RARE, MODERATE EARTHQUAKE (MB 5.7) ROCKS BALKANS REGION IN EAST-CENTRAL EUROPE

SUMMARY

One of the largest earthquakes ever recorded within 100 km of it's
epicenter hit the Balkan region of Kosovo today killing one and injuring
at least 60 others. Considerable damage was done throughout the Kosovo
region including the toppling of a minaret in Gnjilane, Kosovo.
This was the largest earthquake since July 26, 1963 in the region
and the second largest ever recorded in this area. Earthquakes of
comparable size, however have occurred in 1985, 1960, 1942, 1921 and 1911.
In the 1963 event which was Ms 6-6.9 about 1,028 were killed, 4,038
injured. The city of Skopje was almost completely destroyed.
Various epicentral determinations are avialable including:

O: 24APR2002 10:51:51 42.4N 21.5E MB=5.7 NEI NORTHWESTERN BALKAN REGION
O: 24APR2002 10:52:12 42.9N 20.0E ML=5.7 STR EST MONTENEGRO 33

Numerous light to moderate aftershocks have been recorded including
events of Ml 3.8, 4.1, 5.0...

The epicenter lies near the CMB shadow zone from both the Chile and
Mexico quakes of April 18 (109 and 102 degrees distance respectively).

Far field aftershocks are most like from these as follows:

Mexico Ms 6.3

"103-106 degrees***: ... Greece"

Chile Mw 6.7

"103-106 degrees***: ... Sicily, No. Italy, Italy, ..."

The area had also been under seismic watch from a X1.5 flare
which hit on April 21. The watch notice for this had stated (earthquake
summary, April 20, 2002):

" The strongest solar flare since Oct 22, 2001 hit about an hour
ago just as the strong geomagnetic storm was returning to quiet
conditions. A strong proton storm followed this flare. Sub-solar
latitudes at the time of the flare were about 170E, anti-solar
locations at 10W. Areas within about 30 degrees longitude of either
of these longitudes will experience the greatest effects from this
flare and are under seismic watch conditions for the next two days.
High latitudes and areas along the geomagnetic equator are also likely
to see increased seismicity in the next two days. The effect of this
flare is uncertain coming at the end of a strong geomagnetic storm.
Many of the events which were ripe for geomagnetic triggering have
already had earthquakes. Nevertheless, strong earthquakes could still
accompany these storms and this X1.2 flare between April 21 and April
25. This watch includes areas of New Zealand, Kermadec, Tonga, Samoa,
the Aleutians and western Europe."

News reports on this event can be found at:
http://webcenter.newssearch.netscape.com/aolns_display.adp?key=200204241437000140588_aolns.src

http://webcenter.newssearch.netscape.com/aolns_display.adp?key=200204241423000239958_aolns.src

Other regionally significant earthquakes have also occurred in western
Europe in the past two days including a Ml 2.9 in Switzerland today,
a Ml 3.5 and 3.4 in Germany on April 22 and April 23 and a Ml 3.6 in
France on April 23. All of these events lie at the CMB shadow zone boundary
from the Chile earthquake of 18 April.

GLOBAL

The seismic watch region from the X1.5 flare also included the Aleutian
Islands where a Mb 5.2 and aftershock of Mb 4.5 occurred earlier this morning.

A moderate earthquake and numerous aftershocks also hit western Iran
this afternoon. This event of Mb 5.2 was also followed by at least
one aftershock in the same magnitude range and many smaller and preceded
by a Mb 4.2 foreshock. Events in this region commonly cause considerable
damage due to poor construction techniques used.

A Mb 4.3 occurred in the Kuril Islands today as well. This area had
been expected to see FFA from Chile. A possible epicenter of 43N 147E
had been identified in the FFA forecast. Today's event occurred at
44N 148E.

A series of shocks continued in northern Colombia at 7N 73W (Mb 3.9,
3.8, 3.9). The FFA forecast had identifed this epicenter as the site
of likely FFA at this time.

Twp earthquakes (Mb 4.0 and 4.2) were also located off the SE coast
of Honshu. The FFA forecast had noted:

"103-106 degrees*** [from Mexico]: SE of Honshu ..."

The other event listed by NEIS was a Mb 4.8 in the Tonga Islands.
Both the Honshu and the Tonga events were in regions of seismic
watch at this time (see above quote from April 20 Summary).

