Early Earthquake Warning! Safety Potentials and Limits
Possible alert times that earthquake early warning systems can provide people at different levels of ground motion from light to very strong shaking.Read Story
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Every year in the United States, natural hazards threaten lives and livelihoods and result in billions of dollars in damage. We work with many partners to monitor, assess, and conduct targeted research on a wide range of natural hazards so that policymakers and the public have the understanding they need to enhance preparedness, response, and resilience.
Costs and consequences of natural hazards can be enormous; each year more people and infrastructure are at risk. We develop and apply hazards science to help protect U.S. safety, security, and economic well being. These scientific observations, analyses, and research are crucial for the Nation to become more resilient to natural hazards.Read Our Science Strategy
Based on rates of vertical reef accretion in Hawaiʻi and throughout the Pacific, it is unlikely that reefs there and other locations will keep pace with the rising sea levels, and their inability to do so will lead to subtle but important changes in selected physical processes on some coral reefs.
Welcome to the USGS Coral Reef Project website
Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.
An interactive, graphics-rich summary of the hazards in the HayWired Scenario.
Addressing issues concerning mineral resources that occur within the Exclusive Economic Zone of Pacific coastal States, Pacific islands of U.S. affiliation, and areas beyond national jurisdictions.
For a beach town like Santa Cruz, preserving beaches by mitigating coastal erosion is vital. Surveys conducted now and regularly in the future will help scientists understand the short- and long-term impacts of climate change, El Niño years, and sea-level rise on a populated and vulnerable coastline.
Hurricane Joaquin coastal change forecast and pre- and post-storm photos documenting coastal change.
The maps in this archive display estimated intensities and ground motions for the earthquake scenarios - events on faults that have ruptured in the past or have a likelihood of rupturing in the future. These maps are typically used for emergency response exercises and planning as well as for understanding the potential consequences of future large earthquakes.
How do we get ready for big earthquakes in populated areas? An important first step is to learn what a big earthquake could be like. These pages summarize the main patterns — the earthquake effects that show up again and again. Here, urban is shorthand for “cities, towns, and suburbs”.
The Massachusetts Office of Coastal Zone Management (CZM) launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the Massachusetts coast. This update included a marsh shoreline, which was defined to be the tonal difference between low- and high-marsh seen in ortho-photos. Further cooperation between CZM and the U.S. Geological Survey (USGS) has resulted in another...
Collection, analysis, and age-dating of sediment cores from salt marshes on the south shore of Cape Cod, Massachusetts, from 2013 through 2014
Elevation of the marsh surface was measured with RTK-GPS to evaluate where the marsh falls within the current tidal frame. The historic marsh surface elevation was then reconstructed using the calculated age of each depth interval and its elevation, assuming that elevations within this shallow zone (less than 30 cm) have been preserved for the past century.
Oceanographic time-series measurements made by the U.S. Geological Survey between 1975 and the present as part of research programs. The data were collected to address specific research questions and were primarily collected over durations less than a year, using stationary platforms, with sensors near the sea floor. These data have been used to study of ocean dynamics and to validate ocean...
Welcome to the CMGP Internet Map Server, an internet map server and downloadable list of GIS data being served by the USGS, Coastal and Marine Geology Program.
Sampling data collected in Cape Cod Bay, Buzzards Bay, and Vineyard Sound; south of Martha's Vineyard; and south and east of Nantucket, Massachusetts, in 2011, U.S. Geological Survey Field Activity 2011-015-FA
These survey data are used to explore the nature of the sea floor and, in conjunction with high-resolution geophysical data, to make interpretive maps of sedimentary environments and validate acoustic remote sensing data.
Integrated terrain models covering 16,357 square kilometers of the Massachusetts coastal zone and offshore waters were built to provide a continuous elevation and bathymetry terrain model for ocean planning purposes. A Triangulated Irregular Network was created from public-domain bathymetric and LiDAR data using the ArcGIS terrain-model framework.
Conceptual salt marsh units for wetland synthesis: Edwin B. Forsythe National Wildlife Refuge, New Jersey
The salt marsh complex of the Edwin B. Forsythe National Wildlife Refuge (EBFNWR), which spans over Great Bay, Little Egg Harbor, and Barnegat Bay (New Jersey, USA), was delineated to smaller, conceptual marsh units by geoprocessing of surface elevation data. Flow accumulation based on the relative elevation of each location is used to determine the ridge lines that separate each marsh unit....
