Earthquake Summary for October 26, 2001

Earthquake Summary for October 26, 2001

Posted by Lowell on October 26, 2001 at 21:40:10:

MODERATLY STRONG EARTHQUAKE OCCURS IN SOUTHERN VANUATU/LOYALTY ISLANDS (M5.8-6)

SUMMARY

A moderately strong earthquake occurred this evening in the southern
Vanuatu/New Caledonia/Loyalty Islands region (current location is
imprecisely known). The magnitude is probably about Mw 6.0+, preliminary
Mb is 5.8. The area had been expected to see far-field aftershocks (FFA)
from the Banda Sea earthquake of 19 October, 2001 and from the New
Zealand earthquake (Mw 6.8) of 21 October, 2001. The forecast had
stated:

From Banda Sea:

"The most likely events of M>=5 in the next 10 days on the
basis of history and far-field triggering theory appear to be:

....Loyalty Islands"

and

"43-45 degrees: ..... So. Vanuatu, Loyalty Isl."

From New Zealand:

"17-19 degrees: Southern Loyalty, Vanuatu Islands (17-21 S)"

and

"Areas which have had several occurrences of unusual earthquakes
following such events include:
...Loyalty Island/ So. Vanuatu"

This shock was preceded by a Mb 4.7 foreshock(?) in southeast of
the Loyalty Islands yesterday.

GLOBAL

Two other moderately strong earthquakes also occurred today.
These were a Mb 5.6 (NEIS)[Obninsk Russia (GSR) says Mb 6.0]
in Central Peru and a Mb 5.6 near the Indian Ocean Triple Junction. Both were
in regions which were under seismic watch conditions from the geomagnetic
storms of 21-23 October.
Other events of Mb>=4.5 since the last report have occurred in
Myanmar (Mb 4.5); Xinjiang, China (Mb 4.5); in the region
southeast of Honshu, Japan (Mb 4.9) and in the Banda Sea (Mb 4.8).
All were expected FFA from the New Zealand earthquake of Oct. 21 as
stated in the FFA forecast:

"Areas which have had several occurrences of unusual earthquakes
following such events include:
The region south of Honshu (around 30N 130-143E)
Central Asia/Myanmar.
Loyalty Island/ So. Vanuatu
...Banda Sea"

U.S./CANADA

The largest earthquake reported in the U.S./Canada region since
the last report was a Ml 3.9 in the Northwest Territories, Canada
SSW of Ft. McPherson, Canada. Two Ml 2.3 earthquakes also occurred
in the two days since the Maine (Ml 3.5) earthquake in the region
of the Charlevoix Fault Zone, about 200 km north of the Maine epicenter.
The Maine earthquake was the largest in New England in more than
a year and a half.
In the California/Nevada region, the largest reported earthquakes
was a Ml 3.0 south of Yuma, AZ. This area has been quiet for more than
a year after a strong burst of activity in 1999.
Two earthquakes in the general Markleeville, CA/Smoke Creek NV area
registered ML2.2 (NCSN says ML3.0) and ML2.7 respectively. For Northern
California web listing see:

http://quake.wr.usgs.gov/cgi-bin/quake/quake.geo.berkeley.edu/name=quake

The Geysers saw another Ml 2.3. In the area near Los Angeles, a Ml 2.0
was recorded near San Fernando/Pacoima. Several events in the
Ml 2 range occurred in the Yucaipa region of Southern California as well.
Three earthquakes in the low Ml 3 range were registered in northern
Hawaii today. Five such quakes have occurred since the New Zealand
earthquake compared with none in the previous month, these may be FFA.
In Alaska two small events of Ml>=3 were registered in the central/
southern portion of the state.
Earthquakes of Ml>=2 were recorded in the Rocky Mountains near
Old Faithful, Yellowstone N.P (Ml 2.0) and in northwestern Montana (Ml 2.1).

NEW ZEALAND

IGNS, being off for the weekend, did not report any new events
today, however, NEIS did report a Mb 4.9 aftershock of the October
21 earthquake. The on-line seismometer showed at least one light
earthquake in the southern North Island region about 12 NZST.

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. There were
two M-class flares observed on the sun with the following parameters:

Flare # START MAX END CLASS

7110 + 0952 1004 1013 M1.6
7170 + 1428 1435 1437 M2.0

A Ml 3.0 was observed in northern France about 4 minutes after
the start of Flare 7110. For details see:
http://www.emsc-csem.org/cgi-bin/ALERT_all_messages.sh?1
No seismicity has been reported in association with flare 7170.

