Janet Watt
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.
Biography
I received my M.S. in Marine Science (Geological Oceanography) from Moss Landing Marine Laboratories in 2004 while working at the U.S. Geological Survey 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.
Publications
Johnson, S.Y., Watt, J.T., Hartwell, S.R., and Kluesner, J.W., 2018, Neotectonics of the Big Sur Bend, San Gregorio‐Hosgri fault system, central California: Tectonics, https://doi.org/10.1029/2017TC004724.
Gomberg, J.S., Ludwig, K.A., Bekins, B.A., Brocher, T.M., Brock, J.C., Brothers, Daniel, Chaytor, J.D., Frankel, A.D., Geist, E.L., Haney, Matthew, Hickman, S.H., Leith, W.S., Roeloffs, E.A., Schulz, W.H., Sisson, T.W., Wallace, Kristi, Watt, J.T., Wein, Anne, 2017, Reducing risk where tectonic plates collide—U.S. Geological Survey subduction zone science plan: U.S. Geological Survey Circular 1428, 45 p., https://doi.org/10.3133/cir1428.
Johnson, S.Y., Cochrane, G.R., Golden, N.E., Dartnell, P., Hartwell, S.R., Cochran, S.A., and Watt, J.T., 2017, The California Seafloor Mapping Program - Providing science and geospatial data for California’s State Waters: Ocean and Coastal Management, v. 140, p. 88-104. http://dx.doi.org/10.1016/j.ocecoaman.2017.02.004.
Watt, J.; Ponce, D.; Parsons, T.; and Hart, P., 2016. Missing Link between the Hayward and Rodgers Creek Faults. Science Advances, doi: 10.1126/sciadv.1601441
Langenheim, Victoria E.; Rymer, Michael J.; Catchings, Rufus D.; Goldman, Mark R.; Watt, Janet T.; Powell, Robert E.; Matti, Jonathan C., 2016. High-resolution gravity and seismic-refraction surveys of the Smoke Tree Wash area, Joshua Tree National Park, California. U.S. Geological Survey Open-File Report 2016-1027, Report: iii, 15 p. [Link]
Watt, Janet Tilden; Johnson, Samuel Y.; Hartwell, Stephen R.; Roberts, Michelle, 2015. Offshore geology and geomorphology from Point Piedras Blancas to Pismo Beach, San Luis Obispo County, California. U.S. Geological Survey Scientific Investigations Map 3327, Pamphlet: iii, 6 p.; 6 Sheets [Link]
Watt, Janet T.; Dartnell, Peter; Golden, Nadine E.; Greene, H. Gary; Erdey, Mercedes D.; Cochrane, Guy R.; Johnson, Samuel Y.; Hartwell, Stephen R.; Kvitek, Rikk G.; Manson, Michael W.; Endris, Charles A.; Dieter, Bryan E.; Sliter, Ray W.; Krigsman, Lisa M.; Lowe, Erik N.; Chinn, John L.Watt, Janet T.; Cochran, Susan A., 2015. California State Waters Map Series: Drakes Bay and vicinity, California. U.S. Geological Survey Open-File Report 2015-1041, Pamphlet: iv, 36 p.; 10 Sheets [Link]
Watt, Janet T.; Dartnell, Peter; Golden, Nadine E.; Greene, H. Gary; Erdey, Mercedes D.; Cochrane, Guy R.; Johnson, Samuel Y.; Hartwell, Stephen R.; Kvitek, Rikk G.; Manson, Michael W.; Endris, Charles A.; Dieter, Bryan E.; Sliter, Ray W.; Krigsman, Lisa M.; Lowe, Erik; Chinn, John L.; Cochran, Susan, 2015. California State Waters Map Series-Offshore of Point Reyes, California. U.S. Geological Survey Open-File Report 2015-1114, Pamphlet: iv, 39 p.; 10 Sheets [Link]
Cochrane, Guy R.; Watt, Janet T.; Dartnell, Peter; Greene, H. Gary; Erdey, Mercedes D.; Dieter, Bryan E.; Golden, Nadine E.; Johnson, Samuel Y.; Endris, Charles A.; Hartwell, Stephen R.; Kvitek, Rikk G.; Davenport, Clifton W.; Krigsman, Lisa M.; Ritchie, Andrew C.; Sliter, Ray W.; Finlayson, David P.; Maier, Katherine L.Cochrane, Guy R.; Cochran, Susan A., 2015. California State Waters Map Series—Offshore of Pigeon Point, California. U.S. Geological Survey Open-File Report 2015-1232, Pamphlet: iv, 40 p.; 10 Sheets: 50.50 x 36.00 inches or smaller; Data Catalog; Metadata [Link]
Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; edited by Cochrane, Guy R.; Cochran, Susan A.Cochrane, Guy R.; Cochran, Susan A., 2014. California State Waters Map Series: offshore of San Gregorio, California. U.S. Geological Survey Scientific Investigations Map 3306, Pamphlet: iv, 38 p.; 10 Plates [Link]
