The are among the most costly of all natural disasters - in terms of both dollars and in human lives. Whenever the ground shakes, so do people's nerves. Phones ring, emergency services are activated, and the radio comes alive with traffic. Communication lines become jammed as people report damage, call for help, or try to contact their family and friends. The effects are stimulating to some, devastating to others.
Most people dread earthquakes.
It's an opportunity to examine data, search for correlations, and test theories, ultimately with the hope of learning how to predict when and where an earthquake will occur. At the Western Region Headquarters for the USGS in Menlo Park, California, data is collected from more than 500 different recording locations. It is made up of sensors, telemetry links, and analog and digital recording devices. Data is collected from several different types of sensors that measure different motions or, that are especially responsive to specific frequencies of waves. Much of the data arrives at the Menlo Park center by VHF, UHF and microwave radio links.