Category: "Earthquake Locations"
Starting 2015/10/07, the Northern California Seismic System (NCSS) is reporting earthquake depths relative to the earth geoid surface (which is approximately mean sea level) instead of the previously used surface of the velocity model used to locate the… more »
What is Geoid depth? The depth of an earthquake location can be reported relative to the mathematical geoid surface within the earth, which is very close to sea level. In simplified terms, the geoid is an imaginary surface within the earth… more »
June 2nd, 2014 The NCEDC is pleased to announce the availability of double difference (DD) hypocenter solutions from 1984 to the present for earthquakes recorded by the Northern California Seismic System (NCSS). The NCSS catalog can be searched via… more »
The Northern California Seismic System (NCSS), operated by the US Geological Survey in Menlo Park and UC Berkeley Seismological Laboratory, locates ~20,000 earthquakes per year in the Geysers geothermal region (Figure 1). Since 2007/07/23, when data… more »
October 16th, 2006 The NCEDC is pleased to announce the availability of seismic phase and waveform data from the Pacific Gas and Electric seismic network that monitors seismicity in the vicinity of the Diablo Canyon nuclear powerplant. The phase data,… more »