Watt, J.T., Ponce, D.A., Graymer, R.W., Jachens, R.C., and Simpson, R.W., 2014, Subsurface geometry of the San Andreas-Calaveras fault junction: Influence of serpentinite and the Coast Range Ophiolite: Tectonics, doi: 10.1002/2014TC003561 [Download File]
Sliter, Ray W.; Johnson, Samuel Y.; Watt, Janet T.; Scheirer, Daniel S.; Allwardt, Parker ; Triezenberg, Peter J., 2013. High-resolution seismic-reflection and marine-magnetic data from offshore central California--San Gregorio to Point Sur. U.S. Geological Survey Open-File Report 2013-1071
Johnson, S.Y. and Watt, J.T., 2012, Influence of fault trend, bends, and convergence on shallow structure and geomorphology of the Hosgri strike-slip fault, offshore Central California: Geosphere, v. 8, no. 6, 25p. [Download File]
Ponce, David A.; Watt, Janet T.; Bouligand, C., 2011. Geophysical setting of the February 21, 2008 Mw 6 Wells earthquake, Nevada, and implications for earthquake hazards. Nevada Bureau of Mines and Geology Special Publication 36, 12 p. [Link]
Watt, J.T., Ponce, D.A., Graymer, R.W., Simpson, R.W., Jachens, R.C., and Wentworth, C.M., 2011, The Mt. Lewis fault zone: Tectonic implications for eastern San Francisco Bay Area, in Knudsen, K., ed., Proceedings of the third conference on earthquake hazards in the eastern San Francisco Bay area—Science, hazard, engineering and risk: California Geological Survey Special Report 219, p. 313-322. [Download File]
Ponce, David A.; Glen, Jonathan M. G.; Egger, Anne E.; Bouligand, Claire; Watt, Janet T.; Morin, Robert L., 2009. Geophysical Studies in the Vicinity of the Warner Mountains and Surprise Valley, Northeast California, Northwest Nevada, and Southern Oregon. U.S. Geological Survey Open-File Report 2009-1157, 19 p. [Link]
Sliter, Ray W.; Triezenberg, Peter J.; Hart, Patrick E.; Watt, Janet T.; Johnson, Samuel Y.; Scheirer, Daniel S., 2009. High-Resolution Seismic-Reflection and Marine Magnetic Data Along the Hosgri Fault Zone, Central California. U.S. Geological Survey Open-File Report 2009-1100 [Link]
Ponce, David A.; Watt, Janet T.; Casteel, John; Logsdon, Grant, 2009. Physical-Property Measurements on Core samples from Drill-Holes DB-1 and DB-2, Blue Mountain Geothermal Prospect, North-Central Nevada. U.S. Geological Survey Open-File Report 2009-1022, 16 p. [Link]
Watt, Janet T.; Ponce, David A., 2007. Geophysical Framework Investigations Influencing Ground-Water Resources in East-Central Nevada and West-Central Utah. Geological Survey (U.S.) Open-File Report 2007-1163, Report: iv, 43 p. (With a section on Geologic and Geophysical Basin-by-basin Descriptions by Alan R. Wallace, Janet T. Watt, and David A. Ponce); 2 Plates [Link]
Morin, Robert L.; Wheeler, Karen L.; McPhee, Darcy K.; Dinterman, Philip A.; Watt, Janet T., 2007. Principal Facts of Gravity data in the Northern Willamette Valley and Vicinity, Northwestern Oregon and Southwestern Washington. Open-File Report 2007-1058, 9 p.; map, 24 by 24 inches; data files [Link]
Watt, J.T., Glen, J.M.G., John, D.A., Ponce, D.A., 2007, Three-dimensional geologic model of the northern Nevada rift and the Beowawe geothermal system, north-central Nevada, Geosphere, v. 3, no. 6, p.667-682. [Download File]
Selected Media and Public Outreach
November 18, 2016, CBS This Morning "California prepares for next big earthquake"
Science and Products
2019 Seafloor Geodesy cruise
Objectives: Constrain the rate and spatial distribution of locking (stress accumulation) along the megathrust offshore Cascadia with seafloor geodetic instrument arrays that operate using indirect-path acoustic ranging methods with Global Navigation Satellite System positioning (GNSS-A) (Figure 1)
This survey is part of the USGS project, “...
2019 Regional geophysical surveys of northern and central Cascadia (offshore Washington and Oregon)
Objectives: Systematic characterization of upper plate structure and offshore geohazards in northern Cascadia.
