I currently lead a project called "U.S. West Coast and Alaska Marine Geohazards" and I spend about 6-10 weeks per year at sea collecting marine geophysical data.
I received my Ph.D. from the Scripps Institution of Oceanography, then moved to Woods Hole, MA, for a Mendenhall Postdoctoral Fellowship. In 2013, I moved to Santa Cruz, CA, where I currently work as a Research Geophysicist at the USGS Pacific Coastal and Marine Science Center. I grew up in Colorado and spent four years at CU Boulder for undergraduate studies in geophysics.
My research is focused on the following topics:
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Development and application of geophysical approaches to offshore earthquake, landslide and tsunami hazard assessments
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Marine paleoseismology
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Understanding the interplay between tectonic, sedimentary, climatic processes along continental margins
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Combining basic and applied research to study the geomorphic development of continental margins, including substrate fluid flow
News and Outreach
For more recent USGS News stories, click my News tab
February 1, 2016, Anchorage Daily News, "New technology lets scientists pinpoint underwater landslide that triggered deadly 1964 tsunami"
February 2, 2016, FOX NEWS, "USGS discovers source of Alaska tsunami that decimated village in 1964"
January, 2016, USGS Soundwaves, "Investigating the Offshore Queen Charlotte-Fairweather Fault System in Southeastern Alaska, and its Potential to Produce Earthquakes, Tsunamis, and Submarine Landslides"
January, 2016, USGS Soundwaves, "Artificial-Gas-Seep Test Produces 3D Images of Bubble Plumes in the Ocean"
August 24, 2014 NY Times, "Methane is discovered seeping from seafloor off East Coast, scientists say"
October, 2011, USGS Soundwaves, "High-Resolution Multibeam Mapping of Mid-Atlantic Canyons to Assess Tsunami Hazards"
July 6, 2011 LA Times, “Scientists tie Colorado River flooding to San Andreas Quakes”
July 3, 2011 San Francisco Chronicle, “Big quake near Salton Sea may be long overdue”
June 29, 2011 Discovery News, “Smaller Salton Sea silences seismic shocks”
June 29, 2011 USA Today, “Salton Sea floods flipped San Andreas earthquake trigger”
January 9, 2010 Nature News, “Floods linked to San Andreas quakes”
July 28, 2009 LA Times feature “More earthquake faults discovered at the Salton Sea”
May 15, 2009 CBS 5, “Lake Tahoe may be due for huge quake, tsunami”
Science and Products
Cascadia Subduction Zone Marine Geohazards
Seafloor Faults off Southern California
Ecosystems: EXPRESS
Hazards: EXPRESS
U.S. West Coast and Alaska Marine Geohazards
EXPRESS: Expanding Pacific Research and Exploration of Submerged Systems
Resources: EXPRESS
Earthquake Hazards in Southeastern Alaska
2019 Lake Ozette
Digital maps of submarine landslides and mass wasting features offshore of southern California
Multichannel sparker and chirp seismic reflection data collected during USGS field activity 2018-658-FA between Cape Blanco and Cape Mendocino in October of 2018
A bathymetric terrain model of multibeam sonar data collected between 2005 and 2018 along the Queen Charlotte Fault System in the Eastern Gulf of Alaska from Cross Sound, Alaska to Queen Charlotte Sound, Canada
Multibeam bathymetry and acoustic-backscatter data collected in 2017 and 2018 of Noyes Submarine Canyon and vicinity, southeast Alaska
Multibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA
Multibeam bathymetry and backscatter data collected in the eastern Gulf of Alaska during USGS Field Activity 2016-625-FA using a Reson 7160 multibeam echosounder
Reprocessed multichannel seismic-reflection (MCS) data from USGS field activity T-1-96-SC collected in San Diego Bay, California in 1996
Chirp sub-bottom data collected in 2019 in Whiskeytown Lake, California during USGS field activity 2018-686-FA
Multichannel minisparker, multichannel boomer, and chirp seismic-reflection data of USGS field activity 2017-612-FA collected in Puget Sound and Lake Washington in February of 2017
Multichannel minisparker seismic-reflection and chip sub bottom data collected in the Santa Barbara Channel in July of 2018
Multibeam bathymetry, acoustic backscatter, and multichannel minisparker seismic-reflection data of USGS field activity 2016-666-FA collected in the Santa Barbara Basin in September and October of 2016
Quaternary faults offshore of California
Colored shaded-relief bathymetry, acoustic backscatter, and selected perspective views of the northern part of the California Continental Borderland, southern California
Systematic mapping of the ocean-continent transform plate boundary of the Queen Charlotte fault system, southeastern Alaska and western British Columbia—A preliminary bathymetric terrain model
Using active source seismology to image the Palos Verdes Fault damage zone as a function of distance, depth, and geology
