A QUIET DAY ON THE SEISMICITY SCENE TODAY

SUMMARY

Not much news to report today - and they say, no news is good
news. So go enjoy some Spring/Fall weather and stop worrying!!

GLOBAL

The largest earthquake of the day was an Ml 4.8 off the SE
coast of Honshu. Other events of Mb>=4 occurred in Costa Rica
(Ml 4.4) and Xizang, China (Mb 4.0) as reported by NEIS. Local
observatories also reported light activity. In Michoacan Mexico
a Ml 4.3 was recorded near the coast after a Ml 4.8 yesterday
in Oaxaca. Networks in Central America reported a Ml 4.8 near
Guatemala as well. In South America a Mb 4.2 occurred in northern
Chile and was probably an aftershock of the event of March 28 (Mw 6.5).
The largest event in Asia today appears to have been a Ml 4.2
near Tajikistan. Europe fell silent. The largest events on that
continent were Ml 3.1 in Poland and Ml 3.2 in the northeast
Balkans. Events were not reported from other continents -
Australia, Africa, Antarctica or Oceania.

U.S./CANADA

Seismicity throughout the U.S/Canada region was also moderately
low today. The largest event was a Ml 3.4 near Dillingham, Alaska.
In California/Nevada a Ml 3.1 earthquake occurred in the Calexico
swarm followed by a Ml 2.4 aftershock and a Ml 2.2 foreshock. A Ml
2.4 also occurred near Coso Junction CA this morning. In northern
and central California, the strongest activity was a minor swarm
in the Mammoth Lakes region. This included events of Ml 2.4 and 2.0
since last summary. There were 5 events of Ml>=2 in California/Nevada
over the past 24 hours.
Yesterday (April 8) two earthquakes of Ml 2.7 and 2.4 occurred
in the west Yellowstone area. These are the largest of the current
swarm in that area.
The most unusual earthquake of the day was a Ml 2.2 near New
Madrid MO (Blythville, AR). This is the first regional earthquake
since a Ml 1.7 on March 5 and the largest since a Ml 2.9 on
Feb. 17. The region had been expected to see activity following
Sunday's Mw 6.2 south of Australia as in the FFA forecast:

" In the U.S. events in the Illinois/MO/KY
regions have occurred in at least half the cases."

and

"142-146 degrees: Illinois/Indiana, New Madrid ..."

Three earthquakes have occurred in the SE U.S. in the past
three days - a Ml 2.2 near Dalton, GA, a Ml near Newmarket TN
and today's event at Blythville. These were expected FFA.

NEW ZEALAND

IGNS reported one event which occurred this morning (NZST). This
earthquake of Ml 3.6 was felt at Hawke's Bay on the east coast
of North Island. The on-line seismogram did not show other strong
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 remained at quiet conditions throughout
the day. There was two light (M2.1 and M1.0) solar flare observed which
parameters follow:

Flare # START MAX END CLASS

8650 0032 0042 0050 M2.1
8850 1254 1302 1310 M1.1

The first was associated with an earthquake at Fillmore about 15
minutes later. No events in California accompanied the second
smaller 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/20020409events.txt

TIDAL EFFECTS

April 11 is the twenty-eighth day after the beginning of 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

Alaska MB>=4.0 6 2.0 0.05
Aleutians MB>=4.0 40 3.1 0.01
New Britain MB>=4.0 25 2.6 0.03
So. California MB>=3.0 67 2.3 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 So America MB>=4.0 -20 -2.0 0.05

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 10 0 0 0 1739 -0.200 -78.000 0 7.1 Ecuador
4 10 21 22 25 1906 19.000 -113.800 60 7.5 Gulf of California
This generally unrecognized earthquake in the Gulf of California
was one of the largest ever recorded in that region. Having occurred
only 8 days before the great San Francisco Earthquake, it may have
helped trigger that event to the north. 19 degrees separate these
two events, a distance at which FFA are expected.

