LOMA PRIETA
EARTHQUAKE
October 17, 1989
Magnitude: 7.1 on the Richter Scale
Epicenter: Santa Cruz Mountains, CA
0.64 G Force (near epicenter)
Focal Depth was 11 miles (18 km)
Kirsten Anderberg/The Loma Prieta Earthquake: October 17, 1989
Diary of a Catastrophic Earthquake
A chimney on a Santa Cruz lawn, immediately after the Loma Prieta Earthquake (Photo: K. Anderberg 1989)
WATCH FOR KIRSTEN'S NEW BOOK ABOUT THE LOMA PRIETA QUAKE DUE OUT IN FEB. 2012
At 5:04 pm, on October 17, 1989, I had just come from college classes, and was on my way to pick up my 5 year old son from his after school childcare. I decided to drop by
the local library to pick up a few books to read to my son, and as I stood in the library, I began to hear an odd noise. It sounded like a plane was going to crash into the
building. Then I thought maybe it was a train heading for the building, but then realized there were no tracks going *into* the library building. Everyone around me appeared
to stop moving, as they listened. Then I noticed little puffs of dust coming out from in between the bricks of the library walls. Then, it hit. The floor began to shift
dramatically, and I assumed it was an earthquake, and ran for the door. (The sounds I heard first were the P waves, which travel at speeds of about 3.1-3.7 miles per second
through average earth crust, whereas the S waves that accompany quakes travel slower at about 2.0 miles per second. Thus when the quake hit, I heard the P waves *first* as they travelled
faster from the epicenter than the S waves. How close you are to the epicenter also effects when the P and S waves hit you. People in San Francisco, which was 70 miles north
of the epicenter in Santa Cruz, felt the quake approximately 23 seconds later than people in Santa Cruz felt it, and Sacramento (100 miles from the epicenter) felt it about
22 seconds after San Francisco felt it.) More of this story is in my new book and I will post a link to it as soon as it is up and published in Feb. 2012.
Kirsten Anderberg. All rights reserved. For permission to reprint/publish, please contact Kirsten at kirstena@resist.ca.