Large earthquakes are possible today and tomorrow, especially
within 30 degrees of 80W and 100E due to the geomagnetic storms
of October 21-23, with less potential within 20 degrees of 160E
and 20W as well as at high latitudes.
The previous report from October 22 had stated:

" 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."

and

"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)."

[note that sub-solar region at this time were 160E and 20W - strongest
activity is alway expected within 20 degrees longitude of sub- and anti-solar
longitudes even if unstated in the report).

and on October 21, the report stated:

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20010831events.txt

TROPICAL STORMS

Typhoon Podul has weakened from a super-typhoon and is now in the
North Pacific moving NNE. Podul poses no threat to habitation or
to seismicity at this time.
For advisory see:
http://www.wunderground.com/auto/HurricaneSite/tropical/wp200101.public.html

Cyclone Alex is in the Indian Ocean south of Sumatera and moving
northwest. Alex poses no immediate threat to habitation or seismicity,
but will probably move over the mid-Indian Ridge where some induced
seismicity may occur.
For advisory 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.

October 27 is eleven 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

So. Alaska MB>=3.0 9 2.7 0.02
Australia MB>=4.0 33 2.6 0.03
New Madrid MB>=0.0 34 3.4 0.01
So Indonesia MB>=4.0 42 3.1 0.01

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

Geysers MB>=0.0 -6 -2.2 0.05
NE Europe MB>=4.0 -10 -2.3 0.04
Tonga MB>=4.0 -29 -2.0 0.05

EARTHQUAKE LISTINGS

GLOBAL

NEW ZEALAND

O: 25Oct2001 06:53:56 37.0S 179.4E MB=4.9 NEIS OFF E. COAST N. ISL, N.Z.

AUSTRALIA

O: 25OCT2001 18:56 35.3S 148.3E Ml=3.1 AGSC Tumut, NSW, Australia
Note: (AGSO): This earthquake occured in the Snowy Mountains region of
New South Wales, its epicentre about 10 km east of Tumut (or about
80 km west of Canberra). This is the largest event in the area since
July 4, 2001 when a Ml 3.8 occurred south of this epicenter. It was felt
over an area of 22 km.
For details see:
http://www.agso.gov.au/bin/listQuakes
OR
http://www.seis.com.au/EQ/Earthquakes.html

SOUTH PACIFIC ISLANDS

O: 25Oct2001 17:06:25 23.2S 170.1E MB=4.7 NEIS SE OF LOYALTY ISLANDS

ASIA

O: 26OCT2001 15:48:32 47.0N 153.1E MB=5.0 MIX KURIL ISLANDS, RUSSIA

O: 25Oct2001 09:24:17 6.0S 130.6E MB=4.8 NEIS BANDA SEA

O: 25Oct2001 07:42:49 35.2N 141.6E MB=4.4 NEIS NEAR E COAST HONSHU, JAPAN

O: 26Oct2001 08:44:28 30.6N 141.7E MB=4.9 NEIS SOUTHEAST OF HONSHU, JAPAN

O: 25Oct2001 19:18:09 41.2N 78.2E MB=4.4 NEIS KYRGYZ-XINJIANG BDR REG.

O: 25Oct2001 17:21:35 7.5S 128.0E MB=4.2 NEIS BANDA SEA

O: 25Oct2001 17:05:49 22.7N 94.7E MB=4.5 NEIS MYANMAR

O: 26OCT2001 06:08:30 9.3S 120.0E SR=4.9 AEIC1 NW WAINGAPU , INDONESIA

O: 26OCT2001 02:17:20 9.6S 117.1E SR=5.2 AEIC1 SE SELONG , INDONESIA

O: 25OCT2001 15:45:30 9.5S 115.2E SR=5.2 AEIC1 S DENPASAR , INDONESIA
O: 25OCT2001 12:43:30 9.2S 114.5E SR=5.2 AEIC1 SW DENPASAR , INDONESIA
O: 25OCT2001 07:39:30 8.9S 114.9E SR=5.1 AEIC1 SW DENPASAR , INDONESIA

O: 26OCT2001 18:42:37 23.7N 122.1E ML=5.2 CWB Nantou, Taiwan

O: 23OCT2001 20:04 36.8N 141.3E Mj=3.7 NIED E_OFF_IBARAKI_PREF, JAPAN

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

O: 22OCT2001 07:10 34.5N 141.9E Mj=3.6 NIED FAR_SE_OFF_BOSO_PEN, JAPAN

O: 21OCT2001 18:20 35.9N 138.1E Mj=3.6 NIED AKAISHI_MOUNTAINS_REG, JAPAN

CENTRAL/SOUTH AMERICA

O: 24OCT2001 01:42:39 6.9N 73.1W Mc=3.7 ULA Dpto. Santander, Colombia.
O: 24OCT2001 21:02:26 6.7N 73.2W Mc=3.8 ULA Dpto. Santander, Colombia.

