ABSTRACT
In 1850 Philip Thomas Tyson observed that earthquakes of great energy must have occurred in very recent geological periods in the Coast Range of California. A few years later, in 1856, Dr. John Boardman Trask, San Francisco physician, California’s first unofficial state geologist, and a founder of the California Academy of Natural Sciences, began to compile data on California quakes. His first contribution to seismology was a summary paper on California earthquakes from 1812 to 1855, which was followed by annual compilations on earthquake activity through 1865. Trask’s papers were read at meetings of the California Academy of Natural Sciences and were published in the Proceedings of the Academy. Trask made a determination of the probable direction of motion and velocity of several earthquakes by the imaginative use of the telegraph and other means of communication. After 1866 Trask pursued other interests, and the Academy’s concern for earthquakes waned. In the 1880s the center for earthquake studies shifted to the University of California at Berkeley. Edward Singleton Holden, President of the University, in 1887 published the first comprehensive catalog of California earthquakes, and subsequently revived the annual compilations. More importantly, in the same year, Holden established at the University the first seismographic stations in the Western Hemisphere, one at Berkeley, and one at the University’s new Lick Observatory on Mount Hamilton, near San Jose. Although this marks the beginning of the modern period of California earthquake studies, it was the disastrous San Francisco earthquake of April, 1906 that rattled the complacent public and scientific communities alike and launched a new era of seismology.
