The Washington Times-Herald

Community News Network

May 8, 2013

When the earth moves under our feet

One of the most breath-taking geologic events is a major earthquake. In just a few moments, shaking of the Earth can result in billions of dollars of damage and thousands of lives lost.

Many earthquakes are related to the movement of tectonic plates, the large chunks of the Earth’s outer surface that move with respect to each other. Plates are “born” in places like Iceland, where magma comes up from below and creates oceanic plate material. Plates “die” where one plate dives beneath another and ultimately is pulled and pushed down so deeply into the Earth it melts away. Plates vary a bit in how fast they move, but about an inch or two a year is not uncommon.

One example regarding tectonic movement is in the Pacific Northwest. The Cascadia subduction zone is the area where the Juan de Fuca plate is diving under the North American plate. The movement generates major earthquakes from time to time. The most recent mega-quake occurred in 1700. Geologists think the region is about due for another similar event.

Recently I was reading in Science News about new information regarding earthquakes and plate movement. In the Cascadia region something called “slow slip” happens about every 15 months. Slow slip occurs when the rocks on either side of a major fault move about the same amount as in a major earthquake, but they do so over weeks to months rather than almost instantaneously.  

The evidence for slow slip was documented first for Cascadia in the bedrock of Vancouver Island, British Columbia. Now that geologists know what to look for, slow slip events have been identified the world around. In Japan, some slow slip events have been documented that occur about each three to five years and last a few months, while others occur more frequently.

Text Only
Community News Network
  • American sunscreens need an upgrade

    The last time a new sunscreen ingredient came on the U.S. market, the Y2K bug was threatening to destroy our way of life. Intel had just introduced the Pentium III processor, featuring an amazing 500 MHz of computing power.

    April 24, 2014

  • 20140424-AMX-COFFEE24.jpg Coffee growers' prayers for rain met with threat of deluge

    Brazil's drought made arabica coffee this year's best-performing commodity. Now, farmers are facing a downpour that is once more threatening crops.

    April 24, 2014 1 Photo

  • Celebrity quack moms are a terrible influence on everyday parents

    On April 15, the actress Alicia Silverstone released a book called "The Kind Mama: A Simple Guide to Supercharged Fertility, a Radiant Pregnancy, a Sweeter Birth, and a Healthier, More Beautiful Beginning." It's chock-full of attachment parenting lessons and dangerous misinformation.

    April 24, 2014

  • Affirmative action ruling challenges colleges seeking diversity

    The U.S. Supreme Court's support of Michigan's ban on race-based affirmative action in university admissions may spur colleges to find new ways to achieve diversity without using racial preferences.

    April 23, 2014

  • Cuba is running out of condoms

    The newest item on Cuba's list of dwindling commodities is condoms, which are now reportedly in short supply. In response, the Cuban government has approved the sale of expired condoms.

    April 23, 2014

  • A 'wearable robot' helps her walk again

    Science is about facts, numbers, laws and formulas. To be really good at it, you need to spend a lot of time in school. But science is also about something more: dreaming big and helping people.

    April 23, 2014

  • The waffle taco's biggest enemy isn't McDonald's. It's consumer habits.

    Gesturing to Taco Bell, Thompson said McDonald's had "not seen an impact relative to the most recent competitor that entered the [breakfast] space," and that new competition would only make McDonald's pursue breakfast more aggressively.

    April 23, 2014

  • McCain 1 House Republicans are more active on Twitter than Democrats

    Your representative in the House is almost certainly on Twitter. Your senator definitely is. But how are they using the social network? Are Democrats more active than Republicans, or vice versa? Who has the most followers on the Hill?

    April 23, 2014 1 Photo

  • The top 12 government programs ever

    Which federal programs and policies succeed in being cost-effective and targeting those who need them most? These two tests are obvious: After all, why would we spend taxpayers' money on a program that isn't worth what it costs or helps those who do not need help?

    April 22, 2014

  • Cats outsmart the researchers

    I knew a lot had been written about dogs, and I assumed there must be at least a handful of studies on cats. But after weeks of scouring the scientific world for someone - anyone - who studied how cats think, all I was left with was this statement, laughed over the phone to me by one of the world's top animal cognition experts, a Hungarian scientist named Ádám Miklósi.

    April 22, 2014