Ml 5.0 HITS OFF EAST CAPE, NEW ZEALAND

SUMMARY

An earthquake of Ml 5.0 occurred this afternoon off the east
Coast of North Island, New Zealand. This event may have been
felt in the East Cape region according to IGNS. Coincidentally,
the one of the strongest solar flares (M8.2) this year
had occurred at 12:23 UT when the longitude of the epicenter
in New Zealand was nearly exactly anti-solar, and would experience
maximum effects from such a flare.
In another interesting coincidence CSEM has listed an event
at nearly the exact antipode of the New Zealand earthquake of Ml
5.3 in the Balearic Islands, Spain at 15:11 UT this afternoon about
9 hours before the New Zealand earthquake.

GLOBAL

The largest earthquake of the day was a Mb 5.7 in the southern
Vanuatu Islands. This event continued the series of strong regional
events that have occurred in the past several days (Balleny Isl.,
Antarctic-Indian Ridge). Other activity of Mb>4.5 occurred in the
Mariana Islands (Ms 5.0).

The strong seismicity of the past several days in mid-Ocean ridge
systems continued today with new epicenters occurring in the Central
Mid-Atlantic Ridge (Mb 4.4) and the south Mid-Atlantic Ridge (Mb 5.1 and
5.2) and in the Labrador Sea east of Canada (Ml 2.9).

Other moderate activity occurred in northern Chile (Mb 4.4), and in
Sichuan China (Mb 4.5). The Sichuan event is nearly antipodal to the
Mw 6.5 in Central Chile last week. The Labrador Sea earthquake also
is in the antipodal region of the Mw 6.2 south of Australia two
days ago.

U.S./CANADA

The strongest regional events of the day occurred off the Coast of
Northern California this morning (PDT). These events followed by
several hours the strong M8.2 solar flare and registered Mb 4.0 and
3.7 (NEIS).

In the rest of the region of California/Nevada the strongest
the strongest event of the day occurred off the Coast of Southern
California near Pt. Conception, although this is a poorly located
event and the epicenter could change considerably before finalized.
Preliminary Ml for this earthquake is Ml 2.6. Five other events (Ml>=2)
occurred in the SCSN region today - four in the Calexico swarm area
(all about Ml 2.1-2.3) and the other near Tehachapi (Ml 2.0). In
northern and Central California, the only such event was a Ml 2.5
near Mammoth Lakes (other than the events off the No. Coast).

The Pacific Northwest, however, showed a substantial increase
in activity today. Three events of Ml>=2 were recorded today in
the PNSN region after nearly two weeks in which only one such event
had been recorded. The PNSN searchable catalog also shows a strong
(Ml>=3) event near Helena, Montana this afternoon in addition to
a newly listed Ml 3.7 on the Oregon-Idaho border which occurred
on April 6, a significant event for this region.

The eastern U.S. and Canada also saw renewed activity in the
past day and a half. In addition to an event at New Madrid (Ml 2.2),
the first in that area in more than a month, the region of southern
Quebec to New Brunswick was once again active in the past two days
with events of Ml 2.4 in New Brunswick and Ml 2.0, 1.9, 1.8 and 1.7
in the southern Ontario/Quebec region.

No events of Ml>3 were listed in either Hawaii or Alaska today.
A Ml 0.7 event was felt SE of Abbotsford B.C (hard to believe
but true).

NEW ZEALAND

The Ml 5.0 off the East Cape has been discussed in the summary above.
QED also listed several new IGNS events in the Ml 3.5-4.0 range
today which occurred over the weekend. These generally occurred
off North Island. Parameters are listed below.

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, however SEC expects
active to stormy conditions in two to three days when the CME
from today's M8.2 flare arrives. There were two M-class solar flares
observed today. About 20:00 Electron Flux became erratic, often
a sign of a geomagnetic storm in the brew. Most of the strong
seismicity of the day followed the M8.2 flare in time.