U.S./CANADA

The Mb 5.2 and 4.8 in the Andreanoff Islands, Aleutians were the
largest events in the U.S./Canada region today.
Hawaii did not list any new events of Ml>=3.
In the contiguous U.S., the largest earthquake was a Ml 3.1 NW of
Drummond, Montana this morning. This earthquake may have been felt
in the epicentral area.
No other regionally significant earthquakes (Ml>=2) have been listed
from the Rocky Mountains to the eastern U.S. or Canada at this time for
today.
In the Pacific Northwest, there appears to have been an increase
of seismicity in the major volcanic centers over the past several days.
PNSN is showing small events at Mount Hood (Ml 1.4, 1.1, 1.9);
Mount Rainier (Ml 1.5) and Mount Mc Loughlin (Ml 1.0) since the
geomagnetic storms of April 18-19. Volcanic regions often show increased
seismicity associated with strong geomagnetic storms.
The California/Nevada region remained at relatively low seismicity
today. The largest earthquake occurred north of Mammoth Lakes near
Bodie, CA (Ml 2.8), again possibly a volcanic center associated with the
recent geomagnetic storm. Only two other events of Ml>=2 have occurred
in the region in the past 24 hours - a Ml 2.2 near the Pinnacles in
Central California and a Ml 2.3 near Big Bear City in southern California.
This is the first event of Ml>2 in the Southern California area outside
of the Salton Sea/Imperial Valley in the past 7 days.
Microearthquake activity was elevated in the Simi Valley region and
in Central California from Parkfield (Ml 1.9) north to Hollister (Ml 1.8),
San Juan Bautista )Ml 1.9), San Martin (Ml 1.6) and Pleasant Hill (Ml 1.7).

NEW ZEALAND

No new events were listed by IGNS in the New Zealand region today.
The on-line seismogram was relatively quiet except for scattered
microearthquake activity.

The IGNS on-line Seismometer can be found at:
http://www.gns.cri.nz/news/earthquakes/latest_drum.html

GEOMAGNETIC/SOLAR FIELDS

Delayed effects from the recent strong geomagnetic storms were
probably important in the timing of the Balkans and the Andreanoff
Islands earthquakes today. Strong events often follow X-class solar
flares 3-5 days later in sub- and anti-solar regions.
The geomagnetic field, however was at quiet conditions today. The
proton storm was reaching background proton flux. As this occurs,
electrons are more able to form ring currents and associated earthquake
triggering often occurs in higher latitudes and along the geomagnetic
equator in addition to the areas already under seismic watch conditions
from the storms and flares.
One M-class solar flare was recorded today with the following parameters:

Flare # START MAX END CLASS

3620 2145 2156 2201 M1.7

A Ml 1.6 near Corona, CA coincided with the maximum of 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/20020424events.txt

TIDAL EFFECTS

April 26 is the thirteenth 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

Central America MB>=4.0 10 2.1 0.05
Global MB>=6.0 15 2.5 0.03
Utah MB>=0.0 14 2.7 0.03

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 California MB>=2.0 -8 -2.2 0.05

TOMORROW IN EARTHQUAKE HISTORY

GLOBAL:

Unusually strong earthquakes have struck Iceland on this date
on three separate years - 1933 (Mb 5.6); 1971 (Mb 5.0); and 1992 (Mb 5.0).

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 25 0 0 0 1843 44.700 149.700 40 8.2 Hokkaido, Japan
Great damage by the tsunami after the quake. Many houses were
completely washed away and 45 were killed at Shinryu village.

4 25 22 36 0 1909 4.000 127.000 100 7.0 Halmahera
4 25 10 27 48 1912 36.500 70.500 220 7.2 Hindu Kush/Pakistan
4 25 17 56 8 1913 9.500 127.800 60 7.7 Halmahera
4 25 13 54 59 1949 -19.800 -69.000 110 7.3 So. Peru/Bolivia
4 25 2 25 42 1957 36.470 28.560 53 7.1 Turkey
Three strong shocks on 24, 25, and 26 April caused widespread
damage in the eastern part of the island of Rhodes where 16 houses
were entirely destroyed, 186 partially destoyed, 1,318 seriously
damage; there were 11 injured and the damage amounted to $276,000.
Among areas which suffered were Istrio, Monolithos and Rhodes. In Turkey,
along the coast, damage was particularly severe. 80 percent of buildings
were damaged or destroyed at the small port of Fethiye where the causalties
were 198 killed and 70 injured. Other damage was reported at Golenye,
Dalaman, and Marmaris where 43 buildings collapsed. In all about 3,000
houses were destroyed and 5000 damaged. The shock was felt over a
very broad area of about 1.1 million square km from Canakkale, Turkey
to Crete, Lebanon, Israel (Jerusalem). A strong foreshock had occurred
on Feb. 5.

