Posts Tagged ‘tsunami’

You say ‘tsunami’ I say ‘tidal wave’ Who’s right?

June 23, 2014

If you say ‘tsunami’ to describe those immense swells of water that can reach 100 feet in height, travel at more than 500 mph, and are capable of causing widespread destruction, then you are correct. This short video from the TED-Ed series explains tsunamis and how they work.

A tidal wave, by the way, is simply what happens when the tide comes in from a body of water. Because they are caused by gravitational interactions between the Sun, Moon, and Earth, tidal waves are predictable events. Check out the Department of Ecology’s description of Puget Sound tides.

Tsunamis, on the other hand, are unpredictable, and frequently caused by powerful earthquakes under the ocean floor. This type of earthquake pushes a large volume of water to the surface, creating waves that become the tsunami. The waves may be small in the deep, open ocean, but get much bigger and more dangerous as they approach shallower coastal waters. A tsunami also can be triggered by a volcanic eruption, landslide, or other movements of the Earth’s surface.

We cannot prevent tsunamis (or tidal waves, for that matter) but we can take precautions — and we should because the Cascadia Subduction Zone, where two large tectonic plates are rubbing together, lies just off our coast

DNR and its Division of Geology and Earth Resources work closely with the Washington Emergency Management Division, federal agencies, and local governments to prepare maps of recommended tsunami evacuation routes for many coastal Washington communities. Local and state emergency officials rely on maps of earthquake faults, tsunami inundation zones, and other information to plan their responses to earthquakes, tsunamis and other natural disasters.

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Tsunami refuge planned on state’s coast

April 25, 2014
Tsunami zone near Westport and Grayland Beach

Light blue shows the areas of the Washington coast between Westport and Grayland that would be inundated by a tsunami resulting from a large earthquake in the Cascadia Subduction Zone. CLICK graphic to enlarge.

One of the first large tsunami refuges in the U.S. will be built in Washington State. And why not? Just off our coastline is the Cascadia Subduction Zone—a 700-mile-long offshore fault where tectonic plates meet. It is capable of producing earthquakes and tsunamis as large as the ones that pummeled northern Japan in 2011, also caused by an earthquake along an undersea subduction zone. The odds of a 9.0 magnitude earthquake in the Cascadia zone in the next 50 years are about one in 10, according to the Cascadia Region Earthquake Workgroup.

With these risks in mind, residents of Westport and other communities in the Ocosta School District last year approved a $13.8 million bond issue to replace an aging elementary school and build a gymnasium that will double as the nation’s first tsunami refuge structure.

Located less than a mile from the ocean, the school and much of the surrounding community are in the path of the likely tsunami surge from a large earthquake on the Cascadia zone. The new gym’s roof will sit about 55 feet above sea level, well above the highest surges predicted for the school site.

DNR geologists were among the experts who advised local officials and participated in public workshops with residents about tsunami dangers in Westport and other at-risk communities on Washington’s outer coast. Elevated refuges can be the most practical and affordable options to survive a tsunami in communities where rapid evacuation is not possible. Many of the people killed in the 2011 tsunami in northern Japan received warning but could not flee fast enough or reach a high-enough area to avoid the deadly waves created by a 9.1 magnitude earthquake.

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The 12 ‘tips’ of Christmas (they can keep you and your family safe all year long)

December 23, 2013
Nisqually earthquake debris in Olympia

The 2001 Nisqually Earthquake caused building debris to fall into the streets of downtown Olympia. Make sure you’re prepared for the next natural disaster. Photo: Joe Dragovich/DNR.

Maybe you have heard all the carols and holiday music you care to hear for one year. Or, maybe you are still brimming with yuletide enthusiasm. Regardless, we bring you 12 tips that can keep you and your family safe throughout your lifetime. As you spend time with friends and family this holiday season, consider the possible emergencies that can occur and what you can do to keep everyone you love prepared. Here are a dozen tips for year-round preparedness…

1.       Prepare your trees for winter
Winter storms can do a number on your trees. Downed and damaged trees could fall on your home, your car, a powerline, or even a person. Follow these tips to keep your trees healthy and better able to resist storm damage this winter.

