Posted on 12/28/2004 1:17:23 PM PST by CharlieOK1
OKLAHOMA CITY -- Jolts from the enormous earthquake in Indonesia that killed thousands were felt in Oklahoma.
The Oklahoma Geological Survey in rural Tulsa County recorded shock waves from the 9.0-magnitude quake beginning at 7:13 p.m. Saturday, 15 minutes after the temblor occurred beneath the Indian Ocean.
The largest waves, with a .12-inch vertical movement in Oklahoma, were logged at 7:36 p.m., local time.
"This is the type of earthquake that's recorded by every seismograph in the world, and recorded very clearly," said Jim Lawson, chief geophysicist with the OGS. "This is almost the biggest earthquake that could occur."
The large waves felt in Oklahoma may have caused water in Oklahoma ponds and lakes to slosh back and forth slowly, a motion called a seiche, Lawson said. It also may have caused some tall buildings in the state to sway slightly, he said.
Neither phenomenon had been reported as of Monday afternoon, Lawson said.
"If it had been in the middle of the day, I'm sure there would have been hunters and farmers out seeing their ponds moving around a little bit," Lawson said. "It's probable that it happened."
The quake was the most powerful in 40 years, sending walls of water called tsunamis crashing ashore in the region's waterfront communities.
Officials said the death toll -- reaching more than 22,500 -- would rise, warning that disease outbreaks were possible.
The 9.0 magnitude quake is the strongest since the March 28, 1964, quake (9.2) in Prince William Sound in Alaska. It is the fourth strongest since recordings of magnitude began in 1899, tying a 1952 quake in Kamchatka, Russia.
The Oklahoma Geological Survey Observatory, south of Leonard in rural Tulsa County, is a comprehensive geophysical observatory that records, identifies and locates 30 to 167 earthquakes in Oklahoma annually. It also records about seven worldwide earthquakes per day.
Oklahoma ping.
Actually not all that amazing. Hobbyists build seismometers for a few hundred bucks that can easily record much smaller quakes (Mag 6) from all over the world.
Come looky maw. The dang pond is sloshin!
I'd like to know how fast the vibrations were traveling in order to reach OK in 15 minutes.
Are you sure the vibrations felt in Oklahama were from the 'Quake' in Sumatra, and not from Micheal Moore taking a crapper?
And how happy were all the women in between? LOL
The world being about 25,000 miles around, and Oklahoma being roughly on the opposite side of the planet from the quake, that puts Oklahoma about 7,947 miles away from the quake. The tremors traveling 7,947 miles in 15 minutes, means that they traveled roughly 31,789 mph to arrive in Oklahoma when they did.
When traveling to the mooon in 1969, the Appolo capsule achieved roughly 36,000 mph.
LOL...no, what MM does on the crapper would be "scheisse" in German, which sounds a lot like seiche and may've been what that Swiss scientist first said when he saw the pond jiggle.
LOL!!!
Damn that's fast. Thanks for the calculation.
Too true!
A buddy of mine build one out of a metal bandaid box, a couple of magnets, and a coil of wire. It was sensative enought to pick up people walking in the house (he had it burried in the yard outside his window), and trucks on the busy street nearby. He spent about $.05 on the box and about 10 bucks on the analog/digital converter hookup into his computer. (circa 1987)
"I'd like to know how fast the vibrations were traveling in order to reach OK in 15 minutes."
http://www.fcs-net.com/biddled/earthwaves.htm
Which then leads to:
P waves travel, on average, about 4.5 to 5.5 km/s, while S waves travel at about 3.0 km/s through the earth's crust.
Now my brain hurts.
I'm not a siesmologist which probably has the best answer, but it should be basically a compression wave like sound, except through rock. A quick Google search yields a speed of sound through rock page (about earthquakes nonetheless).
6-8 km/s (or around 13 - 18 thousand miles per hour).
Yeah, I think NBC News led off last night with "The quake was picked up in CENTRAL PARK NEW YORK! WOW!" as if that was a big deal.
There's actually a mailing list, PSN-L, for people that build their own seismometers. Most of them end up spending a bit more than your friend, buy old sensors off e-bay, and dig a hole in their backyard and pour some concrete to anchor it in.
I used to subscribe to the list so I could be the ABSOLUTE first to hear about big quakes (faster than FR, faster than NEIC, faster than CNN) but to get that I had to put up with several dozen e-mails a day about how to build the seismometers, which I really am not interested in.
Problem is with one seismometer all you can do is tell how far a quake is from you and how big it is (roughly) not where it is. It's pretty amazing though, through a series of e-mails the people on the list tend to get it figured out pretty fast.
Whoops, I missed the leading decimal point.
Lets add a little more pain. The calculations I've seen are based upon the wave traveling across the surface of the earth. The 15 minute figure accounts for the seismic wave taking the short cut - through the earth.
"Neither phenomenon had been reported"
I feel the title is misleading. Author should have said recorded or measured as by instrument. No one reported feeling it.
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