4 25 12 16 49 1987 17.900 119.700 33 7.0 Luzon, Philippines
Some damage in the Manila area. Felt as far as Hong Kong.

4 25 19 22 10 1987 2.700 98.800 15 7.1 So. Sumatera
Two people killed, 22 injured and more than 300 buildings damaged
in the Tarutung Lake Tabo area. A hot spring in the area stopped
flowing but resumed later. Felt as far as Kuala Lumpur, Malaysia.

4 25 14 29 0 1989 16.773 -99.328 19 7.1 Oaxaca, Mexico

Three people killed, a few injued and some damage in Mexico City.
Minor damage reported in the Acapulco area. Felt strongly in
much of southern Mexico and as far away as Guadalajara.

4 25 18 6 4 1992 40.380 -124.170 14 7.3 Off Coast of No. California
Ninety-eight people injured and considerable damage in southwest Humboldt
County. Preliminary estimate of damage in this area from the series of
earthquakes is $66 million. Maximum intensity VIII at Ferndale, Honeydew.
This is known as the Honeydew earthquake. Landslides and rockslides
occurred in the Honeydew-Petrolia area. Liquefaction was noted
in areas of the Eel and Mattale River Valleys. Felt as far south
as San Francisco and east to Carson City and Reno, NV. Also felt in
many portion of Oregon. A small tsunami was observed which lifted
several cars and boat trailers at Trinidad. Both vehicles had to
be towed out of the sand. The maximum wave height was about 1.2
meters at Crescent City, CA.

U.S./CANADA
Unusually strong earthquakes have struck Iceland on this date
on three separate years - 1933 (Mb 5.6); 1971 (Mb 5.0); and 1992 (Mb 5.0).

The following events of Mw>=5 have occurred on this date in
recorded history:

MO DA HR MN SC YEAR LATIT LONGIT DEP MW LOCATION

4 25 19 31 53 1923 59.000 -138.000 0 5.7 Southeast Alaska
4 25 20 33 28 1954 36.900 -121.700 0 5.3 Central California
East of Watsonville. Heaviest damage was reported in the
Watsonville area, but the tremors were strong enough in San
Francisco and other Bay area cities to shatter a few windows
and knock plaster from walls. East of Watsonville, several
houses were severely damaged. The ground cracked, and loose earth slid
on the road. Several chimneys fell at Aromas and in the Interlaken
District.

4 25 10 43 8 1955 32.300 -115.000 0 5.1 Baja California
4 25 7 15 15 1957 52.000 -173.500 0 5.9 Andreanoff Islands, Aleutians
4 25 21 57 39 1957 33.183 -115.850 10 5.2 So. California
4 25 22 24 12 1957 33.183 -115.850 0 5.1 So. California
At the southwestern end of the Salton Sea. Felt in southern
California and western Arizona. Near Calipatria, water flowed
from blowholes and ground cracks were observed. Slight damage occurred
at Brawley, El Centro and Westmorland. The quake was felt over
7,000 sq. miles. A number of aftershocks occurred.

4 25 14 53 35 1960 56.000 -155.000 0 5.1 Southern Alaska
4 25 9 43 30 1964 59.830 -144.990 30 5.0 Southeast Alaska
4 25 21 15 32 1965 51.300 -176.400 40 5.0 Andreanoff Islands, Aleutians
4 25 23 20 28 1980 46.257 -122.180 5 5.0 Washington state, U.S.
Mt. St. Helens volcanic tremor

4 25 18 6 4 1992 40.310 -124.110 14 7.2 Off Coast of No. California
See description above

4 25 9 29 49 1993 35.750 -112.200 3 5.3 Arizona
Some minor damage occurred at Tusayon, Valle and Pipe Springs
National Monument, Arizona. The earthquake was felt from St.
George UT to Phoenix, Arizona.

