MODERATELY STRONG EARTHQUAKE HIT MANY PORTIONS OF ASIA

SUMMARY

Many portions of Asia have experience moderately strong earthquakes
in the past 24 hours. All of these events were at locations where
FFA triggering was expected, and none could be considered as surprises.
Most were also within 30 degrees of a sub- or anti-solar longitude
at the times of two recent solar flares.

The most interesting from a triggering point of view is the
event which happened in the Mindanao region as this report was being
prepared. This event with initial Mb 5.5 (NEIS) occurred during a M1.4
solar flare. The epicenter of the Mindanao earthquakes was almost
exactly sub-solar (that is it was local sun-noon) at the time of
the earthquake. This suggests a direct relationship betwen the
flare and the simultaneous earthquake.

Other earthquakes today occurred as an Mb 5.6 in the Tajikistan-Xinjiang
China area about 400 km northeast of the recent activity in Hindu Kush.
This earthquake was ideally located for FFA effects. An earthquake of
Mb 5.6 also hit the northern Molucca area and a slightly smaller event
was observed in Kamchatka (magnitude is currently about 5.0-5.5).
Central Philippines (Luzon) was also subject to a Mb 5.0 event earlier
today. All were likely influenced by FFA effects. For details of FFA
distances and forecasts for these events see the Earthquake epicenter
portion of this report.

GLOBAL

Other listed earthquakes today occurred in the Volcano Islands (Mb 5.0);
northern and southern Italy (ML 3.5 and 3.5) and Tunisia (Ml 3.8).
Mexico reported events in Michoacan (Ml 3.9) and Guerrero (series
Ml 3.5-4.5) today.

U.S./CANADA

Activity appeared to be increasing on the southern San Andreas
fault today in the area of San Ardo/Tres Pinos. This often precedes
stronger activity to the north. A minor swarm of 4 Ml>=2 events
occurred in the Tres Pinos area (Ml 2.4, 2.1, 2.0, 2.0) and was followed
later this evening by a Ml 2.0 west of Parkfield near San Ardo, CA.
The only other event of Ml>2 in the Central California area was an
MD 2.0 near Mammoth Lakes.
In southern California only two events of Ml>2 were recorded since
the last summary - a Ml 2.3 near Ridgecrest and a Ml 2.0 near Obsidian
Butte.
In the past week only one earthquake outside of the Calexico area
has reached Ml>3 levels in the California/Nevada area - a Ml 3.3
near the Geysers on April 6 a full week ago. Often after these
long lulls in activity, a strong revival occurs especially if there
are external factors such as a strong flare or geomagnetic storm
situated to have a major impact on this area.

Other areas of the U.S. and Canada were not reporting earthquakes
today or had no significant events to report.

NEW ZEALAND

IGNS reported two small, but felt events today. One in the Poranghau
region on the southeast portion of North Island (Ml 3.3) and the other
near Lewis Pass (Ml 3.4) on South Island. The IGSN on-line seismogram
showed only minor regional activity.

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 slightly disturbed today with arrival
of CME wind from the recent M-class solar flares. There were no
new M- or X-class flares on April 13, however, an M-class flares
has occurred this evening at about 03:21 UT with the following
parameters:

Flare # START MAX END CLASS
0321 0351 0409 M1.4

A Mb 5.5 earthquake occurred in the Philippines and was simultaneous
with this flare. At the time the Philippines epicenter was exactly
sub-solar.

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

April 15 is the third 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

Alaska MB>=4.0 6 1.9 0.05
Central California MB>=2.0 9 2.3 0.05
Mammoth Lakes MB>=2.0 45 2.3 0.05
Mammoth Lakes MB>=3.0 23 2.6 0.03
Mt ST.Helens MB>=1.0 29 2.2 0.05
Spain MB>=4.0 31 2.2 0.05
Arctic MB>=4.0 36 2.3 0.04
Caribbean MB>=4.0 27 3.0 0.01
Caucasus MB>=4.0 23 2.9 0.01
So. California MB>=0.0 10 2.7 0.03
So. California MB>=2.0 22 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

No Regions

TOMORROW IN EARTHQUAKE HISTORY

GLOBAL:

The following events of Mw>=7 have occurred on this date in
recorded history:

MO DA HR MN SC YEAR LATIT LONGIT DEP MW LOCATION

4 14 15 0 0 1700 33.090 129.060 0 7.0 Kyushu, Japan area
4 14 19 53 42 1909 24.000 123.000 80 7.3 Taiwan
This earthquake was followed the next day by a Ms 6.5 in
Yunnan China which killed 19 persons. FFA?

