MODERATE EARTHQUAKE HITS PERU/BRAZIL AREA

SUMMARY

Seismograms show that late this afternoon a moderate earthquake occurred
in the region of Peru/Brazil. This event has not been located at this time but
is likely to have been of Mb>=5.3. More details on this event
will be available later.

GLOBAL

Earthquakes of Mb>=5.0 occurred in the Tonga Islands (Mb 5.3) and
the Solomon Islands (Mb 5.0) today. Earthquakes of Mb>=4.5 also were
recorded in Afghanistan (Mb 4.7); Mongolia (Mb 4.5); the Kermadec
Islands (Mb 4.6) and Peru (Mb 4.9). A small event was also recorded
in Kamchatka (Mb 3.8, GSSC).

U.S./CANADA

The largest earthquake recorded in the U.S./Canada region today
was a Ml 3.0 near Deming, Washington. This was followed by aftershocks
of Ml 2.5 and 1.2.
The California/Nevada region was relatively quiet since the last
report with six events of Ml>=2 recorded - a Ml 2.1 south of
Mammoth Lakes, CA); two events So. of Ocotillo, CA (Ml 2.4 and 2.2)
and a Ml 2.8 West of Idyllwild, CA; Ml 2.0 N of Boron, CA, Ml 2.2
E of Anza and a Ml 2.0 N of Indio. CA.
The only other events of Ml>=2 that were reported in the contiguous
U.S. were recorded at Kanosh, UT (Ml 2.3) and Matane, Quebec (Ml 2.0);

NEW ZEALAND

An earthquakes of Mb 4.6 was recorded in the southern Kermadec Islands,
New Zealand this afternoon (UT). Otherwise the region has been relatively
quiet since the last report.

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 returned to quiet conditions today. There
were no X- or M-class flares recorded on the sun. All seismic watches
currently in effect should end at the end of the day Oct. 6, 2001,
at which time a period of relative global seismic quiet should
begin until the next triggering event.

For general space weather conditions see:
http://sec.noaa.gov/today.html
For Solar flare data see:
http://sec.noaa.gov/ftpdir/indices/events/20011005events.txt

TROPICAL STORMS

The only tropical storm currently affecting the region of North America
is a weak Tropical Depression (eleven) which is currently situated
in the Caribbean Sea and is expected to move westward through the
Carribean for the next 72 hours becoming a tropical storm by Monday
Oct. 8. The only effect of this storm might be to lower atmospheric pressure
over the islands of Puerto Rico and Hispaniola over the next
several days reducing the normal stress between the Caribbean
plate and the subducting North American plate. This effect is
expected to be weak, however, and resulting seismicity should
increase in maximum magnitude by no more than 0.5 units above
previously expected magnitude limits for the region over the next
three days. For tracking details see:
http://www.wunderground.com/auto/HurricaneSite/tropical/tracking/at200111.html

In the western Pacific, Typhoon Krosa is currently located near
Iwo Jima and moving in a northwesterly direction at a leisurely
pace. This typhoon may affect Japan next week. Given the current
elevated Seismicity off the east coast of Honshu, the arrival
of Krosa should be watched carefully for seismic effects. The great
Tokyo earthquake of Sept. 1, 1923 was associated with a strong
typhoon, so effects appear to occur in this region.

TIDAL TRIGGERING (LUNAR)

I have been asked to include some information on statistically
significant tidal triggering in this summary. Statistics have
been done on many regions of the world in terms of relationship
of significant regional earthquakes with respect to lunar cycle.
Each report will summarize the most likely areas for tidal triggering
for the next day based on these statistics. It is expected
that tidal triggering will add an additional 0.5 - 1.0 units of
magnitude to events which are about to occur or will move these
events forward in time by up to seven days in the regions where
there is a statistical correlation between lunar phase and
earthquakes.

October 6 is 19 days after the previous New Moon.
Regions most likely to experience tidal triggering on this day
(With associated magnitude ranges and statistical z-value and
significance level) are:

Region Magnitude range z-value Significance level

China M>=5 1.91 0.05
East Pacific Rise M>=6 1.84 0.075
Iran M>=6 2.22 0.03
Kermadec Isl. M>=4.5 1.95 0.05
M>=5.5 2.38 0.02
Kuril Islands M>=6 1.95 0.05
So. Atlantic M>=5.5 2.38 0.02
Washington St. M>=3 2.11 0.03
So. California M>=5.0 2.11 0.03
West Pacific M>=4.5 1.88 0.06
Yellowstone M>=0 2.22 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:

Alaska M>=6 -1.81 0.08
Arctic Ocean M>=0 -1.82 0.08
Australia M>=6 -1.93 0.05
Caribbean M>=0 -2.84 0.01
Hindu Kush M>=0 -2.07 0.04
Italy M>=4 -1.91 0.05
Kamchatka M>=4.5 -2.10 0.03
SE U.S. M>=2.5 -1.90 0.05
Turkey M>=4 -1.94 0.05
Utah M>=2 -2.20 0.03