My research focuses on characterizing onshore/offshore geologic structure, deformation, and active tectonics to address problems focused on geologic hazards and framework geologic processes. My recent work involves the development and application of integrative geophysical approaches to 3D characterization of faults and fault interactions.
I received my M.S. in Marine Science (Geological Oceanography) from Moss Landing Marine Laboratories while working at the USGS in Menlo Park, CA. As part of the Geophysical Unit of Menlo Park (GUMP), I used potential-field methods (gravity and magnetics) and 3D geologic mapping to understand earthquake and volcano hazards, and mineral and water resources in the western U.S. In 2010, I returned to my marine geology roots and joined the Pacific Coastal and Marine Science Center in Santa Cruz, CA where I currently work as a Research Geophysicist.
Selected Media and Public Outreach
November 18, 2016, CBS This Morning "California prepares for next big earthquake"
October 19, 2016, Popular Mechanics "Two dangerous Fault Lines Under San Francisco Are Connected, Study Finds"
February 1, 2016, Temblor.net Earthquake News & Blog, "Why don't the earthquakes line up with the San Andreas fault?"
January 2, 2016, CBS NEWS, "Alarming Discovery Shows Bay Area’s 2 Most Dangerous Earthquake Faults May Be Connected"
December 31, 2015, San Francisco Chronicle, "New data on 2 Bay Area faults cause worry about next big quake"
November 20, 2014, KQED Science "Using 3D Visualization, Geologists Explore the Complex Areas Where Faults Join and Split"
Science and Products
Cascadia Subduction Zone Marine Geohazards
Offshore Faults along Central and Northern California
U.S. West Coast and Alaska Marine Geohazards
2019 Seafloor Geodesy cruise
2019 Regional geophysical surveys of northern and central Cascadia (offshore Washington and Oregon)
2018 Regional geophysical surveys of southern Cascadia (offshore northern California and southern Oregon)
2018 USGS-NOAA multibeam bathymetry surveys
Margin-wide geological and geophysical synthesis to understand the recurrence and hazards of great subduction zone earthquakes in Cascadia
High-resolution multichannel sparker seismic-reflection and chirp sub-bottom data acquired along the Cascadia margin during USGS field activity 2019-024-FA
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
Multichannel minisparker seismic-reflection and chirp subbottom data collected offshore Northern California during USGS field activity 2019-643-FA
Geophysical properties, geochronologic, and geochemical data of sediment cores collected from San Pablo Bay, California, October 17-20, 2016
Composite multibeam bathymetry surface and data sources of the southern Cascadia Margin offshore Oregon and northern California
Geophysical and core sample data collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18
Geophysical and sampling data collected offshore Oceanside, southern California during field activity 2017-686-FA from 2017-10-23 to 2017-10-31
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
Chirp sub-bottom data of USGS field activity K0211PS collected in Puget Sound, Washington in April of 2011
Magnetotelluric data from San Pablo Bay, California
Multichannel sparker seismic reflection data of USGS field activity 2018-658-FA collected between Cape Blanco and Cape Mendocino from 2018-10-04 to 2018-10-18
California State Waters Map Series Data Catalog--Point Sur to Point Arguello
Offshore geology and geomorphology from Point Piedras Blancas to Pismo Beach, San Luis Obispo County, California
Marine geology and geomorphology were mapped along the continental shelf and upper slope between Point Piedras Blancas and Pismo Beach, California. The map area is divided into the following three (smaller) map areas, listed from north to south: San Simeon, Morro Bay, and Point San Luis. Each smaller map area consists of a geologic map and the corresponding geophysical data that support the geolog
California State Waters Map Series — Offshore of San Gregorio, California
California State Waters Map Series — Offshore of San Gregorio, California
Diving deeper into seep distribution along the Cascadia Convergent Margin, USA
Shallow deformation on the Kirby Hills fault, Sacramento–San Joaquin Delta, California (USA), revealed from high-resolution seismic reflection data and coring in a fluvial system
Mass wasting along the Cascadia subduction zone: Implications for abyssal turbidite sources and the earthquake record
Marine paleoseismic evidence for seismic and aseismic slip along the Hayward-Rodgers Creek fault system in northern San Pablo Bay
