Ad-Express and Daily Iowegian, Centerville, IA

CNHI/Southeast Iowa

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
CNHI/Southeast Iowa
  • 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

  • linda-ronstadt.jpg Obama had crush on First Lady of Rock

    Linda Ronstadt remained composed as she walked up to claim her National Medal of Arts at a White House ceremony Monday afternoon.

    July 29, 2014 1 Photo

  • Can black women have it all?

    In a powerful new essay for the National Journal, my friend Michel Martin makes a compelling case for why we need to continue the having-it-all conversation.

    July 29, 2014

  • 0729 OTT Picture veteran -T -M Veteran finally receives his medals OTTUMWA — A World War II injury may have saved the life of a U.S. Coast Guardsman from Iowa, but he lost friends and a box of military awards. Francis Hardy Harbour was born on Dec.16, 1919, in Drakesville. He joined the Coast Guard in 1941 as a mach

    July 29, 2014 1 Photo

  • Dangerous Darkies Logo.png Redskins not the only nickname to cause a stir

    Daniel Snyder has come under fire for refusing to change the mascot of his NFL team, the Washington Redskins. The Redskins, however, are far from being the only controversial mascot in sports history.  Here is a sampling of athletic teams from all areas of the sports world that were outside the norm.

    July 28, 2014 3 Photos

  • 'Rebel' mascot rising from the dead

    Students and alumni from a Richmond, Va.-area high school are seeking to revive the school's historic mascot, a Confederate soldier known as the "Rebel Man," spurring debate about the appropriateness of public school connections to the Civil War and its icons.

    July 28, 2014

  • Fast food comes to standstill in China

    The shortage of meat is the result of China's latest food scandal, in which a Shanghai supplier allegedly tackled the problem of expired meat by putting it in new packaging and shipping it to fast-food restaurants around the country

    July 28, 2014

  • wd saturday tobias .jpg Stranger’s generosity stuns Ohio veteran

    Vietnam War veteran David A. Tobias was overwhelmed recently when a fellow customer at an OfficeMax store near Ashtabula, Ohio paid for a computer he was purchasing.

    July 28, 2014 1 Photo

  • Screen Shot 2014-07-28 at 1.33.11 PM.png VIDEO: High-dive accident caught on tape

    A woman at a water park in Idaho leaped off a 22-foot high dive platform, then tried to pull herself back up with frightening results. Fortunately, she escaped with only a cut to her finger.

    July 28, 2014 1 Photo

  • CATS-DOGS281.jpg Where cats are more popular than dogs in the U.S.-and all over the world

    We all know there are only two types of people in the world: cat people and dog people. But data from market research firm Euromonitor suggest that these differences extend beyond individual preferences and to the realm of geopolitics: it turns out there are cat countries and dog countries, too.

    July 28, 2014 1 Photo

  • How spy agencies keep their 'toys' from law enforcement

    A little over a decade ago, federal prosecutors used keystroke logging software to steal the encryption password of an alleged New Jersey mobster, Nicodemo Scarfo Jr., so they could get evidence from his computer to be used at his trial.

    July 25, 2014

  • Russia's war on McDonald's takes aim at the Filet-o-Fish

    Russia said earlier this week that it had no intention of answering Western sanctions by making it harder for Western companies to conduct business in Russia.
    But all bets are off, apparently, when you threaten the Russian waistline.

    July 25, 2014

  • cleaning supplies Don't judge mothers with messy homes

    I was building shelves in my garage when a neighbor girl, one of my 4-year-old daughter's friends, approached me and said, "I just saw in your house. It's pretty dirty. Norah's mommy needs to clean more."

    July 25, 2014 1 Photo

  • Taking a look at Iowa's rural bridges and roads

    OSKALOOSA — National statistics indicate that Iowa roads and bridges are in desperate need of repair.According to the Rural Connections: Challenges and Opportunities in America’s Heartland report, 22 percent of Iowa’s rural bridges are deficient.Maha

    July 25, 2014

Obituaries
Featured Ads
Poll

The Iowegian wants readers to think about the solicitation ordinance that will prevent groups or individuals from entering a roadway to solicit money. The Centerville City Council in June by a 5-0 vote passed the first reading of just such an ordinance. Public pressure and during a subsequent special meeting, the council voted 3-2 to table the ordinance. A second special meeting to discuss the solicitation ordinance is scheduled for 5:30 p.m. Thursday, Aug. 7 at City Hall. So, the question of the week is, "Do you or do you not support the ordinance to prevent solicitation of funds in city streets?"

A. I support the ordinance
B. I do not support the ordinance
C. Not sure
     View Results
Iowegian on Facebook