Cumberland Times-News

Community News Network

May 8, 2013

When the earth moves under our feet

(Continued)

Often slow slip is too slow to create seismic waves. But sometimes the rock on either side of the fault may move quickly enough to generate seismic waves that are just large enough to be above background noise. In that case, the slow slip generates what scientists call tremor.

A confusing point is that sometimes tremor occurs before or after the movement of the slow slip. Sometimes slow slip occurs with no tremor at all. The reasons for these facts are not currently understood.

The longest period of slow slip yet detected anywhere started last August under Vancouver Island. It began as tremors there, then moved south. It crossed the international border, moving to and then beyond the Seattle region. All together, the event lasted 42 days.

At first it might seem that slow slip relieves stress on faults and could help us avoid major quakes. But some geologists think that slow slip events transfer stress to areas that then are more likely to rupture when a mega-quake occurs in a region.  

So even when it comes to slow motion earth movement, we’ve got to hang onto our hats.

Dr. E. Kirsten Peters was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human and Natural Resource Sciences at Washington State University.

Text Only
Community News Network
  • Why a see-through mouse is a big deal for scientists

    A group of Caltech researchers announced in Cell Thursday their success in making an entire organism transparent. Unfortunately, this isn't any kind of "Invisible Man" scenario: The organism in question is a mouse, and the mouse in question is quite dead.

    July 31, 2014

  • Screen Shot 2014-07-31 at 2.12.55 PM.png VIDEO: Five-year-old doesn't want her brother to grow up

    Sadie, an adorable 5-year-old from Phoenix, wants her brother to stay young forever, so much so that her emotional reaction to the thought of him getting older has drawn more than 10 million views on YouTube.

    July 31, 2014 1 Photo

  • lockport-police.jpg Police department turns to Facebook for guidance on use of 'negro'

    What seems to be a data entry mistake by a small town police department in western New York has turned into a social media firestorm centered around the word "negro" and whether it's acceptable to use in modern society.

    July 31, 2014 3 Photos

  • The virtues of lying

    Two computational scientists set out recently to simulate the effects of lying in a virtual human population. Their results, published in the Proceedings of the Royal Society B, show that lying is essential for the growth of a cohesive social network.

    July 31, 2014

  • Sunburn isn't the only sign of summer that can leave you itchy and blistered

    You've got a rash. You quickly rule out the usual suspects: You haven't been gardening or hiking or even picnicking, so it's probably not a plant irritant such as poison ivy or wild parsnip; likewise, it's probably not chiggers or ticks carrying Lyme disease; and you haven't been swimming in a pond, which can harbor the parasite that causes swimmer's itch.

    July 30, 2014

  • Survey results in legislation to battle sexual assault on campus

    Missouri U.S. Sen. Claire McCaskill joined a bipartisan group of senators Wednesday to announce legislation that aims to reduce the number of sexual assaults on college campuses.

    July 30, 2014

  • An alarming threat to airlines that no one's talking about

    It's been an abysmal year for the flying public. Planes have crashed in bad weather, disappeared over the Indian Ocean and tragically crossed paths with anti-aircraft missiles over Ukraine.

    July 30, 2014

  • Sharknado.jpg Sharknado 2 set to attack viewers tonight

    In the face of another "Sharknado" TV movie (the even-more-inane "Sharknado 2: The Second One," premiering Wednesday night on Syfy), there isn't much for a critic to say except to echo what the characters themselves so frequently scream when confronted by a great white shark spinning toward them in a funnel cloud:
    "LOOK OUT!!"

    July 30, 2014 1 Photo

  • 20140729-AMX-GIVHAN292.jpg Spanx stretches into new territory with jeans, but promised magic is elusive

    The Spanx empire of stomach-flattening, thigh-slimming, jiggle-reducing foundation garments has expanded to include what the brand promises is the mother of all body-shaping miracles: Spanx jeans.

    July 29, 2014 1 Photo

  • Medical marijuana opponents' most powerful argument is at odds with a mountain of research

    Opponents of marijuana legalization are rapidly losing the battle for hearts and minds. Simply put, the public understands that however you measure the consequences of marijuana use, the drug is significantly less harmful to users and society than tobacco or alcohol.

    July 29, 2014

Latest news
Facebook
Must Read
House Ads