Toward an integrative geological and geophysical view of Cascadia subduction zone earthquakes
Systematic characterization of morphotectonic variability along the Cascadia convergent margin: Implications for shallow megathrust behavior and tsunami hazards
Submarine canyons, slope failures and mass transport processes in southern Cascadia
Cascadia Margin cold seeps: Subduction zone fluids, gas hydrates, and chemosynthetic habitats
Mapping, exploration, and characterization of the California continental margin and associated features from the California-Oregon border to Ensenada, Mexico
Controls on sediment distribution in the coastal zone of the central California transform continental margin, USA
Plate boundary localization, slip-rates and rupture segmentation of the Queen Charlotte Fault based on submarine tectonic geomorphology
Santa Rosa's past and future earthquakes
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 ScienceOffshore Faults along Central and Northern California
From Point Conception to Cape Mendocino, seafloor faults have been, in the past, mapped in varying ways and without enough detail to assess their earthquake potential. To provide this important information, USGS uses advanced technology to image offshore faults that could trigger devastating earthquakes near densely populated areas and a nuclear power plant.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 Science2019 Seafloor Geodesy cruise
Performed maintenance on and retrieved data from seafloor geodetic instrument arrays offshore of Oregon and northern California in 2019, a USGS-Scripps-University of Washington-University of Hawaii partnership2019 Regional geophysical surveys of northern and central Cascadia (offshore Washington and Oregon)
Geophysical data collected offshore of Washington and Oregon in 2019, a USGS-University of Washington partnership2018 Regional geophysical surveys of southern Cascadia (offshore northern California and southern Oregon)
Regional geophysical surveys conducted offshore of northern California and southern Oregon in 2018, a USGS-Humboldt State University partnership2018 USGS-NOAA multibeam bathymetry surveys
Multibeam bathymetric surveys conducted offshore of Oregon and northern California in 2018, a USGS-NOAA partnershipMargin-wide geological and geophysical synthesis to understand the recurrence and hazards of great subduction zone earthquakes in Cascadia
The Cascadia Subduction Zone, located in the U.S. Pacific Northwest and southwestern British Columbia, has hosted magnitude ≥8.0 megathrust earthquakes in the geologic past, a future earthquake is imminent, and the potential impacts could cripple the region. Subduction zone earthquakes represent some of the most devastating natural hazards on Earth. Despite substantial knowledge gained from deca - Data
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High-resolution multichannel sparker seismic-reflection and chirp sub-bottom data acquired along the Cascadia margin during USGS field activity 2019-024-FA
High-resolution multichannel sparker seismic (MCS) data and chirp sub-bottom data were collected by the U.S. Geological Survey in collaboration with the University of Washington (UW) in the summer of 2019 along the Cascadia submarine forearc offshore Oregon and Washington. Data were acquired to characterize quaternary deformation and sediment dynamics along the central and northern Cascadia marginMultichannel 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 deMultichannel minisparker seismic-reflection and chirp subbottom data collected offshore Northern California during USGS field activity 2019-643-FA
High-resoulution multichannel seismic-reflection (MCS) and Chirp sub-bottom data were collected by the U.S. Geological Survey in 2019 offshore Humboldt County of northern California to expand data coverage along the southern Cascadia Margin. Data were acquired to characterize offshore faults and to study sediment distribution. MCS and Chirp data were collected coincidentally and were used to deterGeophysical properties, geochronologic, and geochemical data of sediment cores collected from San Pablo Bay, California, October 17-20, 2016
Geophysical properties (P-wave velocity, gamma ray density, and magnetic susceptibility), geochronologic (radiocarbon, excess Lead-210, and Cesium-137), and geochemical data (organic carbon content and 60 element contents) are reported for select vibracores collected aboard the S/V Retriever October 17-20, 2016 in San Pablo Bay, California. Geophysical properties were measured with a Geotek Multi-Composite multibeam bathymetry surface and data sources of the southern Cascadia Margin offshore Oregon and northern California
