Modified Mercalli Intensity based on the average of horizontal spectral response acceleration for 1.0-second period and peak ground acceleration, with 1-percent probability of exceedance in 1 year
Description
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 2018. 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 in earthquake occurrence and diversity of opinion in the science community. Near some areas of active induced earthquakes, hazard is higher than in the 2014 USGS National Seismic Hazard Model (NSHM) by more than a factor of 3; the 2014 NSHM did not consider induced earthquakes. In some areas, previously observed induced earthquakes have stopped, so the seismic hazard reverts back to the 2014 NSHM.
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. It represents the average Modified Mercalli Intensity (MMI) with a 1-percent probability of exceedance in 1 year. 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 Western United States and are based on the long-term 2014 National Seismic Hazard Model.