4 14 16 20 23 1924 6.500 126.500 60 8.3 Mindanao, Philippines
This is called the Mati earthquak becuase this town on the Pacific
Coast was the nearest to and suffered it most disastrous effects.
It was one of the greatest submarine disturbances originating
in the West Pacific. There was massive destruction in towns
to 8N. Interior partitions were most affected. Fissures and ground
slides abounded in the hills and rockfalls were plentiful. Subsidence
also occurred in alluvial soils. A tsunami flooded low coastal area
but did little damage.

4 14 6 23 34 1927 -32.000 -69.500 110 7.1 Central Chile
4 14 7 15 37 1947 43.600 148.400 60 7.3 Hokkaido, Japan
4 14 0 45 29 1951 -23.300 -66.400 223 7.0 Argentina
4 14 1 28 54 1955 30.400 102.400 0 7.2 So. China
Killed 39 and did moderate damage in Sichuan, China.

4 14 19 18 0 1957 -15.000 -173.250 0 8.0 Samoa Islands
No destruction despite the magnitude beause it hit in a relatively
unpopulated area.

U.S./CANADA

Following are events of Mb>=5 which have occurred in this region on
this date.

4 14 3 20 0 1886 37.200 -117.700 0 5.0 California/Nevada area
This local earthquake broke many dishes in Lida Valley. A dull
thunderous noise preceded the shock.

4 14 21 26 32 1934 41.500 -112.500 0 5.6 Montana/Idaho

4 14 11 3 48 1950 48.000 -122.500 0 5.0 Washington state, U.S.
Near Langley, Washington. May persons awakened in Coupeville.
Plaster cracked and fell.

4 14 20 39 1 1957 51.100 -178.800 33 6.0 Andreanoff Islands, Aleutians
4 14 7 20 28 1959 57.900 -155.000 67 6.0 Southern Alaska
4 14 0 37 52 1960 48.500 -130.400 0 5.7 Vancouver Island area
4 14 7 53 15 1962 40.270 -125.320 0 5.4 Off Coast of No. California
4 14 15 55 8 1964 61.430 -147.120 5 5.4 Central Alaska
4 14 16 59 33 1964 61.490 -150.440 56 5.1 Central Alaska
4 14 22 55 31 1964 58.000 -152.600 30 5.4 Southern Alaska
4 14 7 35 39 1965 56.300 -153.500 27 5.0 Southern Alaska
4 14 15 43 11 1974 64.200 -174.000 15 5.6 Northern Alaska
4 14 13 49 4 1980 46.203 -122.197 1 5.2 Washington state, U.S.
Volcanic activity at Mt. St. Helens prior to explosive eruption.

4 14 16 0 42 1981 52.170 -169.400 37 5.2 Fox Islands, Aleutians
4 14 14 23 8 1987 53.700 -169.700 0 5.1 Fox Islands, Aleutians
4 14 5 33 26 1990 48.845 -122.161 12 5.0 Washington state, U.S.
Slight damage (VI) in the Deming area. Felt (V) at Acme and
(IV ) at Bellingham to Mt. Vernon.

4 14 5 58 32 1993 51.160 -169.010 34 6.0 Fox Islands, Aleutians
4 14 0 32 58 1995 30.290 -103.450 21 5.7 SW U.S.A
Two people slightly injured in Brewster county, Texas. Slight damage
at Alpine and Fort Davis. Also slight damate in Marathon and Ozona
area. Felt in much of western and central Texas as far east as San
Antonio and the Dallas-Fort Worth area. Felt west as far as Sierra
Blanca, Texas and north to Roswell, New Mexico.