4 10 19 36 0 1909 52.000 175.000 0 7.0 Rat Islands
4 10 18 42 24 1911 9.000 -74.000 100 7.2 Colombia
4 10 2 3 56 1918 43.500 130.900 550 7.5 NE China
4 10 13 16 10 1956 -1.000 102.000 0 7.0 So. of Sumatera
4 10 11 29 58 1957 55.750 -153.500 0 7.0 Southern Alaska
4 10 2 6 53 1972 28.434 52.829 33 7.1 So. Iran/Persian Gulf
Qir completely destroyed. 5054 were killed and thousands injured.
The damaged region extened over 1,000 sq. km. It was felt widely
in southern Iran.
More than 20 villages were reduced to rubble and over 30,000 were
left homeless. Gaping cracks and considerable ground failure
accompanied this shallow earthquake. There was also a report of
a volcano near Ghir which was shaken into eruption. The tremor
was felt over 500 square miles. Hardest hit were farming villages
where mudbrick construction is especially vulnerable to earthquake
damage. In Ghir more than a third of the total population was
missing and presumed dead. Not a wall stood there. Aftershocks
continued for days adding to damage and misery. Most of the victims
trapped in the crumbling houses were women and children.
Amont the horror there were a few miracles. Some persons were
buried up to 36 hours before being rescued alive.

4 10 1 42 22 1979 2.963 126.933 37 7.2 Mindanao, Philippines

U.S./CANADA

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

4 10 10 0 0 1881 37.300 -121.300 0 6.0 Central California
In the Modesto regoin, chimneys were damaged. The shock was
felt from Greenville, Plumas County, on the north to Visalia
on the south and west to the coast.

4 10 13 40 16 1921 54.000 -134.000 0 6.5 British Colombia
An earthquake was felt at Masset on the Queen Charlotte Islands.
Pictures swung on walls, but no damage was reported.

4 10 15 58 0 1947 35.000 -116.600 0 6.4 So. California
4 10 17 18 22 1947 34.900 -116.500 0 5.0 So. California
This earthquake, east of Barstow caused huge dust clouds in the
moutains where many rocks were displaced. The banks of the
Mohave River were cracked and the water level raised slightly.
School buildings and Adobe buildings were damaged considerably.
Railroad repairs from subsidence and rockslides needed to be
repaired. Chimneys were thrown down, plaster,pools and adobe walls
were cracked. Tanks on some farms fell as did a stack of
3,000 concrete blocks.

4 10 3 25 30 1957 53.000 -168.000 0 5.2 Fox Islands, Aleutians
4 10 9 9 22 1957 50.500 -176.900 20 6.2 Andreanoff Islands, Aleutians
4 10 11 30 0 1957 55.960 -153.860 0 7.1 Kodiak I. Alaska
4 10 14 30 48 1962 44.150 -73.050 24 5.0 Vermont
Felt over a large area of Vermont, Maine, Massachusetts, New Hampshire
and New York. At Montpelier, a beam dislodged from the state house;
braces dropped about 5 incues. Twenty windopanes cracked; Plaster
cracked. Tile fell from a celing at Barre along with wall cracks.

4 10 1 8 1 1964 58.380 -150.600 19 5.5 Southern Alaska
4 10 19 5 54 1964 59.850 -147.730 15 5.3 Southern Alaska
4 10 21 44 7 1964 60.100 -153.700 15 5.6 Central Alaska
4 10 21 44 12 1964 60.150 -153.510 45 5.6 Central Alaska
4 10 22 27 3 1966 41.370 -125.400 33 5.1 Off Coast of No. California
4 10 19 0 33 1967 39.950 -104.930 5 5.0 Colorado area
One of many earthquakes in the induced swarm near Derby/Commerce
City, Colorado. This event cracked plaster, broke windows,
and caused merchandise to fall in stores. At the Rocky Mountain
Arsenal, where water was pumped into the ground triggering these
earthquakes, 118 windowpanes were borken. An asphalt parking
lot in the Derby area cracked.

