Subj: Re: Anomalous Seismic Signals 03/20/99

Date: 3/21/99 10:35:42 AM Pacific Standard Time

From: (Charlie Plyler)

To: (Frank Condon)

CC: (Kent Steadman)

Enclosed is the data scan during the Andreanof Islands event. Note that reception was better on the East-West antenna array. Also note there was no noticeable time delay so apparently the signals were generated by pizeoelectrical activity.

Precursor signal activity is evident for at least 30 minutes prior to this quake. I have noticed this is also the case in other earthquakes of this size.


20Mar1999 10:47:48.1 51.7N 177.6W 50 mb=6.2 M*EMS ANDREANOF ISLANDS, ALEUTIA1221

20Mar1999 10:47:46.8 51.9N 177.6W 33 MS=6.9 M*GSR ANDREANOF ISLANDS, ALEUTIA1204

20Mar1999 10:47:45.7 51.6N 177.7W 33 MS=6.8 M*NEI ANDREANOF ISLANDS, ALEUTIA1155

20Mar1999 10:47:47.3 52.5N 178.8W 0 mb=6.0 M*MAD ANDREANOF ISLANDS, ALEUTIA1144

20Mar1999 10:47:45.5 51.7N 177.9W 33 mb=6.5 A*NEI ANDREANOF ISLANDS, ALEUTIA1112

20Mar1999 10:47:47.4 51.6N 178.6W 33 mb=5.2 A*NOR ANDREANOF ISLANDS, ALEUTIA1111

20Mar1999 10:48:04.0 54.0N 175.0W 10 mb=5.9 A*LED BERING SEA 1109

20Mar1999 10:47:58.9 53.6N 177.1E 10 mb=6.3 A*SED RAT ISLANDS, ALEUTIAN ISLA