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The U. S. Geological Survey (USGS) makes long-term seismic hazard forecasts that are used in building codes. The hazard models usually consider only natural seismicity; non-tectonic (man-made) earthquakes are excluded because they are transitory or too small. In the past decade, however, thousands of earthquakes related to underground fluid injection have occurred in the central and eastern U.S. (CEUS), and some have caused damage. In response, the USGS is now also making short-term forecasts that account for the hazard from these induced earthquakes. A uniform earthquake catalog is assembled by combining and winnowing pre-existing, authoritative source catalogs. Seismicity statistics are analyzed to develop recurrence...
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Earthquake instability occurs as a result of strength loss during sliding on a fault. It has been known for over 50 years that fault compaction or dilatancy may cause significant weakening or strengthening by dramatically changing the fluid pressure trapped in faults. Despite this fundamental importance, we have no real understanding of the exact conditions that lead to compaction or dilation during nucleation or rupture. To date, no direct measurements of pore pressure changes during slip in hydraulically isolated faults have been reported. We show direct examples of fluid pressure variations during nucleation and rupture using a miniature pressure transducer embedded in an experimental fault. We demonstrate that...
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A comparison of the 2017 USGS South America seismic hazard model and the 2010 USGS preliminary model was made to see how the models differ. The comparison was made as the ratio of PGA at 10% probability of exceedance in 50 years. The ratio map is included here as a geo-referenced tiff (GeoTIFF). The gridded data for the 2017 PGA at 10% probability can be found here, while the gridded data for the 2010 PGA at 10% probability can be found in the zip archive that can be downloaded using a link on this page.
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Maximum considered earthquake geometric mean peak ground acceleration maps (MCEG) are for assessment of the potential for liquefaction and soil strength loss, as well as for determination of lateral earth pressures in the design of basement and retaining walls. The maps are derived from the USGS seismic hazard maps in accordance with the site-specific ground-motion procedures of the NEHRP Recommended Seismic Provisions for New Building and Other Structures and the ASCE Minimum Design Loads for Buildings and Other Structures (also known as the ASCE 7 Standard; ASCE, 2016). The MCEG ground motions are taken as the lesser of probabilistic and deterministic values, as explained in the Provisions. The gridded probabilistic...
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A comparison of the 2017 USGS South America seismic hazard model and the Global Seismic Hazard Assessment Program (GSHAP) model was made to see how the models differ. The comparison was made as the ratio of PGA at 10% probability of exceedance in 50 years. The ratio map is included here as a geo-referenced tiff (GeoTIFF). The gridded data for the 2017 PGA at 10% probability can be found here, while the GSHAP data can be found here. Shedlock, K.M., Giardini, Domenico, Grünthal, Gottfried, and Zhang, Peizhan, 2000, The GSHAP Global Seismic Hazar Map, Sesimological Research Letters, 71, 679-686. https://doi.org/10.1785/gssrl.71.6.679
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On April 25, 2015, a large ( M7.8) earthquake shook much of central Nepal and was followed by a series of M>6 aftershocks, including a M7.3 event on May 12, 2015. This earthquake and aftershocks, referred to as the Gorkha earthquake sequence, caused thousands of fatalities, damaged and destroyed entire villages, and displaced millions of residents. The earthquakes also triggered thousands of landslides in the exceedingly steep topography of Nepal; these landslides were responsible for hundreds of fatalities, and blocked vital roads and trails to affected villages. With the support of the United States Agency for International Development (USAID), Office of Foreign Disaster Assistance (OFDA), and in collaboration...
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On April 25, 2015, a large ( M7.8) earthquake shook much of central Nepal and was followed by a series of M>6 aftershocks, including a M7.3 event on May 12, 2015. This earthquake and aftershocks, referred to as the Gorkha earthquake sequence, caused thousands of fatalities, damaged and destroyed entire villages, and displaced millions of residents. The earthquakes also triggered thousands of landslides in the exceedingly steep topography of Nepal; these landslides were responsible for hundreds of fatalities, and blocked vital roads and trails to affected villages. With the support of the United States Agency for International Development (USAID), Office of Foreign Disaster Assistance (OFDA), and in collaboration...
