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Original post made
on Jan 26, 2011
Interesting. Well, 60% of the time, it works every time.
The Loma Prieta quake, in 1989, was a real local shaker, but it was not a disaster. The real question is, what the is the chance of a 7.5, or greater, quake in the next 30 years?
I have lived here for 20 years and they have been saying that all the time. Does that mean that they are really talking about 10 years, or is it a stretchable 30 years?
IF I keep saying 30 years earthquake warning after every 20 years, I can't be wrong!
There is going to be an earthquake tomorrow in this area. Gee I will be 50% right
Sure, some may scoff at this news and others may scoff at the responses here.
But really, is this news? We live amongst major fault. We get smaller earthquakes all the time. We know that at any time we may get a more moderate and even a big one. But we hear this and it means nothing more than seeing the terror alert at orange (which is about to be scrapped anyway).
Talk about the boy calling wolf.
An earthquake will happen in the Bay Area, but no one knows when or in what section. The USGS is only doing the best it can based on past experience both here and around the world.
Whether anyone chooses to prepare is certainly up to them. But it's easy and inexpensive to do so. Why anyone would not do some planning or preparation is beyond me. After all we know we will retire in 5 to 40 years and plan for that (most of us!!!).
Actually the time to prepare for an earthquake is now. Also the Richter scale is not a perfect measure of the damage an earthquake can cause. If we have another one same "size" as Loma Prieta it might be rather worse
And let's not forget the massive flooding that is also going to destroy California --
Digital News Report California could be faced with a super storm that could produce up to 10 feet of rain, and that is why scientists, the Federal Emergency Management Agency (FEMA), the California Emergency Management Agency (Cal EMA), and the United States Geological Survey met last week in Sacramento to discuss the possibility of massive flooding that could cause a potential of $300 billion in damages.
The "emergency preparedness" business is no doubt a little slow at the moment, so never a bad time to rattle the drums a little. We also have to worry about volcanoes and asteroid impacts, which have been theorized as the source of mass extinction events.
Wow .. maybe we all should just go back to bed and wait 'till it's safe to come out and play again.
Folks, this is serious and it's about you and your loved ones.
People in New Orleans used to joke in bars about Lake Ponchantrain but it's not funny any more. The Bay Area is a great place to live. As anyone who was here in 1989 can tell you, the Big One is really scary. Take a few minutes and:
a) Secure your heavy furniture
b) Prepare an emergency supplies kit (esp. water)
c) Make sure your house is bolted to the foundation
You'll be glad you did.
Shaken, not stirred,
We should trigger earthquakes deliberately using surplus nukes from the worldwide build-down. Thanks to GPS-based plate tracking, the stress build up can be estimated pretty well along the faults. The deep holes needed could also be used for geothermal energy extraction, hopefully paying for the project and more.
> We should trigger earthquakes deliberately using surplus nukes
This has been suggested, from time-to-time. However, no one wants to take responsibility for the project, if it goes wrong.
I work for USGS on the Earthquake program and have a couple things to contribute:
1. The M1.7 event near Permanente Quarry was not an earthquake - it was an explosion set off by the quarrying operations at the quarry. They happen frequently and are easy to recognize by the shallow depth (0 km in this case), the location, occurrence during working hours, etc. The seismograms from a blast are also distinct from those of an earthquake.
The USGS website shows the epicenter in either Google Maps or GoogleEarth so you can zoom right into the quarry to get an idea how good the location is: Web Link
2) The 63% probability of a damaging quake (M6.7 or larger) in the next 30 years in the Bay Area is based on an improving but still incomplete knowledge of faults and strain accumulation in the area. There's nothing special about the 30 year window - it was chosen because that's the length of the average home mortgage, which provides a comprehensible length of time that most people can relate to. If you want to read more about how the probability is determined, it's all on-line at Web Link
3) There have been only 4 historical earthquakes as large as M6.7 in the Bay Area. The first, in 1838, is believed to have occurred on the San Andreas, perhaps in the Portola Valley/Woodside area, though the evidence is limited to a recollection 40 years after the event by a citizen of San Jose who experienced it.
Next was the M6.8 earthquake in 1868 that ruptured the Hayward fault from Fremont to San Leandro. Damage from this quake was so great in San Francisco that they called it the Great San Francisco earthquake.
Of course that name was reassigned a few decades later to the truly "Great" M7.9 quake of 1906 that ruptured the San Andreas from San Juan Bautista to Cape Mendocino.
Fourth and most recent is the M6.9 Loma Prieta quake that killed 63 and produced about $6 Billion in damage. The take-away lesson from Loma Prieta was that it was be "best" earthquake we could hope for in that it was remote from most populated parts of the Bay Area, having occurred beneath the lightly populated Santa Cruz mountains. The next "big one" is almost certain to occur much closer to the more populated and developed areas. For example, think of how many homes, businesses, highways, etc. are built directly over the Hayward fault. A recurrence of the 1868 earthquake will be much more devastating than Loma Prieta for that simple fact.
4) Finally, all this is summarized in a USGS published brochure available in some Home Depots and OSH outlets. It covers the science but also the questions of why people need to be prepared and what they need to do to get ready, whether the quake happens tomorrow or 30 years from now. It's also on-line at Web Link
Seems like some fact checking could have been done by the author of this article.
1 - the quarry where the "earthquake" took place is technically "east" of Portola Valley, kind of in the same sense one could say LA is "east" of Reno. It would have been far more accurate to say the quarry is west of Cupertino.
2 - it wasn't an earthquake (as Steve the USGS guy stated), and the magnitude was 1.2, not 1.7.
3 - the "Kaiser Permanente Quarry" hasn't been that for YEARS! It became the Hansen Quarry in 1999, and then in 2007 became the Lehigh Southwest Cement Company, Permanente Plant.
Looks like another blast today at 1:20pm. This is the M1.2 I think you're referring to. The earlier blast (on Tuesday I think) was a legitimate M1.7 but it looks to have been removed from the web page, probably because the timers confirmed it as an explosion and removed it from the map. Verified explosions are removed to avoid confusion - people expect an earthquake map to have only earthquakes, though seismic networks don't discriminate between tectonic sources and man-made sources.
Thanks for the info on the quarry - it was implanted in my memory as Kaiser Permanente Quarry many years ago and I'm going to have trouble adjusting to the new name. How about Permanente Quarry, since they obviously still quarry limestone to make the cement?
Just to be clear, my comments/criticism was directed to the author of the article, not you. I appreciate your additional info, and it was from your link that I saw the 1.2 magnitude "quake", which I now see was the one that happened today.
The current quarry owner does have a web page - Web Link - and they refer to the cement plant as the Permanente Plant.
If you ever want to visit, just go to Portola Valley and head "east" :-).
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