound and the Mississippi Canyon area on the continental slope of the northern Gulf of Mexico during a Marion Dufresne cruise in July 2002. The carbonates are present as ...

Research paper thumbnail of High-Resolution Chirp and Mini-Sparker Seismic-Reflection Data From the Southern California Continental Shelf - Gaviota to Mugu Canyon

Open-File Report

The US Geological Survey(USGS) collected high-resolution shallow seismic-reflection data in Septe... more The US Geological Survey(USGS) collected high-resolution shallow seismic-reflection data in September, 2007, and June-July, 2008, from the continental shelf offshore of southern California between Gaviota and Mugu Canyon, in support of the California's State Waters ...

Research paper thumbnail of Submarine landslide kinematics derived from high‐resolution imaging in Port Valdez, Alaska

Journal of Geophysical Research: Solid Earth

Submarine landslides caused by strong ground shaking during the M9.2 1964 Great Alaska earthquake... more Submarine landslides caused by strong ground shaking during the M9.2 1964 Great Alaska earthquake generated a tsunami that destroyed much of the old town of Valdez, Alaska, and was responsible for 32 deaths at that location. We explore structural details of the 1964 landslide deposit, as well as landslide deposits from earlier events, in order to characterize kinematics of the landslide process. We present a new high-resolution seismic reflection data set that images the 1964 landslide deposit and six pre-1964 deposits with great detail. These deposits are represented by thick packages (~7-23 m) of debris within >500 m of fjord sedimentation above basement. Internal slide structures are associated with distinctive landslide failure mechanisms, including detailed erosional and depositional features and structures resolved within both landslide blocks and distal debris flow layers. Based on comparisons of deposit volume from subbottom structure and differenced bathymetry, we refine prior interpretations of the source of failed material. New data show evidence for basal erosion and reworking of fjord-floor sedimentation. Additionally, material comprising the 1964 landslide appears to have been translated and deformed by lateral thrusting, rather than having been sourced entirely from upslope evacuation zones. Taking into account these complexities in depositional patterns, we show variations in slide size through Holocene time and relate the history of landslides to the paleoseismic record. Collectively, these new observations demonstrate that Port Valdez has a repeated history of large submarine landslides, which are likely associated with large megathrust earthquakes. Plain Language Summary In Alaska fjords, local tsunamis have caused significant damage and loss of life when they are generated by landslides, often triggered by large earthquakes. In this study, we explore the record of past submarine landslide events in the Port Valdez fjord, which was the location of a deadly tsunami triggered by the 1964 Great Alaska earthquake. New subbottom data are used to characterize the most recent landslide deposit from 1964 that blankets the fjord floor, as well as older landslide deposits below the fjord floor that are likely associated with past earthquake-triggered slide events. Images of these deposits obtained from seismic reflection methods help us to infer the processes of translation and deformation of material that occurred during the landslide, physical properties of the material that failed during the slide, and the size of past events. Characterizing the type of sediment transport processes, as well as the size and source of slides in Port Valdez, is important, as it should help us to better understand the process by which local tsunamis are generated in fjord settings and geohazards in Alaska and along other active margins.

Research paper thumbnail of High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur

Open-File Report

This report consists of high-resolution chirp and single-channel mini-sparker seismic-reflection ... more This report consists of high-resolution chirp and single-channel mini-sparker seismic-reflection profile data from the offshore San Luis Obispo County, California. These data were acquired in 2008 and 2009 using the Research Vessel Parke Snavely (USGS Field Activity IDs: S-6-08-SC, S-6-09-SC). The data are available in binary, TIFF and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser.

Research paper thumbnail of High-resolution marine seismic reflection data from the San Francisco Bay area

Research paper thumbnail of A seismic-reflection investigation of gas hydrates and sea-floor features of the upper continental slope of the Garden Banks and Green Canyon regions, northern Gulf of Mexico: report for cruise G1-99-GM (99002)

Open-File Report

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey e... more This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards or with the North American Stratigraphic Code. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY formation/distribution on stability of the sea floor. Although seismic data alone cannot be used to identify gas hydrate deposits unequivocally, they are useful in delineating the anomalous subsurface features (e.g., structures, acoustic facies, seismic-attributes, etc.) that are commonly associated with areas where gas hydrates have been recovered in cores. During the cruise, about 1400 km of high resolution multichannel and single-channel seismicreflection data and about 500 km of side-scan and chirp seismic-reflection data were recorded (Figures 1 and 2). The following report describes the field operations and equipment systems employed, gives some examples of ship-board seismic-reflection records, and outlines a few preliminary results.

