APPARENT FAR-FIELD AFTERSHOCKS HIT SOUTHERN EUROPE

SUMMARY

A series of regionally significant (Mb>=4.5) earthquakes have occurred
in the past two days in southern Europe. These events have been at
Sicily (Mb 4.7); Central Greece (Mb 4.6); Bulgaria (Mb 4.7 and 4.3);
and southern Italy (Mb 4.7). These all lie near the CM shadow zone
boundary from the two large earthquakes in northern and Central
Chile and are like affected by far-field triggering processes.

Following is a summary of these relations for these events:

Events at CM shadow zone boundary from Northern Chile:
(Shadow zone boundary events are always expected to be larger than
normal)

The Northern Chile forecast had stated:

"103-106 degrees***: Southern, Gulf of Alaska, Western Turkey (near
Istanbul, Bulgaria, Romania, Cyprus, Crete, Aegean Sea, Poland, Egypt,
Fiji, Samoa, western Hawaii"

Regionally significant earthquakes occurred in the past two days at:

Bulgaria/Romania Mb 4.7 - lies at 106 degrees from the Northern Chile earthquake.
Bulgaria Mb 4.3 - lies at 107 degrees from the Northern Chile earthquake.
Greece Mb 4.6 - lies at 103 degrees from the Northern Chile earthquake.
Crete Mb 4.7 - lies at 104 degrees from the Northern Chile earthquake.

The FFA forecast had also noted the possibility of a moderate quake
in the Bulgaria/Romania area as:

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

Romania"

Events at CM shadow zone boundary from Central Chile:
(Shadow zone boundary events are always expected to be larger than
normal)

The Central Chile forecast had stated:

"103-106 degrees***: Southern, Gulf of Alaska, Central, No. Vanuatu Is.
Lake Victoria, Sicily, No. Italy, Italy, Germany, U.K. North Sea, Iceland"

Sicily Mb 4.7 - lies at 105 degrees from the Central Chile earthquake.
So. Italy Mb 4.7 - lies at 107 degrees from the Central Chile earthquake.
So. Italy Mb 3.8 - lies at 106 degrees from the Central Chile earthquake.

The FFA forecast had also noted the possibility of a moderate quake
in the Greece and Sicily areas as:

"The most likely events of Mw>=5 in the next 10 days appear to be:
Northern Greece (Ml 4.5-5.5)
Sicily/Italy (Ml 4.0-5.0)"

GLOBAL

The largest event of the day was a Mb 5.6 (GSSC) in the Samoa Islands
region. The region that this earthquake occurred in (Samoa) had also
been expected to see increased activity from FFA effects from
the earthquake in Northern Chile as noted in the FFA forecast:

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

Samoa/Fiji Islands"

A series of three earthquakes has also occurred in the past two
days in the region of Iran (at three different localities). These events
had Mb of 4.7, 4.1 and 4.9. They also appear to be FFA, but from
Taiwan and the Ryukyu Islands as they lie at 59-61 degrees from those
events, at a distance and location where FFA activity was anticipated
in the FFA forecasts:
From Taiwan and from Ryukyu FFA forecasts:

"59-61 degrees: ... Northern and southern Iran "

and

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

...No/So. Iran"

The other series of moderate earthquakes has been occurring in the
Banda/Arafura Sea area of Indonesia. These events of Mb 5.0 and 4.9 at
Banda Sea and 4.3 in the Arafura area lie between 143 and 146 degrees
from the Northern Chile earthquake are, once again, appear to be
FFA - this time from the boundary between the inner and outer core.
The Northern Chile FFA forecast had stated regarding this possibility:

"The following areas are expected to see increased seismicity
in this period.

142-146 degrees: ... Banda Sea "
and

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

...Flores Sea to So. of Java"

The Banda Sea adjoins the Flores Sea.

No other events of Mb>4.1 were reported outside the U.S. in the past
two days by teleseismic reporters.

U.S./CANADA

Several moderate events have occurred in the U.S./Canada region in the
past two (UT) days. The earthquake of Ml 5.0 near Vancouver Island
yesterday was the largest, however a Mb 4.6 earthquake preceded that
by about 3 hours in the Near Islands, Aleutians in western Alaska.
That event appears to have been an FFA from Taiwan and the Ryukyu Islands
as it lies at 46 degrees from those events in a region and near a
distance where FFA were expected. The FFA forecasts from Taiwan and
the Ryukyus had stated:

"The following areas are expected to see increased seismicity
from March 31 through April 10, 2002.