O: 24OCT2001 02:36:24 8.9N 70.9W Mc=2.2 ULA Justo Briceo, Edo. Merida.

O: 25OCT2001 10:51:29 16.9S 72.8W MB=4.0 IGP SW of Caman, Peru

O: 26Oct2001 18:59:56 14.6S 70.4W MB=5.6 NEIS CENTRAL PERU
O: 26OCT2001 18:59:56 14.6S 70.4W ML=5.6 DGF NNW of JULIACA, PERU
Note: This event was probably related to the geomagnetic storms on
21-23 October. The report on October 21 had stated:

" A strong sudden commencement storm arrived at about 16:48 UT
today (October 21, 2001). This is the first expected arrival of the
CME from the X-flares of two days ago. Areas which were sub-solar
at the time of the commencement are at 72 +/- 20 degrees W longitude
or anti-solar areas are at 108 +/- 20 degrees E longitude. These
regions are expected to see increased seismic activity for the next
4 days WITH STRONG EVENTS POSSIBLE ON Oct. 25-27. Areas at high
latitudes (45+ degrees) and along the geomagnetic equator may
also show increased seismicity if the storm continues for at least
9 hours." [Emphasis added, note that this lies nearly at 72W,
the sub-solar location at the time of storm commencement].

MIDDLE EAST

O: 24OCT2001 05:13:14 27.8N 33.3E ML=3.0 ISR Suez, Israel

O: 25Oct2001 21:34:41 32.3N 47.9E MS=3.6 GSR IRAN-IRAQ BORDER REGION

EUROPE

O: 25OCT2001 10:56:19 47.1N 0.1W ML=2.7 STR S SAUMUR, FRANCE

O: 25OCT2001 17:55:48 47.4N 7.7E ML=2.0 STR SSE MULHOUSE, FRANCE

O: 26OCT2001 13:32:46 38.0N 23.4E Mb=4.0 GSSC GREECE

OCEANIA

O: 26Oct2001 14:09:51 26.1S 70.9E MB=5.6 NEIS INDIAN OCEAN TRIPLE JUNCTION
Note: This is probably a FFA from the Banda Sea (Mw 7.5) earthquake
of October 19. The FFA forecast had stated:

"59-61 degrees: ....Mid-Indian Ridge"

The epicenter is 56 degrees from Banda.

U.S/CANADA

CALIFORNIA/NEVADA

O: 25OCT2001 21:57:02 33.7N 118.2W ML=2.2 SCSN S of Long Beach, CA

O: 26OCT2001 00:00:08 32.1N 114.9W MC=3.0 SCSN SSW of Yuma, AZ

O: 26OCT2001 02:11:45 34.0N 117.0W ML=2.3 SCSN NNE of Yucaipa, CA

O: 26OCT2001 16:15:30 34.2N 118.4W ML=2.0 SCSN WNW of San Fernando, CA

O: 27OCT2001 1:24:10 33.0N 115.9W ML=1.9 SCSN ESE of Ocotillo Wells, CA

O: 26OCT2001 2:11:45 34.0N 117.0W ML=2.3 SCSN NNE of Yucaipa, CA

O: 26OCT2001 16:15:30 34.3N 118.5W ML=2.0 SCSN WNW of Pacoima, CA

O: 26OCT2001 0:40:14 34.4N 116.3W ML=1.8 SCSN SSW of Ludlow, CA

O: 26OCT2001 23:47:38 36.7N 122.0W ML=1.7 NCSN NW of Pacific Grove, CA

O: 26OCT2001 23:34:54 36.5N 121.1W ML=1.7 NCSN ESE of Pinnacles, CA

O: 26OCT2001 23:40:30 36.7N 121.4W ML=1.6 NCSN WSW of Tres Pinos, CA

O: 26OCT2001 5:31:27 38.8N 122.8W ML=2.3 NCSN NNW of The Geysers, CA

O: 26OCT2001 8:47:43 38.9N 119.7W ML=2.2 NCSN S of Gardnerville, NV

O: 27OCT2001 0:38:48 40.5N 119.7W ML=1.7 NCSN N of Smoke Creek, NV
O: 26OCT2001 6:28:07 40.6N 119.9W ML=2.7 NCSN NW of Smoke Creek, NV