Mass wasting along the Cascadia subduction zone: Implications for abyssal turbidite sources and the earthquake record
Recency of faulting and subsurface architecture of the San Diego Bay pull-apart basin, California, USA
Systematic characterization of morphotectonic variability along the Cascadia convergent margin: Implications for shallow megathrust behavior and tsunami hazards
Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)
Morphology, structure, and kinematics of the San Clemente and Catalina faults based on high-resolution marine geophysical data, southern California Inner Continental Borderland
Structural controls on slope failure within the western Santa Barbara Channel based on 2D and 3D seismic imaging
Submarine canyons, slope failures and mass transport processes in southern Cascadia
Mapping, exploration, and characterization of the California continental margin and associated features from the California-Oregon border to Ensenada, Mexico
Plate boundary localization, slip-rates and rupture segmentation of the Queen Charlotte Fault based on submarine tectonic geomorphology
Right-lateral fault motion along the slope-basin transition, Gulf of Santa Catalina, southern California
An active fault system carrying a significant component of right-lateral strike-slip motion extends for ~60 km along the slope–basin transition, ~10 to 20 km offshore of the southern California coast from La Jolla to Dana Point. From south to north, this fault system includes the Carlsbad, San Onofre, and San Mateo fault zones. High-resolution single channel minisparker and chirp seismic reflectio
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
Cascadia Subduction Zone Marine Geohazards
Societal Issue: Uncertainty related to rupture extent, slip distribution, and recurrence of past subduction megathrust earthquakes in the Pacific Northwest (northern CA, OR, WA, and southern BC) leads to ambiguity in earthquake and tsunami hazard assessments and hinders our ability to prepare for future events.ByNatural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, 3-D CT Core Imaging Laboratory, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory, Deep Sea Exploration, Mapping and Characterization, Subduction Zone ScienceSeafloor Faults off Southern California
More than 22 million people live along Southern California’s coast, and many more migrate there every year. Faults and earthquake threats in this region have been heavily studied on land. USGS aims to boost our knowledge about faults on the seafloor, so they can be included in hazard assessments.Ecosystems: EXPRESS
The continental shelf and slope offshore California, Oregon, and Washington are home to deep-sea corals, chemosynthetic communities, and other sensitive habitats that could be impacted by the development of energy and mineral resources. The EXPRESS (Expanding Pacific Research and Exploration of Submerged Systems) campaign will map and characterize these special areas to help guide ocean management...Hazards: EXPRESS
Marine geohazards including earthquakes, landslides, and tsunamis lie offshore of densely populated areas of California, Oregon, and Washington. One goal of EXPRESS is to improve assessments of these hazards.U.S. West Coast and Alaska Marine Geohazards
Marine geohazards are sudden and extreme events beneath the ocean that threaten coastal populations. Such underwater hazards include earthquakes, volcanic eruptions, landslides, and tsunamis.ByNatural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, 3-D CT Core Imaging Laboratory, Core Preparation and Analysis Laboratory and Sample Repositories, Big Sur Landslides, Deep Sea Exploration, Mapping and Characterization, Subduction Zone ScienceEXPRESS: Expanding Pacific Research and Exploration of Submerged Systems
EXPRESS is a multi-year, multi-institution cooperative research campaign in deep sea areas of California, Oregon, and Washington, including the continental shelf and slope. EXPRESS data and information are intended to guide wise use of living marine resources and habitats, inform ocean energy and mineral resource decisions, and improve offshore hazard assessments.ByCoastal and Marine Hazards and Resources Program, Pacific Coastal and Marine Science Center, 3-D CT Core Imaging Laboratory, Core Preparation and Analysis Laboratory and Sample Repositories, Multi-Sensor Core Logger Laboratory, Organic Geochemistry Laboratory, Deep Sea Exploration, Mapping and CharacterizationResources: EXPRESS
Along the U.S. west coast, the Pacific Ocean, ocean floor, and winds above contain potentially vast energy and mineral resources. Developing these resources safely and wisely requires detailed information for each area of interest. One goal of EXPRESS is to inform ocean energy and mineral resource decisions.Earthquake Hazards in Southeastern Alaska
Over the last 100 years, the Queen Charlotte-Fairweather fault system has produced large-magnitude earthquakes affecting both Canada and the U.S. To fill in missing details about its offshore location and structure, USGS uses sophisticated techniques to truly understand the fault’s hazard potential.2019 Lake Ozette
