Dear HCN,
Sam Kennedy, in his
article on the grazing controversy in the new Carrizo Plain
National Monument in California (HCN, 6/4/01: California monument
welcomes cattle) starts by saying “The first thing you notice …
is, well, there’s not much to see.” How wrong he is! Carrizo Plain
is a premier world site for seismology, and probably has more
earthquake fault phenomena more starkly displayed in one place than
anywhere else in the world.
The San Andreas
Fault, which is the boundary between the North American and Pacific
tectonic plates, runs for 30 miles through the monument, and was
the location of the giant 8+” magnitude earthquake of 1857, which
moved the Pacific plate over 30 feet northwest of the North
American plate in the monument. Because of the arid conditions, the
earthquake trace is still fresh and easily seen and followed. The
Carrizo Plain is probably the only place in the world where you can
stand with one foot on one tectonic plate and the other foot on a
separate tectonic plate. The monument is full of old fault traces,
earthquake scarps, sag ponds, canyons that abruptly detour 90
degrees to the right as they meet the fault, and other signs of
great seismic activity, all vividly
displayed.
President Clinton’s decree
establishing the monument mentions the unique geology of the Plain,
but the BLM has done almost nothing in its publicity to mention the
geology on view there. That is probably why Mr. Kennedy returned
from there saying there is nothing to see. Properly developed,
Carrizo Plain could be the most important place in the United
States, if not the world, for viewing earthquake faults and seismic
phenomena, but that will not happen while the monument is under
current management.
I suggest that the U.S.
Geological Survey should be added to the monument management, and
given the assignment of making its marvels of seismic activity
available to the public for their delight and education. Or, if
that cannot be done, the managers of the monument for the state of
California should get the geology departments of some of the
universities in California to identify the geological features of
the monument for public appreciation.
William G. Rhoads
Arlington,
Virginia
This article appeared in the print edition of the magazine with the headline Lots to see in Carrizo.
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