Geophysical data collected along the Atlantic continental slope and rise 2014, U.S. Geological Survey Field Activity 2014-011-FA, cruise MGL1407
In summer 2014, the U.S. Geological Survey conducted a 21-day geophysical program in deep water along the Atlantic continental margin by using R/V Marcus G. Langseth (Field Activity Number 2014-011-FA). The purpose of the seismic program was to collect multichannel seismic reflection and refraction data to determine sediment thickness
Swath bathymetry collected offshore of Fire Island and western Long Island, New York in 2014, U.S. Geological Survey Field Activity 2014-072-FA
Hurricane Sandy, the largest storm of historical record in the Atlantic basin, severely impacted southern Long Island, New York in October 2012. In 2014, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), conducted a high-resolution multibeam echosounder survey with Alpine Ocean Seismic Survey, Inc., offshore of Fire Island and western Long Island...
Using information from recent earthquakes, improved mapping of active faults, and a new model for estimating earthquake probabilities, the 2014 Working Group on California Earthquake Probabilities updated the 30-year earthquake forecast for California. They concluded that there is a 72 percent probability (or likelihood) of at least one earthquake of magnitude 6.7 or greater striking somewhere in
This map shows the location of and evidence for recent movement on active fault traces within the Hayward Fault Zone, California.
The maps in this archive display estimated intensities and ground motions for the largest earthquakes in the HayWired aftershock sequence. The aftershock sequence follows the HayWired M7.0 mainshock that is imagined to occur on April 18, 2018 along the Hayward Fault.These maps have been used in analyses of the HayWired scenario.
The HayWired scenario depicts a hypothetical M7.0 earthquake on California’s Hayward Fault. This site includes an interactive map showing fault traces and ShakeMap contours, information on the tectonic setting of the Hayward Fault and fault rupture history; and a USGS ShakeMap, which provides ground motion information for the HayWired scenario mainshock.
The seismic-landslide probability map covers the counties of Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano, and Sonoma. The slope failures are triggered by a hypothetical earthquake with a moment magnitude of 7.0 occurring on April 18, 2018, at 4:18 p.m. on the Hayward Fault in the east bay part of California’s San Francisco Bay region.
CSMP is a cooperative program to create a comprehensive coastal and marine geologic and habitat base map series for all of California's State waters. Data collected during this project reveal the seafloor offshore of the California coast in unprecedented detail and provide an ecosystem context for the effective management of this precious marine resource.
This portal is a “go to” source for maps related to ocean and coastal mapping. Information is organized by geography or region, by theme, and by the year data was published.
We conduct post-fire debris-flow hazard assessments for select fires in the Western U.S. We use geospatial data related to basin morphometry, burn severity, soil properties, and rainfall characteristics to estimate the probability and volume of debris flows that may occur in response to a design storm.
The size, distribution, and mobility of landslides caused by the 2015 Mw7.8 Gorkha earthquake, Nepal
Coseismic landslides pose immediate and prolonged hazards to mountainous communities, and provide a rare opportunity to study the effect of large earthquakes on erosion and sediment budgets. By mapping landslides using high-resolution satellite imagery, we find that the 25 April 2015 Mw7.8 Gorkha earthquake and aftershock sequence produced at...Roback, Kevin; Clark, Marin K.; West, A. Joshua; Zekkos, Dimitrios; Li, Gen; Gallen, Sean F.; Chamlagain, Deepak; Godt, Jonathan W.
The HayWired Earthquake Scenario
ForewordThe 1906 Great San Francisco earthquake (magnitude 7.8) and the 1989 Loma Prieta earthquake (magnitude 6.9) each motivated residents of the San Francisco Bay region to build countermeasures to earthquakes into the fabric of the region. Since Loma Prieta, bay-region communities, governments, and utilities have invested tens of billions of...Detweiler, Shane T.; Wein, Anne M.