4 25 0 19 6 1994 60.899 -151.142 68 5.7 Central Alaska

EARTHQUAKE LISTINGS

ASIA

O: 24APR2002 15:37:56 32.6N 48.4E MB=4.5 NEI WESTERN IRAN

O: 24APR2002 19:48:06 34.5N 47.3E MS=5.2 NEI WESTERN IRAN

O: 24APR2002 01:17:01 28.0N 143.9E MB=4.0 NEI BONIN ISL, JAPAN REGION
O: 24APR2002 00:50:40 27.2N 142.8E MB=4.2 NEI BONIN ISL, JAPAN REGION

O: 24APR2002 07:02:11 44.9N 148.7E MB=4.3 NEI KURIL ISLANDS

SOUTH PACIFIC ISLANDS

O: 24APR2002 01:38:02 20.2S 174.5W MB=4.8 NEI TONGA ISLANDS

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 23APR2002 22:08:53 17.4N 101.0W ML=4.1 SSN COSTA DE GUERRERO, MEXICO
O: 23APR2002 15:34:05 17.6N 101.1W ML=3.9 SSN COSTA DE GUERRERO, MEXICO

O: 23APR2002 14:27:12 16.4N 98.5W ML=4.1 SSN COSTA OAXACA, MEXICO
O: 23APR2002 14:01:45 16.3N 98.4W ML=3.9 SSN COSTA OAXACA, MEXICO

O: 23APR2002 07:49:51 6.4N 73.6W Mc=3.8 ULA Dpto. Santander, Colombia.
O: 24APR2002 01:04:44 6.5N 73.0W Mc=3.9 ULA Dpto. Santander, Colombia.
O: 24APR2002 04:20:52 6.7N 73.1W Mc=3.8 ULA Dpto. Santander, Colombia.
O: 24APR2002 05:44:48 6.7N 72.9W Mc=3.7 ULA Dpto. Santander, Colombia.

O: 22APR2002 05:12:16 18.1N 67.1W ML=3.0 PRSN Western Puerto Rico
O: 21APR2002 22:51:01 19.1N 67.4W ML=3.4 PRSN Mona Canyon

O: 20APR2002 08:01:11 19.1N 68.4W ML=3.9 PRSN Eastern Dominican Republic

O: 24APR2002 01:19:24 13.1N 89.7W MC=4.3 SIS Guatemala, Central America

O: 24APR2002 03:04:19 8.5N 83.7W MC=4.1 CASC Costa Rica, Central America

NEW ZEALAND/AUSTRALIA

OCEANIA

EUROPE/MIDDLE EAST/AFRICA

O: 24APR2002 10:51:51 42.4N 21.5E MB=5.7 NEI NORTHWESTERN BALKAN REGION
O: 24APR2002 10:52:12 42.9N 20.0E ML=5.7 STR EST MONTENEGRO 33

O: 24APR2002 09:27:47 38.9N 31.1E ML=3.7 KAN AFYON, TURKEY

O: 24APR2002 20:09:55 33.7N 47.2E Ms=4.0 GSSC WESTERN IRAN
O: 24APR2002 19:48:01 33.6N 47.0E Ms=5.0 GSSC WESTERN IRAN
O: 24APR2002 15:38:09 33.2N 48.8E Ms=3.3 GSSC WESTERN IRAN

O: 24APR2002 16:05:05 43.5N 18.3E Ml=3.4 INGV NORTHWESTERN BALKAN PEN.
O: 24APR2002 10:52:11 42.9N 19.6E Ml=5.3 INGV NORTHWESTERN BALKAN PEN.
O: 24APR2002 11:24:56 42.8N 18.0E Ml=3.4 INGV NORTHWESTERN BALKAN PEN.

O: 24APR2002 11:17:56 42.6N 20.6E Ml=4.3 INGV NORTHWESTERN BALKAN PEN.

