Will we have another Blowup?
In 1980, Lehrman, an expert on on-site volcanic studies, made an unusual and frightening statement. “Lake County is due for another eruption through one of the Hot Spots underneath the ground. The cycles come every two or three thousand years. The next one is overdue.” Lehrman’s statement has been confirmed by the United States Geologic Survey Department. Lehrman described the eruptions by referring to them as ‘Disruptive Episodes.’ That’s the same as calling the Grand Canyon, a small cleft in the earth. If you or I had been there when they happened, we would have used much stronger language to describe the upheavals and quakes that rattle your teeth.
Lehrman wrote, ‘The Clear Lake Volcanic Region has had many disruptive episodes. They began more than two million years ago. The first blow-ups were more than 2.2 million years ago. They lasted until 1.3 million years ago. The third eruption lasted until1.1 million to 800,000 years ago. The last episode occurred between 650,000 and 300,000 years ago and created the four peaks of Mt. Konocti.’
That was the sequence of eruptions that gradually built up Konocti to its present height of four thousand feet. Lehrman thinks the mountain is dead. He may be right.
The hot spots are still there under Lake County. The only difference is the ‘Hot Spots,’ under the mantle, are on the move. Each one that followed Konocti’s eruptions formed other mountains; Cobb, Buckingham, Lower Lake Cinder Cones, St. Helena, and others. When the ash beds under Clear Lake, were studied, from those examinations we know there were thirty-four smaller eruptions between 70,000 and 100,000 years; a span of sixty thousand years.
This not the end of the Grand Show. Every few thousand years, the underground Tectonic plates grind one against another. In their inexorable way, west and north, there will be another disturbance in the land. They will continue. Earthquakes great enough to knock you off your feet will come again. The last quake was thirty-seven hundred years ago. Some geologists believe the next ‘Hot Spot’ will be in Long Valley. The next quake is fifteen hundred years overdue.
Lake County citizens, rest easy. You have an unlikely friend, the San Andreas Fault. That huge fracture helps to release some of the tension in the earth. So, as long as we have quakes along the San Andreas Fault, Lake County’s own earth upheavals may be less because of the fault slippages. Surely, we can put up with another 1906 quake rather than a major titanic explosion of the sort that can create mountains.
After all, Lake County hardly suffered compared with San Francisco peninsular folks nearer to the catastrophe. Lake County got its share of the shaking. From Hopland to Lakeport it was quiet. A chimney fell, but there were no cracks in brick or stone. Highland Springs to Lakeport no fissures were reported. In the city of Lakeport, several brick buildings were damaged, and one building was destroyed to the foundation. The Fire Inspectors, when they inspected the damage to the Lakeport High School, found all six of its chimneys had screwed around 20 degrees twisted by a mischievous giant. They were all destroyed. All the clocks in town stopped dead.
Next Week: The Californios
Lake County History. $32. (includes. Tax & Shipping)
Pal Publishing, PO Box 6, Upper Lake, Ca 95485