43-45 degrees: ...Rat/Near Islands, Aleutians"

The strongest earthquake in the California/Nevada region today
was a fairly strong aftershock in the Hector Mine aftershock region.
This Ml 4.2 event was one of the strongest in the area of Joshua
Tree/Hector Mine aftershock zones since June 26, 2000 when an Ml
4.6 occurred in the area. This earthquake occurred at a distance of
72 degrees from the northern Chile mainshock - a distance at which
FFA activity was expected as noted in the FFA forecast:

The following areas are expected to see increased seismicity
in this period.

"71-73 degrees: ... Northern Gulf of California, Calexico, CA,"
Gulf of California (northern)

and

"The current activity in the northern Gulf of California/Calexico
swarm could be enhanced by this Chile earthquake"

The region of Utah to Yellowstone has also seen heightened
levels of seismicity over the past three days. UUSN is showing
eight events of Ml>=2 in the region over the past two days.
Of these. two events of Ml 2.8 occurred in SW Utah this morning
near Orderville and Colorado City Arizona. Four events (Ml>=2)
have occurred in a swarm at Yellowstone and two more in northern
Utah.
A ml 3.3 was also recorded this morning in north-central Wyoming.
This is the largest event within 50 km of this epicenter since
August 31, 1997 (Ml 3.8), although a similar sized event occurred about
30 km north on Feb. 7, 2001 (Ml 3.3). There have been 7 earthquakes
recorded in this 50 km-radius of Ml>=3 since record keeping began.
The reader may recall that a Ml 3.6 occurred several days ago in the
Jackson Lake region, the largest there in at least 5 years, so the
entire region of Wyoming to Utah has shown a strong increase in
seismicity over the past week.
Other areas of the U.S. and Canada did not report significant
earthquake activity today.

NEW ZEALAND

After three moderately strong earthquakes near Milford Sound/Te Anau
region of South Island, the activity moved north to an area near
Murchison and south of Nelson, but remained on South Island. Today's
event was registered by IGNS as a Ml 4.6 east of Karamea by IGNS
and was expected to be felt in the epicentral area.

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. There were no
solar flares of M- or X- class observed. SEC expects some
active periods in the geomagnetic field in one or two days.
The largest flare occurred this morning with the following
Parameters (April 6)

Flare # START MAX END CLASS

0609 0619 0625 C9.5

An earthquake of Ml 2.1 occurred near Cabazon, (So. California)
at 06:25 and may have been affected by 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/20020405events.txt

TIDAL EFFECTS

April 07 is the twenty-fifth 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

Antarctica MB>=4.0 343 2.8 0.02
India MB>=4.0 48 2.0 0.05
Yellowstone MB>=2.0 20 2.1 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

Arctic MB>=4.0 -36 -2.3 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 6 16 7 15 1943 -30.750 -72.000 55 8.3 Central Chile
Destructive at Salamanca and Illapel, Chile. 18 killed; 80 injured
at Ovalle, Chile.

4 6 0 36 16 1953 -7.300 131.000 0 7.5 West Irian, PNG

4 6 13 54 38 1992 50.630 -130.510 9 7.0 British Colombia
Felt at Point Hardy and Port O'Neill, British Colombia.

U.S./CANADA

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

4 6 4 4 45 1961 40.180 -124.750 0 5.1 Off Coast of No. California
4 6 11 19 23 1963 63.400 -149.600 42 5.3 Central Alaska
4 6 10 42 37 1964 59.850 -145.470 15 5.0 Southern Alaska
4 6 13 19 3 1965 51.290 -179.760 50 5.1 Andreanoff Islands, Aleutians
4 6 14 15 0 1965 37.500 -120.000 0 5.0 California/Nevada area
Mariposa. Sidewalks carcked. "The sound of the sidewalks cracking
awakened my son who got up and looked out the window to the west.
My mother heard the noise while listening to the 6:15 a.m. newscast."

4 6 22 28 38 1966 56.470 -154.640 28 5.1 Southern Alaska
4 6 1 46 18 1973 51.310 -178.460 50 5.0 Andreanoff Islands, Aleutians
4 6 1 53 50 1974 54.883 -160.275 35 5.8 Unimak Islands, Aleutians
4 6 3 55 57 1974 55.045 -160.510 6 6.0 Unimak Islands, Aleutians
4 6 14 47 43 1980 61.377 -147.824 49 5.2 Central Alaska
4 6 9 22 14 1983 54.238 -133.814 10 5.0 British Colombia
4 6 0 24 10 1987 51.400 -173.300 29 5.0 Andreanoff Islands, Aleutians
4 6 13 54 34 1992 49.000 -131.000 0 5.9 Vancouver Island area
4 6 13 57 49 1992 50.530 -130.390 10 6.8 British Colombia
4 6 15 16 10 1992 50.250 -130.340 25 6.2 British Colombia

4 6 19 1 4 1994 34.192 -117.095 7 5.0 So. California
Felt (V) from Loma Linda and San Bernardino. Also felt at Los
Angeles, Orange and to San Diego Counties. Occurred during the SSA
meeting that year in Pasadena.

