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California-Nevada Earthquakes

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Recent Earthquakes - Credits and Disclaimer


The data displayed on these recent earthquakes pages are preliminary. They are largely computer generated and may not have received human review or official approval. Inaccuracies in the data may be present because of instrument or computer malfunctions. Subsequent review may result in significant revisions to the data. Data users are cautioned to consider carefully the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences.


People - Northern California Seismic Net - USGS

The web pages you are viewing are the end result of the efforts of many individuals. At the USGS in Menlo Park, California, the process begins with the installation and operation of seismometers and associated telecommunications equipment throughout the state. The following individuals designed, installed and continue to maintain these instruments: Jerry Eaton, John VanSchaack, Wes Hall, Grey Jensen, Dave Reneau, Dave Croker, John Kempe, John McClearn, Gonzalo Mendoza, Tom Burdette, Don Farrell, Sam Rodriguez, Daisy Hom, Don Ritchey, Fred Fischer, Bob Somera, and Lester Sutherland.

The computer systems that detect the occurrence of earthquakes, locate their hypocenters, estimate their magnitude, and compute their focal mechanisms were developed by Rex Allen, Jim Ellis, Alex Bittenbinder, Barbara Bogaert, Lynn Dietz, Will Kohler, Carl Johnson, Bill Ellsworth, David Oppenheimer, Paul Reasenberg, Al Lindh, and Fred Klein. The alarm software that notifies the seismologists by pager, creates the maps, archives the earthquake data, and issues e-mail about earthquakes was written by Bruce Julian and Andy Michael. The computers are maintained by Greg Allen.

The seismologists who are on-call 24 hours/day to review the data from significant events are Rick Lester, Fred Klein, Steve Walter, Jim Luetgert, and David Oppenheimer.

People - Northern California Seismic Net - UC Berkeley

At the Berkeley Seismological Laboratory, many people contribute to the earthquake monitoring program. Rich Clymer, John Friday, Marvin Hilger, Bill Karavas, David Rapkin, and Russel Sell have been responsible for the design, installation, and maintenance of the Berkeley Digital Seismic Network. The software that handles the data acquisition and processes earthquakes for the determination of location, magnitude, and seismic moment tensors was developed by Doug Dreger, Joe Durek, Steve Fulton, Lind Gee, Tom McEvilly, Doug Neuhauser, Mike Pasyanos, Barbara Romanowicz, and Bob Uhrhammer.

Additional data analysis and data archiving are performed by Rick McKenzie and Doug Neuhauser. The computer systems are maintained by Doug Neuhauser and Charley Paffenbarger. Maintenance of web pages is performed by Lind Gee and Doug Neuhauser.

Seismologists who are on-call 24 hours/day to review data and ensure the smooth operation of the earthquake monitoring system are Mike Antolik, Ludovic Breger, Joe Durek, Steve Fulton, Lind Gee, Peg Johnson, John Lynch, Charles Megnin, Doug Neuhauser, Charley Paffenbarger, and Paul Parker.

People - Southern California Seismic Network - USGS & Caltech

(A cooperative project of the U.S.Geological Survey & the Seismological Laboratory at Caltech).

At the SCSN in Pasadena, California the detection and processing of earthquake data presented in these Web pages involves the following individuals. Wayne Miller, Dave Johnson, Chuck Koesterer, Gary Cone, Bob Taylor, Bob Cone, Scott Lydeen, Alberto Devora, Mike Watkins, Carl McCaughey, and Bill Curtis are responsible for the design, installation, and maintenance of seismometers in Southern California. The software that detects the occurrence of earthquakes,and determines preliminary hypocenters and estimates of magnitude was developed by Bob Dollar, Doug Given, Allan Walter, Phil Maechling, Hiroo Kanamori, Sam Stewart, Peter Johnson, Carl Johnson, and Jim Mori. The alarm software that notifies the seismologists by pager, and issues e-mail about earthquakes was written by Doug Given, Steve Bryant, and Phil Maechling. The computers are maintained by Stan Schwarz, Katrin Hafner, and Phil Maechling and Bob Dollar.

Operation of data processing systems and further data analyses are done by Kate Hutton, Bob Dollar, Nick Scheckel, Karen Kahler, Joe Franck, Paul Roberts, and Mandy Johnson. Maintenance of web pages and data archiving are done by Lisa Wald, Katrin Hafner, John Marquis, and Karen Kahler.

The seismologists who rotate call duty are on-call 24 hours/day to review the data from significant events. They are Egill Hauksson, Kate Hutton, Lucy Jones, Bob Dollar, Doug Given, and Nick Scheckel.


California highways were extracted and compiled by volunteer Kirstin Mortensen and Carl Mortensen. Nevada placenames were supplied by Ken Smith and David Vonseggern at UNR, Nevada roads by Robert Miller at USGS.

Faults for the index map were provided by Art Frankel and Jim Lienkaemper. Faults on the zoomed-in maps came from C.W. Jennings, 1992, California Division of Mines and Geology Open-File Report 92-03. (This map has been superseded by Jennings, C.W., 1994, Fault activity map of California and adjacent areas, with locations and ages of recent volcanic eruptions: California Division of Mines and Geology, Geologic Data Map No. 6, map scale 1:750,000.)

Andy Michael wrote the programs to prepare the earthquake data. Doug Neuhauser and Steve Malone assisted with advice and examples in the construction of the catalog merging software. Bob Simpson - with lots of help and suggestions from Bill Ellsworth, Dave Oppenheimer, and Andy Michael - designed the base maps, links, and programs that update the web pages. Jim Luetgert designed and programmed the waveforms pages for northern California. In addition Carl Mortensen, Steve Malone, Lind Gee, Lucy Jones, Stan Silverman, Paul Reasenberg, sharp-eyed Lynn Dietz and many others offered valuable ideas and suggestions.

The appearance of these pages was greatly improved with help and suggestions from Sara Boore. (She bears no responsibility for the remaining defects!) Paul Reasenberg helped select colors that would be distinguishable by color-blind viewers. Barbara Simpson offered advice on colors, and suggested ways to make the earthquake lists more readable.


Maps are updated using the subroutine library gd written by Thomas Boutell, and the gd interpreter tgd written by Bradley K. Sherman. Program XV by John Bradley and xpaint by David Koblas were used extensively in the preparation of the basemaps. Many thanks to these gentlemen for their nifty programs!

The earthquake location data, seismologist comments, and additional information (e.g., seismogram images and mechanisms) are distributed among various operators of the recenteqs software using a program called QDDS written by Stephen Jacob and Alan Jones.

A single, authoritative catalog of earthquake locations is generated from all of the various conflicting reports about an earthquake contributed by different seismic networks using a program called CNSSmerge written by Andy Michael and re-written in Java by Alan Jones.