the glass in my shop-made windows began rattling at about 930 last night. 4.7 and very near los angeles. one of those side-to-side rather than round and round type quakes. gangsters, smog and earthquakes, life in L.A. anybody near here feel it?
eef
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Another California foot massage, eh? ;-)
Considering the recently-discovered v-shaped supersonic shock wave associated with some earthquakes, I'm concerned about the Coachella Valley section of the San Andreas that is aimed right at the heart of L.A. It's several decades over-due for a major release. The seismologists figure that it is this wave that made the 1906 SF quake so much more devastating than would have been expected from its Richter rating.
Note: when I was a lad, I "caused" the 1952 Tehachapi earthquake (7.2) by plugging in my Lionel electric train, which I had been instructed not to play with when unsupervised.
Edited 5/18/2009 1:23 pm by RalphBarker
ralph,
"v-shaped"? "super-sonic shock-wave"? sheesh.
you know, earthquake jokes are not considered funny, here, anymore. i too have experienced a number of very strange "coincidence" moments precisely at the on-set of an earthquake. came to california in 1957 and from that year till 1971 i had never felt one. that was the sylmar quake. seems as though we've had one good one every year since. we tell ourselves the the little ones, 5.0 or less, eases tension, in the tectonic sense, on the mass of faults beneath our feet. quite the "foot massage".
eef
Edited 5/18/2009 2:35 pm ET by Eef
"you know, earthquake jokes are not considered funny, here, anymore."Not a joke, although my description might make it sound like one. I saw this on one of the science channels a week or two ago. Their graphic representation looked just like the shock wave at the nose of a supersonic jet. The impression I got was that the wave makes the quake act like one an order of magnitude or more stronger than the Richter measurement. And, apparently it travels in a straight line from the epicenter, instead of radiating out laterally from the fault.
ralph,boy, am i going to sleep good tonight.eef
The Arizona Commerce Dept is paying me to do this, as part of their beachfront property promotion. ;-)
Yes. I've been buying up future ocean front property in Nevada for quite some time. I figure it's just a matter of time.....
One of my best friends lives in La Jolla, Ca. I have told him on more than one occassion that I think he's nuts for living in a state that is going to be ocean reef some day. Hopefully, later than sooner.
Jeff
"Yes. I've been buying up future ocean front property in Nevada for quite some time."And I'm going to charge you for dropping anchor on my property in what before the quake had been Huntington Beach. :)BruceT
As the new General Manager of Facilities for a big corp. one of my first tasks was to visit all our buildings in 8 states to see what I had just won.
One was the 90.000 sq.ft. warehouse/distribution center in El Segundo Ca. over by LAX for which I was to contract and manage the design and installation of an interior second floor of 60,000 sq.ft. including automated conveyor systems for order picking and shipping from both floors.
After reviewing all the buildings original blue prints and papers I found a large 36"x72" map of the LA region that showed ALL the known faults. This map looked like you took two or three large handfuls of earth worms and dropped them all over . The lines were everywhere, the East, West and North sides of our property each had double lines less than a mile away so at least I knew which way to go---SOUTH which had none for about 5 miles-- if the PCH was still there. I guess I understood why the "Angelinos" were so strang..err, such a laid back unique culture. ha ha . Good luck and God's speed, Paddy
yeah paddy, and new ones are found on a regular basis. i read once that some of the worst quakes in the usa were in the mississippi delta area during the very early 1800's.
and yeah, angelinos are some odd birds.
eef
Edited 5/18/2009 4:10 pm ET by Eef
I think you might be referring to the New Madrid, MO quake that occurred about 1807 (I think.) It ran all the way NE to Louisville, KY. It was so violent that the Mississippi River ran backwards for a short while.Frosty"I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922
"I think you might be referring to the New Madrid, MO quake that occurred about 1807 (I think.) It ran all the way NE to Louisville, KY. It was so violent that the Mississippi River ran backwards for a short while."Repealed the laws of physics and gravity, did it? I would speculate that such reports might have come from sightings of shock waves propagating upstream from the epicenter. To make the river flow upstream would be impossible unless the land were actually raised up, a condition that would not change back to normal after a "short while".BruceT
I think that JFrost is right, Bruce. There was a Science Channel show about the New Madrid quake a couple of years ago with geologists and historians describing it in depth based on settlers accounts and geological evidence.There were actually several additional quakes and aftershocks over a 4-5 year period, but the first quake changed the flow of the Mississippi and IIRC it ran "backward" for a while until it found it's new path.
Here is one point of reference to my report. This is from Wikipedia. The initial quake was in 1811. The town is pronounced "New Mad Rid", not as the city in Spain. The statement "appeared to run backward" probably refers to the phenomena you mentioned."Based on the effects of these earthquakes, it can be estimated that they had a magnitude of 8.0 on the Richter scale. As a result of the quakes, large areas sank into the earth, new lakes were formed (notably Reelfoot Lake, Tennessee), and the Mississippi River changed its course, creating numerous geographic exclaves, including Kentucky Bend, along the state boundaries defined by the river.