4 6 8 31 9 1995 57.000 -154.000 0 5.0 Southern Alaska

EARTHQUAKE/FORECAST COMPARISONS

ASIA

O: 5APR2002 02:41:08 6.7S 130.2E MB=5.2 GSSC BANDA SEA

O: 5APR2002 02:41:12 6.3S 130.1E MB=5.0 NEI BANDA SEA

O: 4APR2002 21:25:33 9.1S 132.3E MB=4.3 NEI ARAFURA SEA

O: 4APR2002 20:50:09 6.8S 129.9E MB=4.9 NEI BANDA SEA

O: 4APR2002 20:32:13 28.0N 52.7E MB=4.2 NEI SOUTHERN IRAN

O: 4APR2002 15:44:31 27.0N 55.3E MB=4.7 NEI SOUTHERN IRAN

O: 5APR2002 20:31:17 36.3N 71.7E mb=4.0 GSR AFGHANISTAN-TAJIKISTAN BO

O: 5APR2002 18:40:18 32.0N 56.1E MB=4.9 NEI NORTHERN AND CENTRAL IRAN

O: 5APR2002 15:31:11 52.3N 160.6E MB=4.1 NEI OFF EAST COAST OF KAMCHATKA

O: 5APR2002 08:59:50 6.7S 107.1E MR=5.1 AEIC1 NW CIANJUR

O: 5APR2002 08:28:30 9.7S 117.9E MR=5.0 AEIC1 S SUMBAWABESAR

O: 5APR2002 16:57 33.4N 132.5E Mj=4.8 NIED SW_EHIME_PREF, Japan

O: 6APR2002 05:54:25 24.4N 122.0E ML=4.7 TAI Ilan, Taiwan

O: 5APR2002 09:33:30 39.6N 76.9E ML=4.1 ASC ENE of Jiashi (Xinjiang),
O: 5APR2002 05:33:24 39.5N 76.9E ML=4.3 ASC ESE of Jiashi (Xinjiang),
O: 4APR2002 21:09:20 39.4N 77.1E ML=4.3 ASC Jiashi (Xinjiang), China

SOUTH PACIFIC ISLANDS

O: 5APR2002 23:02:33 14.4S 173.2W MS=5.4 GSR SAMOA ISLANDS REGION

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 5APR2002 01:45:16 16.0N 97.6W ML=3.9 SSN COSTA DE OAXACA, MEXICO

O: 4APR2002 13:08:05 17.5N 101.7W ML=4.4 SSN COSTA DE GUERRERO, MEXICO
O: 4APR2002 11:34:15 17.4N 101.6W ML=4.3 SSN COSTA DE GUERRERO, MEXICO
O: 4APR2002 11:19:16 17.4N 101.7W ML=4.1 SSN COSTA DE GUERRERO, MEXICO

O: 4APR2002 11:10:55 9.8N 84.0W MC=3.1 CASC Costa Rica, Central America

O: 5APR2002 14:45:00 7.1N 82.8W MC=4.2 CASC Costa Rica, Central America

NEW ZEALAND

O: 5APR2002 23:47 41.3S 172.4E ML=4.6 IGNS East of Karamea, N.Z.

OCEANIA

EUROPE/MIDDLE EAST/AFRICA

O: 5APR2002 04:52:23 38.5N 14.7E Ml=3.9 INGV SICILY, ITALY
O: 5APR2002 04:52:26 38.9N 15.2E Ms=3.5 GSSC SICILY, ITALY

O: 5APR2002 10:42:57 37.7N 30.3E ML=3.2 KAN BURDUR, TURKEY
O: 5APR2002 10:38:47 37.7N 30.3E ML=4.1 KAN BURDUR, TURKEY

O: 5APR2002 07:55:32 37.4N 22.6E Ml=4.7 INGV SOUTHERN GREECE

O: 5APR2002 07:55:57 39.5N 22.2E Mb=4.6 LDG GREECE

O: 5APR2002 13:14:01 42.1N 24.8E MB=4.7 NEI BULGARIA

O: 5APR2002 04:52:22 38.4N 15.1E MB=4.7 NEI SICILY, ITALY

U.S/CANADA

CALIFORNIA/NEVADA

O: 5APR2002 00:02:55 34.5N 116.3W ML=4.2 SCSN SSW of Ludlow, CA
Note: This is the largest event in the Joshua Tree/Hector Mine
aftershock zone since June 2000. It lies 72 degrees from the mainshock
in Norhern Chile on 28 March. It is probably a FFA of that earthquake. T
he forecast had stated:

