Historic Earthquakes

Magnitude 6.9 COSTA RICA
1999 August 20 10:02:21 UTC

Theoretical P-wave Travel Times

This map shows the predicted (theoretical) travel times, in minutes, of the compressional (P) wave from the earthquake location to points around the globe. The travel times are computed using the spherically-symmetric IASP91 reference earth velocity model. The heavy black lines shown are the approximate distances to the P-wave shadow zone (103 to 140 degrees).

Theoretical P-Wave Travel Times
City Distance
(degrees)
Travel Time
(min:secs)
Arrival Time
UTC
Phase
Miami, Florida 17.05 3:57.2 10:06:18.2 Pn
Mexico City, Mexico 17.82 4:06.8 10:06:27.8 Pn
San Juan, Puerto Rico 19.84 4:29.5 10:06:50.5 P
Brownsville, Texas 21.02 4:42.3 10:07:03.3 P
Lima, Peru 22.15 4:54.5 10:07:15.5 P
Knoxville, Tennessee 26.80 5:38.7 10:07:59.7 P
St. Louis, Missouri 30.00 6:07.2 10:08:28.2 P
Washington, D.C. 30.40 6:10.8 10:08:31.8 P
Wichita, Kansas 30.98 6:15.8 10:08:36.8 P
Philadelphia, Pennsylvania 31.81 6:23.1 10:08:44.1 P
New York, New York 32.80 6:31.8 10:08:52.9 P
Albuquerque, New Mexico 33.09 6:34.3 10:08:55.3 P
Boston, Massachusetts 35.09 6:51.7 10:09:12.7 P
Golden, Colorado 35.89 6:58.6 10:09:19.6 P
Ottawa, Canada 36.96 7:07.7 10:09:28.7 P
Bangor, Maine 38.03 7:16.7 10:09:37.7 P
Duluth, Minnesota 38.19 7:18.1 10:09:39.1 P
Los Angeles, California 39.99 7:33.1 10:09:54.1 P
San Francisco, California 44.79 8:12.1 10:10:33.1 P
Seattle, Washington 50.29 8:54.9 10:11:15.9 P
Anchorage, Alaska 70.55 11:13.6 10:13:34.6 P
Honolulu, Hawaii 71.63 11:20.1 10:13:41.1 P
Palmer Station, Antarctica 77.96 11:56.7 10:14:17.7 P
London, England 79.25 12:03.8 10:14:24.8 P
Bergen, Norway 81.96 12:18.3 10:14:39.3 P
Rome, Italy 88.95 12:53.1 10:15:14.1 P
Moscow, Russia 99.56 13:41.4 10:16:02.4 Pdiff
Wellington, New Zealand 104.21 14:02.1 10:16:23.1 Pdiff
Tokyo, Japan 119.27 15:09.0 10:17:30.0 Pdiff
Nairobi, Kenya 120.79 15:15.7 10:17:36.7 Pdiff
Brisbane, Australia 123.20 15:26.4 10:17:47.4 Pdiff
Agana, Guam 126.55 15:41.3 10:18:02.3 Pdiff
Beijing, China 127.70 15:46.4 10:18:07.4 Pdiff
Kathmandu, Nepal 142.09 16:50.2 10:19:11.2 Pdiff