Patterico's Pontifications

2/27/2010

Earthquakes and Tsunamis

Filed under: Current Events — DRJ @ 1:07 am

[Guest post by DRJ]

A 7.0 magnitude earthquake off the coast of Japan and an 8.8 magnitude quake off the Chilean coast sparked tsunami warnings in both nations, although the Japanese warning appears to have been rescinded. There is no tsunami warning for Alaska or the West Coast of the United States as a result of the earthquake in Chile [UPDATE BY PATTERICO: there is now a warning for the West Coast], but there may be an impact in Hawaii.

— DRJ

35 Responses to “Earthquakes and Tsunamis”

  1. Damn that George W. Bush!

    Beldar (ac33f9)

  2. We wondered when he would get around to it. It was the only thing he had not caused yet.

    White House Press Office (db4a41)

  3. Miss me yet?

    You will.

    Ok Dick, crank-up the machine again.

    George W Bush (e72a45)

  4. I’m wondering if geologists are now going to come up with a comprehensive prediction regarding the increased activity of severe earthquakes in so many different regions of the world recently. Maybe the Ring of Fire is really undergoing a dramatic shift in intensity along it’s borders – in the past year alone we’ve seen many significant quakes, only recently in Haiti and just before that outside Manila.

    Dmac (799abd)

  5. It’s Kronos trying to break out of Tartarus and overthrow the Olympians, with the help of George W. Bush and Dick Cheney. What’s that? Yes, the First Family did go to see “The Lightning Thief”.

    White House Press Office (db4a41)

  6. Neal Abercrombie resigns from HofR to run for Gov of HI…
    will there be a state there to govern?

    AD - RtR/OS! (13c1a1)

  7. To put this earthquake into perspective, it’s described as 500 times more powerful than the one that struck Haiti. Thoughts and prayers are with Chileans.

    GeneralMalaise (c58b20)

  8. This is just another example of anthropogenic global warming, along with the severe winter in the Northern hemisphere.

    daleyrocks (718861)

  9. I agree with the above conclusion, because those well – known scientists Joy Behar and Eve Ensler said the same thing.

    Dmac (799abd)

  10. See! I told you wingnuts this was going to happen.

    Al Gore (9e58d8)

  11. There’s a tsunami warning out for the California coast now, expected wave height up to the 2 ft range, possibly larger in bays and inlets. Expected to hit the SF Bay Area around 1 PM, Los Angeles area around noon, and up to several hours afterwards.

    Ernst Blofeld (fda24d)

  12. Will our own Jr.Obama, aka Mayor Tony Vilar, stand at L.A.Light and turn-back the raging sea?
    Enquiring minds want to know.

    AD - RtR/OS! (13c1a1)

  13. Damn that George W. Bush!

    Nononono!

    It’s because Chile sold their soul to Satan. Pat Robertson tells me so…

    Scott Jacobs (d027b8)

  14. I thought Mr. Awesome promised to lower our sea levels if elected. Another one thrown under that articulated bus.

    Dmac (799abd)

  15. Chile’s 8.8 earthquake released about 500 times the energy as the mere 7.0 quake that hit Haiti, and more than 1000 times the energy of the Northridge quake. If it was a hydrogen bomb it would have been the equivalent of about 19,000 1 Megaton bombs, or rather more than the entire US nuclear arsenal.

    It is probably a good thing that most of that energy went into displacing thousands of cubic miles of seawater, rather than adding to the shaking of inhabited land. Tsunamis can be avoided.

    Kevin Murphy (3c3db0)

  16. oops, only 16,000 1 megaton bombs. My bad.

    Kevin Murphy (3c3db0)

  17. My wife allows me one stupid question per day…here it is: Would a tidal wave of great magnitude (as this one may be) be visible from space or overflying aircraft, or does it need to be near land before the actual wave forms? In other words, can it be tracked along it’s path?

    Al Gore (9e58d8)

  18. Sorry, #18 is me…Al Gore is my sockpuppet from a previous post.

    Old Coot (9e58d8)

  19. My impression is that the wave forms as the water becomes shallower and the only place it has to go is up. Out to sea a ship crossing over it would feel it only as a ripple.

    I don’t know if it can be tracked from the air.

    nk (db4a41)

  20. There are bouys in the ocean to track these things, but the wave force isn’t all that spectacular to nobodies like me until the wave hits a shelf. Then, that force stacks itself up to make the wall of water.

    You have energy pushing 5000 feet of water across the ocean where, suddenly, that 5000 feet becomes 300 feet and shrinking as the ocean bottom rises up. No place for the energy to go but up, creating the wall of water.

    John Hitchcock (6186ea)

  21. BTW, John, aren’t supposed to be a grandaddy by now? And will we be getting Hersheys with almonds or plain?

    nk (db4a41)

  22. NK, I updated this morning. I rarely hear from her except on the weekends, so I don’t know what’s up right now. Due date March 4, so…

    John Hitchcock (6186ea)

  23. there are deep sea buoys which detect their passage and relay data via satellite. there is also a paper where someone used shore station GPS units to track land movement, and then inferred tsunami amplitude, etc…. my understanding is that in open, deep water, they are virtually undetectable by the eye. whether they can be detected via radar from space i’m not sure…but i’m sure someone has, or will, look at the issue.

    redc1c4 (fb8750)

  24. And will we be getting Hersheys with almonds or plain?

    I was thinking Butterfingers but Laura might have a problem with that.

