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This inventory was originally created by Garcia-Delgado and others (2019) describing the landslides triggered by the M 5.7 Mesetas, Columbia earthquake that occurred on 24 December 2019 at 19:19:03 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory also could be associated with other earthquakes such as aftershocks or triggered events. Please check the author methods summary and the original data source for more information on these details and to confirm the viability of this inventory for your specific use. With the exception of the data from USGS sources, the inventory data and associated metadata were not acquired by the...
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The USGS Geomagnetism Program operates a network of magnetic observatories that collect vector and scalar magnetometer data for use in Earth main-field modeling, geophysics research, space physics research, and space weather hazard assessment and mitigation. Until mid-2011, only 1-minute time resolution magnetic field measurements were archived with the INTERMAGNET consortium following international magnetic observatory standards. 1-second time resolution magnetic field measurements, which had already been collected by all the USGS observatories for up to almost a decade prior, started being archived with INTERMAGNET on June 13, 2011, or July 27, 2012 in the case of the more recently constructed Deadhorse (DED)...
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Hurricane Maria brought intense rainfall and caused widespread landsliding throughout Puerto Rico during September 2017. Previous detailed landslide inventories following the hurricane include Bessette-Kirton et al. (2017, 2019). Here we continue that work with an in-depth look at two areas in San Lorenzo, which is a municipality in the east-central part of the main island. To study a characteristic sample of landslides in San Lorenzo, we mapped all visible landslides in two physiographically diverse areas, but all within the San Lorenzo Formation. We used aerial imagery collected between 9-15 October 2017 (Quantum Spatial, Inc., 2017) to map landslide source and runout areas, and 1-m-resolution pre-event and post-event...
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Chalk Cliffs, located 8 miles southwest of Buena Vista, Colorado, is one of the most active debris-flow areas in the state (U.S. Geological Survey). This "Child item" page includes videos of debris flows captured by one of the high-definition cameras at the monitoring site in Chalk Cliffs, CO. This camera (Wide-angle Camera) is located on the opposite side of the basin from Station 1 and has a broad view of the channel. The attached figure "station_and_camera_locations.png" provides an overview figure with the location of the four cameras and three stations along the channel. Video recording for all cameras is triggered using a rainfall threshold (Michel et al., 2019). The complete videos for all the cameras are...
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Earthquake stress drop is a critical parameter for estimating seismic hazard. This parameter can have a strong effect on ground motion amplitudes above ~1Hz and is especially important in Oklahoma and Kansas where earthquake rates have increased sharply since 2008. We estimate stress drops for 1121 earthquakes greater than ~M3 in and near the conterminous United States using spectral ratios between collocated events at given stations. We find that the average stress drop for the few eastern United States (EUS, 26–340 Bars) tectonic main shocks studied, which tend to be deeper thrusting events with few foreshocks and aftershocks, is about three times greater than tectonic main shocks in the western United States...
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Memphis has a dense urban population near faults capable of producing major earthquakes. A high probability of a moderate earthquake in the near future (e.g., a 25-40% probability of a magnitude 6.0 or greater in the next 50 years) from the New Madrid seismic zone, and relatively low regional attenuation (in other words, seismic waves do damage over a greater area in this region than for the same magnitude earthquake in the west) necessitates being prepared for earthquake hazards. This dataset provides maps of probabilistic and deterministic earthquake ground motions and liquefaction hazard for the Memphis area. Deterministic ground motion maps show different types of motions for a single specific hypothetical earthquake...
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Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model. Probabilistic seismic hazard data and maps are available for peak ground acceleration (PGA) and 0.2, 0.3, and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years and 10 percent in 50 years, assuming firm rock soil conditions at 760 m/s. Development of the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model is documented at https://doi.org/10.1193/1.3277667 and https://pubs.usgs.gov/of/2003/ofr-03-379/ofr-03-379.html. This dataset is considered a legacy dataset. The original dataset was uploaded...