4 10 19 57 35 1967 58.542 -154.233 84 5.6 Southern Alaska
4 10 0 36 44 1971 52.150 -169.944 48 5.0 Fox Islands, Aleutians
4 10 0 3 59 1990 53.500 -158.200 0 5.4 Alaska Peninsula

RECENT EARTHQUAKE EPICENTERS

ASIA

O: 8APR2002 07:51:35 7.3S 128.3E MB=4.4 NEI BANDA SEA

O: 7APR2002 22:50:30 38.4N 45.3E MB=4.6 NEI ARMENIA-AZERBAIJAN-IRAN

O: 7APR2002 20:53:35 35.5N 72.2E MB=4.2 NEI PAKISTAN

O: 9APR2002 07:19:45 30.0N 140.8E mb=4.8 GSR SOUTH OF HONSHU, JAPAN

O: 7APR2002 14:51:50 30.9N 142.2E MB=4.3 NEI SOUTHEAST OF HONSHU, JAPA

O: 7APR2002 05:28 45.7N 142.4E MJ=3.7 NIED Sakhalin
O: 7APR2002 04:57 45.7N 142.4E MJ=3.8 NIED Sakhalin

O: 4APR2002 10:13 44.6N 149.2E Mj=3.7 NIED SE_OFF_ETOROFU, Japan

O: 9APR2002 12:02:55 37.2N 71.8E ML=3.3 ASC NE of Ezwan (Badakhshan),
O: 9APR2002 10:18:28 37.7N 72.7E ML=4.2 ASC E of Garmchashma,

O: 8APR2002 19:59:27 37.2N 70.7E ML=3.0 ASC W of Kulan (Badakhshan),

O: 8APR2002 15:36:36 37.1N 69.8E ML=3.3 ASC Shingoli (Takkhar),

O: 8APR2002 13:17:34 36.3N 68.9E ML=3.1 ASC Qazaq (Baghlan),

O: 7APR2002 22:23:13 36.3N 67.3E ML=3.2 ASC SW of Kurchi (Samangan),

O: 7APR2002 20:53:27 35.2N 74.1E ML=3.6 ASC Khirim Jammu

O: 7APR2002 20:40:29 34.6N 76.2E ML=3.2 ASC W of Lalu (Jammu &

O: 7APR2002 11:41:32 38.7N 77.7E ML=3.1 ASC NE of Kizilawat

O: 7APR2002 10:59:40 39.8N 76.7E ML=3.8 ASC ENE of Sugun (Xinjiang),

O: 7APR2002 03:00:30 36.2N 69.8E ML=3.6 ASC W of Enjin (Takkhar),

O: 7APR2002 01:53:08 31.1N 66.7E ML=3.7 ASC SE of Kacey (Kandahar),

O: 6APR2002 17:53:09 37.4N 71.8E ML=3.2 ASC NE of Zanints, Tajikistan

O: 6APR2002 10:54:55 36.2N 68.8E ML=4.4 ASC E of Bagal Mast

O: 6APR2002 04:40:24 34.1N 69.3E ML=3.5 ASC Afghanistan

O: 5APR2002 20:31:14 36.4N 70.5E ML=4.1 ASC SE of Khombok

O: 5APR2002 18:40:47 38.7N 70.6E ML=3.4 ASC SW of Chugorak,

O: 5APR2002 10:13:23 36.7N 76.1E ML=3.8 ASC Xinjiang, China

O: 9APR2002 02:09:43 29.9N 87.9E MB=4.0 NEI XIZANG

O: 8APR2002 20:33:42 22.4N 141.9E MB=4.0 NEI VOLCANO ISL, JAPAN REGION

O: 8APR2002 20:04:22 1.6N 126.1E MB=4.6 NEI NORTHERN MOLUCCA SEA

O: 8APR2002 18:31:00 36.5N 52.2E MB=4.7 NEI NORTHERN AND CENTRAL IRAN

O: 8APR2002 16:34:05 27.0N 55.3E MB=4.8 NEI SOUTHERN IRAN

O: 9APR2002 02:09:43 29.9N 87.9E MB=4.0 NEI XIZANG

SOUTH PACIFIC ISLANDS

O: 7APR2002 15:40:40 7.3S 156.1E MB=4.4 NEI SOLOMON ISLANDS

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 9APR2002 04:12:28 17.5N 103.1W ML=4.3 SSN COSTA DE MICHOACAN, MEXICO