Flare # START MAX END CLASS

9220 1223 1231 1240 M8.2
9320 1848 1907 1915 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/20020312events.txt

TIDAL EFFECTS

April 12 is the first day of the new lunar month (new moon).
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 9 2.6 0.03
Aleutians MB>=4.0 38 2.9 0.02
New Britain MB>=4.0 26 2.7 0.02
N Indonesia MB>=4.0 37 2.0 0.05
Central So America MB>=4.0 20 2.0 0.05
Kuriles MB>=4.0 36 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

East Pacific Rise MB>=4.0 -40 -2.4 0.04
Canada MB>=0.0 -23 -2.0 0.05

TOMORROW IN EARTHQUAKE HISTORY

GLOBAL:

April 11 is a relatively light day in global earthquake and U.S. history
with the only damaging event in Chile in 1819.

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 11 15 0 0 1819 -27.350 -70.350 0 8.3 Coast Central Chile
Additional severe damage occurred in Copiapo following three other
damaging event in the month of April 1819. The whole city had been
destroyed by the shocks of April 3 and 11. The inhabitatns barely
had time to escape. There are no estimates of deaths in this event.

4 11 10 42 2 1925 -34.000 59.000 60 7.0 So. Indian Ocean
4 11 1 52 20 1946 -1.000 -14.500 60 7.2 No. of Ascension Isl
4 11 23 11 33 1958 47.800 152.640 140 7.4 So. Kurils

U.S./CANADA

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

4 11 19 0 0 1872 37.500 -118.500 0 6.9 California/Nevada area
Felt strongly at Round Valley, Inyo Country, CA. this shock
knocked down stone buildings and frame structures were twisted. This
was probably an aftershock of the Owen's Valley earthquake of March
26, 1872.

4 11 7 57 0 1910 33.670 -117.320 0 5.0 So. California
4 11 19 0 0 1917 40.000 -118.000 0 5.1 Montana/Idaho
No confirmation for either of these two events could be found.

4 11 11 22 57 1945 42.000 -126.000 0 5.0 Off Coast of Oregon
4 11 7 47 7 1947 34.966 -116.550 16 5.0 So. California
Aftershock of event of April 10 same area.

4 11 17 41 15 1957 52.000 -168.500 0 5.2 Fox Islands, Aleutians
4 11 11 36 0 1964 60.370 -146.440 15 5.0 Central Alaska
4 11 23 0 24 1966 56.600 -152.100 33 5.4 Southern Alaska
4 11 4 5 43 1970 59.720 -142.490 7 6.2 Southeast Alaska
4 11 5 12 19 1973 64.890 -159.490 0 6.0 Northern Alaska
4 11 5 12 55 1978 53.535 -163.731 33 5.6 Unimak Islands, Aleutians
4 11 1 45 4 1980 49.260 -127.910 10 5.0 Vancouver Island area
4 11 23 51 60 1980 46.208 -122.168 0 5.0 Washington state, U.S.
Part of Mt. St. Helens eruptive phase earthquakes.

4 11 17 22 21 1986 54.164 -167.883 33 6.0 Fox Islands, Aleutians
4 11 16 22 10 1987 53.389 -167.243 37 5.0 Fox Islands, Aleutians
4 11 13 3 38 1991 53.980 -163.900 29 5.7 Unimak Islands, Aleutians
4 11 6 0 55 1993 51.130 -178.420 35 5.8 Andreanoff Islands, Aleutians

EARTHQUAKE EPICENTERS

ASIA

O: 9APR2002 07:19:41 29.8N 140.8E MB=4.3 NEI SOUTHEAST OF HONSHU, JAPAN

O: 10APR2002 11:47:22 11.7N 142.0E MB=5.1 NEI W. CAROLINE ISL, MICRONESIA

O: 10APR2002 12:56:47 24.3N 122.2E ML=4.7 TAI Ilan, Taiwan
O: 11APR2002 03:26:53 24.6N 121.9E ML=4.2 TAI Ilan, Taiwan
O: 11APR2002 00:10:21 24.3N 121.8E ML=4.3 TAI Ilan, Taiwan

O: 11APR2002 02:57:16 24.3N 121.6E ML=4.5 TAI Hualien, Taiwan

O: 10APR2002 16:55 37.1N 138.8E Mj=3.8 NIED MID_NIIGATA_PREF, Japan

O: 9APR2002 13:09:55 14.5N 146.1E MB=4.5 NEI MARIANA ISLANDS

O: 10APR2002 12:40: 23.4N 70.4E ML=4.1 ASC N of Vondh (Gujarat), IMD

O: 10APR2002 12:40: 23.4N 70.4E ML=4.1 ASC N of Vondh (Gujarat), IMD

O: 9APR2002 02:09:43 29.9N 87.9E ML=4.0 ASC of Yagmo (Xizang), China NEI

O: 10APR2002 06:30:18 27.4N 102.5E MB=4.5 NEI SICHUAN, CHINA

SOUTH PACIFIC ISLANDS

O: 10APR2002 10:51:12 20.8S 169.3E MB=4.9 NEI VANUATU ISLANDS
O: 10APR2002 10:09:20 20.8S 169.2E MB=5.9 NEI VANUATU ISLANDS

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 10APR2002 10:44:53 16.9N 100.5W ML=4.0 SSN COSTA DE GUERRERO, MEXICO
O: 9APR2002 12:11:44 17.0N 100.1W ML=3.5 SSN COSTA DE GUERRERO, MEXICO
O: 10APR2002 10:10:10 16.9N 100.5W ML=4.2 SSN COSTA DE GUERRERO, MEXICO
O: 10APR2002 09:58:34 16.9N 100.5W ML=3.8 SSN COSTA DE GUERRERO, MEXICO

O: 9APR2002 15:20:48 16.4N 99.0W ML=4.0 SSN COSTA DE GUERRERO, MEXICO

O: 9APR2002 14:05:59 15.7N 98.8W ML=4.6 SSN COSTA DE OAXACA, MEXICO
O: 9APR2002 19:57:00 15.9N 98.9W ML=4.4 SSN COSTA DE OAXACA, MEXICO

O: 9APR2002 09:24:40 18.9N 103.5W ML=3.9 SSN COSTA DE MICHOACAN, MEXICO

O: 9APR2002 19:57:00 15.9N 98.9W ML=4.4 SSN COSTA DE OAXACA, MEXICO
O: 9APR2002 19:18:10 15.8N 98.7W ML=4.4 SSN COSTA DE OAXACA, MEXICO

O: 10APR2002 00:56:16 6.8N 73.2W Mc=3.5 ULA Dpto. Santander, Colombia.
O: 10APR2002 10:43:31 7.1N 73.4W Mc=3.6 ULA Dpto. Santander, Colombia.
O: 10APR2002 12:13:10 6.8N 73.2W Mc=4.2 ULA Dpto. Santander, Colombia.

O: 10APR2002 09:18:41 8.7N 83.0W MC=3.3 CASC Costa Rica, Central America

O: 9APR2002 16:47:29 18.3S 72.8W MB=4.5 NEI OFF COAST OF NORTHERN CHILE

NEW ZEALAND

O: 11APR2002 01:05 38.1S 179.3E ML=5.0 IGNS East of Tokomaru Bay, N.Z.

O: 7APR2002 20:38:51 37.8S 174.7E MB=3.9 QED NORTH ISLAND, NEW ZEALAND.

O: 7APR2002 13:12:51 40.3S 173.5E MB>3.0 QED COOK STRAIT, NEW ZEALAND.

OCEANIA

O: 10APR2002 00:13:43 44.1S 16.1W MB=5.2 NEI SOUTHERN MID-ATLANTIC RIDGE
O: 10APR2002 10:04:50 44.0S 15.8W MB=5.1 NEI SOUTHERN MID-ATLANTIC RIDGE

O: 10APR2002 01:35:46 59.1N 54.5W ML=2.9 GSC LABRADOR SEA.

EUROPE/MIDDLE EAST/AFRICA

O: 6APR2002 19:16:21 51.5N 16.2E MB=4.0 QED POLAND.

O: 9APR2002 20:25:14 27.2N 33.9E ML=4.1 ISR EGYPT

O: 10APR2002 05:20:58 36.3N 31.0E ML=3.9 KAN AKDENIZ, TURKEY

O: 10APR2002 08:57:31 36.9N 36.0E ML=3.3 KAN DORTYOL (HATAY), TURKEY

O: 9APR2002 23:06:27 40.1N 29.3E ML=3.0 KAN BURSA, TURKEY

U.S/CANADA

CALIFORNIA/NEVADA

O: 10APR2002 16:58:22 40.5N 127.1W ML>3.0 PNSN Off Coast of California
O: 10APR2002 17:35:16 40.9N 126.8W ML>3.0 PNSN Off Coast of California

O: 10APR2002 19:29:42 34.5N 120.6W ML=2.6 SCSN W of Pt. Conception, CA

O: 10APR2002 14:40:33 37.5N 118.8W ML=2.5 NCSN W of Toms Place, CA

O: 10APR2002 16:58:12 40.6N 127.4W MB=4.0 NEI OFF COAST OF N CALIFORNIA

O: 10APR2002 10:59:48 35.1N 118.6W ML=2.0 SCSN W of Tehachapi, CA

O: 10APR2002 15:02:22 32.1N 115.5W ML=2.1 SCSN S of Calexico, CA

O: 10APR2002 17:48:57 32.0N 116.3W ML=2.3 SCSN SSW of Ocotillo, CA

O: 10APR2002 12:01:44 32.8N 117.1W ML=1.7 SCSN NW of La Mesa, CA

O: 10APR2002 12:33:46 33.4N 117.4W ML=1.8 SCSN W of Fallbrook, CA

O: 9APR2002 20:05:39 40.5N 119.4W ML=2.1 REN California/Nevada Border

PACIFIC NORTHWEST/CANADA

O: 10APR2002 12:28:33 48.1N 121.9W ML=2.0 PNSN ENE of Granite Falls, WA

O: 10APR2002 15:26:56 46.6N 122.5W ML=1.1 PNSN W of Mount Rainier

O: 10APR2002 17:34:28 45.9N 120.2W ML=2.3 PNSN SW of Prosser, Wa

O: 6APR2002 11:13:50 44.7N 116.1W ML=3.7 PNSN IDAHO/OREGON BORDER

O: 10APR2002 09:02:58 48.9N 122.0W ML=0.7 PGC SE Abbotsford BC

O: 10APR2002 00:38:23 47.7N 120.1W ML=2.9 PNSN E of Entiat, WA

ROCKY MOUNTAIN AREA

O: 10APR2002 17:05:72 46.5N 111.8W ML>2.5 PNSN Helena, MT region

O: 6APR2002 05:04:56 46.1N 112.1W ML=2.1 MBMG 20 km S of Whitehall

O: 6APR2002 11:13:50 44.7N 116.1W ML=3.7 PNSN IDAHO/OREGON BORDER
O: 6APR2002 19:13:49 44.6N 116.3W ML=3.7 MBMG WNW of Cascade, ID

O: 7APR2002 13:02:34 46.0N 111.4W ML=3.2 MBMG Clarkston Valley
O: 7APR2002 13:29:44 46.0N 111.4W ML=2.5 MBMG Clarkston Valley
O: 7APR2002 16:45:09 46.0N 111.4W ML=2.0 MBMG Clarkston Valley

O: 7APR2002 18:21:13 44.5N 112.7W ML=2.3 MBMG 15 km SW of Lima
O: 8APR2002 08:01:20 44.5N 112.7W ML=2.2 MBMG 15 km SW of Lima
O: 8APR2002 08:25:27 44.5N 112.7W ML=2.5 MBMG 15 km SW of Lima

O: 8APR2002 10:48:52 44.8N 111.1W ML=2.0 MBMG Hebgen Lake region; UUSS

O: 8APR2002 15:09:17 41.1N 112.9W ML=1.9 UUSN SSW of Lakeside, UT

O: 9APR2002 04:22:03 39.7N 110.5W ML=2.0 UUSN NNW of E. Carbon City, UT

EASTERN U.S./CANADA

O: 9APR2002 09:14:48 45.9N 74.8W MN=1.9 GSC NW FROM HAWKESBURY, ONT.

O: 9APR2002 15:00:29 47.0N 66.5W MN=2.4 GSC W FROM MIRAMICHI CITY, N

ALASKA

HAWAII