FOUR LIGHT EARTHQUAKES HIT EASTERN U.S./CANADA

SUMMARY

In the past 24 hours four light, but unusual earthquakes have hit in
the eastern U.S. and Canada. These earthquakes have occurred in
Oklahoma (Ml 2.5), Missouri (Ml 3.6), off the southern coast of
Maine (Ml 3.3) and in southeastern Quebec, Canada (Ml 2.4). In each
case the event was the largest in at least a year in the general
area of the epicenter. Most of these events appear to be expected FFA from
Hindu Kush.
Following is a brief summary of these events:

OKLAHOMA:

O: 12MAR2002 10:52:04 34.3N 97.6W ML=2.2 TUL JEFFERSON? OK
O: 12MAR2002 10:52:04 34.3N 97.6W LG=2.5 NEI OKLAHOMA
O: 12MAR2002 10:52:04 34.3N 97.6W ML=2.5 CERI NNW of Cornish, OK

Note: This earthquake occurred at a distance (108 degrees) and area where
FFA from Hindu Kush were expected. This is the largest earthquake
listed in Oklahoma by CERI since a similar event of Ml 2.6 on Jan. 25, 2002.

MISSOURI:

O: 12Mar2002 08:30:48 37.2N 90.0W LG=3.6 NEI CAPE GIRARDEAU, MISSOURI
O: 12MAR2002 08:30:47 37.1N 90.0W LG=3.6 NEI EASTERN MISSOURI
O: 12MAR2002 08:30:47 37.1N 90.0W ML=3.6 CERI WNW of Advance, MO

Note: This may also have been a Far-Field aftershock from Hindu Kush as it
lies at a distance Of 104 degrees from that event at the p- and s-wave
core-mantle shadow zone boundary, an area where seismic energy is
concentrated after strong earthquakes. The FFA forecast From Hindu Kush
had suggested the possibility:

"Areas of U.S. and Canada where triggering may occur (Ml>=3.5)

Southern states (... Missouri)"

This is the second event in the U.S. of Ml>3.5 (NEIS) at this
distance from Hindu Kush - the other being the Mammoth Lakes
earthquake yesterday (Ml 3.7). A Ml 2.8 also occurred at 104 degrees
from Hindu Kush in Utah two days ago.

Yesterday's earthquake summary had included a discussion on
other events lying at this core-mantle boundary shadow zone including
the Ml 5.0 in the Virgin Islands yesterday, the largest there
in some time as well.

The complete listing of possibilities for this distance was given
in the FFA forecast as:

"103-107 degrees***: Central California from Pinnacles to Mammoth
Lakes, north to San Francisco, south to L.A. Virgin Islands,
Leeward Islands, Central Vanuatu Islands."

Moderate or unusual earthquakes have now occurred in each area
mentioned.

OFF SOUTHERN COAST OF MAINE:

O: 12MAR2002 07:13:23 41.2N 69.6W Ml=3.2 LDGO SE of South Yarmouth, MA
O: 12Mar2002 07:13:25 41.6N 69.3W LG=3.0 NEI SOUTHERN NEW ENGLAND
O: 12MAR2002 07:13:22 41.2N 69.1W MN=3.0 GSC ATLANTIC OCEAN.

Note: This is a highly unusual event. NO earthquakes have ever
been located within 50 km of this epicenter.

SOUTHEAST QUEBEC:

O: 11MAR2002 15:16:17 50.1N 65.3W MN=2.4 GSC E FROM SEPT-ILES, QUE.

Note: This is also an unusual earthquake. It is the largest event within
50 km of this epicenter since Dec 10, 2000 when a Ml 3.0 occurred.
In the last 6 years only 4 events of Ml>=2.4 have occurred in this
50 km radius. The last occurred in 2000.

There have been occasions in the past, most notably prior to the
great Alaska earthquake of March 28, 1964, when a series of aligned
earthquakes occurred prior to a great earthquake at an FFA distance
to that event. These events all lie approximately 60 degrees from
a location in Northern Chile at about 20N 68W (or it's antipode at
20N 112E), although there is enough give and take in the alignment
that a number of other focal points could be found (such as Taiwan,
So. Sandwich Islands, etc.). Generally these alignments of quakes
in the eastern U.S. appear to presage great events by no more than
2 days, but there are also cases where no great event follows.
Coincidentally, several hours after these four events occurred
(three occurred within 4 hours of each other) the largest earthquake
of the day hit at 20S 68W with Ms 5.2 in Northern Chile.

