Printer Friendly

The quaking ionosphere.

On April 12, 1978, something strange happened to the ionosphere above Chatanika, Alaska. Scientists routinely monitoring the flow of ionospheric particles detected very large verticle oscillations corresponding at times to ion velocities of up to 100 meters per second. Normally, ionospheric winds travel almost exclusively in the horizontal direction. And any verticle motions --rarely larger than 2 m/sec -- are usually associated with changes in the magnetic field, but no such variations were recorded that day.

The mystery was solved when Michael Kelley at Cornell University in Ithaca, N.Y., and Robert Livingston and Mary McCready at SRI International in Menlo Park, Calif., linked the nine-hour-long ionospheric disturbance to an earthquake that had occurred 1,000 kilometers from the radar site just before the oscillations began. As discussed in the September GEOPHYSICAL RESEARCH LETTERS, the researchers found that their data compared well with a theory developed 18 years ago, which predicts that a nuclear explosion or earthquake will excite atmospheric motion near the event much like that created when a pebble falls in water.

In order to fit the data to the model, however, they had to assume that the ionosphere was hotter than normal, suggesting that the earthquake had heated the upper atmosphere. According to Kelley, energy from earthquakes, tornadoes and weather in the lower atmosphere may play a much more important role in warming the upper atmosphere than has usually been assumed.
COPYRIGHT 1985 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1985, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:earthquake disturbs ionosphere
Publication:Science News
Date:Oct 19, 1985
Previous Article:No laughing matter.
Next Article:Fish, fatty acids and physiology; fish, long called brain food, turns out to be heart food as well.

Related Articles
A large and late quake.
More shakers felt in Mexico.
New traces of ancient eastern quakes.
The sound of silent earthquakes.
Seismic Sunday; recent jolts boost Southern California's hazard.
Great quake followed slow precursor.
Los Angeles faces a dangerous quake debt.
Great earthquake shakes off theories.
The Sky is Falling.
Earth sometimes shivers beneath thick blankets of ice.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters