STRONG GEOMAGNETIC STORM CONTINUES THROUGH OCTOBER 23

SUMMARY

The strong geomagnetic storm which began yesterday has continued
off-and-on at high levels throughout the day and appears to have
been reenergized this morning about 01:35 UT. (October 23). The
Virgin Islands, which has been quiet since October 17 saw a series
of earthquakes begin this afternoon coinciding with the near
maximum of an M6.7 solar flare. On October 17 in this report,
it had been observed that the previous event in the Virgin Islands
had also coincided with an M-class solar flare, the first in some
time. Strong seismicity often follows great geomagnetic storms
by about 4-5 days. A proton storm began with the renewed activity
at 17:12 UT. This is a fairly strong proton event and may trigger
some activity in the regions of the geomagnetic poles, but otherwise
is expected to reduce general seismicity of the world for one to
two days.

GLOBAL

There were no large events in the world today. The strongest swarm
occurred in the Virgin Islands with events of Mb 4.4, 4.4, 5.0, 4.7 and
4.7 in a 1.5 hour period this afternoon following a large M6.7 solar
flare. The Tonga-Fiji area has seen events of Mb 5.3 and 5.0 since
the last report. The region surrounding the Banda Sea earthquake
of October 19 has also seen a high rate of activity in the last
two days including earthquakes of Mb 5.7 in the Molucca Sea and
of Mb 5.3 in Halmahera and Mb 4.7 in the Talaud Islands as well as
classical aftershocks of Mb>5 in the Banda Sea region. The regional
aftershock zone of Guam has also seen several events - a Mb 4.7 in
the Caroline Islands southwest of Guam, an area where a large
far-field aftershock was thought possible, and two events in central
Mariana Islands Mb 4.2 and 4.4. Other earthquakes in Asia since the
last report included a Mb 4.2 in central China; Mb 4.6 in the Ryukyu
Islands, Mb 4.5 in the northern Kuril Islands; Mb 4.6 in Hindu Kush;
Mb 4.5 south of Honshu, SR 5.1 and 5.7 in Sumatera.
Central and South America have also seen some activity this past day.
The largest events occurred in Oaxaca, Mexico (Mb 4.4); and northern
Chile (Mb 4.6)
Activity on mid-ocean ridges continued with a Mb 4.6 on the
Chagos Archipelago southwest of India.

U.S./CANADA

The long quiet in California was broken today with a Ml 3.0 and
aftershocks in the Beverly Hills region west of Los Angeles and a
Ml 3.5 along the northern coast of California near Trinidad. Both
could be considered far-field aftershocks. The Geysers region also
saw a series of mild quakes including Ml 2.4 and 2.3, and a small
swarm was developing this evening in that region. PNSN reported several
shocks of Ml>?3.0 off the coast of Northern California, but these
have yet to be confirmed except for the Trinidad event. Also in
northern California a Ml 2.6 was registered NW of Burney by local
and regional networks.
In southern California besides the Ml 3.0 and Ml 2.3 near Beverly
Hills, a Ml 2.2 was recorded east of Parkfield near Kettleman City, CA.
In the Banning/Loma Linda/Cabazon area two Ml 2.1's were observed.
Finally, a Ml 2.3 and 2.4 were recorded by SCSN near the Calexico region.
The only other events reported in the U.S./Canada region of Ml>=2 today
occurred in the Fox Islands, Alaska (Ml 4.4, 4.6) and in Hawaii (Ml 3.1).
No reports on todays activity were available from PNSN, MBMG, UUSN
or the eastern portions of the U.S. or Canada.

NEW ZEALAND

A strong series of at least 7 earthquakes occurred last night
and this morning in the area of New Zealand south of Wellington
(Cook Strait). IGNS has located only one of these events, a Ml 4.7
south of Wellington and east of Seddon, N.Z., but
all showed as light to moderate sized earthquakes on the IGNS
on-line seismometer.
Two light aftershocks of the Mw 6.8 earthquake off North Island
have also been located, but there many which have yet to be
processed and reported at this time.

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

GEOMAGNETIC/SOLAR FIELDS

The strong geomagnetic storm which began yesterday continued
throughout October 22, 2001. It is expected that strong seismicity
will begin in about 2-3 days. The storm re-invigorated about
17:12 UT this afternoon. Areas where seismicity might be enhanced
due to this re-invigoration would be within 20 degrees of 80W and
100E. This includes most of south and Central America and the
eastern U.S. and Canada as sub-solar regions and Central Asia
as anti-solar areas. Maximum event size in these area could
increase by up to 1.0 magnitude units over the next 5 days.
Two M-class and one X-class flare were observed on the
sun today with the following parameters:

Flare # START MAX END CLASS

5320 + 0022 0040 0048 M1.0
5510 + 1427 1508 1531 M6.7
5580 + 1744 1759 1814 X1.2

The first was followed at 00:28 by a Ml 3.0 in the Beverly
Hills area west of Los Angeles.
The second was accompanied at 14:42 by a new series or earthquakes
in the Virgin Islands. You may recall from previous reports,
that the last earthquake in the Virgin Islands also occurred in
association with a strong solar flare. A discussion of this
relation was made in this report at that time. See October 17, 2001
report for that discussion.

Strong variations were registered on the Hockley, Texas seismogram
today associated with the arrival of two CME. This author believes
this reflects real ground motion from the pressure wave created
when the CME encounters the earth's ionosphere and upper troposphere,
however induced currents associated with the CME are also a possible
explanation for these observations. Further examination of seismograms
at the times of CME will be necessary to determine which explanation
is valid (if any).

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20011022events.txt

TROPICAL STORMS

Tropical Storm Narda continues moving towards Hawaii in the
Central Pacific. Narda reached Class one hurricane status briefly,
but is now back to Tropical Storm status. A Ml 3.1 earthquake
occurred in Hawaii today, the first in several weeks.
For tracking details see:
http://www.wunderground.com/auto/HurricaneSite/tropical/tracking/ep200121.html

Typhoon Podul is located WSW of Wake Island and is tracking
WNW. No population centers are near the current position. For
information see:
http://www.wunderground.com/auto/HurricaneSite/tropical/wp200101.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.

October 23 is seven days after the beginning 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

No Regions

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

East US MB>=1.0 -13 -2.5 0.03

EARTHQUAKE LISTINGS

GLOBAL

OCEANIA

O: 21Oct2001 13:07:39 3.4S 68.2E MB=4.6 NEIS CHAGOS ARCHIPELAGO REGION

O: 18Oct2001 12:55:58 55.1S 126.9W MS=5.3 NEIS SOUTHERN EAST PACIFIC RISE

NEW ZEALAND

O: 22Oct2001 02:03 41.6S 174.4E ML=4.7 IGNS E. of Seddon, N.Z.
Note: (IGNS) This earthquake will have been felt in the Wellington region.

O: 21Oct2001 15:42:04 37.5S 178.6E MB=4.1 NEIS OFF E. COAST N. ISL, N.Z.

O: 21Oct2001 01:32:55 37.0S 177.8E ML>4.0 NEIS OFF E. COAST N. ISL, N.Z.

SOUTH PACIFIC ISLANDS

O: 20Oct2001 17:49:04 18.4S 174.5W MB=4.7 NEIS TONGA ISLANDS

O: 20Oct2001 01:51:40 24.2S 178.6E MB=4.1 NEIS SOUTH OF FIJI ISLANDS

O: 22Oct2001 22:10:51 15.7S 173.9W mb=5.0 GSR TONGA ISLANDS

O: 22Oct2001 06:46:47 20.9S 179.2W MB=5.3 NEIS FIJI ISLANDS REGION

O: 20Oct2001 13:28:07 13.0S 174.1E MB=4.5 NEIS FIJI ISLANDS REGION

ASIA

O: 21Oct2001 22:46:31 11.8N 141.0E MB=4.7 NEIS W. CAROLINE ISL

O: 21Oct2001 19:02:46 4.9S 124.0E MS=5.2 NEIS BANDA SEA

O: 21Oct2001 18:56:12 49.6N 156.4E MB=4.5 NEIS KURIL ISLANDS

O: 21Oct2001 18:37:46 29.8N 129.4E MB=4.6 NEIS RYUKYU ISLANDS, JAPAN

O: 21Oct2001 13:40:10 18.2N 145.6E MB=4.2 NEIS MARIANA ISLANDS

O: 21Oct2001 13:36:24 36.4N 103.2E MB=4.2 NEIS GANSU, CHINA

O: 21Oct2001 13:24:09 37.3N 71.8E MB=4.6 NEIS AFGHAN-TAJIK BORD REG.

O: 21Oct2001 12:36:52 3.9N 128.5E MB=5.4 NEIS N OF HALMAHERA, INDONESIA

O: 21Oct2001 03:40:18 1.9N 126.5E MB=5.7 NEIS NORTHERN MOLUCCA SEA

O: 21Oct2001 01:42:38 12.7N 143.1E ML>4.0 NEIS SOUTH OF MARIANA ISLANDS

O: 20Oct2001 20:01:06 18.8N 145.4E MB=4.4 NEIS MARIANA ISLANDS

O: 19Oct2001 07:04:34 21.1N 93.6E MB=5.0 NEIS MYANMAR

O: 23Oct2001 00:40:38 3.7N 126.7E MS=4.7 GSR TALAUD ISLANDS, INDONESIA

O: 22Oct2001 19:58:27 2.2N 126.3E mb=4.9 GSR NORTHERN MOLUCCA SEA

O: 22OCT2001 13:17 33.8N 139.3E Mj=4.5 NIED NEAR_MIYAKEJIMA_ISLAND, JAPAN

O: 22OCT2001 14:24:10 1.2N 98.2E SR=5.1 AEIC1 GUNUNG SITOLI, INDONESIA

O: 22OCT2001 14:18:00 0.3N 99.4E SR=5.7 AEIC1 LUBUKSIKAPING, INDONESIA

O: 22OCT2001 08:10:10 8.1S 114.9E SR=4.8 AEIC1 W SINGARAJA, INDONESIA

O: 21OCT2001 22:40:20 9.2S 118.2E SR=5.0 AEIC1 SW DOMPU, INDONESIA

O: 21OCT2001 14:48:40 8.6S 115.8E SR=4.9 AEIC1 SE AMLAPURA, INDONESIA

O: 20Oct2001 14:03:47 5.8S 124.3E MB=4.8 NEIS BANDA SEA

O: 21OCT2001 03:41:20 0.9N 121.7E SR=5.2 AEIC1 E TOLI TOLI, INDONESIA

CENTRAL/SOUTH AMERICA

O: 21Oct2001 23:25:13 17.0N 94.1W MB=4.4 NEIS CHIAPAS, MEXICO

O: 21Oct2001 16:32:52 22.3S 70.7W MB=4.6 NEIS NEAR COAST OF N CHILE

O: 22OCT2001 19:37:49 2.4N 80.6W MC=4.1 CASC SO OF PANAMA

O: 21OCT2001 23:43:22 12.1N 86.8W MC=3.6 SIS NICARAGUA, C.A.

O: 20OCT2001 15:26:35 22.1S 68.3W ML=5.1 DGF NE of CALAMA, CHILE

O: 19Oct2001 18:26:01 1.8S 77.6W MB=4.6 NEIS ECUADOR

O: 20Oct2001 13:26:35 22.1S 68.3W MB=5.1 NEIS NORTHERN CHILE

O: 20Oct2001 10:56:20 9.2S 76.0W MB=4.3 NEIS CENTRAL PERU

O: 20Oct2001 02:31:14 17.0S 73.3W MB=4.6 NEIS NEAR COAST OF PERU

CARIBBEAN

O: 22Oct2001 16:12:53 19.3N 64.7W MB=4.7 NEIS VIRGIN ISLANDS
O: 22Oct2001 15:39:18 19.3N 64.8W MB=4.7 NEIS VIRGIN ISLANDS
O: 22Oct2001 15:36:10 19.3N 64.8W MB=5.0 NEIS VIRGIN ISLANDS
O: 22Oct2001 15:29:18 19.3N 64.7W MB=4.4 NEIS VIRGIN ISLANDS
O: 22Oct2001 14:42:52 19.2N 64.7W MB=4.4 NEIS VIRGIN ISLANDS

EUROPE

O: 21OCT2001 07:32:21 35.8N 23.9E ML=3.7 NOA GREECE
O: 21OCT2001 10:21:20 35.2N 24.4E ML=3.6 NOA GREECE

O: 22OCT2001 03:10:49 38.6N 25.3E ML=3.6 NOA GREECE

U.S/CANADA

CALIFORNIA/NEVADA

O: 21OCT2001 18:14:16 32.1N 115.7W MC=2.4 SCSN SSW of Calexico, CA
O: 21OCT2001 18:26:20 32.3N 115.2W MC=2.3 SCSN SSE of Calexico, CA

O: 22OCT2001 1:36:41 33.9N 116.8W ML=2.1 SCSN SSE of Cabazon, CA
O: 22OCT2001 7:19:19 33.9N 116.9W ML=1.2 SCSN ENE of Banning, CA

O: 22OCT2001 8:35:58 34.0N 118.2W ML=1.7 SCSN NW of South Gate, CA

O: 22OCT2001 20:13:49 34.0N 117.2W ML=1.6 SCSN SSE of Loma Linda, CA
O: 22OCT2001 5:47:32 34.0N 117.3W ML=2.1 SCSN W of Loma Linda, CA
O: 22OCT2001 18:33:09 34.3N 117.1W ML=1.3 SCSN NE of Lake Arrowhead, CA

O: 22Oct2001 00:28:57 34.1N 118.4W ML=3.0 NEIS SOUTHERN CALIFORNIA
O: 22OCT2001 0:28:57 34.0N 118.4W ML=3.0 SCSN SSE of Beverly Hills, CA
O: 22OCT2001 0:36:34 34.1N 118.4W ML=1.5 SCSN SSW of Beverly Hills, CA
O: 22OCT2001 20:06:32 34.1N 118.4W ML=2.3 SCSN SSW of Beverly Hills, CA
O: 22OCT2001 2:06:41 34.1N 118.4W ML=1.5 SCSN ESE of Beverly Hills, CA
O: 22OCT2001 1:11:50 34.1N 118.4W ML=1.7 SCSN WNW of Beverly Hills, CA
O: 23OCT2001 1:11:44 34.1N 118.2W ML=1.6 SCSN NE of Silver Lake, CA

O: 22OCT2001 1:58:30 34.2N 119.2W ML=1.0 SCSN W of Oxnard, CA

O: 22OCT2001 1:16:56 34.3N 118.5W ML=1.3 SCSN SSE of Newhall, CA

O: 23OCT2001 0:42:59 35.3N 118.7W ML=1.6 SCSN NE of Arvin, CA

O: 22OCT2001 12:07:05 35.9N 119.9W ML=2.2 SCSN SE of Kettleman City, CA

O: 22OCT2001 0:09:30 36.0N 120.6W ML=1.3 NCSN NW of Parkfield, CA

O: 22OCT2001 10:14:51 36.1N 121.5W ML=1.6 NCSN NE of Lopez Point, CA

O: 22OCT2001 18:58:29 37.0N 122.1W ML=1.0 NCSN W of Felton, CA
O: 22OCT2001 6:40:36 37.1N 121.5W ML=1.4 NCSN NE of San Martin, CA

O: 23OCT2001 3:22:50 38.8N 122.7W ML=2.4 NCSN E of The Geysers, CA
O: 22OCT2001 21:12:34 38.8N 122.8W ML=1.8 NCSN NNE of The Geysers, CA
O: 22OCT2001 7:53:07 38.9N 122.8W ML=2.3 NCSN N of The Geysers, CA

O: 22OCT2001 8:24:36 39.6N 120.6W ML=1.1 NCSN SSW of Portola, CA

O: 22Oct2001 08:23:51 41.0N 124.2W ML=3.5 NEIS NEAR COAST OF N CALIF.
O: 22OCT2001 8:23:51 41.0N 124.2W ML=3.5 NCSN SW of Trinidad, CA

O: 22OCT2001 9:20:04 41.0N 121.9W ML=2.6 NCSN NW of Burney, CA

O: 19OCT2001 13:23:29 41.0N 126.2W ML>2.7 PNSN OFF COAST OF CALIFORNIA

O: 20OCT2001 22: 5:54 41.3N 124.8W ML>3.5 PNSN OFF COAST OF CALIFORNIA

O: 22OCT2001 8:24:14 40.7N 124.5W ML>3.5 PNSN OFF COAST OF CALIFORNIA

O: 22OCT2001 9:20: 9 41.2N 122.1W ML>2.0 PNSN NORTHERN CALIFORNIA

PACIFIC NORTHWEST/CANADA

O: 20OCT2001 02:35:58 48.7N 122.5W ML=1.1 PGC SSW Abbotsford BC
O: 19OCT2001 23:30:06 48.9N 122.2W ML=1.3 PGC SE Abbotsfordd BC

O: 20OCT2001 00:18:55 50.1N 127.8W ML=3.5 PGC SSW Pt. Hardy B

O: 19OCT2001 22:13:49 55.5N 119.4W ML=2.7 PGC ESE Dawson Creek BC

O: 19OCT2001 15:59:53 48.7N 128.5W ML=2.8 PGC WSW Tofino BC
O: 19OCT2001 07:36:01 48.7N 128.5W ML=2.5 PGC WSW Tofino BC

O: 19OCT2001 05:56:54 59.4N 136.2W ML=2.2 PGC WNW Haines AK

O: 22OCT2001 9:20:04 41.0N 121.9W ML=2.6 PNSN SSE of Mount Shasta

O: 22OCT2001 4:36:07 48.1N 120.2W ML=1.9 PNSN NNW of Chelan, WA

O: 21OCT2001 12:04:42 48.9N 122.2W ML=1.1 PNSN NNE of Deming, WA

O: 21OCT2001 10:41:12 48.3N 122.2W ML=1.8 PNSN SSE of Mount Vernon, WA
O: 21OCT2001 3:47:59 47.8N 122.9W ML=1.5 PNSN W of Poulsbo, WA

O: 20OCT2001 0:19:16 49.5N 126.1W ML>3.2 PNSN WASHINGTON

ROCKY MOUNTAIN AREA

O: 21OCT2001 3:21:33 40.6N 111.6W ML=0.2 UUSN NE of Alta, UT
O: 19OCT2001 17:47:32 40.8N 111.9W ML=1.1 UUSN S of N. Salt Lake, UT

O: 20OCT2001 13:32:12 44.8N 110.8W ML=1.5 UUSN WNW of Norris Junc., WY
O: 20OCT2001 6:32:07 44.8N 111.2W ML=1.2 UUSN NW of W. Yellowstone, MT

O: 19OCT2001 18:08:02 37.9N 113.3W ML=2.0 UUSN NW of Cedar City, UT

O: 19OCT2001 16:19:57 40.7N 112.1W ML=1.1 UUSN NE of Magna, UT

O: 19OCT2001 10:04:28 44.5N 110.2W ML=1.6 UUSN ESE of Fishing Bridge, WY

O: 19OCT2001 6:51:26 39.6N 111.2W ML=2.1 UUSN E of Fairview, UT

O: 22OCT2001 07:39:01 47.3N 114.1W MD>0.4 MBMG MONTANA
O: 22OCT2001 07:38:37 47.3N 114.1W MD>1.0 MBMG MONTANA

O: 22OCT2001 05:31:35 44.7N 111.1W MD>1.0 MBMG MONTANA

O: 21OCT2001 13:50:23 46.9N 112.3W MD>0.8 MBMG MONTANA

EASTERN U.S./CANADA

O: 22OCT2001 02:13:23 45.1N 75.2W MN=1.5 GSC N from IROQUOIS, ONT.

O: 20OCT2001 21:20:13 48.1N 77.4W MN=2.0 GSC E from VAL-D'OR, QUE

ALASKA

O: 21Oct2001 16:56:53 52.7N 166.9W MB=4.4 NEIS FOX ISL, ALEUTIAN ISLANDS
O: 21Oct2001 14:40:10 52.7N 166.9W MB=4.6 NEIS FOX ISL, ALEUTIAN ISLANDS

HAWAII

O: 21OCT2001 13:13:34 19.2N 155.6W ML=3.1 HVO W of Pahala, Hawaii