Collected bathymetric data, seismic data, and sediment cores from Lake Ozette in 2019, a USGS-US National Park Service partnership - Data
Filter Total Items: 25
Digital maps of submarine landslides and mass wasting features offshore of southern California
This data release provides the locations and certain key metrics of landslide features offshore southern California, including landslide perimeters, scarps, evacuation zones, debris aprons, and slide-prone areas in geographic information system (GIS) shapefile format. The offshore region of southern California is a tectonically active area that includes more than 20 fault-bounded basins and ridgesMultichannel sparker and chirp seismic reflection data collected during USGS field activity 2018-658-FA between Cape Blanco and Cape Mendocino in October of 2018
This data release contains processed high-resolution multichannel sparker seismic-reflection (MCS) data and chirp sub-bottom data that were collected aboard Humboldt State University's R/V Coral Sea in October of 2018 on U.S. Geological Survey cruise 2018-658-FA on the shelf and slope between Cape Blanco, Oregon, and Cape Mendocino, California. MCS data were collected to characterize quaternary deA bathymetric terrain model of multibeam sonar data collected between 2005 and 2018 along the Queen Charlotte Fault System in the Eastern Gulf of Alaska from Cross Sound, Alaska to Queen Charlotte Sound, Canada
This data publication is a compilation of six different multibeam surveys covering the previously unmapped Queen Charlotte Fault offshore southeast Alaska and Haida Gwaii, Canada. These data were collected between 2005 and 2018 under a cooperative agreement between the U.S. Geological Survey, Natural Resources Canada, and the National Oceanic and Atmospheric Administration. The six source surveysMultibeam bathymetry and acoustic-backscatter data collected in 2017 and 2018 of Noyes Submarine Canyon and vicinity, southeast Alaska
This data release provides U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) and National Oceanic and Atmospheric Administration (NOAA) 2017 and 2018 bathymetry and acoustic-backscatter data collected on the Noyes Submarine Canyon and vicinity in southeast Alaska. In 2017 and 2018 the NOAA survey vessel Fairweather collected bathymetry and acoustic-backscatter data uMultibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA
In 2015 the U.S. Geological Survey, Pacific Coastal and Marine Science Center, in cooperation with the Alaska Department of Fish and Game (ADFG), collected bathymetry and acoustic-backscatter data near Cross Sound in southeast Alaska using a Reson 7111 multibeam echosounder mounded to the ADFG R/V Solstice. The bathymetry and acoustic-backscatter data are provided as GeoTIFFs with 10-m spatial resMultibeam bathymetry and backscatter data collected in the eastern Gulf of Alaska during USGS Field Activity 2016-625-FA using a Reson 7160 multibeam echosounder
Marine geophysical mapping of the Queen Charlotte Fault in the eastern Gulf of Alaska was conducted in 2016 as part of a collaborative effort between the U.S. Geological Survey and the Alaska Department of Fish and Game to understand the morphology and subsurface geology of the entire Queen Charlotte system. The Queen Charlotte fault is the offshore portion of the Queen Charlotte-Fairweather FaultReprocessed multichannel seismic-reflection (MCS) data from USGS field activity T-1-96-SC collected in San Diego Bay, California in 1996
This data release presents reprocessed multichannel seismic-reflection (MCS) data that was originally collected in 1996 in partnership with the California Division of Mines and Geology and Caltrans as part of a seismic hazard assessment of the Coronado Bridge in San Diego Bay, California. The original survey collected 130 km of data with a 14-cubic inch sleeve-gun (airgun) source, a 24-channel strChirp sub-bottom data collected in 2019 in Whiskeytown Lake, California during USGS field activity 2018-686-FA
High-resolution chirp sub-bottom data were collected by the U.S. Geological Survey, Pacific Coastal and Marine Science Center in May of 2019 in Whiskeytown Lake, California using an Edgetech SB-512i sub-bottom profiler. These data were collected to measure possible debris flows into the lake during the 2018-2019 rainy season following the July-August 2018 Carr fire that burned vegetation around thMultichannel minisparker, multichannel boomer, and chirp seismic-reflection data of USGS field activity 2017-612-FA collected in Puget Sound and Lake Washington in February of 2017
High-resolution multichannel minisparker, multichannel boomer and chirp seismic-reflection data were collected by the U.S. Geological Survey and the University of Washington in February of 2017 west of Seattle in Puget Sound and in Lake Washington, Washington. Data were collected aboard University of Washington's R/V Clifford A. Barnes during USGS field activity 2017-612-FA. Sub-bottom acoustic peMultichannel minisparker seismic-reflection and chip sub bottom data collected in the Santa Barbara Channel in July of 2018