Application and evaluation of a rapid response earthquake-triggered landslide model to the 25 April 2015 Mw 7.8 Gorkha earthquake, Nepal
The 25 April 2015 Mw 7.8 Gorkha earthquake produced strong ground motions across an approximately 250 km by 100 km swath in central Nepal. To assist disaster response activities, we modified an existing earthquake-triggered landslide model based on a Newmark sliding block analysis to estimate the extent and intensity of landsliding...Gallen, Sean F.; Clark, Marin K.; Godt, Jonathan W.; Roback, Kevin; Niemi, Nathan A
Evolution of strain localization in variable-width three-dimensional unsaturated laboratory-scale cut slopes
To experimentally validate a recently developed theory for predicting the stability of cut slopes under unsaturated conditions, the authors measured increasing strain localization in unsaturated slope cuts prior to abrupt failure. Cut slope width and moisture content were controlled and varied in a laboratory, and a sliding door that extended the...Morse, Michael S.; Lu, Ning; Wayllace, Alexandra; Godt, Jonathan W.
Designing a solution to enable agency-academic scientific collaboration for disasters
As large-scale environmental disasters become increasingly frequent and more severe globally, people and organizations that prepare for and respond to these crises need efficient and effective ways to integrate sound science into their decision making. Experience has shown that integrating nongovernmental scientific expertise into disaster...Mease, Lindley A.; Gibbs-Plessl, Theodora; Erickson, Ashley; Ludwig, Kristin A.; Reddy, Christopher M.; Lubchenco, Jane
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, Kristin A.; Bekins, Barbara; Brocher, Thomas M.; Brock, John C.; Brothers, Daniel; Chaytor, Jason D.; Frankel, Arthur; Geist, Eric L.; Haney, Matt; Hickman, Stephen H.; Leith, William S.; Roeloffs, Evelyn A.; Schulz, William H.; Sisson, Thomas W.; Wallace, Kristi; Watt, Janet; Wein, Anne M.
Reducing risk where tectonic plates collide
Most of the world’s earthquakes, tsunamis, landslides, and volcanic eruptions are caused by the continuous motions of the many tectonic plates that make up the Earth’s outer shell. The most powerful of these natural hazards occur in subduction zones, where two plates collide and one is thrust beneath another. The U.S. Geological Survey’s (USGS) “...Gomberg, Joan S.; Ludwig, Kristin A.
The HayWired Earthquake Scenario—Earthquake Hazards
The HayWired scenario is a hypothetical earthquake sequence that is being used to better understand hazards for the San Francisco Bay region during and after an earthquake of magnitude 7 on the Hayward Fault. The 2014 Working Group on California Earthquake Probabilities calculated that there is a 33-percent likelihood of a large (magnitude 6.7 or...Detweiler, Shane T.; Wein, Anne M.
Observations and a linear model of water level in an interconnected inlet-bay system
A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the...Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard
Inner-shelf ocean dynamics and seafloor morphologic changes during Hurricane Sandy
Hurricane Sandy was one of the most destructive hurricanes in US history, making landfall on the New Jersey coast on Oct 30, 2012. Storm impacts included several barrier island breaches, massive coastal erosion, and flooding. While changes to the subaerial landscape are relatively easily observed, storm-induced changes to the adjacent shoreface...Warner, John C.; Schwab, William C.; List, Jeffrey; Safak, Ilgar; Liste, Maria; Baldwin, Wayne E.
Evidence for coseismic subsidence events in a southern California coastal saltmarsh
Paleoenvironmental records from a southern California coastal saltmarsh reveal evidence for repeated late Holocene coseismic subsidence events. Field analysis of sediment gouge cores established discrete lithostratigraphic units extend across the wetland. Detailed sediment analyses reveal abrupt changes in lithology, percent total organic matter,...Leeper, Robert; Rhodes, Brady P.; Kirby, Matthew E.; Scharer, Katherine M.; Carlin, Joseph A.; Hemphill-Haley, Eileen; Avnaim-Katav, Simona; MacDonald, Glen M.; Starratt, Scott W.; Aranda, Angela
Development of a coupled wave-flow-vegetation interaction model
Emergent and submerged vegetation can significantly affect coastal hydrodynamics. However, most deterministic numerical models do not take into account their influence on currents, waves, and turbulence. In this paper, we describe the implementation of a wave-flow-vegetation module into a Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST)...Beudin, Alexis; Kalra, Tarandeep S.; Ganju, Neil K.; Warner, John C.
