MARMARA SEA (ISTANBUL, TURKEY ML 4.8); FIJI ISLANDS (Mb 5.4) MOST ACTIVE

SUMMARY

Generally quiet conditions continued in most study areas today.
The largest earthquake occurred in the current activity in the
Fiji Islands (Mb 5.4). The most unusual and strongest felt earthquake
today occurred south of Istanbul, Turkey in the Marmara Sea region at
about 29E longitude. Local networks are giving this event Ml 4.8; it
was followed by a Ml 3.8 aftershock and an Ml 3.9 event in eastern Turkey
later in the day. The daily summary yesterday had noted that this area
was sub-solar at the time of a moderate flare and that a possibility
of some triggering in the region existed:

" ... The flare occurred while areas within 30 degrees longitude of
30E were sub-solar and those within 30 degrees of 150W were anti-solar.
These area may experience a slight increase in seismicity over the next
day."

This is also an area where far-field triggering from the Hindu
Kush earthquake earlier this month had been expected in the FFA forecast:

"Secondary location where event tend to occur but are not
as large or as likely . MB>=4.8 considered likely in next
10 days.

Istanbul Turkey area (1)"

This epicenter is located 34 degrees from Hindu Kush, a distance
at which FFA area expected.

GLOBAL

Other earthquakes of Ml>=4 were recorded today in the Colima/Jalisco
region of Mexico (Ml 4.2); Nantou, Taiwan (Ml 4.3); south of the Mariana
Islands (ms 4.2); at Halmahera south of the Philippines (Ms 4.6);
the Banda Sea, Indonesia (Mb 4.9) and in the Andreanoff Islands
(not well parameterized) this evening. A moderately light earthquake was
probably located in the region south of Yuma, AZ or the upper
Gulf of California this morning, but also has not yet been
located by any on-line source.
Attached is a listing of earthquakes recorded today.

U.S./CANADA

The strongest earthquake in the U.S./Canada area was probably the
event this evening in the western Alaska area. LDG which is generally
unreliable for this area places this event with Mb 5.0 in the Bering
Sea, but no other reports are available at this time. Similarly,
an event of Mb 4-5 appears to have occurred south of Yuma, Arizona
at about 14:03 (from seismograms), but has not yet been located.
The largest events thus far listed for today occurred in Alaska -
at Kodiak (Ml 3.5) and at Valdez in Prince William Sound near Anchorage
(Ml 3.7). No events have been listed for Hawaii today.
In the northwestern U.S. the largest event was a Ml 2.0 near
Canby, Oregon just south of Mt. St. Helens. This area has been
active for two or three days not.
In the Rocky mountain states/provinces, the minor swarm near
Yellowstone contined with several more events in the Ml>=2 range.
South of Yellowstone a Ml 2.3 occurred SSW of Hobakc Jct., WY
NE of Georgetown, ID and near Jackson Lake, WY.
A light Ml 3.4 earthquake near Big Bear City, CA was the largest
event in the California/Nevada area today. It was followed by a
Ml 2.0 aftershock. This area still has occasional aftershocks following
the Ms 6.7 at Big Bear after the Landers earthquake of June, 1992.
Besides a Ml 2.0 at the Geysers, the only other Ml2+ event in
northern California today was near Madera, in Central California.
This is a relatively uncommon epicenter. In the past 7 years 25
events of Ml>=2 have been recorded within 25 km of today's Madera
epicenter, a daily probability of occurrence of 0.01, or odds
of about 1 in a hundred for an earthquake to occur in that region
on a given day.
Other areas of the U.S. and Canada did not report earthquake
parameters today and except for the event at 14:03 seismograms
do not suggest any regionally significant events occurred.


NEW ZEALAND

The on-line seismometer showed no moderate or strong earthquake
in the region of New Zealand today. IGNS did not report any
earthquake parameters either.

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 today.
There were no M- or X-class solar flares observed.
The electron flux and Hp geomagnetic field became very erratic
at about 00:00 UT on March 24, perhaps from a gust of solar
wind. No immediate effects on global seismicity were observed.

Flare # START MAX END CLASS

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20020323events.txt

TIDAL EFFECTS

March 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:

Two deadly earthquakes occurred on this date in history (March 24).
The most destructive occurred in 1923 in Sichuan China causing severe
damage throughout the province (Mw 7.3) and killing approximately
5000.
The other event which killed people occurred in Iran (Karkhaneh)
and caused severe damage while killing up to 100 (Mw 7.2). Following
are other events on this day which were of Mw>=7.

MO DA HR MN SC YEAR LATIT LONG DEP MW LOCATION

3 24 14 41 52 1921 51.500 158.200 50 7.0 Kamchatka
3 24 12 40 6 1923 31.500 101.000 60 7.3 Sichuan, China
3 24 12 4 26 1934 -10.000 161.500 60 7.1 Solomon Islands
3 24 0 17 36 1951 -10.500 166.000 150 7.1 Santa Cruz Islands
3 24 12 44 3 1963 34.400 47.900 40 7.2 Iran
3 24 4 46 4 1976 -29.900 -177.900 33 7.3 Kermadec Islands
3 24 19 47 51 1978 44.244 148.862 33 7.6 Kuril Islands
3 24 21 5 48 1978 42.839 78.606 33 7.1 Alma Ata
3 24 3 59 50 1980 52.940 -167.700 24 7.1 Fox Islands, Aleutians
3 24 9 44 3 1984 44.117 148.192 44 7.0 Kuril Islands

