The Trembling Earth

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Tag Archives: base isolation

Sunday Reading #3

Apologies for the tardiness. I suppose for some of you this is Sunday evening reading, if that’s what people even do on Sunday evenings. Maybe for those of you hunkering down in the U.S. midwest.

Here are two weeks’ worth of seismic tidbits I posted on Twitter, since the first week was a little dry. Catch up on all things quakey!

Overcompensating in L’Aquila
In oh-so-foreseeable news, Italian officials are now trigger-happy with evacuation orders in the wake of the manslaughter conviction of seismic hazard officials. Caution is good… but, this is why we have legends like the boy who cried wolf.

“Why evacuate for an earthquake no one can feel?”
http://www.bbc.co.uk/news/magazine-22039903

A nice antidote to that painful bit of news is a call to arms about the risky state of building design in such a quake-prone region:
http://www.csmonitor.com/World/Europe/2012/0521/Italy-earthquake-modern-buildings-not-ancient-ones-pose-biggest-threat-video

Man-made Earthquakes
The seismic hot-topic of the decade, human-induced earthquakes, gets a summary treatment by Popular Mechanics. The summary is good. You’ll be hearing more about this from me and all of us in the future:
http://www.popularmechanics.com/science/energy/coal-oil-gas/how-big-could-a-man-made-earthquake-get-15299728

“Rolling” versus “sharp” earthquakes, explained

“The Earthquake Machine”
How do you scale down faults so that you can understand their frictional and mechanical behavior in controlled tests? Popular Science has a neato infographic on the equipment used in rock mechanics tests–earthquake laboratories.
http://www.popsci.com/technology/article/2013-03/earthquake-machine

Earthquakes and Society
Christchurch residents and architectural pros alike balk at the rebuild designs for the downtown cathedral:
http://www.dezeen.com/2013/04/08/critics-back-restoration-of-earthquake-christchurch-cathedral/

Nepal introduces an emergency plan for a crucial post-quake lifeline, its airport:
http://www.irinnews.org/Report/97766/Priming-Nepal-s-airport-for-earthquake

Exposé of an ethically questionable but increasingly common industry–disaster tourism:
http://travel.nytimes.com/2013/04/07/travel/tourism-in-javas-land-of-ghosts.html

Animal earthquake predictors
There has been a modest buzz this week about research on a longstanding legend of seismic phenomena. Animals have occasionally been reported to appear to foretell earthquakes, but anecdotal evidence generally fails any rigorous scientific test, and most such observations are thus dismissed as unreliable indicators of any impending quake. Researchers in Germany, however, have begun to study ants that live in colonies along fault lines. Surprising finding: their level of activity changes from a daily average before small tremors. I wouldn’t make too much of this yet, but I think it’s really cool to finally see some potential for scientific tests of a long-standing, intractable myth/puzzle about quake phenomena. Now if only we could fill all our fault lines with German Redwood ants…. I wonder if they distinguish between magnitude 2 and magnitude 7…

The news release:
http://www.ouramazingplanet.com/4360-ants-sense-earthquakes.html

The researchers’ website:
http://www.uni-due.de/geology/research/ants_earthquakes.shtml

Landslide in Utah Copper Mine

Quarry collapse at the Bingham Copper Mine, Utah

Quarry collapse at the Bingham Copper Mine, Utah

A noteworthily massive collapse occurred this week at a quarry outside of Salt Lake City, Utah. The event is outside of my scientific jurisdiction, but Dave Petley has been covering it with great interest, and has reported a bit about the seismic signature of this mighty landslide:
http://blogs.agu.org/landslideblog/2013/04/12/the-unusually-large-bingham-canyon-mine-landslide-an-impressive-example-of-prediction-using-monitoring/

Honshu quake

DYFI130413Honshu

A modest but substantial 5.8 tremor rattled the southern Japanese island of Honshu this week, doing a fair bit of damage on Awaji island and the densely populated area surrounding it. A collection of videos record the shaking from a few urban cameras, the second of which demonstrates the noise created by a rattling city:

YouTube user KOJI PEI posted a video showing a real-time (actually ~2 or 3x speed) animation of shaking intensity at each of Japan’s seismometers during this quake. I’m not sure where this video came from nor how specifically it was generated (it appears to be maximum acceleration averaged over a several second time window), but I’m hoping to find out and to find more like it. You can see seismic waves radiate outward from the epicenter, with the relatively gentle P-waves leading the charge, and swishy S-waves ringing outward behind them.

Seismic engineering – For your Office, Museum, or Bedroom!
Scaled down base isolators can secure servers, lab apparati, antiques etc. on specialized tables.
http://gizmodo.com/5994528/watch-this-anti+earthquake-table-shrug-off-a-violent-simulated-tremor 

The principle of base isolation is already successfully applied in buildings around the world, and this mini-version may be hugely popular with companies and museums whose equipement and specimens need to be seismically protected. One of the commenters also has some insightful things to add, including the major deficiencies in maximum displacement and vertical protection.

Big news on a big move this week – I’ll update you all shortly!

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