PACIFIC NORTHWEST/CANADA

O: 26OCT2001 8:19:18 48.8N 122.1W ML=1.1 PNSN E of Deming, WA
O: 26OCT2001 09:06:41 48.9N 122.1W ML=0.8 PGC SE Abbotsford BC
O: 26OCT2001 08:19:19 48.8N 122.1W ML=1.0 PGC SSE Abbotsford BC

O: 26OCT2001 04:41:58 65.2N 133.1W ML=3.9 PGC SSE Ft. McPherson NT

O: 25OCT2001 03:21:07 59.4N 136.6W ML=2.4 PGC WNW Haines AK

O: 26OCT2001 18:30:03 47.7N 122.0W ML=2.1 PNSN S of Duvall, WA

O: 26OCT2001 13:06:37 46.2N 122.2W ML=1.7 PNSN ENE of Mount St. Helens

ROCKY MOUNTAIN AREA

O: 25OCT2001 20:19:22 44.3N 111.0W ML=2.1 UUSN SW of Old Faithful, WY
O: 24OCT2001 21:53:38 44.8N 111.1W ML=0.8 UUSN N of W. Yellowstone, MT
O: 24OCT2001 3:33:04 44.8N 110.6W ML=1.6 UUSN NE of Norris Junc., WY
O: 23OCT2001 23:43:29 44.4N 110.7W ML=1.7 UUSN WSW of West Thumb, WY

O: 23OCT2001 21:41:50 40.5N 111.5W ML=1.9 UUSN WNW of Midway, UT

O: 26OCT2001 19:10:37 45.0N 111.8W MD=0.6 MBMG MONTANA
O: 26OCT2001 19:10:21 45.3N 111.7W MD=1.4 MBMG MONTANA

O: 25OCT2001 22:01:33 49.1N 114.3W MD=2.1 MBMG MONTANA

EASTERN U.S./CANADA

O: 26OCT2001 05:08:30 47.4N 70.2W MN=2.3 GSC SE from BAIE-SAINT-PAUL, QUE.
O: 25OCT2001 08:11:59 47.3N 70.2W MN=2.3 GSC CHARLEVOIX SEISMIC ZONE, QUE.

O: 25OCT2001 0:24:28 45.0N 68.3W MC=3.5 LDGO E of Old Town, ME
Note: This is the largest event in New England in more than 1.5 years
(see earlier reports). A regional aftershocks of Ml 2.3 occurred
about 8 hours later in the Charlevoix Seismic Zone, Quebec (see
above event). The area was expected to be active at this
time with FFAs from the Banda Sea. The FFA forecast had stated:

"Areas of U.S. and Canada where triggering may occuR (Ml>=3)

New England/Eastern New York"

ALASKA

O: 25Oct2001 13:01:36 62.2N 151.0W ML>3.0 NEIS CENTRAL ALASKA
O: 26OCT2001 19:17:09 62.4N 149.5W ML=3.1 AEIC ENE of Talkeetna, Alaska

O: 26OCT2001 20:14:03 59.9N 150.1W ML=3.0 AEIC SW of Seward, Alaska

HAWAII

O: 26OCT2001 12:39:39 20.0N 155.5W ML=3.1 HVO SSW of Honoka`a, Hawaii
O: 26OCT2001 10:45:38 20.0N 155.5W ML=3.2 HVO SSW of Honoka`a, Hawaii
O: 26OCT2001 9:43:14 20.1N 155.5W ML=3.1 HVO S of Honoka`a, Hawaii
Note: These are the 3th, 4th and 5th earthquakes of ML>=3 in the five
days since the Banda Sea and New Zealand earthquakes. There had been
no earthquakes of Ml>=3 in the region in the previous month. The area
had been expected to experience heightened seismicity as per FFA forecasts:

From New Zealand:

"Other areas which should be watched
Hawaii"

and
59-61 degrees: .... Hawaii"

These events lie at 60 degrees from the New Zealand mainshock