Bathymetry data from various sources, including newly released 2018 and 2019 multibeam data collected by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS), were combined to create a composite 30-m resolution multibeam bathymetry surface of the southern Cascadia Margin offshore of Oregon and northern California. The bathymetry data are available as a 3Geophysical and core sample data collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18
The U.S. Geological Survey (USGS) collected geophysical and core sample data aboard the R/V Bold Horizon in 2019 on cruise 2019-649-FA offshore San Francisco, California. The data were collected to assess sand and gravel resources in Federal and State waters for potential use in future beach nourishment projects along stretches of the coast where critical erosion hotspots have been identified. ThiGeophysical and sampling data collected offshore Oceanside, southern California during field activity 2017-686-FA from 2017-10-23 to 2017-10-31
This data release contains geophysical and sediment sample data that were collected aboard the R/V Snavely in 2017 on U.S. Geological Survey cruise 2017-686-FA offshore Oceanside, southern California. The goal of the survey was to provide high-resolution imaging, magnetic anomaly profiles and sediment analysis to characterize the surface and subsurface properties of the study area such as unconsolMultichannel 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 peChirp sub-bottom data of USGS field activity K0211PS collected in Puget Sound, Washington in April of 2011
High-resolution chirp sub-bottom data were collected by the U.S. Geological Survey in April 2011 south of Bainbridge Island and west of Seattle in Puget Sound, Washington. Data were collected aboard the R/V Karluk during field activity K0211PS using an Edgetech SB-512i sub-bottom profiler. Sub-bottom acoustic penetration spans several tens of meters and is variable by location.Magnetotelluric data from San Pablo Bay, California
This dataset consists of 14 magnetotelluric (MT) stations collected in 2015 near San Pablo Bay, California along a east-northeast profile. The U.S. Geological Survey acquired these data to understand the fault geometry of the Hayward Fault and the Rodgers Creek Fault.Multichannel sparker seismic reflection data of USGS field activity 2018-658-FA collected between Cape Blanco and Cape Mendocino from 2018-10-04 to 2018-10-18
This data release contains processed high-resolution multichannel sparker seismic-reflection (MCS) 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 deformation and sediment dynCalifornia State Waters Map Series Data Catalog--Point Sur to Point Arguello
As part of the USGS's California State Waters Mapping Project, a 50-m grid of sediment thickness for the seafloor within the 3-nautical mile limit between Point Sur and Point Arguello was generated from seismic-reflection data collected between 2008 and 2014, and supplemented with geologic structure (fault and fold) information following the methodology of Wong (2012). Water depths determined from - Maps
Offshore geology and geomorphology from Point Piedras Blancas to Pismo Beach, San Luis Obispo County, California
Marine geology and geomorphology were mapped along the continental shelf and upper slope between Point Piedras Blancas and Pismo Beach, California. The map area is divided into the following three (smaller) map areas, listed from north to south: San Simeon, Morro Bay, and Point San Luis. Each smaller map area consists of a geologic map and the corresponding geophysical data that support the geolog
California State Waters Map Series — Offshore of San Gregorio, California
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California's State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, andCalifornia State Waters Map Series — Offshore of San Gregorio, California
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California's State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and - Multimedia
- Publications
Filter Total Items: 55
Diving deeper into seep distribution along the Cascadia Convergent Margin, USA
Previous margin-wide studies of methane seep distribution along the Cascadia Subduction Zone indicate peaks in seep density within the landward limit of the of gas hydrate stability zone (GHSZ; ≤500 m depth), suggesting a link between current ocean warming, acceleration of hydrate dissociated, and methane emissions. This inferred connection, however, may not account for regional geologic and/or stAuthorsJane A. Rudebusch, Nancy G. Prouty, James E. Conrad, Janet Watt, Jared W. Kluesner, Jenna C. Hill, Nathaniel C. Miller, Sally J. Watson, Jess I.T. HillmanShallow deformation on the Kirby Hills fault, Sacramento–San Joaquin Delta, California (USA), revealed from high-resolution seismic reflection data and coring in a fluvial system