U.S/CANADA

The largest earthquake in the U.S/CANADA region on this date
occurred in western Vancouver in 1957. This earthquake was Mw 6.9
but did little damage because it hit in a relatively unpopulated
location.
An earthquake of Ms 6.2 also hit off the Coast of Oregon in
1949 on this date, but also did little damage. It was reported
as felt at Grants Pass Oregon, "Vase and silver chest on
refrigerator shook and rattled. Chair made slight movement
from side to side, Bed Shook." Windows rattled in Phoenix.
This earthquake was followed by a Ms 7.1 in the Olympia, Washington
region on April 13, 1949 and may have helped trigger that event.
The most unusual earthquake affecting the U.S. on this date
occurred on March 24, 1978 in the middle of the strong Kuril
Island swarm which contained at least 6 events of Ms>=7 and lasted
from March 22 to March 24. This event was a Ms 6.3 in the north
Atlantic Ocean near Bermuda. This area has no tectonic features
which would suggest seismic activity, however the area has been
active ever since this event at a M 4-5 level. This event
was reported felt as far away as Boston, Massachusetts and in
parts of North Carolina. The cause of this earthquake is unknown
however, it could be a far-field aftershock from the Kurils. The
epicenter lies at 105 degrees from the Kuril swarm. Locations at
this distance from strong earthquakes often show seismicity during
the days following the mainshocks. This distance is at the core-mantle
boundary shadow zone boundary where seismic energy is focussed
after a great quake. The additional ground motion at these distances
could easily trigger earthquakes which were about to happen
earlier than they would have occurred without the ground motion
caused by distant earthquakes.

Lowell Whiteside
March 23, 2002

EARTHQUAKE/FORECAST COMPARISONS

ASIA

O: 24MAR2002 02:53:25 24.0N 121.0E ML=4.3 TAI Nantou, Taiwan

O: 23MAR2002 03:06:17 11.9N 143.1E Ms=4.2 GSSC SOUTH OF MARIANA ISLANDS

O: 23MAR2002 05:15:39 0.9N 128.1E Ms=4.6 GSSC HALMAHERA, INDONESIA

O: 23MAR2002 04:01:07 7.6S 128.6E MB=4.9 GSSC BANDA SEA

SOUTH PACIFIC ISLANDS

O: 23MAR2002 03:29:57 15.7S 177.5W MS=5.4 GSSC FIJI ISLANDS REGION

CARIBBEAN/CENTRAL/SOUTH AMERICA

O: 22MAR2002 14:10:02 20.0S 69.6W ML>3.0 RES Tarapaca, Chile
O: 22MAR2002 18:19:30 19.7S 69.9W MB>3.0 RES Tarapaca, Chile

O: 23MAR2002 03:19:38 12.8N 87.1W MC=3.7 SIS Nicaragua, Central America

O: 23MAR2002 09:13:13 13.4N 88.6W MC=3.7 SIS El Salvador, Central America

O: 23MAR2002 11:01:55 11.9N 87.4W MC=3.2 SIS Nicaragua, Central America

O: 23MAR2002 02:32:56 17.1N 100.0W ML=3.4 SSN GUERRERO, MEXICO

O: 22MAR2002 14:33:51 18.3N 105.6W ML=4.3 SSN COSTA COLIMA, MEXICO
O: 22MAR2002 12:56:50 18.4N 105.6W ML=4.2 SSN COSTA COLIMA, MEXICO

NEW ZEALAND

OCEANIA

EUROPE/MIDDLE EAST/AFRICA

O: 23MAR2002 07:38:42 40.8N 27.9E ML=3.8 KAN MARMARA SEA, TURKEY
O: 23MAR2002 07:38:42 40.8N 27.9E ML=3.8 KAN MARMARA SEA, TURKEY
O: 23MAR2002 06:57:30 39.6N 28.9E ML=3.1 KAN DURSUNBEY (BALIKESIR),
O: 23MAR2002 04:36:11 40.8N 27.9E ML=4.8 KAN MARMARA DENIZI, TURKEY
O: 22MAR2002 16:22:37 40.0N 28.8E ML=3.1 KAN ORHANELI (BURSA), TURKEY

O: 23MAR2002 20:42:53 40.3N 43.6E ML=3.9 KAN DIGOR (KARS), TURKEY

U.S/CANADA

CALIFORNIA/NEVADA

O: 23MAR2002 04:27:32 34.3N 116.8W ML=3.4 SCSN E of Big Bear City, CA
O: 23MAR2002 04:29:08 34.3N 116.8W ML=2.0 SCSN E of Big Bear City, CA

O: 23MAR2002 04:29:08 34.3N 116.8W ML=2.0 SCSN E of Big Bear City, CA

O: 23MAR2002 04:43:41 38.8N 122.8W ML=2.0 NCSN N of The Geysers, CA
O: 23MAR2002 15:31:47 38.8N 122.8W ML=2.0 NCSN NE of The Geysers, CA

O: 23MAR2002 09:01:29 35.6N 118.4W ML=1.6 SCSN SSE of town of Lake

O: 23MAR2002 09:38:05 37.2N 118.2W ML=1.7 NCSN NE of Big Pine, CA

O: 23MAR2002 17:43:02 38.5N 118.3W ML=2.0 NCSN WSW of Luning, NV

PACIFIC NORTHWEST/CANADA

O: 23MAR2002 14:22:24 45.7N 122.5W ML=2.0 PNSN NNE of Canby, OR

ROCKY MOUNTAIN AREA

O: 23MAR2002 23:24:16 43.2N 110.8W MD=2.3 USBR SSW of Hoback Jct, WY

EASTERN U.S./CANADA

ALASKA

O: 23MAR2002 08:35:17 56.8N 151.7W ML=3.5 AEIC Kodiak, Alaska

O: 23MAR2002 22:01:58 60.6N 146.2W ML=3.7 AEIC Valdez, Alaska