I brought this up in the Quake Watch and Volcano Watch topic but think it warrants a topic of its own. It appears on the surface that perhaps the
volcanic region at the Salton Sea in Southern California may be coming to life.
Of interest is this quote...
"Volcanic activity of any type requires a heat source close to the surface. Geophysical studies of seismic activity, of heat flow in the earth, and
of magnetic anomalies in the area around the south end of the Salton Sea all suggest that active igneous and metamorphic processes are now going on
associated with an intrusive mass that lies below the sedimentary cover.
The intrusion under the Salton Sea is thought to be a pluton, an arm or protrusion from a deeply buried molten magma. This intrusion is parallel to
the axis of the Salton Trough. It is about 20 miles long by four miles wide, and is at least one to two miles thick. It lies within the upper 10,000
feet of the crust, and possibly as close as 4,000 feet from the surface. It is centered beneath the community of Niland, at the southeast shore of the
This pluton is acting upon the sedimentary fill, altering the rocks into a low grade metamorphic series under low-temperature/low-pressure
metamorphism. Associated with the metamorphism of the rocks, chemical analysis of hot brines brought to the surface by deep thermal wells in the
Imperial Valley and Mexico show that active ore formation is probably taking place around the pluton. This involves the concentration of sulfides of
iron, lead, zinc and copper."
This area is obviously alive. But to what extent? Here is a quake map that shows a swarm of quakes at Obsidian Butte on the south shore of the
Salton Sea. The quake data is good through September 1st, 2005.
About 16,000 years ago this region erupted from 4 vents. I am speculating that the Salton Sea isn't simply a sea but rather a caldera that was left
many thousands of years ago. Even if this is a simple volcano it would seem that it would be able to disrupt the regions air traffic flow which is
heavy when you factor in LAX, Burbank and San Diego.
Does anyone here have more detailed information on the previous events at Salton Sea and Obsidian Butte? I have yet to find estimates as to the size
of the previous eruptions. I am trying to find what scale they happen on. Is this something on the Mount St. Helens scale? Or is it something more
along the lines of a sister system a little further up the state called the Long Valley Caldera?
Input on this would be appreciated. I'll post more as I find it.