The Sacramento–San Joaquin Delta (Delta) in California (USA) is an important part of the state’s freshwater system and is also a major source of agricultural and natural resources. However, the Delta is traversed by a series of faults that make up the easternmost part of the San Andreas fault system at this latitude and pose seismic hazard to this region. In this study, we use new high-resolutionAuthorsShannon Klotsko, Jillian Maloney, Janet WattMass 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. BrothersMarine paleoseismic evidence for seismic and aseismic slip along the Hayward-Rodgers Creek fault system in northern San Pablo Bay
Distinguishing between seismic and aseismic fault slip in the geologic record is difficult, yet fundamental to estimating the seismic potential of faults and the likelihood of multi-fault ruptures. We integrated chirp sub-bottom imaging with targeted cross-fault coring and core analyses of sedimentary proxy data to characterize vertical deformation and slip behavior within an extensional fault benAuthorsJanet Watt, Mary McGann, Renee K. Takesue, Thomas LorensonToward an integrative geological and geophysical view of Cascadia subduction zone earthquakes
The Cascadia subduction zone (CSZ) is an exceptional geologic environment for recording evidence of land level changes, tsunamis, and ground motion that reveals at least 19 great megathrust earthquakes over the past 10 kyr. Such earthquakes are among the most impactful natural hazards on Earth, transcend national boundaries, and can have global impact. Reducing the societal impacts of future eventAuthorsMaureen A. L. Walton, Lydia M. Staisch, Tina Dura, Jessie Kathleen Pearl, Brian L. Sherrod, Joan S. Gomberg, Simon E. Engelhart, Anne Trehu, Janet Watt, Jonathan P. Perkins, Robert C. Witter, Noel Bartlow, Chris Goldfinger, Harvey Kelsey, Ann Morey, Valerie J. Sahakian, Harold Tobin, Kelin Wang, Ray Wells, Erin WirthByNatural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, National Cooperative Geologic Mapping Program, Geosciences and Environmental Change Science Center, Pacific Coastal and Marine Science Center, Core Preparation and Analysis Laboratory and Sample Repositories, Deep Sea Exploration, Mapping and Characterization, Subduction Zone ScienceSystematic 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. BrothersSubmarine 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. KluesnerCascadia Margin cold seeps: Subduction zone fluids, gas hydrates, and chemosynthetic habitats
Priority Geographic Area: The outer continental shelf and upper continental slope from Canada/U.S. border offshore Washington State to the Mendocino Fracture Zone (Northern California), entirely within the U.S. Exclusive Economic Zone (EEZ), from the outermost shelf to at least 2000 m water depth (Figure 1). Description of Priority Area: Since 2015, over a thousand water column gas plumes originatAuthorsAmanda Demopoulos, Carolyn D. Ruppel, Nancy G. Prouty, Janet Watt, Tamara Baumberger, David A ButterfieldMapping, 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 CaldowControls on sediment distribution in the coastal zone of the central California transform continental margin, USA
We use >10,000 km of high-resolution seismic-reflection data together with multibeam bathymetry to document complex and highly variable post-Last Glacial Maximum (LGM) sediment distribution and thickness in the coastal zone (~10 m isobath to 5.6 km offshore) along a ~800 km section of central California's transform continental margin. Sediment thickness ranges from 0 (seafloor bedrock) to 64 m witAuthorsSamuel Y. Johnson, Jeffrey W. Beeson, Janet Watt, Ray Sliter, Antoinette PapeshPlate 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 DartnellSanta Rosa's past and future earthquakes
Santa Rosa is no stranger to earthquakes. This northern California city was damaged several times in the late 19th and early 20th centuries by shaking from earthquakes, culminating in the devastating earthquake of 1906, whose rupture passed 20 miles to the west of the city on the San Andreas Fault. Then in 1969, Santa Rosa was again strongly shaken and buildings were damaged by a pair of nearby, mAuthorsSuzanne Hecker, Darcy K. McPhee, Victoria E. Langenheim, Janet T. Watt - News