Research paper thumbnail of Cruise report for a seismic investigation of gas hydrates in the Mississippi Canyon region, northern Gulf of Mexico; cruise M1-98-GM

Open-File Report

The equipment systems used during the cruise are listed in Table 1. Most equipment was provided b... more The equipment systems used during the cruise are listed in Table 1. Most equipment was provided by USGS, with exception of the SeaScope recording system and 15 in 3 water gun, which were furnished by MMTC. Technical specification for the Ocean Bottom Seismometer (OBS) experiment are given in Table 2, and an operations log showing the amounts of data recorded with these systems is outlined in Table 3. Appendix A gives a detailed list of trackline data collected, and Appendix B gives a detailed list of OBS operations. Survey speeds ranged from 2.5 to 4 knots. Seismic systems were fired at different energy levels and rates, as noted. The seismic data were sampled at fast rates (4 kHz to 200 kHz) at or near the

Research paper thumbnail of Cruise report for A1-00-SC southern California earthquake hazards project, part A

Open-File Report

assisted Todd Chandler as marine mammal observers on the survey. Lisa Schlender computer coded th... more assisted Todd Chandler as marine mammal observers on the survey. Lisa Schlender computer coded the data gathered in the field. Support for the marine mammal observations was provided by the US Geological Survey. The National Marine Fisheries Service provided a permit for the research. Our thanks to the USGS personnel who assisted including Chris Gutmacher, Jon Childs, Bill Normark, and Mike Fisher. We thank the crew of the Auriga for their help.

Research paper thumbnail of GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey

Open-File Report

David C Twichell, VeeAnn A Cross, Valerie F Paskevich, Deborah R Hutchinson, William J Winters, P... more David C Twichell, VeeAnn A Cross, Valerie F Paskevich, Deborah R Hutchinson, William J Winters, Patrick E Hart Open-File Report. ... with the publication, include digital sidescan sonar imagery, digital seismic-reflection data, and descriptions and analyses of piston and gravity ...

Research paper thumbnail of Cruise Report for G1-03-GM, USGS Gas Hydrates Cruise, R/V Gyre, 1-14 May 2003, Northern Gulf of Mexico

Open-File Report

This report gives a summary of the field program and instrumentation used on the R/V Gyre in the ... more This report gives a summary of the field program and instrumentation used on the R/V Gyre in the Gulf of Mexico in May, 2003 to collect multichannel seismic data in support of USGS and Department of Energy gas hydrate studies. Tabulated statistics, metadata, figures and maps are included to show the breadth of data collected and preliminary interpretations made during the field program. Geophysical data collected during this cruise will be released in a separate report. At the start of the cruise, three test lines were run to compare different source configurations in order to optimize data quality for the objectives of the cruise. The source chosen was the 13/13 in 3 Generator-Injector (GI) Gun. Following these tests, a total of 101 lines (approximately 1033 km) of 24-channel high-resolution seismic reflection data were collected in the northern Gulf of Mexico. 59 lines (about 600 km) were collected in and around lease block Keathley Canyon 195. An additional 4 lines (85 km) provided a seismic tie between the Keathley Canyon data and USGS multichannel data collected in 1999. About 253 km of data were collected along 35 short lines in and around lease block Atwater Valley 14 on the floor of the Mississippi Canyon. Three lines (53 km) completed the cruise and provided a seismic tie to USGS multichannel data collected in 1998. Two on-board trained marine-mammal observers fulfilled the requirements determined by NOAA/National Marine Fisheries Service to avoid incidental harassment of marine mammals as established in the Marine Mammal Protection Act (MMPA). A total of three species of dolphins were observed during the cruise and one basking shark. No sperm whales were sighted. During the cruise, seismic operations were not delayed or terminated because of marine mammal activity.

Research paper thumbnail of High-resolution chirp seismic reflection data acquired from the Cap de Creus shelf and canyon area, Gulf of Lions, Spain in 2004

Open-File Report

This report consists of high-resolution chirp seismic reflection profile data from the northern G... more This report consists of high-resolution chirp seismic reflection profile data from the northern Gulf of Lions, Spain. These data were acquired in 2004 using the Research Vessel Oceanus (USGS Cruise ID: O-1-04-MS). The data are available in binary and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser.

Research paper thumbnail of Geophysical Surveys of the San Andreas and Crystal Springs Reservoir System Including Seismic-Reflection Profiles and Swath Bathymetry, San Mateo County, California

Research paper thumbnail of High-resolution multichannel seismic-reflection data acquired in the northern Gulf of Mexico, 2003

Open-File Report

This report consists of two-dimensional marine seismic reflection profile data from the northern ... more This report consists of two-dimensional marine seismic reflection profile data from the northern Gulf of Mexico. These data were acquired in 1998 and 1999 with the Research Vessels Tommy Munro (M1-98-GM) and Gyre (G1-99-GM). The data are available in binary and GIF image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and GIF images of the profiles may be viewed with your Web browser.

