SEISMICITY HEATS UP FOLLOWING AFTERNOON SOLAR FLARE AND PROTON STORM

SUMMARY

Global seismicity remained in the doldrums today until a moderately
strong solar flare occurred at 10:12 UT maximizing at 11:14 UT (M1.6).
Several hours later a mild proton storm began at 14:00 UT. The first
event of Ms>5.2 occurred about fours hours later in the Talaud
Islands south of the Philippines (Ms 5.4). The flare occurred while
areas within 30 degrees longitude of 30E were sub-solar and those
within 30 degrees of 150W were anti-solar. These area may experience
a slight increase in seismicity over the next day. The proton storm
occurred while areas within 30 degrees of 30W were subsolar. This
includes mostly areas of the Mid-Atlantic Ocean and the western
Pacific (anti-solar). The first and largest earthquakes to occur
after these events reflected this pattern with three of four
in these longitude bands.

GLOBAL

The largest earthquake of teh day was a Ms 5.4 in the Talaud
Islands region south of Mindanao, Philippines. This may be a
reaction to the strong Mindanao event earlier this month, or may
be a new, unrelated epicenter. Two earthquakes of Ms 5.0 and
5.2 occurred in the western portion of Papua New Guinea, also
an area under seismic watch conditions at the time of these
events.
The Fiji Islands continued active with an earthquake of Mb 4.4.
There have been 5 such earthquakes in this area in the past four
days. Other events which were listed today were an Mb 4.2 in
Jalisco, Mexico and a Ml 3.0 near San Jose, California; a Ml 4.9
in the Hindu Kush area of Afghanistan; a Ml 4.3 in the Bonin
Islands south of Japan and a Mb 4.6 in the Andaman Islands of
eastern India. A Mb 4.5 was also recorded in Argentina today.

U.S./CANADA

One earthquake of Mb>=3 was recorded in the California/Nevada
area - at Coso Junction (Ml 3.0). Oddly, this was a lone earthquake.
Events of this size or larger at Coso Junction area often
are accompanied by a swarm of lighter events.
California saw six earthquakes of Ml>=2 today. Four of these
occurred in southern California - in the Calexico swarm (Ml 2.8);
off shore near Santa Barbara (Ml 2.9); near Chino (Ml 2.5);
and south of Coso Junction (Ml 4.0). The other two occurred
in northern California at San Jose (Ml 2.7) and at an unusual
epicenter directly north of Parfield (Ml 2.2).
The minor swarm of events of Ml>=2 continued at Yellowstone
Park today with events of Ml 2.1, and 2.2, An Ml 2.4 also
hit near E. Carbon City, WY this afternoon. This is about
500 km south of Yellowstone.
Only one event of Ml>=3 was recorded elsewhere in the U.S./Canada
today - a Ml 3.1 in southern Alaska.
PGC from western Canada did report two events of Ml 3.5 -
one in western Vancouver late last night and a Ml 3.5 at
Sach's Harbor in northern Nunavit this afternoon.
Other areas of the U.S/Canada did not report any events
of Ml>=2 today.

NEW ZEALAND

Two light earthquakes may have occurred in the vinicity
of Cannon Point, New Zealand today, however IGNS was off
for the Saturday and weekend and did not report earthquake
parameters 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 remained quiet today despite the
occurrence of a mild proton storm starting at about 14:00 UT
and a moderate M1.6 solar flare beginning at 10:12 UT.
A moderate increase in seismicity is expected in areas
sub-solar at the start of flare 4080.

Flare # START MAX END CLASS

4080 1012 1114 1152 M1.6

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20020322events.txt

TIDAL EFFECTS

March 25 is the twelvth 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

Australia MB>=4.0 38 3.0 0.01
So Indonesia MB>=4.0 49 3.7 0.01
Global MB>=5.0 5 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

Tonga MB>=4.0 -28 -2.0 0.05
Turkey MB>=4.0 -10 -2.0 0.05

TOMORROW IN EARTHQUAKE HISTORY

GLOBAL:

No damaging earthquakes have been recorded on this date in earthquake
catalogs. Earthquakes of Mw>=7 have occurred mostly in unpopulated
areas or at great depth on this date. The Kuril Island swarm that
was noted in yesterdays history section which occurred in 1978
continued on March 23, 1978 unabated. Following are the earthquake
of Mw>=7 which have been recorded on March 23:

3 23 20 47 18 1913 24.000 142.000 80 7.0 VOLCANO ISLANDS
3 23 23 14 13 1945 -62.000 153.000 60 7.1 MACQUARIE ISLANDS
3 23 21 38 51 1951 -32.070 -179.430 326 7.1 KERMADEC ISLANDS
3 23 5 12 43 1957 -5.500 131.000 147 7.3 BANDA SEA
3 23 7 32 36 1975 22.740 122.800 21 7.0 TAIWAN REGION
3 23 0 31 1 1978 44.270 149.010 40 7.6 KURILE ISLANDS
3 23 3 15 20 1978 44.932 148.439 33 7.5 KURILE ISLANDS
3 23 19 12 24 1978 44.400 149.630 44 7.1 KURILE ISLANDS

U.S./CANADA

In California/Nevada an earthquake of M 5.5 occurred on this
date in 1872, This event occurred near Austin, NV in southern
Lander County. Plaster fell in the Austin Courthouse. The
event was described as a violent shock. Three days later
one of the largest earthquakes in recent California history
was recorded several hundred km South of this in Owens Valley.
Was this a precursory shock to the Owen's Valley event?
The largest shock on this date in the California/Nevada
region and in the U.S./Canada occurred 87 years later in 1959 in
the same area as the earthquake of March 23, 1872. This event
near Dixie Valley, NV cracked plaster from Carson City to
Frenchman Station (Mw 6.3). The top of a new addition to the
State printing office was also damaged. No fresh ground cracks
could be found following this earthquake. Stronger events in
the Dixie Valley region had occurred in 1954 with much ground
cracking.