Based on historical averages, Goldfinger says the southern end of the fault - from about Newport, Ore., to northern California - has a 37 percent chance of producing a major earthquake in the next 50 years. The odds that a mega-quake will hit the northern segment, from Seaside, Ore., to Vancouver Island in British Columbia, are more like 10 to 15 percent.
http://www.cnn.com/2010/WORLD/asiapcf/07/23/phillipines.earthquake/index.html?hpt=T2
(CNN) -- A series of four strong earthquakes spanning just over an hour struck the Philippines' Moro Gulf on Saturday morning, according to the U.S. Geological Survey.
Three of the four earthquakes had magnitudes between 7.3 and 7.6; the other came in at a 5.4 magnitude. The first quake struck at 6:08 a.m. (6:08 p.m. ET Friday) and the fourth hit at 7:15 a.m. The last quake ran the deepest at 616 (382 miles) kilometers.
http://www.cnn.com/2010/WORLD/asiapcf/07/23/phillipines.earthquake/index.html?hpt=T2
I don't remember the exact figure, but isn't there an earthquake SOMEWHERE in the world approximately every 2-3 minutes?
Zee plates! Zay move!
\
:judge:
Quote from: Suu on July 24, 2010, 04:37:41 PM
I don't remember the exact figure, but isn't there an earthquake SOMEWHERE in the world approximately every 2-3 minutes?
Zee plates! Zay move!
\
:judge:
Of course the plates and formations, etc. move. I have no idea how often a quake hits.
The National Earthquake Information Center (U.S.) reports 12,000-14,000 earthquakes a year around the world, or 35 a day. Throughout the world, there are one "great" (magnitude 8.0 or more), 18 "major" (7.0-7.9), 120 "large" (6.0-6.9) and 1,000 "moderate" (5.0-5.9) earthquakes in an average year. Each year, California generally gets two or three earthquakes large enough to cause moderate damage to structures (magnitude 5.5 and higher).
http://www.conservation.ca.gov/index/Earthquakes/Pages/qh_earthquakes.aspx
We actually have a shit ton over here in the Northeast. I mean, they are really minor, topping out at 3.0 or 4.0 on the Richter (snort) scale, but we did have that one last month that was a 5.0 in Quebec.
Quote
Earthquakes in the Northeast U.S. cannot be associated with specific known faults, as opposed to the typical seismic activity evident in California. While California earthquakes typically occur at, or near the conjunction of two of the Earth's major tectonic plates ("inter-plate" activity), earthquakes in New England occur in the middle of plates ("intra-plate" activity), far from the plate boundaries .
The immediate cause of most shallow earthquakes is the sudden release of stress along a fault, or fracture in the earth's crust, resulting in movement of the opposing blocks of rock past one another. These movements cause wave-like vibrations to pass through the ground, just as ripples are generated when a pebble is dropped into a pond.
Did You Know?
The Northeast experiences an average of 40 - 50 earthquakes per year.
Due to the solid bedrock geology of the Northeast, a large earthquake will affect a much wider area than an earthquake of similar magnitude in California.
:kingmeh:
Kansas looks safe.
http://www.emporia.edu/earthsci/student/johnson1/presentation.html
Actually, this is fascinating stuff. They actually have no solid idea as to WHY New England and Quebec have earthquakes, because it defies what should be the norm. Our faults have technically been inactive for millions of years, and we're far enough from the Mid Atlantic Ridge to where that won't effect us.
The hot spot in Missouri is always fun too, and South Carolina also has a spot.
(http://neic.usgs.gov/neis/qed/thirty.gif)
That's the past 30 days around the world. Gah.
That is really interesting.
I wonder if we would be able to tell if a fissure was opening up in a plate. Would we know?
Most hypotheses include magma flow beneath the old faults, or Cthulhu.
Millions of years ago, the Appalachians, especially up here with the Andirondacks, Green, and White Mountains, which are STILL huge as far as old mountains go, were REALLY active. All sorts of fun volcanoes and earthquakes, which is still pretty evident in the soil (well, the stuff that hasn't been destroyed by the plowline).