U.S/CANADA

CALIFORNIA/NEVADA

O: 24APR2002 04:13:56 34.3N 118.4W ML=1.6 SCSN NNW of San Fernando, CA
O: 24APR2002 04:32:47 33.9N 118.3W ML=1.7 SCSN ESE of Hawthorne, CA

O: 24APR2002 05:16:47 36.6N 121.2W ML=2.2 NCSN NNW of Pinnacles, CA

O: 24APR2002 05:49:06 36.8N 121.5W ML=1.9 NCSN SSE of San Juan Bautista, CA

O: 24APR2002 08:09:56 33.9N 118.0W ML=1.7 SCSN ENE of Cerritos, CA

O: 24APR2002 13:19:04 36.8N 121.4W ML=1.8 NCSN WSW of Hollister, CA

O: 24APR2002 12:47:54 38.0N 118.7W ML=2.8 NCSN SE of Bodie, CA
O: 24APR2002 13:38:48 38.0N 118.7W ML=1.6 NCSN SE of Bodie, CA

O: 24APR2002 13:45:52 34.3N 116.7W ML=2.3 SCSN E of Big Bear City, CA

O: 24APR2002 14:24:06 37.1N 121.5W ML=1.6 NCSN ENE of San Martin, CA

O: 25APR2002 01:13:04 35.9N 120.5W ML=1.9 SCSN NW of Parkfield, CA

PACIFIC NORTHWEST/CANADA

O: 23APR2002 19:04:45 45.3N 121.7W ML=1.9 PNSN S of Mount Hood, OR
O: 23APR2002 19:09:34 45.3N 121.7W ML=1.1 PNSN S of Mount Hood, OR

ROCKY MOUNTAIN AREA

O: 24APR2002 10:00:51 46.9N 113.3W ML=3.1 MBMG NW of Drummond

O: 19APR2002 16:20:41 46.0N 111.4W ML=2.2 MBMG Clarkston Valley
O: 20APR2002 15:45:17 46.0N 111.4W ML=2.9 MBMG Clarkston Valley

O: 19APR2002 18:11:18 47.9N 114.3W ML=1.1 MBMG near Elmo
O: 23APR2002 06:55:28 48.1N 114.7W ML=1.0 MBMG near Marion
O: 19APR2002 19:26:17 48.0N 114.3W ML=1.1 MBMG near Lakeside

O: 20APR2002 19:23:11 44.8N 112.8W ML=1.6 MBMG Red Rock Valley

O: 21APR2002 23:35:01 44.8N 114.5W ML=2.6 MBMG NW of Challis, ID

O: 23APR2002 05:30:34 47.5N 113.8W ML=1.1 MBMG SW of Condon

O: 24APR2002 13:53:11 43.9N 110.2W MD=2.8 USBR E of Moran, WY

EASTERN U.S./CANADA

ALASKA

O: 24APR2002 18:57:20 61.3N 146.8W ML=3.2 AEIC Valdez, Alaska
O: 24APR2002 17:58:36 61.9N 149.9W ML>3.0 NEI SOUTHERN ALASKA

O: 24APR2002 07:08:17 50.0N 177.0W mb=5.4 LED ANDREANOF ISLANDS, ALEUTI
O: 24APR2002 07:08:18 51.5N 178.0W MS=5.1 GSR ANDREANOF ISLANDS, ALEUTI
O: 24APR2002 07:08:16 51.2N 177.9W MB=5.2 NEI ANDREANOF ISL, ALEUTIAN IS.
O: 24APR2002 07:59:00 51.2N 177.9W MB=4.8 NEI ANDREANOF ISL, ALEUTIAN
Note: This earthquake is 70 degrees from the Ms 6.3 Guerrero Mexico
quake of April 18 and is probably a FFA. The FFA forecast had stated:

"71-73 degrees: Near Island, Rat Isl. Aleutians"

The area was also under seismic watch conditions from the expected
effects of the X1.5 solar flare which occurred on April 21. The watch
as published in the daily report of April 20 had stated:

"The strongest solar flare since Oct 22, 2001 hit about an hour
ago just as the strong geomagnetic storm was returning to quiet
conditions. A strong proton storm followed this flare. Sub-solar
latitudes at the time of the flare were about 170E, anti-solar
locations at 10W. Areas within about 30 degrees longitude of either
of these longitudes will experience the greatest effects from this
flare and are under seismic watch conditions for the next two days.
HIGH LATITIDES and areas along the geomagnetic equator are also likely
to see increased seismicity in the next two days. The effect of this
flare is uncertain coming at the end of a strong geomagnetic storm.
Many of the events which were ripe for geomagnetic triggering have
already had earthquakes. Nevertheless, strong earthquakes could still
accompany these storms and this X1.2 flare between April 21 and April
25. This watch includes areas of New Zealand, Kermadec, Tonga, Samoa,
the ALEUTIANS and western Europe."

Emphasis added

HAWAII