GLOBAL

The largest earthquake recorded in the world today was the Ms 5.2
in northern Chile which immediately followed the series of light
earthquakes in eastern North America which were all approximately
60 degrees from the Chile epicenter. Other earthquakes of Mb>=4.5
occurred in the Andaman Islands, India (Mb 5.0) and in Northern
Xinjiang, China (Mb 4.7).

U.S./CANADA

The highly unusual activity in the eastern area of North America
today is discussed in the summary above. No earthquakes of Ml>=3
hit in Alaska, Hawaii or U.S. possessions today and other areas of
the U.S. showed very light activity as well.
No Ml>=2 earthquakes occurred in the Pacific Northwest or the
Rocky Mountain regions today.
In California, there were no earthquakes of Ml>=2 in the Calexico
swarm for the first time in nearly two weeks. Other areas
of southern California were also very quiet.
Central California also was at extremely quiet conditions today
after a highly seismic day yesterday. After 12 events of Ml>=2
were recorded in the NCSN area on March 11, only one small M2.1
occurred in that area today (at the Geysers).
Extreme quiet conditions often seem to occur before strong
activation in California, but this is not always the case.

NEW ZEALAND

A Ml 3.4 was located near Weber, N.Z. south of Hawke's Bay
this morning. Otherwise, seismicity of the Islands was relatively
subdued today.

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 was quiet today. One M-class flare
was observed with the following parameters:

Flare # START MAX END CLASS

1150 2301 2313 2324 M1.5

No strong or moderate seismic activity was associated with this flare.

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20020312events.txt

TIDAL EFFECTS

March 15 is the first day after the beginning of the new 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

Caucasus MB>=4.0 18 2.3 0.04
Idaho MB>=1.0 20 2.6 0.03
Italy MB>=4.0 43 2.8 0.02
Kuriles MB>=4.0 34 2.9 0.01
Tonga MB>=4.0 27 1.9 0.05
Mammoth Lakes MB>=0.0 46 2.0 0.05
Mammoth Lakes MB>=2.0 37 1.9 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

Central America MB>=4.0 -10 -2.0 0.05
Canada MB>=0.0 -29 -2.5 0.03
So. Alaska MB>=3.0 -7 -2.2 0.05

TOMORROW IN EARTHQUAKE HISTORY

The largest and most destructive earthquakes on this day in recorded
history have each occurred near Southern Honshu, Japan. The largest
was a Mw 8.3 off the southeast coast of Honshu, near the epicenter
of yesterday's Mb 5.9 on March 13, 1909. This was under the ocean
at a depth of 80 km and no record of damage has been passed down.
The most destructive event occureed 36 years earlier in 1872 in south-
western Japan near Hamada. Damage was severe and over 600 were killed.
A strong destructive tsunami was also generated with this event.
This earthquake was followed less than two weeks later by one of
the strongest earthquakes ever recorded in California - the Owen's
Valley earthquake of March 26, 1872 (Mw 8.5). Owen's Valley is
southeast of Mammoth Lakes.
The second most destructive event on this day occurred in 1992 in
eastern Turkey as a Mw 7.3. At least 500 people were killed and
2,000 injured in the Erzincan area of Turkey were thousands of
homes were heavily damaged. Landslides and avalanches blocked
a number of roads in the region of the epicenter.

U.S./CANADA

Aftershocks continued in the Aleutians in 1957 and in Long Beach
CA in 1933 on this day, but the largest mainshocks of the day both
occurred in the Pacific Northwest. The first of these was a Ms 6.1
off of Vancouver Island in 1971 about a month after the San Fernando
earthquake on Feb 9, 1971; the second was a Ms 6.3 off the coast
of Oregon which was felt mildly at Cottage Grove and Portland areas
in Oregon and as far north as Forks and Takeland, Washington. Neither
of these events were damaging. Vancouver Island observed the 8th
anniversay of the 1971 earthquake with a series of shocks in the
Ms 5-6 range on MArch 13, 1979.
Strong earthquake occurred on March 13 in the Andreanoff Islands
area of Alaska in 1957 (Ms 6.9); 1965 and 1967 (Fox Islands, Ms 5.5, 5.1);
1985( Ms 5.1); 1992( Ms 6.3) and 1994 (Ms 5.6).