Research paper thumbnail of Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska

Open-File Report

Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska" is... more Bathymetric map of the continental shelf, slope, and rise of the Beaufort Sea north of Alaska" is based primarily on new bathymetric data acquired during the course of seismic reflection surveys conducted by the U.S. Geological Survey in 1972-74 and 1977-78 and by the Geophysical Corporation of Alaska in 1973 (figs. 1 and 2). The primary data sets provide regional coverage of the shelf, slope, and parts of the continental rise north of Alaska with good position control by satellite or integrated satellite (satellite plug doppler sound) navigation. These data were supplemented in the western half of the map by soundings from the continental slope and rise furnished by R. L. Fisher of the Scripps Institutipn of Oceanography (in part published in Fisher and others, 1958), near the coast by data published by the National Ocean Survey, and on • the lower slope and rise by both published and unpublished soundings from the U.S. Naval Oceanographic Office. Numerous spot soundings obtained during the course of gravity surveys north of Alaska were contributed by Peter Dehlinger of the University• of Connecticut, and a dense network of soundings obtained in the course of gravity surveys north of Canada was contributed by J. R. Tanner of the Earth Physics Branch, Department •of Energy, Mines and Resources, Canada. The supplemental data sets were positioned mainly by radar •and celestial navigation. Except for the data of the Earth Physics Branch, which were positioned by a shore-based Lambda-Decca navigation system, and the nearshore data of the National Ocean Survey, the supplemental data sets provide coverage that is generally less systematic and less closely positioned than the primary sets.

Research paper thumbnail of Missing link between the Hayward and Rodgers Creek faults

Science advances, 2016

The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will m... more The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults. Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery. Detailed subsurface imaging provides definitive evidence of active faulting along the Hayward fault as it traverses San Pablo Bay and bends ~10° to the right toward the Rodgers Creek fault. Integrated geophysical interpretation and kinematic modeling show that the Hayward and Rodgers Creek faults are directly connected at the surface-a geometric relationship that has significant implications for earthquake dynamics and seismic hazard. A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact.

Research paper thumbnail of The Distribution of Subsea Permafrost and Shallow Methane on the Central U.S. Beaufort Inner Shelf from Newly Acquired Geophysical Data

Research paper thumbnail of National Archive of Marine Seismic Surveys (NAMSS): U.S. Geological Survey Program to Provide new Access to Proprietary Data

ABSTRACT During the last four decades, hundreds of thousands of line kilometers of 2D marine seis... more ABSTRACT During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic reflection data have been collected by the hydrocarbon exploration industry within the United States Exclusive Economic Zone. The commercial value of much of these data has decreased significantly because of drilling moratoria and new technology such as 3D acquisition. However, these data still have tremendous value for scientific research and education purposes. The U.S. Geological Survey has recently made agreements with two commercial owners of large data holdings to transfer to the public domain over 250,000 line kilometers of marine data from off the eastern, western, and Alaskan coasts of the United States. In order to provide access to the data, the USGS has developed the National Archive of Marine Seismic Surveys (NAMSS) program. For a small fraction of the money that would be required to collect new data, work is underway to organize and recover digital data currently stored on tens of thousands of 9-track tapes. Even where new data collection efforts could be funded, current environmental restrictions on marine seismic exploration could preclude operations. The NAMSS web site at http://walrus.wr.usgs.gov/NAMSS/ has trackline maps of surveys that are now or will soon be available for downloading in SEG-Y format. As more owners and users become aware of this new data resource, it is hoped that additional partners in will join this data rescue effort.

Research paper thumbnail of A new look at Northwind Ridge: implications for the history of the Canada Basin

Agu Fall Meeting Abstracts, Dec 1, 2010

Researchers from the US and Canada are conducting collaborative seismic, multibeam, and sampling ... more Researchers from the US and Canada are conducting collaborative seismic, multibeam, and sampling studies in the mostly ice-covered regions of the Canada Basin (CB) of the Arctic Ocean. Recently acquired data sets, together with older acoustic and coring data, yield new details about the stratigraphic and structural history of CB, particularly regarding its boundary with Northwind Ridge (NR). As previously

Research paper thumbnail of Degradation of Subsea Permafrost and Associated Gas Hydrates Offshore of Alaska in Response to Climate Change

Research paper thumbnail of National Archive of Marine Seismic Surveys (NAMSS): Status Report on U.S. Geological Survey Program Providing Access to Proprietary Data

During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic refle... more During the last four decades, hundreds of thousands of line kilometers of 2D marine seismic reflection data have been collected by the hydrocarbon exploration industry within the United States Exclusive Economic Zone. The commercial value of much of these data has decreased significantly because of drilling moratoria and new technology such as 3D acquisition. However, these data still have tremendous value for scientific research and education purposes. The U.S. Geological Survey has recently made agreements with two commercial owners of large data holdings to transfer to the public domain over 250,000 line kilometers of marine data from off the eastern, western, and Alaskan coasts of the United States. In order to provide access to the data, the USGS has developed the National Archive of Marine Seismic Surveys (NAMSS) program. For a small fraction of the money that would be required to collect new data, work is underway to organize and recover digital data currently stored on tens ...