2.       Identify your hazards
Identify the potential hazards in your home and learn how to fix them. People are often injured or killed in earthquakes by unsecured objects such as bookshelves. Secure anything heavy enough to hurt you if it falls on you, or fragile enough to be a significant loss if it falls.

3.       Learn about your area’s natural hazards
Learn about the natural hazards that put your family at risk and what to do if they occur. Teach your kids what to do and practice your emergency action plan.

4.       Develop an Emergency Action Plan
Make an emergency plan with your family and practice it! Have different plans for different variables. What if your kids are at school or a sports practice? Make sure they know what to do if you can’t be there to help them.    

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Marine debris hotline to be suspended at year’s end

December 11, 2013
Boat washed up on beach.

This 20-ft power boat washed ashore at Cape Disappointment State Park on June 15, 2012 and was confirmed missing after the March 11, 2011 Japan tsunami. Photo: Washington Department of Ecology.

Washington’s coast has not had a major marine debris incident in almost a year. Overall, debris sightings decreased in 2013.

Today, the state announced it will suspend the special hotline that was set up for reporting marine debris.

As of 5 p.m. on December 31, the 1-855-WACOAST state hotline will be taken off-line.

“The hotline hasn’t been getting calls, so it makes sense to suspend it,” said Terry Egan, head of the state’s Marine Debris Task Force. “The state’s response plan was set up to conserve resources when it makes sense to do so, and that’s what we are doing here.”

Reporting marine debris
If you discover nonhazardous marine debris on Washington beaches that’s suspected to be from the tragic 2011 Japan tsunami, please contact DisasterDebris@noaa.gov. If possible, include photographs and any identifying information, such as GPS coordinates.

You can still report hazardous marine debris—such as gas cans, cylinders and oil drums—24 hours a day to 1-800-OILS-911.

Marine debris resources
The National Oceanic and Atmospheric Administration (NOAA) is the best source of information for marine debris:

Other marine debris resources:

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Prepare in a year Step 3: Meeting drinking water needs after a disaster

November 13, 2013
water storage

Two-liter soda bottles can store emergency water supplies (plan for at least six per person in your household).

With massive water shortages in the wake of Typhoon Haiyan (the Toronto Sun reports desperate survivors digging up water pipes), we continue a disaster preparation series initiated last month on Ear to the Ground: Prepare in a Year. The goal is to break the preparation effort into easier-to-handle monthly tasks. The Washington Emergency Management Division outlines a 12-part plan called Prepare in a Year — spend one hour on disaster preparedness each month and within a year you’ll be better prepared for disasters whenever they occur. Here in Washington State, the list of potential disasters includes earthquakes, large storms, landslides, wildfires, tsunamis, and volcanic eruptions for starters.

Here briefly are the basic steps of planning for your water needs during the first three days after a major disaster. Experience shows that it may take three days or more for outside help to arrive following a major natural disaster.

  • Store at least three gallons per person for the first 72 hours (don’t forget pets)
  • Use appropriate containers
  • Store safely in a cool, dark place that won’t freeze
  • Be prepared to treat or distill water of questionable purity

Get important details about how to Prepare in a Year

What are the geohazards in your area? See the DNR online Interactive Geology Maps Portal

See our previous posts on this topic:

Do you have an out-of-area contact in case of a major disaster? (October 9)

What’s your plan if a disaster strikes? (October 8)

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Scientists untangle events of mega-earthquake that hit Washington more than 300 years ago

July 29, 2013
Ghost Forest

DNR Chief Hazards Geologist Tim Walsh explains to a National Geographic documentary crew how these red cedars along the Copalis River were killed by a flood of seawater more than 300 years ago after a magnitude 9 earthquake..

DGER Chief Hazards Geologist Tim Walsh recently explained to a National Geographic television crew how scientists used radiocarbon dating and tree ring analysis to correlate the sudden coastal subsidence that drowned millions of trees in the Pacific Northwest 300 years ago and a tsunami documented in Japan in the same time period.

An analysis of these red cedar trunks indicated that they were submerged sometime between August 1699 and May 1700. This time frame coincides with numerous accounts of a tsunami of unknown origin — also known as the Orphan Tsunami of 1700 — that reached Japanese shores on January 26, 1700.