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Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2007 Afghanistan Seismic Hazard Model. Probabilistic seismic hazard data and maps of Afghanistan for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404), 5 percent in 50 years (annual probability of 0.001026), and 10 percent in 50 years (annual probability of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 2007 Afghanistan Seismic Hazard Model is documented in the USGS Open-File Report 2007-1137 (https://pubs.usgs.gov/of/2007/1137/index.html). This...
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Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model. Probabilistic seismic hazard data and maps of Guam and the Northern Mariana Islands for peak ground acceleration (PGA) and 0.2 and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404) and 10 percent in 50 years (annual probability of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 2012 Guam and Northern Mariana Islands Seismic Hazard Model is documented in the USGS Open-File Report 2012-1015 (https://pubs.usgs.gov/of/2012/1015/)....
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This inventory was originally created by Okuyama and others (2013) describing the landslides triggered by the M 9.1 Tohoku-Oki, Japan earthquake that occurred on 2011-03-11 at 05:46:24 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory also could be associated with other earthquakes such as aftershocks or triggered events. Please check the author methods summary and the original data source for more information on these details and to confirm the viability of this inventory for your specific use. With the exception of the data from USGS sources, the inventory data and associated metadata were not acquired by the U.S. Geological...
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Steep glacial and paraglacial landscapes often exhibit evidence of gravitationally-driven slope deformation. In recently deglaciated coastal environments, catastrophic failures of these bedrock instabilities as rapid landslides have the potential to generate tsunamis that may pose hazards for communities, infrastructure, mariners, and important natural and cultural resources. We present a first inventory of manually mapped bedrock instabilities in western Prince William Sound and nearby locations in the Chugach Mountains. Slope instabilities included in this inventory are defined as large areas (> 0.01 km2) that exhibit evidence of slope deformation, including scarps, tension cracks, and signs of recent smaller-scale...
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On January 15, 1997, a landslide of approximately 100,000-m3 from a coastal bluff swept five cars of a freight train into Puget Sound at Woodway, Washington, USA, 25 km north of downtown Seattle. The landslide resulted from failure of a sequence of dense sands and hard silts of glacial and non-glacial origin, including hard, jointed clayey silt that rarely fails in natural slopes. Joints controlled ground-water seepage through the silt and break-up of the landslide mass. During September of 1997, the U.S. Geological Survey began measuring rainfall, ground-water pressures, and ground movement at the bluff where the landslide occurred. The original sensor array comprised a tipping-bucket rain gauge, four extensometers...
The significant rise in seismicity rates in Oklahoma and Kansas (OK–KS) in the last decade has led to an increased interest in studying induced earthquakes. Although additional instruments have been deployed in the region, there are still relatively few recordings at the distances (<20 km) and magnitudes (M4+) most relevant to earthquake hazard. In contrast, the USGS Did You Feel It? (DYFI) system has collected more than 200,000 observations during this period with 22,000+ observations at distances less than 20 km. This dataset has already been used to study the unique characteristics of induced earthquakes, to evaluate the extent of felt area, shaking, and damage, to compare intensity and ground motion metrics,...
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Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interface of subduction zones host our largest earthquakes, and are the only faults capable of M9+ ruptures. Despite these facts, our knowledge of subduction zone geometry - which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes - is incomplete. Here we calculate the three- dimensional geometries of all active global subduction zones. The resulting model - Slab2 - provides for the first time a comprehensive geometrical analysis of all known slabs in unprecedented detail.
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Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interface of subduction zones host our largest earthquakes, and are the only faults capable of M9+ ruptures. Despite these facts, our knowledge of subduction zone geometry - which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes - is incomplete. Here we calculate the three- dimensional geometries of all active global subduction zones. The resulting model - Slab2 - provides for the first time a comprehensive geometrical analysis of all known slabs in unprecedented detail.
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The USGS is offering earthquake alerts via two twitter accounts: @USGSted and @USGSBigQuakes. On average, @USGSted and @USGSBigQuakes will produce about one tweet per day, however, aftershocks following major earthquakes can greatly increase this number. Users interested in custom alerts based on specific geographic regions and magnitude thresholds should sign up for e-mail alerts distributed by our Earthquake Notification Service (ENS).