" The current activity in the northern Gulf of California/Calexico
swarm could be enhanced by this Chile earthquake."

and

71-73 degrees: ...Northern Gulf of California, Calexico, CA,"

O: 5APR2002 05:17:13 32.2N 115.3W ML=2.0 SCSN SSE of Calexico, CA

O: 5APR2002 06:16:14 37.4N 118.6W ML=2.1 NCSN SSE of Toms Place, CA

O: 5APR2002 08:11:08 33.7N 116.7W ML=2.2 SCSN SSW of Idyllwild, CA

O: 5APR2002 08:34:24 36.4N 121.0W ML=2.1 NCSN SSE of Pinnacles, CA

O: 5APR2002 09:59:55 32.5N 116.3W ML=2.7 SCSN SW of Ocotillo, CA

O: 5APR2002 10:18:50 35.4N 118.5W ML=1.8 SCSN NNW of Tehachapi, CA

O: 5APR2002 14:37:44 38.8N 118.0W ML=2.3 NCSN SW of Gabbs, NV

O: 5APR2002 22:37:44 38.8N 118.0W ML=2.3 REN California/Nevada Border

PACIFIC NORTHWEST/CANADA

ROCKY MOUNTAIN AREA

O: 5APR2002 12:27:41 43.2N 110.8W MD=2.3 USBR SSW of Hoback Jct, WY

O: 4APR2002 11:19:22 44.8N 111.1W ML=2.6 MBMG Hebgen Lake region

O: 4APR2002 21:11:03 44.7N 112.0W ML=1.4 MBMG W Centennial Valley

O: 5APR2002 00:39:16 45.2N 112.7W ML=1.8 MBMG near Dillon

O: 5APR2002 01:18:51 44.1N 108.2W ML=3.5 MBMG NW Wyoming

O: 5APR2002 04:08:24 47.8N 113.7W ML=1.2 MBMG 20 km SE of Swan Lake
O: 5APR2002 05:19:21 47.7N 113.7W ML=1.4 MBMG 15 km N of Condon

O: 5APR2002 05:23:23 46.1N 112.1W ML=1.8 MBMG N of Whitehall

O: 1APR2002 05:31:16 37.3N 113.3W ML=2.0 UUSN NNW of La Verkin, UT

O: 1APR2002 12:35:44 39.7N 110.6W ML=2.0 UUSN NE of Wellington, UT

O: 1APR2002 05:31:16 37.3N 113.3W ML=2.0 UUSN NNW of La Verkin, UT
O: 1APR2002 15:24:57 39.0N 113.0W ML=2.1 UUSN SSW of Hinckley, UT

O: 1APR2002 13:52:03 41.1N 112.9W ML=1.9 UUSN SSW of Lakeside, UT
O: 1APR2002 15:38:54 41.1N 112.9W ML=2.0 UUSN SSW of Lakeside, UT

O: 3APR2002 01:18:47 39.7N 110.6W ML=2.1 UUSN NW of E. Carbon City, UT

O: 3APR2002 06:13:03 39.3N 112.2W ML=2.2 UUSN N of Holden, UT

O: 3APR2002 12:54:08 44.2N 110.5W ML=2.5 UUSN SSE of West Thumb, WY

O: 4APR2002 02:32:59 44.8N 111.1W ML=2.3 UUSN N of W. Yellowstone, MT
O: 4APR2002 04:19:22 44.8N 111.1W ML=2.4 UUSN N of W. Yellowstone, MT
O: 4APR2002 04:22:35 44.8N 111.1W ML=2.4 UUSN N of W. Yellowstone, MT

O: 4APR2002 12:44:58 41.8N 110.7W ML=2.5 UUSN WSW of Diamondville, WY

O: 4APR2002 23:36:10 37.1N 112.9W ML=2.8 UUSN NNE of Colorado City, AZ
O: 5APR2002 04:55:34 37.2N 112.8W ML=2.8 UUSN SW of Orderville, UT

EASTERN U.S./CANADA

O: 5APR2002 01:18:49 43.9N 108.1W MB=2.9 NEI NORTH-CENTRAL WYOMING

ALASKA

HAWAII