4 14 2 20 13 2001 56.080 -119.810 10 5.4 Alberta

EARTHQUAKE LOCATIONS

ASIA

O: 14APR2002 04:05:24 7.3N 126.3E Mb=5.5 NEIA MINDANAO, PHILIPPINE ISLANDS
Note: This event occurred at nearly local sun-noon as a strong M-class
solar flare was erupting directly overhead. The area had also been expected
to see strong FFA effects from the Taiwan/Ryukyu earthquakes and more
recently from the event south of Australia. This epicenter is at 17 degrees
from the Taiwan mainshock and 60 degrees from the event south of Australia.
The Taiwan FFA forecast had noted as a possibility:

"The most likely events of Mw>=5 in the next 10 days appear to be:

Central Philippines"

and

"17-19 degrees: ... Halmahera"

while the FFA forecast from south of Australia had stated:

"59-61 degrees: ... Mindanao"

and

" The most prominent locations appear to be ...
Luzon and Talaud/Halmahera Philippines"

O: 13APR2002 15:36:00 1.2N 125.1E Mb=5.6 NEIA NORTHERN MOLUCCA SEA
O: 13APR2002 15:36:29 2.1N 125.1E MB=5.8 GSSC TALAUD ISLANDS, INDONESIA
Note: This event occurred 146 degrees from the Central Chile earthquake
and had been an expected FFA location:

"142-146 degrees: ... Moluccas"

A strong M4.0 solar flare occurred on April 12, 2002 at 17:31 UT. This
epicenter is within 30 degrees of the antisolar longitude (97.5E)
at the time of that flare and may have been affected by that flare
occurrence.

O: 13APR2002 13:27:13 18.2N 120.7E MB=5.0 NEI LUZON, PHILIPPINES
Note: This event occurred at 72 degrees from the mainshock south of
Australia and was an expected FFA. The FFA forecast had stated:

The most prominent locations appear to be ... Luzon ... Philippines"

and

"71-73 degrees: Luzon, No. Marianas"

A strong M4.0 solar flare occurred on April 12, 2002 at 17:31 UT. This
epicenter is within 30 degrees of the antisolar longitude (97.5E)
at the time of that flare and may have been affected by that flare
occurrence.

O: 13APR2002 06:18:17 53.1N 159.6E MB=4.7 NEI NEAR EAST COAST OF KAMCHATKA
Note: This event had been anticipated as a FFA from both the event south
of Australia and from the Taiwan earthquake. From the FFA forecast from
Australia we read:

"103-106 degrees***: ... Kamchatka (wavefront parallel to
arc in this area - larger event possible)"

and from the FFA forecast from Tawain we find:

"Other possible events of Mw>=4.5 in the next 10 days appear to be:

...Komandorsky/Kamchatka/No. Kuriles"

A strong M8.2 solar flare occurred on April 11, 2002 at 12:23 UT. This
epicenter is within 30 degrees of the antisolar longitude (174E)
at the time of that flare and may have been affected by that flare
occurrence.

O: 13APR2002 17:12:46 22.9N 142.6E MB=5.0 GSSC VOLCANO ISLANDS, JAPAN, REGION
Note: This event falls 74 degrees from the Indian-Antarctic Ridge
event in an area where FFA were expected:

"71-73 degrees: ...... No. Marianas "

It also occurred 19 degrees from Taiwan. The FFA forecast from Taiwan
had stated:

"17-19 degrees: ... Volcano Is."

O: 14APR2002 01:59:42 38.5N 73.4E Mb=5.6 NEIA TAJIKISTAN-XINJIANG BORDER REG
Note: This is probably a FFA aftershock with contributions
from several sources and a near field aftershock from Hindu Kush.
It lies at FFA distances from northern Chile (143 degrees - IOC shadow
zone boundary); at 106 degrees (CM shadow zone boundary) from the
event south of Australia and at 45 degrees from Taiwan and The Ryukyu
Islands. It also lies within the 5 degrees local triggering boundary
from the Hindu Kush events.

