Nicolas Luco

1.6 : American Samoa

Each of the downloadable files below contains spectral response accelerations at 22 periods on a grid of latitudes and longitudes that cover this geographic region. See the parent item for how Risk-Targeted Maximum Considered Earthquake (MCER) spectral response accelerations are derived from the data in these files.

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

2 of 2 : Maximum Considered Earthquake Geometric Mean Peak Ground Accelerations

For background, please see the Parent Item. The Maximum Considered Earthquake Geometric Mean (MCEG) peak ground acceleration (PGA) values of the 2009 NEHRP Recommended Seismic Provisions and the 2010 ASCE/SEI 7 Standard are calculated from the data in the downloadable files below, via the following equations: PGA = min[ PGAUH , max( PGAD84th , 0.6 ) ] for the 2009 NEHRP Recommended Seismic Provisions; PGA = min[ PGAUH , max( PGAD84th , 0.5 ) ] for the 2010 ASCE/SEI 7 Standard; where PGAUH = uniform-hazard peak ground acceleration; PGAD84th = 84th-percentile peak ground acceleration; and 0.6 or 0.5 = deterministic lower limit peak ground acceleration. These peak ground...

Categories: Data

It is well know that every earthquake can spawn others (e.g., as aftershocks), and that such triggered events can be large and damaging, as recently demonstrated by L’Aquila, Italy and Christchurch, New Zealand earthquakes. In spite of being an explicit USGS strategic-action priority (http://pubs.usgs.gov/of/2012/1088; page 32), the USGS currently lacks an automated system with which to forecast such events and official protocols for disseminating the potential implications. This capability, known as Operational Earthquake Forecasting (OEF), could provide valuable situational awareness to emergency managers, the public, and other entities interested in preparing for potentially damaging earthquakes. With the various...

Categories: Data, Project; Tags: Active, All Working Groups, California, Earthquakes, Natural Hazards

For designing buildings and other structures to safely resist earthquakes, the 2009 National Earthquake Hazards Reduction Program (NEHRP) Recommended Seismic Provisions and the 2010 American Society of Civil Engineers, Structural Engineering Institute (ASCE/SEI) 7 Standard contain maps of Risk-Targeted Maximum Considered Earthquake (MCER) spectral response accelerations, Maximum Considered Earthquake Geometric Mean (MCEG) peak ground accelerations, and long-period transition periods (TL). The MCER ground motions are also in the 2013 ASCE/SEI 41 Standard and the 2012 and 2015 editions of the International Building Code. The MCER, MCEG, and TL maps are derived from the U.S. Geological Survey (USGS) National Seismic...

Tags: USGS Science Data Catalog (SDC)

A comparison of the 2017 USGS South America seismic hazard model with the Global Seismic Hazard Assessment Program (GSHAP) model and the 2010 USGS preliminary model was made to see how the models differ. The comparisons were made as ratios of PGA at 10% probability of exceedance in 50 years. Ratio maps of each comparison are included as a geo-referenced tiff (GeoTIFF).

Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service