    John Hitchcock (6186ea)

  25. Well, I should certainly hope so. Crushed nuts? What are you thinking?

    nk (db4a41)

  26. 1.Damn that George W. Bush!

    Comment by Beldar — 2/27/2010 @ 5:24 am

    Nothing like using an emergency situation to be a partisan jerk-head.

    Intelliology (00d844)

  27. Heh, I’m a bit slow on the draw sometimes, nk. I didn’t catch what you meant so I made a different joke. They’ve already picked out a name, Joshua Treyshawn, so that should answer that, I think.

    John Hitchcock (6186ea)

  28. There’s this theory that the baby is born exactly nine calendar months from conception. We didn’t believe it when we had our daughter — we had made an appointment to induce labor — and then my wife’s water broke exactly nine calendar months from the hour of conception.

    nk (db4a41)

  29. Nothing like using an emergency situation to be a partisan jerk-head.

    Comment by Intelliology — 2/27/2010 @ 1:10 pm

    Something I can finally agree with!!! Throw Rahm Emanuel out!

    John Hitchcock (6186ea)

  30. #27

    That was Beldar, not Rahm

    SteveG (909b57)

  31. We’re now 10 minutes out from the time of estimated impact. While I will be happy that Hawaii dodged this bullet, I hate that this will be another overstatement of harm/crying wolf.

    I must say I loved Julie Banderas on FNC getting all hysterical when she saw some folks near the ocean. “These people should know better! What is going on here?!” Of course, it was obvious they were on a cliff high above the shore, but she haaaaad to jump to the conclusion she wanted.

    Ed from SFV (f6a87d)

  32. Truman said, “The buck stops here”. Obama says, “Send the buck to Bush and let me eat my Wagyu”.

    nk (db4a41)

  33. (@18 Old Coot) Would a tidal wave of great magnitude (as this one may be) be visible from space or overflying aircraft, or does it need to be near land before the actual wave forms? In other words, can it be tracked along it’s path?

    Mr. Coot, after browsing the web, I discovered this is not a trivial problem. Here are my non-expert findings:

    As noted by other readers, the tsunami-wave in the open water is indistinguishable from normal wave activity. In an effort to detect such waves, the NOAA employs a system called DART. It consists of pressure sensors resting on the ocean floor, coupled with surface buoys that measure the ocean height. This information is then subject to an algorithm that filters out normal wave activity and identifies tsunami-wave characteristics. If wave activity of a proper frequency and amplitude (generally larger than 3 cm) matches a tsunami and is detected consistently, then an alert is sent by satellite to the reporting agency. Here is a map of the location of the DART sensors (a graphical representation of the waveform is viewable by placing the cursor over a sensor icon).

    This article explains the DART process and its limitations in more practical terms:

    However, in the open ocean, detecting, characterizing, and imaging tsunami waves is still a challenge. The offshore vertical tsunami displacement (on the order of a few centimeters up to half a meter in the case of the Sumatra tsunami) is hidden in the natural ocean wave fluctuations, which can be several meters or more. In addition, the number of offshore instruments capable of tsunami measurements, such as tide gauges and buoys, is very limited – there are only about 70 buoys in the whole world. As a tsunami propagates with a typical speed of 600-700 km per hour, a 15-minute confirmation system would require a worldwide buoy network with a 150-kilometer spacing.

    In many cases, the tsunami can only be identified several hours after the seismic event due to the poor distribution of sensors. This delay is necessary for the tsunami to reach the buoys and for the signal to be recorded for a minimum of one wave period (a typical tsunami wave period is between 10 and 40 minutes) to be adequately filtered by removing the “noise” due to normal wave action.

    The article goes on to describe a new potential method of tsunami detection, which is accomplished by detecting the tsunami’s physical disturbances in the atmosphere (specifically in the ionosphere) and using GPS technology.

    Recently, observational and modeling results have confirmed the existence and detectability of a tsunamigenic signature in the ionosphere. Physically, the displacement induced by tsunamis at the sea surface is transmitted into the atmosphere where it produces internal gravity waves (IGWs) propagating upward.

    The normal ocean surface variability has a typical high frequency (compared to tsunami waves) and does not transfer detectable energy into the atmosphere. In other words, the Earth’s atmosphere behaves as an “analog low-pass filter.” Only a tsunami produces propagating waves in the atmosphere.

    At an altitude of about 300 kilometers, the neutral atmosphere is strongly coupled with the ionospheric plasma producing perturbations in the electron density. These perturbations are visible in GPS and satellite altimeter data since those signals have to transit the ionosphere. The dual-frequency signal emitted by GPS satellites can be processed to obtain the integral of electron density along the paths between the satellites and the receiver, the total electron content (TEC).

    Within about 15 minutes, the waves generated at the sea surface reach ionospheric altitudes, creating measurable fluctuations in the ionospheric plasma and consequently in the TEC. This indirect method of tsunami detection should be helpful in ocean monitoring, allowing us to follow an oceanic wave from its generation to its propagation in the open ocean.

    So in short, Mr. Coot, as best as I could determine (inside half-an-hour anyway), the answer to your first question is “no” and to your second question “yes, but within limitations”. My $0.02 anyway.

    Pons Asinorum (95faa4)

  34. As Artie Johnson would say:

    Verrry Interrresting!

    AD - RtR/OS! (7d5017)


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