O: 13APR2002 10:01 35.9N 139.6E Mj=4.1 NIED EASTERN_SAITAMA_PREF, Japan

O: 12APR2002 21:02:23 24.5N 121.8E ML=4.4 TAI Ilan, Taiwan

O: 12APR2002 23:46:09 37.4N 72.3E ML=4.8 KYZ Robat, Tajikistan
O: 12APR2002 04:56:57 37.8N 72.4E ML=4.8 KYZ NNW of Bachor, Tajikistan KYZ
O: 11APR2002 18:48:30 37.9N 71.7E ML=4.2 KYZ NW of Rid-Devlekh, KYZ

O: 12APR2002 04:58:41 38.5N 71.9E ML=4.2 KYZ E of Rovand, Tajikistan KYZ

SOUTH PACIFIC ISLANDS

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 13APR2002 05:28:30 18.4N 103.5W ML=3.9 SSN COSTA DE MICHOACAN, MEXICO

O: 12APR2002 11:29:06 16.8N 99.6W ML=3.4 SSN COSTA DE GUERRERO, MEXICO

O: 12APR2002 17:01:27 17.1N 100.2W ML=3.2 SSN GUERRERO, MEXICO
O: 12APR2002 15:46:32 17.1N 100.5W ML=3.7 SSN GUERRERO, MEXICO
O: 12APR2002 12:02:23 16.9N 100.2W ML=3.4 SSN COSTA DE GUERRERO, MEXICO
O: 12APR2002 11:51:19 16.9N 100.1W ML=3.4 SSN COSTA DE GUERRERO, MEXICO

NEW ZEALAND

O: 13APR2002 12:49 40.5S 176.7E ML=3.3 IGNS South of Porangahau, N.Z.

O: 13APR2002 19:55 41.6S 171.9E ML=3.4 IGNS NE of Westport, N.Z.
Note (IGNS): May have been felt on the West Coast of the South Island
near Westport.

Note (ED): A strong M8.2 solar flare occurred on April 11, 2002 at 12:23 UT.
These epicenters are within 30 degrees of the antisolar longitude (174E)
at the time of that flare and may have been affected by that flare
occurrence.

OCEANIA

EUROPE/MIDDLE EAST/AFRICA

O: 13APR2002 20:30:10 37.9N 10.0E Ml=3.8 INGV TUNISIA

O: 13APR2002 12:58:59 41.5N 12.4E Ml=3.4 SED SOUTHERN ITALY

A strong M8.2 solar flare occurred on April 11, 2002 at 12:23 UT. This
epicenter is within 30 degrees of the sub-solar longitude (6W)
at the time of that flare and may have been affected by that flare
occurrence.

O: 13APR2002 20:33:35 39.0N 26.7E ML=3.2 KAN AEGEAN SEA, TURKEY

O: 13APR2002 01:34:09 37.3N 36.3E ML=3.0 KAN OSMANIYE, TURKEY

U.S/CANADA

CALIFORNIA/NEVADA

O: 13APR2002 00:14:58 37.6N 118.8W ML=2.0 NCSN W of Toms Place, CA

O: 13APR2002 00:43:00 35.6N 117.6W ML=2.3 SCSN E of Ridgecrest, CA

O: 13APR2002 05:12:00 36.8N 114.9W ML=1.4 NCSN SW of Hoya, NV

O: 13APR2002 11:21:25 36.7N 121.3W ML=2.4 NCSN SSE of Tres Pinos, CA
O: 13APR2002 14:45:32 36.7N 121.3W ML=2.0 NCSN SSE of Tres Pinos, CA

O: 13APR2002 14:48:34 40.1N 119.7W ML=1.6 NCSN SSE of Zenobia, NV

O: 13APR2002 15:33:07 36.0N 121.0W ML=2.0 NCSN W of San Ardo, CA

PACIFIC NORTHWEST/CANADA

ROCKY MOUNTAIN AREA

O: 9APR2002 01:20:47 47.0N 114.3W ML=1.4 MBMG near Frenchtown

O: 9APR2002 21:50:06 45.2N 112.7W ML=1.6 MBMG near Dillon

O: 10APR2002 09:16:44 47.5N 115.8W ML=1.5 MBMG near Mullen, ID

O: 10APR2002 15:01:35 46.1N 112.1W ML=1.6 MBMG 20 km N of Whitehall

O: 10APR2002 21:47:26 44.8N 111.5W ML=2.2 MBMG S Madison Valley; Felt

O: 10APR2002 22:19:51 46.0N 111.4W ML=2.1 MBMG Clarkston Valley
O: 9APR2002 05:05:02 46.0N 111.4W ML=2.0 MBMG Clarkston Valley

O: 11APR2002 05:05:37 46.9N 113.2W ML=1.5 MBMG 15 km W of Helmville

EASTERN U.S./CANADA

ALASKA

HAWAII