RELATIVELY QUIET SEISMICITY STARTS DECEMBER, 2001

SUMMARY

The first day of December saw only relatively moderate seismicity
in all areas. The rare events that occurred yesterday did not
repeat today, and regional seismicity in most areas was at or below
background levels.

GLOBAL

The only events recorded of Mb>=5 since last report occurred in
the continuing swarm in the Kermadec Islands N.Z. (Mb 5.5) and
north of Bengkulu, Sulawesi, Indonesia (Mb 5.4).
Other earthquakes of Mb>=4 were listed as occurring east of
the Qinghai mainshock of Nov. 14 (Mb 4.9); in the southern Kuril
Islands (Mb 4.8); in the Rat Islands, central Aleutians (Mb 4.6);
South of Mindanao (Mb>4.5); Central Peru (Mb 4.3); Off the coast
of Central America (Mb 4.4); along the Guerrero/Michoacan border
in Mexico (Ml 4.4) and in Chiapas Mexico (Ml 4.2).
An unusual earthquake of Ml 3.7 was located in the subduction
zone near Montserrat Volcano on Thursday, Nov. 29 and reported
today. This event does not appear to be part of the on-going eruption
of that volcano.

U.S./CANADA

Alaska was the most active seismic region today, where 5 earthquakes
of Ml>=3 occurred along with the largest earthquake of the day in
the Rat Islands (Mb 4.6). An earthquake of Ml 4.3 also occurred
in Southern Alaska north of Homer. The other events occurred WNW
of Homer (Ml 3.4); W of Seldovia (Ml 3.5); on the Alaska Peninsula (Ml 3.7).
An event of Ml 2.4 was listed today which occurred in the eastern
Tennessee seismic zone on Nov. 28. A Ml 2.5 occurred near this epicenter
on Oct 29. Otherwise this region has been relatively quiet for the
past 6 months. This earthquake is located near the s-wave shadow zone
boundary from the Kunlun quake and may be considered an FFA of that event.
A light earthquake of Ml 3.2 was belatedly reported today which
occurred on Nov. 30 in the Dixie Valley, NV area. This area has been
relatively quiet recently with only two earthquakes of Ml>=3 in the
past 2 1/2 years (since June, 1999). These two events occurred on Dec 12,
1999 (Ml 4.0) and Nov. 18, 2000 (Ml 3.8).
No events of Ml>=3 were listed today in the rest of the U.S./Canada
region, however, because it is the weekend, many observatories are
closed and some events may have occurred which have not been reported.
In the California/Nevada region, light earthquakes of Ml>=2 continued
to occur in a wide-spread pattern. Today's events of Ml>=2 were located
near Big Bear Lake (Ml 2.3); Simi Valley, where two other events of
Ml>=2 occurred two days ago (Ml 2.2); Coalinga (Ml 2.2); Obsidian
Butte (Ml 2.3; 2.1) and the Geysers (Ml 2.0).

NEW ZEALAND

The on-line seismogram showed only light activity in the New
Zealand area today after nearly a week of moderately high seismicity.
A good weekend rest for local seismic personnel.

The IGNS on-line Seismometer can be found at:
http://www.gns.cri.nz/news/earthquakes/latest_drum.html

GEOMAGNETIC/SOLAR FIELDS

The geomagnetic field remained at quiet conditions today despite
a moderately strong, long-lasting M- class flare. Two M-class solar
flares occurred today with the following parameters:

Flare # START MAX END CLASS

8290 + 0647 0651 0654 M2.2
8420 + 1430 1445 1456 M1.2
8470 1500 1555 1628 M4.8
8490 1729 1731 1733 M1.5
8530 1739 1749 1754 M1.8

None of these flares were associated with significant seismicity.

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20011201events.txt

TROPICAL STORMS

OLGA

Tropical Depression Olga continues to approach the Carribean
from the northeast today. She is currently located north of the
Island of Hispaniola at about 22N 70W. Olga is expected to take
a sharp turn to the northwest tonight and not make landfall in the
Caribbean, but move into the So. Carolina area instead. Seismicity
is still possible in the Caribbean from this storm, as well as
in the So. Carolina/Appalachian Mts. region should she make landfall
in that area..