O: 8APR2002 23:55:24 15.5N 94.5W MB=4.5 NEI NEAR COAST OAXACA, MEXICO
O: 8APR2002 22:55:27 15.5N 94.8W ML=4.8 SSN GOLFO DE TEHUANTEPEC, MEXICO

O: 9APR2002 03:19:55 23.3S 69.0W MB=4.2 DGF Chuquicamata, Chile

O: 5APR2002 23:22 15.7S 73.9W mb=4.2 IGP Chala

O: 9APR2002 04:58:08 10.7N 86.5W MC=4.4 SIS Nicaragua, Central America
O: 9APR2002 04:58:10 10.8N 86.5W MC=4.3 CASC Costa Rica, Central America

O: 9APR2002 09:53:52 11.9N 88.5W MC=3.5 SIS Nicaragua, Central America

O: 9APR2002 12:14:21 13.9N 90.7W MC=4.8 SIS Guatemala, Central America

O: 9APR2002 17:22:49 12.3N 86.5W MC=2.2 SIS Nicaragua, Central America
O: 9APR2002 17:30:04 11.8N 87.3W MC=2.9 SIS Nicaragua, Central America

NEW ZEALAND

O: 8APR2002 12:21 39.7S 177.1E ML=3.6 IGNS 20 km south-east of Havelock N

OCEANIA

O: 8APR2002 14:45:10 73.8N 8.0E MB=4.5 NEI GREENLAND SEA
O: 8APR2002 04:17:38 73.8N 7.7E MB=4.7 NEI GREENLAND SEA
O: 8APR2002 03:55:38 73.7N 8.1E MS=4.8 NEI GREENLAND SEA
O: 7APR2002 18:10:07 73.4N 9.6E MB=4.2 NEI GREENLAND SEA

O: 8APR2002 05:08:26 19.4N 109.3W MB=4.7 NEI REVILLA GIGEDO ISL REGION

EUROPE/MIDDLE EAST/AFRICA

O: 8APR2002 01:20:46 42.3N 19.4E MB=4.6 NEI NORTHWESTERN BALKAN REGIO

O: 9APR2002 17:24:42 40.1N 3.0W mb=3.9 MAD SPAIN

U.S/CANADA

CALIFORNIA/NEVADA

O: 8APR2002 21:48:37 32.2N 117.5W ML=2.0 SCSN SW of San Ysidro, CA

O: 9APR2002 09:29:43 37.5N 118.8W ML=2.0 NCSN WSW of Toms Place, CA
O: 9APR2002 09:34:17 37.5N 118.8W ML=2.4 NCSN WSW of Toms Place, CA

O: 9APR2002 10:15:03 32.3N 115.3W ML=3.0 SCSN SSE of Calexico, CA

O: 9APR2002 07:05:20 35.7N 118.1W ML=2.3 SCSN SSW of Coso Junction, CA

PACIFIC NORTHWEST/CANADA

O: 9APR2002 00:07:18 45.4N 122.8W ML=1.2 PNSN NE of Newberg, OR

ROCKY MOUNTAIN AREA

O: 8APR2002 08:20:08 38.9N 107.4W ML=2.9 NEI COLORADO

O: 8APR2002 04:48:52 44.8N 111.1W ML=2.7 UUSN N of W. Yellowstone, MT
O: 8APR2002 05:03:35 44.8N 111.1W ML=2.4 UUSN N of W. Yellowstone, MT

O: 9APR2002 02:56:31 46.0N 111.6W ML>2.0 PNSN Montana

EASTERN U.S./CANADA

O: 8APR2002 23:04:50 36.0N 89.8W ML=2.2 CERI NNE of Blytheville, AR

ALASKA

O: 9APR2002 14:35:11 59.3N 153.3W ML=3.2 AEIC Seldovia, Alaska

O: 9APR2002 15:41:59 57.8N 156.8W ML=3.4 AEIC Dillingham, Alaska

HAWAII

O: 8APR2002 20:36:02 19.2N 155.4W ML=2.8 HVO NE of Pahala, Hawaii
O: 9APR2002 02:01:22 19.4N 154.9W ML=2.9 HVO W of `Opihikao, Hawaii
O: 9APR2002 02:12:03 19.4N 155.3W ML=2.2 HVO S of Kilauea Summit, Hawaii