We have a lot of deposits of granite and quartz up here, so at one time, there was a shit ton of lava that cooled, and it was everywhere.
I'm pretty sure it's Cthulhu, actually.
Quote from: Suu on July 24, 2010, 05:31:12 PM
Actually, this is fascinating stuff. They actually have no solid idea as to WHY New England and Quebec have earthquakes, because it defies what should be the norm. Our faults have technically been inactive for millions of years, and we're far enough from the Mid Atlantic Ridge to where that won't effect us.
The hot spot in Missouri is always fun too, and South Carolina also has a spot.
(http://neic.usgs.gov/neis/qed/thirty.gif)
That's the past 30 days around the world. Gah.
It is fascinating. That map is incredible.
Quote from: Doktor Charley Brown on July 24, 2010, 04:29:24 PM
Based on historical averages, Goldfinger says the southern end of the fault - from about Newport, Ore., to northern California - has a 37 percent chance of producing a major earthquake in the next 50 years. The odds that a mega-quake will hit the northern segment, from Seaside, Ore., to Vancouver Island in British Columbia, are more like 10 to 15 percent.
http://www.cnn.com/2010/WORLD/asiapcf/07/23/phillipines.earthquake/index.html?hpt=T2
Pshaw! They've been saying that about the New Madrid Fault for the last 50 years and still nothing major. I've come to the conclusion that it is impossible to predict earthquakes and anyone who says differently is trying to sell you something.
This map is fun and handy: http://www.ess.washington.edu/recenteqs/
Mt. St. Helens is always a rumblin' and a bubblin'. Nigel (or maybe another Portland spag?), didn't you say that you can see smoke coming from Mt. Hood all the time too?
It's always steaming... usually you have to get right up on it to see, though. And you don't want to sit by the steam vents or you'll die of carbon monoxide poisoning!
...I like the East Coast.
Sure, it's a bug infested swamp full of very angry people with threats of severe hurricanes and baby earthquakes, but damnit, I don't know if I can do the volcano thing. I still say the day I'm actually in the PNW to finally check it out, the fault will accidentally the whole Cascades.
But then again, if I gotta go...being burning alive in boiling hot magma from like 7 volcanoes at once is one of the coolest ways.
Quote from: Iason Ouabache on July 24, 2010, 07:40:55 PM
I've come to the conclusion that it is impossible to predict earthquakes and anyone who says differently is trying to sell you something.
This.
There's subtle hints on major volcanic fault lines, but at New Madrid or in the Northeast, there's NO WAY to tell. And you never know if it's going to be a 3.0 or 8.0 either. There's just no way, because by the time you get enough information, the damage is already done.
You can get out of the way of a hurricane, and you can tell if a storm is going to spawn tornadoes, but anything seismic is 99% unpredictable.
There's no smoke coming off Mt. Hood unless it's a campfire, but St. Helens is still quite active.
The one that would cause a real problem in the area if it blew is Mt. Rainier, which IIRC is considered "active".
This, of course, presumes that one would consider the sudden immolation of Tacoma, Lakewood, and Puyallup and every living thing in them a "problem". many Washingtonians would not.
Yeah, but Rainier isn't small. I would assume damage to Seattle would be imminent as well. Then again, Mt. St. Helens blew practically around the corner from Portland, and nobody heard a thing.
Quote from: Suu on July 25, 2010, 03:20:27 PM
Yeah, but Rainier isn't small. I would assume damage to Seattle would be imminent as well. Then again, Mt. St. Helens blew practically around the corner from Portland, and nobody heard a thing.
... other than the earthquakes, the massive explosion, the freeway closure, and the ashfall that darkened the region for a week or so. Oh, and how fucked up our crops were for years.
Mt. Hood will definitely erupt again eventually, but it probably won't have that much more of an effect on Portland than St. Helens did. Mt. Adams is kind of a wild card in terms of potential disruption of the Columbia River, though.
I was under the impression that Portland was in the "Dead Zone" during the eruption. Or more or less, considering it's proximity got off really fucking lucky.