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On April 25, 2015, a large ( M7.8) earthquake shook much of central Nepal and was followed by a series of M>6 aftershocks, including a M7.3 event on May 12, 2015. This earthquake and aftershocks, referred to as the Gorkha earthquake sequence, caused thousands of fatalities, damaged and destroyed entire villages, and displaced millions of residents. The earthquakes also triggered thousands of landslides in the exceedingly steep topography of Nepal; these landslides were responsible for hundreds of fatalities, and blocked vital roads and trails to affected villages. With the support of the United States Agency for International Development (USAID), Office of Foreign Disaster Assistance (OFDA), and in collaboration...
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Output from the 2021 National Seismic Hazard Model for Hawaii includes probabilistic seismic hazard curves calculated for a 0.02° x 0.02° grid of latitude/longitude locations across Hawaii. The new model provides an expanded suite of hazard curves for twenty-three different ground motion intensity measures, including PGA, PGV, and spectral accelerations for 0.01, 0.02, 0.03, 0.05, 0.075, 0.1, 0.15, 0.2, 0.25, 0.3, 0.4, 0.5, 0.75, 1, 1.5, 2, 3, 4, 5, 7.5 and 10 second, and eight separate soil site classes (VS30 = 1500, 1080, 760, 530, 365, 260, 185, and 150 m/sec), representing NEHRP site classes A/B, B, B/C, C, C/D, D, D/E, and E. This data set represents the hazard curves for a grid of points with a spacing...
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This inventory was originally created by Tanyas and others (2022) describing the landslides triggered by the M 7.5 Papua New Guinea earthquake that occurred on 25 February 2018 at 17:44:44 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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This inventory was originally created by Xu and others (2014) describing the landslides triggered by the M 7.9 Wenchuan, China earthquake that occurred on 12 May 2008 at 06:28:01 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 Survey...
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This inventory was originally created by the Ministerio de Medio Ambiente y Recursos Naturales, El Salvador (2001) describing the landslides triggered by the M 6.6 San Salvador, El Salvador earthquake that occurred on 13 February 2001 at 14:22:05 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...
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This inventory describes the landslides triggered by the the M6.2 Norcia, Italy earthquake that occurred on 2016-08-24 at 01:36:32 UTC. The inventory comes from the Italian Catalogue of Earthquake-Induced Ground Effects (Italian acronym CEDIT) by Martino and others (2014), which contains inventories from multiple earthquakes. To obtain the most up to date version of the entire, original catalog along with more details about its compilation, please visit the CEDIT webpage on the website of the Centre for Research (CERI) of the Department of Earth Sciences in the Sapienza University of Rome: http://www.ceri.uniroma1.it/index.php/web-gis/cedit/. Care should be taken when comparing with other inventories because different...
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This inventory was originally reated by Sekiguchi and Sato (2006) describing the landslides triggered by a sequence of earthquakes, with the largest being the M 6.6 Niigata-Chuetsu, Japan earthquake that occurred on 23 October 2004 at 08:56:00 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory includes landslides triggered by a sequence of earthquakes rather than a single mainshock. 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...
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These data are from a 3-month long deployment of nodal seismometers that ran from May 18th, 2022 until September 1st, 2022 as part of a Distributed Acoustic Sensing (DAS) experiment above the Gorda plate (McGuire, et al., 2022). The sensors were deployed at 44 locations along Old Arcata Rd between Arcata and Eureka California (Figure 1); these locations track the approximate location of the fiber optic cable used as part of the DAS experiment. The instruments have a battery recording life of approximately one month and were swapped out in the same locations in Mid-June, and Mid-July. Thus, there are 132 instruments that were deployed at 44 distinct locations.