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The ANSS Comprehensive Catalog (ComCat) contains earthquake source parameters and other products produced by contributing seismic networks. Important digital catalogs of earthquake source parameters (e.g. Centennial Catalog, Global Centroid Moment Tensor Catalog) are loaded into ComCat. New and updated data are added to the catalog dynamically as sources publish or update products. Access to the ComCat is via the online search page, on which a user can select a wide variety of criteria to locate earthquake events of interest. Source Parameters: -amplitude - hypocenter - magnitude - phase data - finite fault - focal mechanism - moment tensor - tectonic summary - regional information Products: - Did You Feel It? -...
A revised version of the storm-time disturbance index Dst is calculated using hourly-mean magnetic-observatory data from four standard observatories and collected over the years 1958–2007. The calculation algorithm is a revision of that established by Sugiura et al., and which is now used by the Kyoto World Data Center for routine production of Dst. The most important new development is for the removal of solar-quiet variation. This is done through time and frequency-domain band-stop filtering – selectively removing specific Fourier terms approximating stationary periodic variation driven by the Earth’s rotation, the Moon’s orbit, the Earth’s orbit around the Sun, and their mutual coupling. The resulting non-stationary...
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The USGS collaborates with organizations (such as the Building Seismic Safety Council) that develop model building and bridge design codes to make seismic design parameter values available to engineers. The design code developers first decide how USGS earthquake hazard information should be applied in design practice. Then the USGS calculates gridded values of seismic design parameters based on USGS hazard values in accordance with design code procedures. The U.S. Seismic Design Maps application provides seismic design parameter values from the following design code editions: 2013 ASCE/SEI 41, 2012/09/06 International Building Code, 2010/05 ASCE/SEI 7 Standard, 2009/03 NEHRP Recommended Seismic Provisions, 2009...
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This tool is used to calculate risk-targeted ground motion values from probabilistic seismic hazard curves in accordance with the site-specific ground motion procedures defined in “Method 2” of 2010 ASCE 7 Standard Section 21.2.1.2.


map background search result map search result map Influence of Lithostatic Stress on Earthquake Stress Drops in North America Slab2 - A Comprehensive Subduction Zone Geometry Model, Cascadia Region Slab2 - A Comprehensive Subduction Zone Geometry Model, New Guinea Region Data Release for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model Data Release for the 2007 Afghanistan Seismic Hazard Model Data Release for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model Debris Flow Video Files for Wide Angle Camera (Station 1), Chalk Cliffs, Colorado, USA, 2017 Garcia-Delgado and others (2021) Okuyama and others (2013) One-second USGS Boulder (BOU) magnetic observatory data collected before 2013 Map data from landslides triggered by Hurricane Maria in select areas of San Lorenzo, Puerto Rico Memphis Urban Seismic Hazard Maps, v2008 Inventory of Large Slope Instabilities, Prince William Sound, Alaska Debris Flow Video Files for Wide Angle Camera (Station 1), Chalk Cliffs, Colorado, USA, 2017 One-second USGS Boulder (BOU) magnetic observatory data collected before 2013 Map data from landslides triggered by Hurricane Maria in select areas of San Lorenzo, Puerto Rico Memphis Urban Seismic Hazard Maps, v2008 Okuyama and others (2013) Garcia-Delgado and others (2021) Inventory of Large Slope Instabilities, Prince William Sound, Alaska Data Release for the 2003 Puerto Rico and U.S. Virgin Islands Seismic Hazard Model Data Release for the 2012 Guam and Northern Mariana Islands Seismic Hazard Model Slab2 - A Comprehensive Subduction Zone Geometry Model, Cascadia Region Slab2 - A Comprehensive Subduction Zone Geometry Model, New Guinea Region Data Release for the 2007 Afghanistan Seismic Hazard Model Influence of Lithostatic Stress on Earthquake Stress Drops in North America