High-resolution multichannel minisparker seismic-reflection and chirp sub-bottom data were collected by the U.S. Geological Survey in July of 2018 between Point Conception and Coal Oil Point in the Santa Barbara Channel, California. Data were collected aboard the USGS R/V Parke Snavely during field activity 2018-645-FA. Data were acquired to support the USGS geologic hazards projects to aide hazarMultibeam bathymetry, acoustic backscatter, and multichannel minisparker seismic-reflection data of USGS field activity 2016-666-FA collected in the Santa Barbara Basin in September and October of 2016
High-resolution multichannel minkisparker seismic-reflection (MCS) profiles were collected by the U.S. Geological Survey in September and October of 2016 from the northern portion of the Santa Barbara Basin offshore southern California. Data were collected aboard the USGS R/V Parke Snavely and NOAA R/V Shearwater during field activity 2016-666-FA. Data were acquired to support USGS geologic hazarQuaternary faults offshore of California
A comprehensive map of Quaternary faults has been generated for offshore of California. The Quaternary fault map includes mapped geometries and attribute information for offshore fault systems located in California State and Federal waters. The polyline shapefile and matching KML file have been compiled from previously published mapping where relatively dense, high-resolution marine geophysical da - Maps
Colored shaded-relief bathymetry, acoustic backscatter, and selected perspective views of the northern part of the California Continental Borderland, southern California
The California Continental Borderland is the complex continental margin in southern California that extends from Point Conception southward into northern Baja California (Fisher and others, 2009). This colored shaded-relief bathymetry map of the northern continental borderland in southern California was generated primarily from multibeam-echosounder data collected by the University of Washington i - Multimedia
- Publications
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Systematic mapping of the ocean-continent transform plate boundary of the Queen Charlotte fault system, southeastern Alaska and western British Columbia—A preliminary bathymetric terrain model
In 2015, U.S. Geological Survey scientists in collaboration with scientists from other institutions began a study of the Queen Charlotte fault—the first systematic study of the fault in more than three decades. The primary goal of the study was to gain a better understanding of the earthquake, tsunami, and underwater-landslide hazards throughout southeastern Alaska, as well as gather data to develAuthorsBrian D. Andrews, Daniel S. Brothers, Peter Dartnell, J. Vaughn Barrie, Peter J. Haeussler, Kristen M. Green, H. Gary Greene, Nathaniel C. Miller, Jared W. Kluesner, Uri S. ten BrinkUsing active source seismology to image the Palos Verdes Fault damage zone as a function of distance, depth, and geology
Fault damage zones provide a window into the non-elastic processes of an earthquake. Geological and seismic tomography methods have been unable to measure damage zones at depth with sufficient spatial sampling to evaluate the relative influence of depth, distance, and lithological variations. Here, we identify and analyze the damage zone of the Palos Verdes Fault offshore southern California usingAuthorsTravis Alongi, Emily Brodsky, Jared W. Kluesner, Daniel S. BrothersMass wasting along the Cascadia subduction zone: Implications for abyssal turbidite sources and the earthquake record
The only submarine records of large (>Mw7) prehistoric earthquakes along the Cascadia subduction zone are derived from sequences of deep sea turbidites interpreted to represent synchronous, shaking-induced failures along the continental slope. However, the spatial correlation of these deposits along the margin is complicated and the chronological constraints involve significant uncertainties, raisAuthorsJenna C. Hill, Janet Watt, Daniel S. BrothersRecency of faulting and subsurface architecture of the San Diego Bay pull-apart basin, California, USA
In southern California, plate boundary motion between the North American and Pacific plates is distributed across several sub-parallel fault systems. The offshore faults of the California Continental Borderland (CCB) are thought to accommodate ~10-15% of the total plate boundary motion, but the exact distribution of slip and the mechanics of slip partitioning remain uncertain. The Newport-InglewooAuthorsDrake Moore Singleton, Jillian M. Maloney, Daniel S. Brothers, Shannon Klotsko, Neal W. Driscoll, Thomas K. RockwellSystematic characterization of morphotectonic variability along the Cascadia convergent margin: Implications for shallow megathrust behavior and tsunami hazards