Lush thicket of staghorn coral in the Dry Tortugas National Park
Cover of The HayWired Earthquake Scenario—We Can Outsmart Disaster, USGS Fact Sheet 2018-3016
The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical magnitude-7.0 earthquake on the Hayward Fault. The fault is along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, because it runs through a densely urbanized and interconnected region.
Get Ready! Analyses...
USGS geomorphologist Pat Limber drives an all-terrain vehicle equipped with differential GPS, on Ellwood Beach in Goleta, California, collecting topographic, or elevation and contour, data. These data, accurate to about 1 inch (about 2 centimeters) both horizontally and vertically, are used to monitor seasonal beach changes.
USGS volunteer Josh Brown on Santa Claus Beach, Carpinteria, at the start of a 14-mile walking survey of southern California beaches. The differential GPS equipment carried in the backpack collects elevation, or topographic, data of the beach, accurate to about 1 inch (2 centimeters) both horizontally and vertically. Data are used to monitor seasonal beach changes and are incorporated into...
USGS geomorphologist Pat Limber drives an all-terrain vehicle equipped with differential GPS, on San Buenaventura Beach south of Ventura Pier, Ventura California, collects topographic, or elevation and contour, data. These data, accurate to about 1 inch (about 2 centimeters) both horizontally and vertically, are used to monitor seasonal beach changes.
Cave diving scientist David Brankovits from the USGS and Woods Hole Oceanographic Institution and DSO Jake Emmert (Moody Gardens) recover the OPP water sampling device designed and engineered by Emile Bergeron (USGS). The OPP collects samples across a chemical interface where bacteria entrain methane -- a dissolved gas -- into the food web. The OPP is powered by compressed gas and is able to...
Jackson Currie and Alex Snyder of the USGS Pacific Coastal and Marine Science Center drive personal watercraft (PWCs) offshore of San Ysidro and Oak Creeks, which let out onto Miramar Beach in Montecito, California. The equipment on the PWCs collects bathymetry, or depth, data which is used to map the nearshore. USGS has been mapping this area twice yearly—every spring and fall—since 2005. The...
Jackson Currie of the USGS Pacific Coastal and Marine Science Center drives a personal watercraft (PWC) offshore of Butterfly Beach in Montecito, California. The equipment on the PWC collects bathymetry, or depth, data which is used to map the nearshore. USGS has been mapping this area twice yearly—every spring and fall—since 2005. The data collected is incorporated into models of future...
USGS collaborates with key academic, state, local, and industry partners to provide a new look at what could happen during a major earthquake in the San Francisco Bay Area.
On Thursday, April 26, research geologist Curt Storlazzi of the USGS Pacific Coastal and Marine Science Center will give a public lecture on “The Role of U.S. Coral Reefs in Coastal Protection—Rigorously valuing flood reduction benefits to inform coastal zone management decisions.”
Documentary about sea-level rise threatening the Republic of the Marshall Islands features USGS findings
USGS research in the Republic of the Marshall Islands forms part of the scientific foundation of an interactive documentary released April 6 by PBS Frontline.
USGS oceanographer Dan Hoover explained how USGS coastal surveys are conducted and why they are important in a radio interview with NPR affiliate KCLU. KCLU was one of several outlets that reported on ...
Clarifying Latitude and Longitude for Planets besides Earth
Tracking the movement of sediment and contaminants from northern California wildfire areas to San Francisco Bay
USGS research geologist Renee Takesue of the Pacific Coastal and Marine Science Center collected 20 sediment samples from Sonoma Creek and Napa River north of San Francisco Bay on March 17.
In a newly published study, U.S. Geological Survey scientists and their partners calculate possible alert times that earthquake early warning systems can provide people at different levels of ground motion from light to very strong shaking.
During the week of March 26, scientists from the U.S. Geological Survey will begin four days of mapping selected beaches and the adjacent seafloor in Santa Barbara and Ventura counties. Results will be compared to surveys from last fall to highlight changes due to winter waves, and to sediment inputs from area streams.
Collecting clues to the geologic history and mineral resources of the Rio Grande Rise, southwest Atlantic Ocean
USGS scientists James Hein and Kira Mizell participated in a University of São Paulo research cruise to the western Rio Grande Rise, an underwater plateau in international waters of the Atlantic Ocean off Brazil.
Pacific Coastal and Marine Science Center researchers plan to survey selected beaches and parts of the shallow seafloor in Santa Barbara and Ventura counties from March 27-30.