Alan, when I saw your note about how you'd feel silly sending a report to the USGS saying that you felt an earthquake, I wrote a response, but I don't see it now. Incase it never properly posted, here's a word on that. It's not only by seismic readings that the USGS evaluates an earthquake. Revision of an initial finding (as from 6.9 to 7.1) relies on reports from people like yourself. When people say they felt the earthquake and how strongly, that is excellent location information that shows them how the vibrations traveled through rock and whatnot and how much real impact it had. On the USGS page, they ASK for such reports.
I really don't think that if a hurricane should hit New England you would bother to call in to the NOAA to report that it rained at your place, listener.
I figure there will be more than enough nervous Norberts to take care of that, besides which there are seismographs all over out here. Which reminds me of a story that was in the news a few years ago: In a storage room at one of the campuses of the University of California (not Berkeley) they discovered a seismograph that had recorded the 1906 ["San Francisco"] earthquake. They had long had the seismogram itself, but because the instruments weren't uniformly calibrated in those early days they could not judge the magnitude of the quake. Setting up the seismograph and checking its responsiveness they could get the only measurement of the magnitude--it wasn't as strong as they had estimated from the damage reports.
It seems I misremembered the story about the seismograph.Here [Click] and here [Click] is more and better information.
Here are recent estimates of the magnitude of the 1906 quake. [Click] The energy released in the 1906 quake would seem (to me, if I understand the equations correctly) to be sixteen times as much as was released in a 7.1 moment magnitude quake.
Some more things about earthquakes. In California they don't propagate very far because of the complex geology of the state. East of the Rockies most of the US is on the North American craton--i.e., solid rock--and the waves propagate for great distances. For an extreme example, consider the Lisbon earthquake of 1755, which rang church bells in the Carolinas. There were people whose houses were built on solid rock next to the San Andreas fault who slept through the 1906 quake; in the South of Market area, where the ground was poorly consolidated fill in what had been a salt marsh people reported seeing waves coming up the streets, about three feet high and thirty feet between crests. When waves pass through materials of high elastic modulus (stiffness) the amplitude decreases and the frequency increases, so the ground (and things built on it) buzzes; the same train of wave energy passing through materials of low elastic modulus decreases in frequency and increases in amplitude. In addition to that there may be liquifaction, and if the waves are reflected from physical boundaries (like hills) the incoming and reflected waves will interact to add in places and cancel in places. Location counts for a lot. Yesterday we went up to the Bay Area (I think I didn't mention that--all went well, traffic wasn't heavy) and in one place we drove along an old freeway through a beautiful canyon going more or less north-south toward Berkeley. It has long been built up with very nice suburban houses. It also is the main trace of the Hayward Fault, which is active and has't had a big quake since the 19th Century. Bad idea to live there.
Biden: “C’mon on, man!” [Click] The man frequently speaks in antiquated and meaningless juvenile expressions; that is likely to weigh hevily on his prospects when contrasted with other candidates who can compose reasoned responses on their feet.
Come to think of it, I recall someone pointing out that the UK really can't refuse to pay the UK divorce bill. If they refuse to pay it up front, the UK will simply collect it a little bit at a time. Say five euros per vehicle or some such.
Appeals court’s decision on Affordable Care Act could create political havoc for GOP
A ruling that the health-care law is unconstitutional would almost certainly catapult the issue back before the Supreme Court — and to the forefront of the 2020 campaign, legal and political analysts say.
Headline: "California governor: Trump committed to helping earthquake recovery" He's going to give people 5%-off coupons for rakes, so they can prevent earthquakes by raking the desert.
Alan, when I saw your note about how you'd feel silly sending a report to the USGS saying that you felt an earthquake, I wrote a response, but I don't see it now. Incase it never properly posted, here's a word on that. It's not only by seismic readings that the USGS evaluates an earthquake. Revision of an initial finding (as from 6.9 to 7.1) relies on reports from people like yourself. When people say they felt the earthquake and how strongly, that is excellent location information that shows them how the vibrations traveled through rock and whatnot and how much real impact it had. On the USGS page, they ASK for such reports.
ReplyDeleteI really don't think that if a hurricane should hit New England you would bother to call in to the NOAA to report that it rained at your place, listener.
DeleteI figure there will be more than enough nervous Norberts to take care of that, besides which there are seismographs all over out here. Which reminds me of a story that was in the news a few years ago: In a storage room at one of the campuses of the University of California (not Berkeley) they discovered a seismograph that had recorded the 1906 ["San Francisco"] earthquake. They had long had the seismogram itself, but because the instruments weren't uniformly calibrated in those early days they could not judge the magnitude of the quake. Setting up the seismograph and checking its responsiveness they could get the only measurement of the magnitude--it wasn't as strong as they had estimated from the damage reports.