Earthquake-triggered ground-failure, such as landsliding and liquefaction, can contribute significantly to losses, but our current ability to accurately include them in earthquake hazard analyses is limited. The development of robust and transportable models requires access to numerous inventories of ground failure triggered by earthquakes that span a broad range of terrains, shaking characteristics, and climates. We present an openly accessible, centralized earthquake-triggered ground-failure inventory repository in the form of a ScienceBase Community to provide open access to these data, and help accelerate progress. The Community hosts digital inventories created by both USGS and non-USGS authors. We present...
A seismic hazard model for South America, based on a smoothed (gridded) seismicity model, a subduction model, a crustal fault model, and a ground motion model, has been produced by the U.S. Geological Survey. These models are combined to account for ground shaking from earthquakes on known faults as well as earthquakes on un-modeled faults. This data set represents the hazard curves for a grid of points with a spacing of 0.1 degrees in latitude and longitude. It represents the annual rate of exceedance versus 0.2-second spectral response acceleration.
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Potential tsunami hazard for the Umnak Island community of Nikolski is evaluated by numerically modeling the extent of inundation from tsunami waves generated by hypothetical earthquake sources. Worst-case hypothetical scenarios are defined by analyzing results of a sensitivity study of the tsunami dynamics related to various slip distributions along the Aleutian megathrust. The worst-case scenarios for Nikolski are thought to be thrust earthquakes in the Umnak Island region with their greatest slip at 10-30 km (6.2-19 mi) depth. We also consider Tohoku-type ruptures and an outer-rise rupture in the area of Umnak Island. The maximum predicted water depth on Main Street is about 15 m (49 ft), while the maximum current...
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A one-year seismic hazard forecast for the Central and Eastern United States, based on induced and natural earthquakes, has been produced by the U.S. Geological Survey. The model assumes that earthquake rates calculated from several different time windows will remain relatively stationary and can be used to forecast earthquake hazard and damage intensity for the year 2016. This assessment is the first step in developing an operational earthquake forecast for the CEUS, and the analysis could be revised with updated seismicity and model parameters. Consensus input models consider alternative earthquake catalog durations, smoothing parameters, maximum magnitudes, and ground motion estimates, and represent uncertainties...


map background search result map search result map Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_05282015-I Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_05292015-D Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_06012015-B Chance of damage from an earthquake in 2016 based on horizontal spectral response acceleration for 1.0-second period for the Western United States Xu and others (2014) Sekiguchi and Sato (2006) Ministerio de Medio Ambiente y Recursos Naturales, El Salvador (2001) Comparison with the 2010 USGS preliminary model Comparison with the 1999 Global Seismic Hazard Assessment (GSHAP) model Tsunami inundation map for the village of Nikolski, Alaska Martino and others (2016) - M6.2 Norcia, Italy, 2016 Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults 01. Hazard curves Tanyas and others (2022) Spring 2022 Arcata to Eureka, California, Distributed Acoustic Sensing (DAS) experiment: Nodal Seismometer data Data from the manuscript: Direct evidence for fluid pressure, dilatancy, and compaction affecting slip in isolated faults Tsunami inundation map for the village of Nikolski, Alaska Sekiguchi and Sato (2006) Martino and others (2016) - M6.2 Norcia, Italy, 2016 Tanyas and others (2022) Spring 2022 Arcata to Eureka, California, Distributed Acoustic Sensing (DAS) experiment: Nodal Seismometer data Xu and others (2014) 01. Hazard curves Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_05282015-I Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_05292015-D Video data files to accompany USGS OFR 2015-1142--Assessment of existing and potential landslide hazards resulting from the April 25, 2015 Gorkha, Nepal earthquake sequence:  USGS_Nepal_06012015-B Chance of damage from an earthquake in 2016 based on horizontal spectral response acceleration for 1.0-second period for the Western United States Comparison with the 2010 USGS preliminary model Comparison with the 1999 Global Seismic Hazard Assessment (GSHAP) model