Hazard curve data for the 2018 one-year seismic hazard forecast from induced and natural earthquakes

These data sets represent the hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. They represent the annual rate of exceedance versus peak horizontal acceleration or horizontal spectral response acceleration for 0.2- or 1.0-second periods.

Chance of potentially damaging ground shaking in 2018

These data sets are the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. They represent the chance of experiencing potentially damaging ground shaking for fixed ground shaking levels that corresponds with MMI = VI and MMI = VII. The values are obtained by averaging the probability of experiencing MMI VI or VII based on a peak ground acceleration, and the probability of experiencing MMI VI or VII based on 1.0-second spectral acceleration. The data are for the Central and Eastern United States, and the Western United States.

Modified Mercalli Intensity

These data sets represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. It represents the average Modified Mercalli Intensity (MMI) with a 1-percent probability of exceedance in 1 year. Using a topographic-based soil classification method, the ground motions are amplified for soil type. The MMI values are the average of the MMI values obtained by converting peak ground acceleration to MMI and 1.0-second spectral response acceleration to MMI. The data are for the Central and Eastern United States, and the Western United States.

Modeled and observed magnitude-frequency distribution, Oklahoma-Kansas potential induced earthquake catalog, 2016-2017

The b-value for the earthquake catalog from the Oklahoma-Kansas potentially induced earthquake zone is computed with the maximum likelihood method (MLE) (Aki, 1965). We use the minimum magnitude of completeness that is used for the seismicity rate models (Mc=2.7) and the earthquakes from 2016 and 2017 and find b=1.5 (1.48+/-0.05). However, we find that the b-value from the full (non-declustered) catalog is sensitive to the minimum magnitude of completeness, perhaps due to the moment magnitudes at these values being highly dependent on the conversion relations and the measurements of local magnitudes. Aki, K. (1965). Maximum likelihood estimate of b in the formula log N= a-bM and its confidence limits. Bull. Earthq....

Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile

Seismicity catalog used in the 2018 one-year seismic hazard forecast for the Central and Eastern United States from induced and natural earthquakes

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 source catalogs. Seismicity statistics are analyzed to develop recurrence models,...

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Probabilistic seismic hazard

Probabilistic seismic-hazard maps were prepared for the Central and Eastern United States, as well as the Western United States. These maps portray peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with a probability of exceedance of 1 percent in 1 year. This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude.

Supplemental hazard curve data

These hazard curves are based on the full seismicity catalog and a calculated b-value of 1.5. The full catalog hazard curves for the 2016 and 2017 one-year forecasts were not previously made available, so they are being made available here, along with the hazard curves for the 2018 one-year forecast. These data sets represents the hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. They represents the annual rate of exceedance versus peak horizontal acceleration or horizontal spectral response acceleration for 0.2- or 1.0-second periods.