ReplyDeleteIt seems I misremembered the story about the seismograph.Here [Click] and here [Click] is more and better information.
DeleteHere are recent estimates of the magnitude of the 1906 quake. [Click]
The energy released in the 1906 quake would seem (to me, if I understand the equations correctly) to be sixteen times as much as was released in a 7.1 moment magnitude quake.
I don't think that if a hurricane should hit New England you would bother to call in to the NOAA to report that it rained at your place, listener.
DeleteI've been in both a hurricane and tornadoes. There would be no calls to NOAA because there is no phone service in either case.
DeleteSome more things about earthquakes. In California they don't propagate very far because of the complex geology of the state. East of the Rockies most of the US is on the North American craton--i.e., solid rock--and the waves propagate for great distances. For an extreme example, consider the Lisbon earthquake of 1755, which rang church bells in the Carolinas. There were people whose houses were built on solid rock next to the San Andreas fault who slept through the 1906 quake; in the South of Market area, where the ground was poorly consolidated fill in what had been a salt marsh people reported seeing waves coming up the streets, about three feet high and thirty feet between crests. When waves pass through materials of high elastic modulus (stiffness) the amplitude decreases and the frequency increases, so the ground (and things built on it) buzzes; the same train of wave energy passing through materials of low elastic modulus decreases in frequency and increases in amplitude. In addition to that there may be liquifaction, and if the waves are reflected from physical boundaries (like hills) the incoming and reflected waves will interact to add in places and cancel in places. Location counts for a lot. Yesterday we went up to the Bay Area (I think I didn't mention that--all went well, traffic wasn't heavy) and in one place we drove along an old freeway through a beautiful canyon going more or less north-south toward Berkeley. It has long been built up with very nice suburban houses. It also is the main trace of the Hayward Fault, which is active and has't had a big quake since the 19th Century. Bad idea to live there.
DeleteAwh. Great photos, Listener.
ReplyDeleteReplies on the last thread.
ReplyDeleteWarren and Harris Rise In the Democratic Race [Click] Howsabout President Warren and AG Harris? I could go for that.
ReplyDeleteBiden: “C’mon on, man!” [Click] The man frequently speaks in antiquated and meaningless juvenile expressions; that is likely to weigh hevily on his prospects when contrasted with other candidates who can compose reasoned responses on their feet.
[“New”] Democrats Spooked by New Primary Threats [Click] From politico.com, so consider the source.
Also from politico.com: Threat of Budget Disaster Increases [Click]
USA women’s football team takes second world cup [Click]
The Observer view on the self-destruction of the Conservative party [Click] Things seem on course to become far too interesting in the UK…
ReplyDeleteThings are looking pretty bleak.
DeleteIf the UK refuses to pay the EU divorce bill, it seems only fair that Scotland should refuse to pay the UK divorce bill.
DeleteCome to think of it, I recall someone pointing out that the UK really can't refuse to pay the UK divorce bill. If they refuse to pay it up front, the UK will simply collect it a little bit at a time. Say five euros per vehicle or some such.
DeleteAffordable Care Act threatened as Trump administration, GOP states fight U.S. House, Democratic states in court [Click] If the GOPers trash it, let it happen well before the election—long enough in advance that it will sink in through the thickest skulls.
ReplyDeleteWashington Post:
DeleteAppeals court’s decision on Affordable Care Act could create political havoc for GOP
A ruling that the health-care law is unconstitutional would almost certainly catapult the issue back before the Supreme Court — and to the forefront of the 2020 campaign, legal and political analysts say.
These poll numbers are sobering, not to say depressing.
ReplyDelete<a href="https://www.realclearpolitics.com/epolls/other/president_trump_job_approval-6179.html</a>Trump's Job Approval</a> - Click
Oops! Let's try that link again.
DeleteTrump Job Approval - Click
Headline: "California governor: Trump committed to helping earthquake recovery"
ReplyDeleteHe's going to give people 5%-off coupons for rakes, so they can prevent earthquakes by raking the desert.
Sounds like our boy. :P
DeleteOn re-reading it, it doesn't come across as sarcastic as I intended it to.
DeleteNYT: Warren and Harris Rise in Democratic Primary, Challenging Male Front-Runners [Click] I don’t think the writer is very perceptive— lots of hackneyed old political punditisms in the column, but there are still some nuggets.
ReplyDelete