Studies of recent destructive megathrust earthquakes and tsunamis along subduction margins in Japan, Sumatra, and Chile have linked forearc morphology and structure to megathrust behavior. This connection is based on the idea that spatial variations in the frictional behavior of the megathrust influence the tectono-morphological evolution of the upper plate. Here we present a comprehensive exaAuthorsJanet Watt, Daniel S. BrothersFocused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)
Fluid seepage along obliquely deforming plate boundaries can be an important indicator of crustal permeability and influence on fault-zone mechanics and hydrocarbon migration. The ~850-km-long Queen Charlotte fault (QCF) is the dominant structure along the right-lateral transform boundary that separates the Pacific and North American tectonic plates offshore southeastern Alaska (USA) and western BAuthorsNancy G. Prouty, Daniel S. Brothers, Jared W. Kluesner, J. Vaughn Barrie, Brian D. Andrews, Rachel Lauer, Gary Greene, James E. Conrad, Thomas Lorenson, Michael D. Law, Diana Sahy, Kim Conway, Mary McGann, Peter DartnellMorphology, structure, and kinematics of the San Clemente and Catalina faults based on high-resolution marine geophysical data, southern California Inner Continental Borderland
Catalina Basin, located within the southern California Inner Continental Borderland (ICB), is traversed by two active submerged fault systems that are part of the broader North America-Pacific plate boundary: the San Clemente fault (along with a prominent splay, the Kimki fault) and the Catalina fault. Previous studies have suggested that the San Clemente fault (SCF) may be accommodating up to halAuthorsMaureen A. L. Walton, Daniel S. Brothers, James E. Conrad, Katherine L. Maier, Emily C. Roland, Jared W. Kluesner, Peter DartnellStructural controls on slope failure within the western Santa Barbara Channel based on 2D and 3D seismic imaging
The Santa Barbara Channel, offshore California, contains several submarine landslides and ample evidence for incipient failure. This region hosts active thrust and reverse faults that accommodate several mm/yr of convergence, yet the relationships between tectonic deformation and slope failure remain unclear. We present 3‐D and 2‐D multichannel seismic reflection (MCS) data sets, multibeam bathymeAuthorsJared W. Kluesner, Daniel S. Brothers, Alexis L Wright, Samuel Y. JohnsonSubmarine canyons, slope failures and mass transport processes in southern Cascadia
The marine turbidite record along the southern Cascadia Subduction Zone has been used to interpret paleoseismicity and suggest a shorter recurrence interval for large (>M7) earthquakes along this portion of the margin; however, the sources and pathways of these turbidity flows are poorly constrained. We examine the spatial distribution of sediment storage, downslope transport, and slope failures aAuthorsJenna C. Hill, Janet Watt, Daniel S. Brothers, Jared W. KluesnerMapping, exploration, and characterization of the California continental margin and associated features from the California-Oregon border to Ensenada, Mexico
Priority Geographic Area: Both within and outside US Exclusive Economic Zone (EEZ). California continental margin. This area includes and continues south of the geographic area captured in the Watt et al. white paper. Description of Priority Area: The California continental margin, from the narrow shelf to abyssal depths, contains diverse seafloor features that influence benthic community types, bAuthorsAmanda Demopoulos, Nancy G. Prouty, Daniel S. Brothers, Janet Watt, James E. Conrad, Jason Chaytor, Chris CaldowPlate boundary localization, slip-rates and rupture segmentation of the Queen Charlotte Fault based on submarine tectonic geomorphology
Linking fault behavior over many earthquake cycles to individual earthquake behavior is a primary goal in tectonic geomorphology, particularly across an entire plate boundary. Here, we examine the 1150-km-long, right-lateral Queen Charlotte-Fairweather fault system using comprehensive multibeam bathymetry data acquired along the Queen Charlotte Fault (QCF) offshore southeastern Alaska and westernAuthorsDaniel Brothers, Nathaniel C. Miller, Vaughn Barrie, Peter J. Haeussler, H. Gary Greene, Brian D. Andrews, Olaf Zielke, Peter DartnellRight-lateral fault motion along the slope-basin transition, Gulf of Santa Catalina, southern California
An active fault system carrying a significant component of right-lateral strike-slip motion extends for ~60 km along the slope–basin transition, ~10 to 20 km offshore of the southern California coast from La Jolla to Dana Point. From south to north, this fault system includes the Carlsbad, San Onofre, and San Mateo fault zones. High-resolution single channel minisparker and chirp seismic reflectio
AuthorsJames Conrad, Daniel Brothers, Katherine Coble, Holly F. Ryan, Peter Dartnell, Ray SliterNon-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- News