I mean, crap, we got ashfall on Long Island...
http://www.pnsn.org/NEWS/PRESS_RELEASES/MSH_09_2004.html
First time I've seen pictures of the Mt. St Helens crater top. It looks pretty disgusting, tbh.
Quote from: Suu on July 25, 2010, 04:00:57 PM
I was under the impression that Portland was in the "Dead Zone" during the eruption. Or more or less, considering it's proximity got off really fucking lucky.
I mean, crap, we got ashfall on Long Island...
The sun was obscured by the ash cloud for a week or so, and we got some pretty significant ashfall. It could have been a lot worse. I think I understand your confusion about Portland being unaffected; we didn't HEAR the blast here, even though it was audible much farther away. We did get darkness and ash.
Quote from: Sigmatic on July 25, 2010, 04:17:54 PM
http://www.pnsn.org/NEWS/PRESS_RELEASES/MSH_09_2004.html
First time I've seen pictures of the Mt. St Helens crater top. It looks pretty disgusting, tbh.
You should go up there sometime; it's really amazing. The fallen trees all lined up by the blast, for miles and miles and miles, are frightening and beautiful.
Quote from: Nigel on July 25, 2010, 07:04:50 PM
Quote from: Suu on July 25, 2010, 04:00:57 PM
I was under the impression that Portland was in the "Dead Zone" during the eruption. Or more or less, considering it's proximity got off really fucking lucky.
I mean, crap, we got ashfall on Long Island...
The sun was obscured by the ash cloud for a week or so, and we got some pretty significant ashfall. It could have been a lot worse. I think I understand your confusion about Portland being unaffected; we didn't HEAR the blast here, even though it was audible much farther away. We did get darkness and ash.
Yeah that's what I meant, sorry for being unclear. It's pretty weird that you guys didn't hear anything and Seattle did.
Quote from: Suu on July 25, 2010, 03:20:27 PM
Yeah, but Rainier isn't small. I would assume damage to Seattle would be imminent as well. Then again, Mt. St. Helens blew practically around the corner from Portland, and nobody heard a thing.
Well, most projections show the mudflows being contained on the north by the Duwamish river, thus sparing Seattle proper from major damage, but those same projections show that 700,000+ people (and this was years ago, it's probably alot more now) would have less than an hour to evacuate.
The one I'd be worried about (especially if I had an apartment in PDX that was only 10 blocks away, which I do) is Mt. Tabor, which is the only active volcano inside the city limits of a major American city.
When Mount Saint Helens went off in 1980 I thought it was the end of the world. I thought we had been nuked. (My parents did too)
Quote from: Sigmatic on July 24, 2010, 05:43:33 PM
That is really interesting.
I wonder if we would be able to tell if a fissure was opening up in a plate. Would we know?
Naw, I think it's more likely a martin or a mink.
:argh!:
Quote from: Exit City Hustle on July 26, 2010, 05:51:19 AM
Quote from: Suu on July 25, 2010, 03:20:27 PM
Yeah, but Rainier isn't small. I would assume damage to Seattle would be imminent as well. Then again, Mt. St. Helens blew practically around the corner from Portland, and nobody heard a thing.
Well, most projections show the mudflows being contained on the north by the Duwamish river, thus sparing Seattle proper from major damage, but those same projections show that 700,000+ people (and this was years ago, it's probably alot more now) would have less than an hour to evacuate.
The one I'd be worried about (especially if I had an apartment in PDX that was only 10 blocks away, which I do) is Mt. Tabor, which is the only active volcano inside the city limits of a major American city.
I thought Tabor was extinct? :? All of the sources I'm finding says it a Plio-Pleistocene cinder cone, like the cones we have over here in the Northeast.
Yeah, like Rocky Butte and Powell Butte, Tabor's on the Boring Lava Field, which is extinct, in the sense that the lava tubes that fed it are blocked and cold. However, some geologists think this whole region is sitting on either a steam or lava bed (there's some kind of research underway to try to figure out which) of unfathomable size.
It would make sense. Magma feeding St. Helens et al is somewhere under there.