Earthquake off the Coast of Jalisco, Mexico Ml 4.4

The daily summary which I post contains three portions:
1) A summary of the observations of earthquakes that occurred
during the previous 24 hours
2) Statistical information on the occurrence of
similar events in the past. That is a measure of
the rarety of the more significant events is included.
3) Speculation, based on statistics and observations
(statistics are just compilations of observational data)
that I and others have made regarding forces which MAY
change seismicity on a short-term basis in a local area.

A current discussion is occurring elsewhere on this board regarding the
"good" or "bad" nature of such information. Since "good" and "bad"
are defined by the user (a terrorist may think it is a "good"
thing to crash a plane into the World Trade Center, while you
and I might think it is an abhorrently "bad" thing to do), such a semantic
discussion is unlikely to yield useful results other than to
confirm our own previously held opinions.

What might be useful, however, is to observe that while some
consider linking of such phenomena such as hurricanes and storms
to subsequent earthquakes, this is a testable hypothesis. Make
a prediction and then see what happens. It does not require
endless rounds of people talking past each other.

In the daily summaries of October 4 and October 5, I noted
that Tropical Storm Lorena had the potential to trigger minor
seismicity along the Jalisco coast of Mexico:

On October 3:

" A new tropical storm - Tropical Storm Lorena formed off the coast
of southwestern Mexico today. Lorena is not expected be be long-lasating
or powerful and forecasters expect it to hit the coast of Jalisco,
Mexico tomorrow. Seismicity along the Mexican subduction zone, especially
in Michoacan and Jalisco may be affected as the winds push Mexico
north reducing normal stress on the subduction zone and the tidal
surge adds about 1 million tons per sq. mile to the subduction zone off
the coast, pushing it down. These two effects tend to decouple the
subduction zone from the North American plate. Larger earthquakes
can occur under these circumstances (Mb 5-6). The force of Lorena
is relatively minor, so this effect should not increase the maximum
magnitude in the region by more than 0.5-0.75 units over previous
estimates. This watch is in effect until 6 October, 2001. "

On October 4:

" Tropical Depression Lorena will make landfall on the Mexican coast of
Jalisco tonight and dissipate over the mainland tomorrow. Only
minor seismicity is expected to be associated along the western
coastline of Mexico."

Today SSN (The U. of Mexico Seismic Service) is reporting the
following event:

2001/10/05 22:53:32 18.74 -106.88 14 ML=4.4 COSTA DE JALISCO

This is the largest earthquake within 100 km of this epicenter
since Feb. 21, 2000 (more than 1.5 years ago) when a Ms 5.8
occurred in the area. The only comparable earthquake in the area
in the last one-and-a-half years was a Ml 4.3 on July 6, 2001.

While it may be another of those "coincidences" that Tropical Storm
Lorena passed directly over this epicenter 1 day before this
earthquake occurred, that can only be known by continued predictions
and subsequent observations.

Data on Mexican earthquakes can be found at:

http://www.ssn.unam.mx/~yi/SSN/ssn-ultimos.html

• Earthquakes in Mexico