There is going to be a large earthquake in California. Someday. At some point
the San Andreas fault won't be able to help itself. The fault has not been
slipping as much as it should have in recent centuries. Remember, this is
geophysics. Things move a bit more slowly in the world of geophysics than
in the rest of the world, but they do move. A group of scientists have predicted
that there will be a greater than magnitude 6.5 earthquake somewhere along
the southern portion of the San Andreas fault between now and September 2004.
There are quite a few different sensors scattered around the desert in the
area where the San Andreas fault begins. They are all being dusted off and
fired up. (It is now August 30th and the big one has not hit yet.)
A close-up of the desert. Is that a sea shell??
This was a quickie project that took place along the north shore of the Salton Sea. The Salton Sea is California's largest inland body of water. It was accidentally created starting in December 1904 when a levee broke along the Colorado River which is over 80 kilometers away. It took two years to stop the flow of water into the Salton Trough. The trough is a desert area that is more than 200 feet below sea level The Salton Sea is currently about 35 miles long and 9 to 15 miles wide.
The Salton Sea is dying. It was originally a freshwater lake, but it has
become about 25 percent more salty than the Pacific Ocean, and its salinity
continues to rise. Freshwater flows into the Salton Sea from agricultural
runoff and surrounding streams, but there is no outlet to remove water and
dissolved salts. The water level is maintained through evaporation. As the
water evaporates it leaves behind salts that increase the salinity. Fishing
is predicted to collapse within the next 15 years if nothing is done to reduce
the salinity. Fish and birds are dying in large numbers. Resort communities
along the shores are having trouble attracting tourists because of the dead
fish and birds, poor water visibility, and odor from large algal blooms. We
were treated to one of the algal blooms while we were there. That's one flower
you don't want to smell too often.
Our intended target for the instrumentation was Bombay Beach. The project name was the Bombay Beach Array Deployment, or BBAD. Below is a map of the area. We stayed in Indio in the upper left-hand corner. Bombay Beach is half-way down the northern shore of the Salton Sea where the shoreline makes a turn to the northeast.
Below is a map from the Southern California Earthquake Data Center which shows the various fault systems in southern California. The red lines are part of the San Andreas fault. Now lookie where the red line ends...right at Bombay Beach.
From the Southern California Earthquake Data Center