For more on TD Olga's path see:

http://www.wunderground.com/auto/HurricaneSite/tropical/tracking/at200117.html

BESSI

Tropical Cyclone Bessi continues in the South Indian Ocean near
Cocos Island. This storm is not expected to impact regional seismicity
significantly. For more details see:

http://www.wunderground.com/auto/HurricaneSite/tropical/sp200101.public.html

TIDAL TRIGGERING (LUNAR)

Statistics have been done on many regions of the world in terms of
relationship of significant regional earthquakes with respect to lunar cycle.
Each report will summarize the most likely areas for tidal triggering
for the next day based on these statistics. It is expected
that tidal triggering will add an additional 0.5 - 1.0 units of
magnitude to events which are about to occur or will move these
events forward in time by up to seven days in the regions where
there is a statistical correlation between lunar phase and
earthquakes.

December 02 is the eighteenth day after the beginning of the lunar month.
Regions most likely to experience tidal triggering
on this day (With associated magnitude ranges; the percent change in
seismicity rate over background seismicity rate on this
day of the lunar month; statistical z-value and
significance level) are:

Region Magnitude range %change z-value Significance level

Pacific-Antarctic Ridge MB>=4.0 58 2.0 0.05
East Africa MB>=4.0 23 3.1 0.01
New Zealand MB>=4.0 19 2.2 0.05
Yellowstone MB>=2.0 19 2.0 0.05

Regions expected to experience reverse triggering (i.e. they are
unlikely to experience a significant event at this period of the
lunar cycle) are:

Region Magnitude range %change z-value Significance level

Utah MB>=2.0 -19 -2.0 0.05

EARTHQUAKE LISTINGS:

GLOBAL

NEW ZEALAND/AUSTRALIA

O: 30Nov2001 18:02:08 33.1S 178.2W MS=5.5 NEIS SOUTH OF KERMADEC ISLANDS

ASIA

O: 01Dec2001 12:25:18 35.5N 94.0E MB=4.9 NEIS QINGHAI, CHINA

O: 01Dec2001 05:09:00 4.8S 101.7E MS=5.4 NEIS S SUMATERA, INDONESIA

O: 01Dec2001 16:28:07 43.7N 147.4E MB=4.8 NEIS KURIL ISLANDS

O: 01DEC2001 19:42:00 9.6S 116.5E SR=5.0 AEIC1 S PRAYA, INDONESIA
O: 01DEC2001 10:10:10 9.1S 117.1E SR=4.8 AEIC1 SUMBAWABESAR, INDONESIA

O: 01dec2001 05:09:02 4.3S 101.8E MS=5.1 ASC WSW of Pasamgalam, Sumatera
O: 01DEC2001 05:08:50 5.5S 101.2E SR=5.5 AEIC1 SW BENGKULU, INDONESIA

O: 29NOV2001 17:02:00 8.6S 107.1E SR=5.7 AEIC1 SW GARUT, INDONESIA

O: 29NOV2001 15:22:10 1.4S 119.4E SR=5.7 AEIC1 W PALU, INDONESIA

O: 28NOV2001 17:58:00 0.7N 125.2E SR=5.3 AEIC1 TONDANO, INDONESIA

O: 01DEC2001 20:42:20 5.2N 127.7E SR=5.9 AEIC1 NE BITUNG, INDONESIA

O: 28NOV2001 09:31:10 5.3N 126.3E SR=4.9 AEIC1 N BITUNG, INDONESIA

O: 28NOV2001 09:27:10 10.6S 113.1E SR=4.8 AEIC1 LUMAJANG, INDONESIA

CENTRAL/SOUTH AMERICA

O: 01DEC2001 15:37 9.9S 78.1W ML=4.3 IGP Huarmey, Peru

O: 01Dec2001 13:36:02 12.0N 88.7W MB=4.4 NEIS OFF COAST OF CEN AMERICA
O: 01DEC2001 09:00:12 12.6N 88.1W MC=4.1 SIS NICARAGUA, C.A.
O: 01DEC2001 13:36:17 13.0N 88.6W MC=4.1 SIS NICARAGUA, C.A.

