January 2, 2012
by John Vidale
Ironically, reports of the Seahawk thunderclap (see previous blog entry) led some to claim it was just a late copycat an SEC original. They said the 1988 LSU-Auburn game registered on a seismogram following a game-winning touchdown. In order to give the Seattle signal its proper place in history, it is important to dismiss the prior claim.
Here is a patched-together piece of the seismogram from the “Earthquake game”. The wiggly lines record the ground motion, with the little bumps showing the passage of each minute. Each revolution of the seismic recorder takes ten minutes – we are seeing five minutes in the image. The black blur in the middle is reputed to be the fans cheering, recorded 1000 feet away in the Geology Department.
Here is a close-up, with the arrow showing one minute’s time.
The claim does not bear up, and likely was not the roar of the crowd. No signal even a tenth as big was seen at the time of the extra point 50 seconds later, which actually won the game. The time of the noise on the seismogram was 9:23 pm, while the one reference to the time of the touchdown found by us is 9:32 pm. The game up to that point appeared nearly silent to the seismometer, except for some noise 11 minutes earlier and a short burst at 1:15, in the half of the time that is visible (5/10 minutes per revolution) for the prior 2.5 hours. And the bursts afterwards do not have the tempo expected for a football game, so just a mistake in marking the seismogram of reversing time wouldn't help much.
This week, while writing up this clearly erroneous reporting, I found a 2007 blog from the losing side, Auburn, offering a rebuttal of the official story. The blog suggests that ESPN essentially created the earthquake hype out of a dubious seismogram a year or more after the LSU-Auburn game.
Perhaps the stands had a special resonant personality that night, and jumping in them both drove the especially strong vibrations and destroyed the seating that fostered it, as the second comment on the blog claims. I don’t believe it either, I think the signal did not come from the stadium, but can’t think of an obvious way to prove it wrong.
I must admit the Lynch Seahawk signal is not the first football-related noise captured on a seismogram. No doubt it has happened numerous times, even in Seahawk games earlier in the season, as could be seen on the graphic of all the home games in the last blog entry. Boise State has had well studied recordings of the roar of the crowd, for example.
However, the Seahawk signal was real and really loud, a signal the PNSN is proud to have reported. The hype from the SEC often is just that.
- Large Mount Baker debris Avalanche this fall
- Speedy ETS in the works
- Peppy seismic swarm 20 km NW of Mount St Helens
- Glacier outburst flood on Mount Baker recorded by the PNSN
- Three new ways to view recent earthquakes in the Northwest
- M3.5 event west of Tacoma early Sunday morning
- Oregon ETS is over, but....
- Small swarm near Mount McLoughlin last night
- Earthquake early warning workshop quick report
- thePNSN Facebook discussions
- October (1)
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- April (3)
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- December (1)
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- July (2)
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- The wech-o-meter takes over all of Cascadia
- Keystone Cops: Italy prosecutes seismologists for failure to predict deadly quake
- UFOs in eastern Washington? No, rather UTEs (Unidentified Terrestrial Events)
- New Sodo Seattle Liquefaction Array Installed
- Why we should constantly watch the deformation of the seafloor
- Mystery chirp near Newberry Volcano
- Planting seismographs causes earthquakes? or maybe ice-quakes?
- Tunneling rumbles south under Capitol Hill
- 15 years of mostly silent magma inflation near Three Sisters, Oregon
- Mount Hood earthquake swarm of Feb 23, 2012
- Web glitches: duplicate (and even triplicate!) earthquakes
- How earthquake magnitude scales work
- Mine blast masquerades as volcanic tremor
- The Spokane Swarm about 10 years ago
- Another hum around Mount St. Helens
- Slow slip: A new kind of earthquake under our feet
- PNSN and social media
- 3am M3.4 earthquake in St. Helens Seismic Zone
- The wrong kind of volcano noise
- Fast chatter on Rainier an hour ago
- Can slush-mageddon trigger earthquakes?
- Rainier Repeating Earthquakes Update and Comparison with Weather Patterns
- 22-minutes drumbeat icequakes(?)
- Mount Rainier popping away
- Repeating Earthquakes on Mount Rainier - are glaciers the culprit?
- Debunking another SEC football myth by the PAC-12
- One year ago, Seattle Seahawks 12th Man Earthquake
- The odds this year of a megaquake on the Pacific Northwest coast
- Is the plague of great earthquakes this decade a sign of increased danger?
- Nile Valley landslide talks to PNSN seismologists
- Good vs evil in central US earthquake hazard analysis
- Why does a volcano scream?
- Predicting big quakes from patterns of little ones
- 1-hour warning for Japanese M9 earthquake?
- Sound Transit train under Interlaken keeps a rollin'
- Invisible changes under the hood at the PNSN
- Sound Transit Tunneling Noise
- "Visionary" toads
- Earthquake early warning in the PNW
- November (1)
- December (13)