Download the Double-Difference Catalogs

Download the 1984-2011 double-difference base catalog, the 2012-present double-difference real-time catalog or create a custom slice of either catalog using the form below.

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This website displays automatic near-real-time double-difference (DD-RT) hypocenter locations for earthquakes recorded in northern California and routinely processed at the Northern California Seismic Network (NCSN). more...The DD-RT process relocates new earthquakes relative to a high-resolution DD catalog of background seismicity, NCAeqDD, by using differential times between the new event and its neighboring (reference) events in the DD catalog. Routinely determined parametric data of new events, such as phase picks and hypocentral information, are automatically sent to LDEO by the NCSN and waveforms are accessed from the real-time DART server at the Northern California Earthquake Data Center (NCEDC) in Berkeley. Data associated with the reference events are accessed from a locally stored copy of the entire Northern CA seismic archive. See Waldhauser (BSSA, 2009) for more information.