STRONG EARTHQUAKE HITS HINDU KUSH (MW 7.2)

SUMMARY

A strong Mw 7.2 earthquake occurred in the Hindu Kush region of
Afghanistan today.

NEIS gives the event parameters as:

O: 03MAR2002 12:08:06 36.4N 70.45E MW=7.2 HINDU KUSH REGION, (195 km depth)

This is the first event of M>=7 in the world since an earthquake
of Mw 7.3 in the Vanuatu Islands on January 2, 2002. It followed
upon a sudden change in the geomagnetic field, possibly due to
a shower of electrons in the solar wind.

A number of forecasts for this event were extant including
a researcher in Europe who had analyses suggesting that a large
event (possibly as great as Ms 7.7) would occur between March
and May 2002 in the Hindu Kush region. This and other forecasts
for this event are on record. Two other forecasts of interest
were made on the basis of a strong perigee and full moon on
Feb. 27 (syzgy) and on observed earth motions in India. All seemed
to point to an event in Hindu Kush around this date. Other
forecasts were generally less precise or compelling. More information
on this event is available from the USGS at:

http://wwwneic.cr.usgs.gov/neis/bulletin/020303120806.html

This is the largest event in this area since December 1983 when a
Similar-sized earthquake of Ms 7.2 occurred. The last event which was
Larger occurred on July 30, 1974 (Ms 7.4). In the past century 23
Earthquakes of Ms>=7 have occurred within 200 km of today's epicenter
About one every 4 years.

A far-field triggered event forecast was produced.

GLOBAL

Shortly before the Hindu Kush earthquake a Ms 5.6 earthquake
had occurred on the opposite side of the world in Southern Chile.
This was the largest event in that area since August 12, 1999
when a Ms 5.5 occurred in conjunction with an total elcipse
of the sun in Europe and only 5 days before the great Izmit earthquake
in Turkey which killed more than 15,000.
A shock, probably regionally triggered, of Ml 4.0 occurred in
Pakistan after the Hindu Kush event as did a Ml 3.8 in Taiwan
another area where far-field triggering was expected.

U.S./CANADA

The largest earthquake listed for the U.S./Canada region today
was a Ml 3.8 south of Anchorage, Alaska. This area has been
active over the past several days including a Ml 4+ event on
March 1. Because of weekend shore leave seismological observatories
in most areas of the U.S. and Canada did not report event
parameters today.
The California-Nevada region had seismicity slightly above
average today with 15 events of Ml>=2. Aftershocks were back
in the Calexico/Ocotillo zone where 10 aftershocks of Ml>2 were recorded
including two of Ml > 3 (Ml 3.3 and 3.0). A Ml 2.9 also occurred
this evening in this sequence. An earthquake near Baker, southern
California also registered Ml 3.0 last night. An Ml 2.3 was also
recorded near Anza. Since it was Sunday, several earthquakes
had to happen in the Los Angeles area. Today's were small though-
1.5 and Ml 1.7 near Century City and Ml 1.4 near Hollywood.
The largest earthquakes of the day in Northern and Central
California occurred within 5 minutes of each other this evening
near Bishop, south of Mammoth Lakes (Ml 2.7) and near Oroville
in No. California (Ml 2.2). A Ml 2.7 was also recorded off the
Coast of No. California near Eureka this morning.
A Ml 2.0 also was listed near Lockes, in central Nevada.
The USBR also recorded 4 earthquakes in the Jackson Lake area
of Wyoming this morning (Ml 2.0, 2.1, 2.0, 2.5). This area
is intermittently seismic at these levels.

NEW ZEALAND

The IGNS on-line seismometer returned to noisy conditions today,
but IGNS has not yet released any new seismic parametric data.

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

GEOMAGNETIC/SOLAR FIELDS

As the interplanetary wind hit the earth with gusts today,
the geomagnetic field intensity fluctuated occasionally rapidly.
On the of these fluctuations coincided with the Hindu Kush earthquake.
By evening, a moderate geomagnetic storm had begun at about 21:00 UT,
but did not continue long enough to have strong effect on seismicity.
At the time areas of the western U.S. and Canada were sub-solar and
seismicity in these areas did increase slightly in the hours following
the geomagnetic storm.
There were no solar flares of M- or X-class observed today.

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20020303events.txt

TIDAL EFFECTS

March 3-4, 2002 the ninteenth 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

Arctic MB>=4.0 30 1.9 0.05
India MB>=4.0 68 2.9 0.02
Hindu Kush MB>=4.0 14 2.0 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

Mammoth lakes MB>=3.0 -18 -2.1 0.05

Lowell Whiteside
March 01, 2001

TOMORROW IN SEISMIC HISTORY

On March 4, 1949 a Ms 7.5 earthquake hit the Hindu Kush region
of Afghanistan near the same epicenter as today's Ms 7.2 event.
This earthquake did considerable damage in West Punjab and was
felt at Intensity VIII in the Hindu Kush region.

The largest earthquake to have occurred on March 4 was in 1952 in
the Hokkaido/Kuril Islands region. This earthquake measuring Mw 8.6
killed 31 and injured 572. The number of houses destroyed was 713 while
nearly 6,000 were damaged. 28 were and warehouses were destroyed
in Kushiro. 3 were killed and 309 houses destroyed at Kiratapu.
1,000 houses were destroyed or damaged at Shiranuka and 400 houses
were destroyed at Hamanka. 4 schools collapsed at Sapporo.
The earthquake triggered a 10-foot tsunami and was followed by
and aftershock of Ms 7.1 on March 9 which injured 17 more and destroyed
113 additional houses. The tsunami affected areas around the
Pacific including Crescent City, CA where there was a 36 cm
tsunami recorded. Due to the efficient warning system in Japan
at the time, however, no fatalities were caused by the tsunami.
The March 4 earthquake off Hokkaido was appears to have begun
a chain reaction of great earthquakes in the Kuril chain. This can
happen when a segment ruptures, putting strain on the adjoining
segments. The following is a quote from

"Earthquakes and the Deep structure of the South Kuril Arc" by
S.A. Fedotov, A.M. Badasarova, I.P Kuzin and R.Z. Tarakanov, 1971
NOAA/Dept of Commerce.

"The earthquake of 4 March 1952 marked the beginning of a series
of disastrous Kurile-Kamchatka earthquakes in March and November 1952
[Kamchatka Mw 8.3], November 1958 [Mw 8.2 in the next segment of
the Kurile arc to the north - the Etorofu quake], May 1959 [Kamchatka
Mw 8.0]; and October 1963 [Mw 8.2 in the next segment of the
Kuril Arc north of the Etorofu quake]. These were probably interrelated
events of a single high-seismicity period."

These were the strongest earthquakes in the southern Kurils since
1843. The area has an average interevent occurrence interval of
great shocks of about 140 +/- 40 years. At Mw>=7.5, the interval
is around 40+/- 5 years. The largest earthquakes off Hokkaido in
1910 (Ms 7.5) then 42 years later in 1952 (Mw 8.6) and then again
42 years later in 1994 (Mw 8.1). At that rate we should expect
to see the next such event in 2036.

U.S./CANADA

No earthquakes of Mw>=6 have occurred on this day in the U.S.
or Canada. No damaging events have marked this day either.
The largest earthquake on March 4 in the U.S was a Mb 5.6
in 1986 in the Fox Islands, Alaska.