Established
in 1937
|
Historic quake proof of present danger
By ROGER BRANDT
Special to IVNOne of the more notable disasters in Josephine County history hit this region in 1873, a time when Illinois Valley was a major center of commerce and Kerby was the county seat.
Ironically, the event is almost completely forgotten -- even though it is quitelikely that it will happen again at any time and without warning. It always pays to look back at history so we can be better prepared for tomorrow.
The event occurred the evening of Nov. 23, a time of the year when residents in the region were probably preparing for Thanksgiving as winter rain beat on the roof of their homes and snow fell in the mountains. We can only imagine how startled they must have been when one of the largest earthquakes in Oregon history shook the mountains and communities of Southwestern Oregon.
Based on the damage, and the distance from the epicenter where the shockwaves were felt, the size of the quake is estimated to have been about magnitude 7.3, almost the size of the quake that destroyed the city of San Francisco in 1906. The epicenter is estimated to have been near the southern tip of the Kalmiopsis Wilderness, approximately 25 miles southwest of Cave Junction.
Damage was substantial. All the chimneys were knocked down in the coastal communities of Smith River valley and hardly a brick building in Crescent City escaped damage. Chimneys were damaged in many places as far north as Port Orford and east to Jacksonville. Similar damage was noted in the Illinois Valley communities of Waldo, Browntown and Kerby.
Travelers on the busy supply trail between Crescent City and Illinois Valley reported large cracks in the ground. Shaking was felt as far away as San Francisco and Portland. Despite the potential danger of the event, there was no mention of human death caused by the quake.
It is not surprising that earthquakes occur in this region considering the geologic activity taking place approximately 20 miles below Illinois Valley. A massive slab of ocean crust extending the entire length of Oregon is being pushed slowly inland beneath us. As this massive slab of rock is pushed deeper, it melts and creates the volcanoes of the Cascade Mountains.
Pieces of this ocean crust are scraped off under the continent and, as these pieces accumulate, they push up the mountains around us at a rate of around 1-to-2 millimeters a year.
One of the most important aspects about the earthquake of 1873 is the reminder that we need to be prepared.
Subscribe
to the Illinois Valley News
Click Here
© Copyright 2005-2006 Illinois Valley News, All rights reserved.