O: 01DEC2001 04:32:39 17.9N 102.9W ML=4.4 SSN COSTA GUERRERO-MICH , MEXICO

O: 01DEC2001 03:00:53 15.5N 93.5W ML=4.2 SSN COSTA DE CHIAPAS , MEXICO

O: 30NOV2001 08:23:07 16.4N 99.0W ML=3.7 SSN COSTA GUERRERO-OAXACA , MEXICO
O: 30NOV2001 02:28:12 16.9N 98.2W ML=3.7 SSN COSTA GUERRERO-OAXACA, MEXICO

CARIBBEAN

O: 29NOV2001 12:48 16.8N 62.2W ML=3.6 UWI Montserrat, Leeward Islands
Note (UWI): An earthquake was felt in Montserrat at 12:48 PM on Thursday
November 29. The epicentre was at 16.802 degrees north, 62.233 degrees west
and the depth was 5.8 km. This location is just off the north coast of
Montserrat. Magnitude was 3.6. Although the magnitude was low the earthquake
was felt at intensity IV on the Modified Mercalli scale in northern Montserrat.
This is because the earthquake originated close to the Earth's
surface and close to the major population centre in northern Montserrat.
Although the eruption in southern Montserrat continues it is highly unlikely
that this earthquake was connected with it. It is much more likely that the
earthquake was what is called a near plate boundary intraplate tectonic
earthquake. These are fairly common in the zone Montserrat-Redonda-Nevis
and a particularly severe sequence happened in 1985-86.
Source:
http://www.uwiseismic.com/

EUROPE/AFRICA/MIDDLE EAST

O: 1DEC2001 15:41:15 39.8N 41.5E ML=3.8 KAN TEKMAN (ERZURUM),TURKEY

U.S/CANADA

CALIFORNIA/NEVADA

O: 30NOV2001 14:38:15 39.5N 118.0W ML=3.2 NCSN S of Dixie Valley, NV

O: 01DEC2001 12:34:04 33.1N 115.6W ML=1.9 SCSN ESE of Obsidian Butte, CA
O: 01DEC2001 13:55:46 33.1N 115.6W ML=2.3 SCSN SSE of Obsidian Butte, CA
O: 01DEC2001 0:01:12 33.2N 115.7W ML=2.1 SCSN NNW of Obsidian Butte, CA

O: 2DEC2001 0:58:35 34.2N 116.9W ML=2.3 SCSN ESE of Big Bear Lake, CA

O: 01DEC2001 18:34:45 34.2N 118.7W ML=2.2 SCSN SW of Simi Valley, CA

O: 01DEC2001 5:58:46 34.3N 118.5W ML=1.3 SCSN WNW of Pacoima, CA

O: 01DEC2001 16:32:19 36.2N 120.3W ML=2.2 NCSN NNE of Coalinga, CA

O: 01DEC2001 10:56:25 38.8N 122.7W ML=2.0 NCSN E of The Geysers, CA

PACIFIC NORTHWEST/CANADA

O: 30NOV2001 18:13:16 46.5N 122.3W ML=1.1 PNSN SW of Morton, WA

ROCKY MOUNTAIN AREA

O: 01DEC2001 22:39:30 46.3N 112.1W MD=1.0 MBMG MONTANA

O: 01DEC2001 17:04:37 44.7N 111.0W MD=0.0 MBMG MONTANA
O: 28NOV2001 01:00:18 44.7N 111.0W MD=0.0 MBMG MONTANA

O: 01DEC2001 16:16:11 44.6N 109.9W MD=2.2 MBMG MONTANA

O: 01DEC2001 10:38:27 47.2N 113.1W MD=0.4 MBMG MONTANA

O: 30NOV2001 16:51:03 46.8N 114.0W MD=0.0 MBMG MONTANA

EASTERN U.S./CANADA

O: 28NOV2001 06:27:18 35.2N 84.7W ML=2.4 JIEE 5 km NNW of Benton, TN

ALASKA

O: 01DEC2001 18:26:13 63.2N 150.8W ML=3.1 AEIC SSE of Kantishna, Alaska

O: 01DEC2001 15:22:02 59.8N 152.6W ML=3.4 AEIC WNW of Homer, Alaska

O: 01DEC2001 07:29:01 59.4N 153.5W ML=3.5 AEIC W of Seldovia, Alaska

O: 30NOV2001 18:47:27 55.5N 161.0W ML=3.7 AEIC WNW of Sand Point, Alaska

O: 30NOV2001 17:55:47 60.3N 151.5W ML=4.3 AEIC N of Homer, Alaska

O: 01Dec2001 16:40:44 51.0N 178.5E MB=4.6 NEIS RAT ISL, ALEUTIAN ISLANDS