It’s Relative, I Suppose
Did you hear the news? Oklahoma had a big earthquake! A 4.5 on the Richter scale!
OK, nobody’s actually calling it a “big” quake. But it’s making the news. The thing is, hearing about this in Tokyo, it’s kind of risible. I mean, we had a 4.2 just two days ago, on Friday, and a 4.3 the day before that.
In the news report, however, they make note of Oklahoma’s “strongest earthquake on record,” back in November of 2011—a 5.6 on the Richter scale.
Yeah, we know what that’s like. We had a 5.5 last Tuesday. Right after a 4.7, with a 4.6 two days before that. Fact is, we tend to have at least four or five quakes in the 4-range every week, and a five-point-something every week or two. And we tend to get a quake around 7 on the scale every few months.
As for 2011, well, you know what we got that year.
It reminds me of living in Toyama, on the Japan Sea side of Japan,where we got several meters of snow each year, and it was typical to have several feet of snow on the ground at any one time. Then we would watch the news on TV and laugh at the big reports of Tokyo getting a few inches of snow, and everything shut down.
M7’s are actually pretty big . . .
http://www.artemis.bm/blog/2013/11/22/m7-3-tokyo-earthquake-could-cost-3-trillion-in-economic-losses/
Loma Prieta was a 6.9 and did a number on the Bay Area, Northridge 1994 was a measly 6.4, and the ’71 Sylmar quake was 6.6.
Tuesday’s M5.5 quake 100 miles out in the Pacific can’t be compared to a 4.5 going off right under you:
“The earthquake was centered near Arcadia, about 14 miles northeast of Oklahoma City, and was about 5 miles deep”
Back in ’83 a M6.5 went off ~60 miles away from me:
http://en.wikipedia.org/wiki/1983_Coalinga_earthquake
and it was a pretty strong one in my experience, equal to the worst I experienced in Tokyo.
In the 25 years I lived in California, I experienced a handful of earthquakes, only 2 particularly memorable. (The other one was a M5 in 1989 with an epicenter 20 miles away).
In the 8 years I was in Tokyo, temblors were old hat of course, with one rattling through like you say pretty often.
Pretty amazing that Tokyo escaped with so little loss of life in 2011, just that Costco garage collapse, of all things.
But proximity counts for a lot wrt EQs . . . the pacific plate instability isn’t Tokyo’s main threat . . .
http://geology.about.com/od/eq_prediction/a/aa_tokaiquake.htm
Hardly all of them are that far off. The 5.5 a month ago was under Chiba, as was a 5.4 a week later.
Nor are they all that deep, either. A 5.9 in September was inland and only 10km deep, as was a 6.2 earlier in the year.
And remember that large quakes happening 100K out at sea are not exactly the least dangerous of things…
yeah, a 9.0 is the big kahuna, a million times more energy/work release than a 5.0
The Tohoku quake was tied for #4:
http://en.wikipedia.org/wiki/Lists_of_earthquakes#Largest_earthquakes_by_magnitude
Strike-slip faults like the S. A. can’t even generate that degree of crustal tension:
http://en.wikipedia.org/wiki/Megathrust_earthquake
I think the bigger issue with Oklahoma isn’t the size of the quake, but the fact that they are occurring at all.
Oklahoma is on the great plans. They are geologically fairly stable.
The big question is whether fracking is causing these quakes.
The quake in 2011 occurred in the middle of Oklahoma and we felt it all the way over in Kansas City. Something like 350 miles away.
I happened to be joking with my friend today. We were talking about the fact that Minneapolis has an unemployment rate of 4.8% – the only major metropolitan area that is below 5% and expected to have a low unemployment rate for the next 10 years. We speculated on the reasons, one being the metropolitan area that services the ag states that surround it, including the Dakotas that also have an energy boom going on, thanks to fracking.
My friend joked, that is, until it sets off the Yellowstone volcano.
For any one that doesn’t know, Yellowstone National Park is actually the crater of a super-volcano. One day, it has the potential of going off and covering (destroying) half of North America with it.
So he was just joking of course but I wonder if scientist have fully considered all the possible negative aspects of fracking.
Could fracking awaken Yellowstone caldera?
http://billingsgazette.com/news/opinion/mailbag/could-fracking-awaken-yellowstone-supervolcano/article_85e30062-b3bf-5e6c-a345-5446412792af.html
Speaking of ‘relative’, I made this graph today:
http://research.stlouisfed.org/fred2/graph/?g=q5e
blue is per-capita (age 25-54) gov’t debt for Japan, red is US
this is something of an artifact of the fluctuating yen; rebasing the Japanese amount to a yen at constant ¥100 per USD:
http://research.stlouisfed.org/fred2/graph/?g=q5h
might make the comparison more accurate.
Thing is, Japan’s 25-54 population is going to decline (from the early 2000s peak) 30% by 2030, and 40% by 2040!
I really don’t understand what is going to happen to Japan this decade and next with their debt. I don’t think the ‘bug looking for a windshield’ analysis is correct, since you Japanese just owe this money to yourselves mostly, but *how* the next generation is going to pay on the promises of the boomers (age ~61-67 now) is a great mystery to me.
Well, the echo boomer age group is age ~39-45 now, so maybe they’re on the hook for it.
Japanese births by decade:
1946-55: 21.8M
1956-65: 16.6M
1966-75: 19.2M
1976-85: 16.0M
1986-95: 12.6M
1996-05: 11.7M
2006-15: 10.7M
2016-25: 8.8M
This fall-off is visible here:
http://research.stlouisfed.org/fred2/series/LFWA24TTJPM647S