These surveys are part of the USGS project, “Cascadia Subduction Zone Marine Geohazards.”
2018 Regional geophysical surveys of southern Cascadia (offshore northern California and southern Oregon)
Objectives: Characterize offshore geohazards and source-to-sink sedimentary dynamics offshore southern Cascadia.
These surveys are part of the USGS project, “Cascadia Subduction Zone Marine Geohazards.”
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.
2018 USGS-NOAA multibeam bathymetry surveys
Objectives: Fill in critical baseline bathymetric mapping gaps along the mid- to upper-slope (200 m to 1,500 m water depths).
These surveys are part of the USGS project, “Cascadia Subduction Zone Marine Geohazards.”
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.
Devastating earthquakes in Japan (2011) and Chile (2010) that spawned pan-oceanic tsunamis sent a sobering reminder that U.S. coastlines are also vulnerable to natural disasters that originate in...
Offshore 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.
Margin-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...
Submarine 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...
Hill, Jenna C.; Watt, Janet; Brothers, Daniel; Kluesner, Jared Controls 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...
Johnson, Samuel; Beeson, Jeffrey W.; Watt, Janet; Sliter, Ray; Papesh, Antoinette
Santa 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...
Hecker, Suzanne; McPhee, Darcy K.; Langenheim, Victoria E.; Watt, Janet T.
Offshore shallow structure and sediment distribution, Point Sur to Point Arguello, central California
This publication consists of three map sheets that display shallow geologic structure, along with sediment distribution and thickness, for an about 225-km-long offshore section of the central California coast between Point Sur and Point Arguello. Each map sheet includes three maps, at scales of either 1:150,000 or 1:200,000, as well as a set of...
Johnson, Samuel Y.; Hartwell, Stephen R.; Watt, Janet T.; Beeson, Jeffrey W.; Dartnell, Peter Neotectonics of the Big Sur Bend, San Gregorio‐Hosgri fault system, central California
The right‐lateral San Gregorio‐Hosgri fault system (SGHF) extends mainly offshore for about 400 km along the central California coast and is a major structure in the distributed transform margin of western North America. We mapped a poorly known 64‐km‐long section of the SGHF offshore Big Sur between Piedras Blancas and Point Sur using high‐...
Johnson, Samuel Y.; Watt, Janet; Hartwell, Stephen; Kluesner, Jared
Reducing risk where tectonic plates collide—U.S. Geological Survey subduction zone science plan
The U.S. Geological Survey (USGS) serves the Nation by providing reliable scientific information and tools to build resilience in communities exposed to subduction zone earthquakes, tsunamis, landslides, and volcanic eruptions. Improving the application of USGS science to successfully reduce risk from these events relies on whole community efforts...
Gomberg, Joan S.; Ludwig, K.A.; Bekins, Barbara; Brocher, Thomas M.; Brock, John C.; Brothers, Daniel; Chaytor, Jason D.; Frankel, Arthur; Geist, Eric L.; Haney, Matthew M.; Hickman, Stephen H.; Leith, William S.; Roeloffs, Evelyn A.; Schulz, William H.; Sisson, Thomas W.; Wallace, Kristi; Watt, Janet; Wein, Anne M. The California Seafloor and Coastal Mapping Program – Providing science and geospatial data for California's State Waters
The California Seafloor and Coastal Mapping Program (CSCMP) is a collaborative effort to develop comprehensive bathymetric, geologic, and habitat maps and data for California's State Waters. CSCMP began in 2007 when the California Ocean Protection Council (OPC) and the National Oceanic and Atmospheric Administration (NOAA) allocated funding for...
Johnson, Samuel Y.; Cochrane, Guy R.; Golden, Nadine; Dartnell, Peter; Hartwell, Stephen; Cochran, Susan A.; Watt, Janet Missing link between the Hayward and Rodgers Creek faults
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...
Watt, Janet; Ponce, David A.; Parsons, Thomas E.; Hart, Patrick E.
USGS-NOAA cruise maps Cascadia subduction zone to assess earthquake hazards
From July 31 to August 23, a joint USGS-NOAA cruise mapped seafloor depths, texture, and gas seeps in the Cascadia subduction zone offshore of Washington, Oregon, and northern California.
Mystery Gap: Connecting Earthquake Faults near San Francisco, California, Requires Many Approaches
New USGS mapping studies in San Pablo Bay, California, show that two of the region’s earthquake faults—the Hayward and Rodgers Creek faults—connect beneath the bay.
CBS This Morning features USGS scientists studying link between earthquake faults near San Francisco, California
Coring the Hayward-Rodgers Creek fault zone in San Pablo Bay, California, to unravel the history of faulting beneath the bay