Some sections of the Mississippi River appeared to run backward for a short time. Sand blows were common throughout the area, and their effects can still be seen from the air in cultivated fields. Church bells were reported to ring as far as Boston, Massachusetts and York, Ontario (now Toronto) and sidewalks were reported to have been cracked and broken in Washington, D.C.[2] There were also reports it toppled chimneys in Maine."
Frosty"I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922
hey!, you guys are pretty cavalier about all this seismic stuff...
have you ever FELT 7.0? i shudder, no pun intended, at the very thought of 8.0. it is easy for me to imagine rivers going backwards in such a scenario. i saw my street ripple and wave like a waterway and things were only at 7. something.
eef
We were in Anchorage, AK last summer and went to the earthquake museum. In 1964 there was an 8.4 quake and the videos, photos and first-person accounts were gripping. I'll never forget a woman telling of holding the arm or ankle of her child to keep him from falling to the bottom of a 50' deep (?) crevasse in her front yard. As to the New Madrid quake, we lived for a time in Owensboro, KY. About 10 miles south of town there is a 'cut' on the Parkway going south. I forget the name of the road. The side-walls of the 'cut' exposed the displacement of the earth by the 1811 quake. The earth and rock 'rippled' just like a fudge-swirl ice cream dip, only the displacement was 40' - 50'.Me? I've never felt an earthquake. From what I've heard. I should take a Dramamine about an hour before - but don't I think that kind of notice is available.Frosty"I sometimes think we consider the good fortune of the early bird and overlook the bad fortune of the early worm." FDR - 1922
You quoted Wikipedia as stating, "Based on the effects of these earthquakes, it can be estimated that they had a magnitude of 8.0 on the Richter scale."8+ on the Richter is a whopper of a quake, in fact 100 times larger than a 6.0.From the USGS website I learned that there were in fact 4 earthquakes (and possibly an unreported 5th one) between December 1811 and February 1812, all of them around magnitude 8 as well as thousands of smaller quakes. Some areas of historic uplifting rose during the events of 1811/12 and some sank, by as much as 6 meters. "Large waves were generated on the Mississippi River by fissures opening and closing below the surface. Local uplifts of the ground and water waves moving upstream gave the illusion that the river was flowing upstream. Ponds of water also were agitated noticeably."You can read more at http://earthquake.usgs.gov/regional/states/events/1811-1812.phpBruceT
You're probably thinking of the New Madrid quake in SE MO in 1804. IIRC, it's been estimated at ~8.0, and rang church bells in Boston. It also rerouted the Mississippi river.My favorite quake story happened in the late 80's when my folks visited from MO. We were doing tourist things and visited the old Spanish mission at San Juan Bautista. As we were leaving, my Mom asked me where the San Andreas fault was located. I took her arm and we walked over to the guardrail around the parking lot. I pointed into the depression on the other side of the guardrail and said "It's right there." (It actually is, BTW)Her eyes got sorta big and she decided that right now would be a good time to leave. I don't think that she really relaxed until they got back to St. Louis. - lol
eef:
I'm in the San Gabriel Valley and I didn't feel it at all or the one today, somewhere near Hawthorne. I've managed to be out of town for the big ones so it's been a long time since I felt an earthquake. I've been in SoCal since the forties and I'm glad I live here rather than where the tornadoes or the hurricanes occur several times a year.
Jim
At least you get some advance notice of hurricanes and tornadoes.
-Steve (who spent the 1989 Loma Prieta "World Series" earthquake underneath a workbench in Berkeley)
Hurricanes, yes. Tornadoes, very often not.Jim, (who lived in Oklahoma and was scared poopless more than once from tornadoes in our area.)
Even in tornado country, all it takes to be aware of the possibility of tornadoes is to keep an eye on the Weather Channel or equivalent.
-Steve (who lived in Oklahoma for 11 years and only had tornadoes come within a mile of his house on three occasions...)
jim,
you were out of town for the '71 quake and the northridge big one? lucky man.
eef
eef:Yeah, I was in San Francisco during the "71" quake and I was camping at Kings Canyon National Park when the Northridge quake hit. I didn't even know there had been a quake until I came home a few days later. No damage at home.I prefer not to use the term lucky however. I'll just knock on wood or some such thing.Jim
I live on the north end of the tornado belt and have had to many encounters. Lucky that if you keep your head cocked to the north west from spring to fall you get pretty good at reading the sky. and the local CBC radio keep weather reports pretty good.
Just couldn't imagine the ground shaking under me? mind you I am a woosey on a 8 foot ladder.
just got news that my friends in Santa Barbra did not lose there house to the fires but got with in 400 feet. Can't California start a proposition banning earthquakes?
shoe,
"...a proposition banning earthquakes.after one of our many freeways fell down, caltrans began retro-fitting the columns that support things. i guess that kind of legislating and subsequent doing puts people's minds to, somewhat, rest. but it's all the man made crap becoming air-borne that poses threat during the tremblors. when things start shaking, i tend to want to make for the trees.
eef
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