Data Sources


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. Mitch Withers took the California stuff and made it work for the Central and Southeast U.S. 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.