CompuServe Thread

Landers Quake Today

9 messages in this thread
#134742From: William HamptonJun 16, 1994 12:49 PM
At 9:24 this morning we had a sharp quake here in the Landers/Yucca Valley area in S. California at a preliminary 5.0 on the Richter scale. It is being called an aftershock of the 1992 Landers/Big Bear earthquake. It was preceeded by about 2 seconds of a low, loud thunder-like rumbling. Then the sharp quivering and shaking hit, knocking pictures off walls. It was alarming. It was felt all the way into the Los Angeles basin 100 miles away. There have a been a number of lesser shocks for the past hour. They are preceeded by audible low rumblings. Standing outside in the quiet desert (there goes another one) I can hear an almost faint thunderlike rumbling in the distance. It sounds to be coming from the north, but the epicenter was 2 miles south. I believe this tremor should not be called an aftershock. This is an earthquake of its own entity. It just happens to be a continuing of the tearing and moving of a long fault that appears to be north and south oriented. I think the word "aftershock" might be too simplistic. Maybe a "continuing" shock or further fault movement is more descriptive. There are two dormant volcano craters just north and east of here. They supposedly erupted 6000 years ago. One 30 miles, the other 33 miles away. Also there is a flat lava flow bed one mile wide 18 miles NE of here on the Marine base. I think we may see new volcanic action in this area, and maybe in the sleeping cones! W.H.
#134784From: Doug MitchellJun 16, 1994 10:06 PM
Hi, William– Welcome to the forum/section! Thanks for the info on the new Landers quake; as a southern Californian temporarily in Oklahoma, I like to hear how things are going back home. I am not a pro geologist, but I had the impression quakes on major faults would not be a big factor in starting up volcanoes. Harmonic tremors caused as flowing magma pushes the earth around are likely forerunners of eruptions, but the Landers quakes are more a matter of moving plates as I understand it. I would be more worried about other quakes triggered by new Landers activity. The big quake seems to have triggered not only the Big Bear quake, but lesser ones as far as Nevada, and is theorized to have put more stress on the dangerous segment of the San Andreas fault near Yucaipa. The new quake should be adding insult to injury there. –Doug
#135048From: William HamptonJun 20, 1994 12:38 AM
Hi Doug, I don't know if you are aware of this but something like 3 hours before the 7.6 Landers Quake a volcanic plum erupted from the side of a mountain in Alaska. There were also a number of alarming foreshocks in Landers about 9 pm the night before. People were saying soemthing was coming. There is a line of volcanos and lava flows, one right after another, along route 66 from Dagget to Amboy. Lots of previous activity just 30 miles north of Landers. W.H.
#134795From: Roger D. HerzlerJun 16, 1994 10:40 PM
I also have to agree with Doug. I am not a pro geologist either but I have been instructed that the volcanos in that area have long moved off the hot spot that assisted in their eruption. The plates and other earthquakes being helped along by this quake would worry me more. If this sort of thing was occurring around something like Mt. Saint Helens I would be more apt to conclude that it may develop into volcanic activity. Thanks though, I can see why you would be worried. I am currently apprehensive about the Rose Canyon fault by where I live in San Diego so I understand earthquake worries.
#135083From: William HamptonJun 20, 1994 12:19 PM
Roger, In reference to the Pisgah crater west of Ludlow on old Route 66- we went there yesterday for the first time to see it and hopefully climb to the top. It was then I was struck with shock and disgust. What some people won't do for the dollar bill! As we approached the crater and saw the massive lava bed, I noticed there was something wrong with the look of the Pisgah cone. We soon found out that they are MINING it. They have gone all around and up and down the crater stripping it of it volcanic material. There was a tall mining crane chomping away at the crater's side and producing huge piles of egg-sized landscape rock which trucks take away to be sold all over America. You've probably seen pieces of Pisgah at your local Home Depot. This is a National Disgrace! The Pisgah cone was a geological wonder; a national landmark that should have been saved for all generations to see and explore and learn from. How many craters like Pisgah do we have in America that we can so unceremoniously chop them down? The only one left I can think of around here is the Amboy crater 30 miles east. I don't want these business people or their corporate friends to take even so much as a plastic spoon to the Amboy volcano. I figure that someone got possession of the Pisgah crater during the land giveaway out here in the 1950's and early 60's and will end up making millions $ from it. The land was free if you built a structure on it within one year. This mining travesty of Pisgah has apparently been going on for a long time as we saw old "no trespassing" signs that probably date back to the early 1960's. Other signs forbade admittance to the crater. Private Property! I am considering contacting Bruce Babbitt about this, although it is certainly too late for Pisgah. Does anyone know about this situation or the legality of the mining? Thanks, Bill H.
#135330From: Bill Webb /CAJun 22, 1994 11:06 PM
Hello Bill.. The mining of Pisgah has been going on for years. I first saw this cinder cone back in the late 30's (yes!), and photographed it. Even then it was not in pristine condition, but there was far more of it then there is now. I share your sorrow about these landmarks disappearing because of indifference and selfishness. OTOH, one must ask at some point just where any minerals, rocks, etc. would come from if there wasn't some mining. There are lots of cinder cones in California, and perhaps some of them are not of the quality and interest of Mt. Pisgah, and perhaps these could have more appropriately been mined. Yes, we should try to save Amboy Crater. I suppose that the interest in these two cones in the Mojave is due to their isolation and the clarity with which the results of their eruptions can be observed. Have you heard of the plans to open a landfill in the Amboy area? That would be a REAL insult! Bill..
#135545From: William HamptonJun 25, 1994 2:21 AM
Bill, No, I have not YET heard of mining at Amboy but I feel now I should be concerned. I saw an article out of an old magazine written in 1929 and they did not mention mining at Pisgah but it may have already begun. I have found some other lesser craters on the map but they are not easily travelled to by the general public. So what will be next to get MINERALs, Mt. Rushmore? Hurry, get your piece of Teddy Roosevelt's nose!
#135251From: Don KenneyJun 22, 1994 4:52 AM
>>> I am currently apprehensive about the Rose Canyon fault by where I live in San Diego so I understand earthquake worries. Seems to me to be a valid concern. How anyone can look at up from I5 and look at rocks pitched at 30 degrees on Mt Soledad on one side and beds of the same age 200 feet higher and horizontal on the Kearney Mesa side and then say there's no problem, the fault is inactive, is beyond me. I'm just as happy to be living somewhere else nowdays. ON the other hand, it hasn't moved since Fr Serra showed up in 1710. Maybe it's good for another century or two.
#135357From: SyndesisJun 23, 1994 8:43 AM
You think the average citizen realizes that those are real rocks, and not something sculpted as pretty landscaping by Disney engineers when they built the highway? 🙂