I’ll just say that it might have been a wake up call, but many people are not getting the message. My wife worked for a school who took until 2005 to make any changes in response to that earthquake, and their solution was to buy extra cell phones. A Superbowl parade was enough to take down cell service in Seattle… do they really think that’s a solution in a serious earthquake? And that was not the only laughable part of their earthquake preparedness. (For example, their disaster plans actually prioritized recovering dead bodies from rubble over erecting shelters for the survivors. Because we all know that middle school students should be out in the rain looking for their dead friends in a collapsed building.)
The earthquakes in the Challis area have nothing to do with Yellowstone. What would make us potentially worried about volcanic activity there would be swarms of low-magnitude quakes centered around the magma chamber, not fairly shallow ones hundreds of miles away.
The Challis earthquakes (both this recent one and the huge 1983 one) are part of the Intermountain Seismic Belt, which is the result of the the western US being under tension. The Challis valley is one of the northernmost of the Basin and Range valleys, and the earthquakes there are the result of the valley floor dropping relative to the adjacent mountain ranges. Unlike the relatively deep earthquake we’d have to worry about for Yellowstone, the fault that moved in the '83 earthquake is right at the surface and left a cool scarp: http://www.idahogeology.org/DrawOnePage.asp?PageID=199
Although, on the topic of the OP and speaking of the Intermountain Seismic Belt, the Wasatch Front by Salt Lake City is another one of these basin and range faults that is known to have powerful earthquakes.
This reminds me of something I’ve wondered about. Let’s say that a major earthquake (8.5+) ocurrs directly under Los Angeles. How devastating would that be?
Oh, but also more generally, no there haven’t been more earthquakes lately. You just hear about them more. In the past, you would have heard about an earthquake overseas only if there was significant damage or loss of life, but given the 24 hour news cycle (and the fact that the USGS’s seismograph network is on the internet and generates automatic alerts) they’re more likely to get a passing mention on the US news these days.
Most buildings would have some danger of collapsing, which means that many would collapse. Elevated freeway sections would collapse, much like the Loma Prieta quake in the 80’s. Water & gas mains would probably rupture, resulting in loss of service as well as fire danger and inability to douse same. Remember, San Francisco was levelled in the 1906 quake because everybody’s kitchen stove fell over, spilled coals on the floor, fire broke out, and there was no water to fight the fires with.
There has been some extensive upgrading of quake-proofing since the last few big quakes down there, but any building which hasn’t gotten upgraded would be at a fairly serious risk in a major earthquake.
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100%, for some values of “soon”.
I live just a few blocks from the Hayward Fault - in fact they dug a hole in our park to let people see it, and a curb in the parking lot is split due to the motion of the fault.
Besides water and food, it is good to have a way of shutting off the gas. We have a gas wrench attached to the shutoff valve so it will be available.
But you can never tell. The first earthquake I ever felt was in the middle of Illinois.
There are many factors that determine the damage, not just Richter number. There is the depth of the quake, is it a jolt or a roll, the wave pattern, etc. Even in a large metro area, the real impact gets somewhat isolated. Buildings will fall right there along the faultline, and 2 blocks away it’s just shake-n-bake. It’s not like everything for 20 miles is flattened.
When the Northridge quake hit, I seem to recall it was a jolt. Based on how things like cabinets and shelves fell over you could tell which direction it was traveling. The property damage was centered to the epicenter, and also curiously there was a pocket of damage in Santa Monica 20 miles away.
Where we are they installed a tip-over turnoff on everyone’s gas line. There is some dispute about this. The worry is that quake will be strong enough to turn off everyone’s gas, but not really big enough to cause damage. And then everyone (all 7 million) will be calling to get someone out to turn their gas back on!
Odds of a major earthquake happening somewhere in the world before the end of the month: almost a certainty.
Odds of an earthquake major enough to make world history (like the Indian Ocean Tsunami), cause tens of thousands of deaths, etc., happening before the end of the month: 1 in 1,000.
Odds of a devastating earthquake (think: Loma Prieta or Norridge) hitting a major metro area in the U.S. before the end of the month: 1 in 50 maybe?
Think the odds are significantly higher than that, considering we’ve experienced a historically catastrophic earthquake on average every five years (Indonesia '04, Haiti '10, Japan '11, etc.)
Is there a typo here? Because 1 in 50 seems a lot higher than 1 in 1,000.
I don’t consider Loma Prieta or Norridge “devastating” in the sense that the recent quakes in Haiti and Japan were.
Nitpicking myself: I meant to say the odds are “lower”, not “higher”. :smack:
One thing to consider whilst everyone is calculating away on the back of their envelopes: the basis for Charles Richter’s original research was the observation that there is a fairly close relationship between the intensity and frequency of earthquakes. Just like a 7.0 quake Is 10 times stronger than a 6.0, they tend to occur 10 times less frequently, and so on.
Over time, this relationship hasn’t proved to be 100% accurate for every region and of course the moment magnitude scale gives slightly different results, but in general it’s a good approximation of how often to expect strong earthquakes.
Of course, earthquake intensity isn’t everything. The Haiti earthquake was fairly similar in size to the Loma Prieta and Northridge quakes. Quakes that are relatively minor events in a place with good siesmic building codes can be major catastophies elsewhere.
having recently moved to Oregon I am very interested in this subject!
I recently found this report but I have no idea how reliable it is - be interested in what people think.
it says about a 40% chance of a 8.0 - 9.4 quake in the Cascadian Subduction Zone within 50 years, especially the southern half, Southern California and Northern California (down to about Sacramento)
Case in point: Just this morning, a 7.2 struck the Mexican coast, but there’s been no reports of casualties or major damage.
Some hear and prepare, some do not. The above is mind boggling.
My biggest fear would be not getting home if a quake happened in the daytime, as the Hood Canal Bridge would likely go down, and I’d bet Liliwaup would slide into the water, along with a good bit of 101 along the Canal. OTOH, I’ve contacts amongst The Swift and Silent;) (though they’d likely have their own issues).
Aside from relatively basic preparedness, it’s best not to dwell overly on it. Do be alert for the warnings, whether it be quake, hurricane, tornado, or volcanic eruption. I’ve lived through all except the Volcano, and if Ranier blows, well, I’ve had a good life…
The idea that people who are “prepared” for an earthquake have some sort of advantage over the unprepared always makes me laugh…
“The building just fell over on me. Thank goodness I was prepared for that.”
“My neighborhood is on fire. But I was prepared.”
“A bridge fell apart as I was driving across. But I was prepared.”
“My bugout bag had enough food for 7 days. But my neighbor stole it after we started starving.”
etc