Apparently, a megathrust earthquake on the Cascadia Subduction Zone triggered land subsidence and seawater inundation that submerged coastal forests in the Pacific Northwest. Multiple records kept by Native American peoples of the Pacific Northwest also suggested violent shaking and flooding in the same time period as the Orphan Tsunami.

The earthquake of 1700 is the type of Cascadia megathrust earthquake that geologists say can happen again in the Pacific Northwest at any time. It rivaled the magnitude and character of the Tohoku earthquake that devastated northern Japan on March 11, 2011.

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DNR expert shows international visitors the sites and geologic hazards of Puget Sound

July 26, 2013
geo hazards tour of Puget Sound

Tim Walsh (center, in Navy blue shirt) gave emergency planning officials from Australia and New Zealand, as well as from FEMA, a tour of Puget Sound’s geologic hazards. Photo: Meredith Payne/DNR.

It was one of those rare, gloriously clear and warm days on Puget Sound a week ago last Thursday. What a perfect time for a guided tour of the area’s major geological hazards, we thought. DNR Chief Hazards Geologist Tim Walsh led a field trip composed of FEMA and state officials and their counterparts from Australia and New Zealand.

While traversing Elliott Bay on the Seattle-Bainbridge Island ferry, Walsh described the numerous earthquake and tsunami threats to the Seattle area, recounting evidence of past Seattle Fault activity and associated tsunami events along the ferry’s route. The Australian and Kiwi emergency managers reflected on their own personal experiences during the ensuing discussion of the impacts and mitigation of geological disasters. The officials were in Washington state, July 15-17, to attend a conference hosted by the regional FEMA office.

 The DNR Division of Geology and Earth Resources provides:

  • • Evaluation of geologic hazards and advice on their mitigation
    • Information to aid disaster response and damage assessment
    • Mapping of surface and subsurface geological formations

The division also maintains the Washington State Geologic Information Portal, which allows you to create, save, and print custom maps showing various geologic hazards for almost any location in the state.

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DNR weekend reading: Earthquake acoustics can warn of tsunamis; big batteries for big cities; and other news

June 8, 2013
Blanchard Forest National Trails Day

With the breathtaking view of the San Juan Islands in the background, these volunteers were among the 93 people who helped out at the DNR-managed Blanchard Forest during National Trails Day last weekend. Photo: Roger Brock/DNR. CLICK PHOTO for larger image.

Here are links to articles about natural resources, climate, energy and other topics published recently by universities, scientific journals, organizations, and other sources:

Stanford University: Earthquake acoustics can indicate if a massive tsunami is imminent
Scientists have identified key acoustic characteristics of the 2011 Japan earthquake that indicated it would cause a large tsunami. The technique could be applied worldwide to create an early warning system for massive tsunamis

Scientific American: Bright Lights, Big City–Big Battery
The needs for businesses and utilities to store energy in cities where they are located is turning urban areas into crucial proving grounds for energy storage technologies that will be vital components of a future electricity grid that relies on solar, wind and other renewable-but-variable energy sources.

The World Bank: Global Tracking Framework Puts Numbers to Sustainable Energy Goals
If combined with an expansion of renewable energy sources and improved efficiencies, bringing electrical power to the 1.2 billion people who still do not have access to it (and 2.8 billion who still rely on burning wood or other biomass for household fuel) would increase CO2 emissions by less than 1 percent, concludes a report by the World Bank and the United Nations.

University of California-Davis: Stranded orcas hold critical clues for scientists
Using the protocols of a standardized killer-whale necropsy system developed in 2004 will provide more data that can help scientists better understand the life history of the orca species and, ultimately, help improve the fate of the species.

Monterey Bay Aquarium Research Institute: Research shows where trash accumulates in the deep sea
The problems of discarded trash in the ocean are not limited to beaches — large amounts of trash are accumulating in the deep sea, and the majority of it comes from land-based sources rather than boats and ships.

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Great Alaskan earthquake hit 49 years ago; effects felt in Washington State, too.

March 28, 2013
Copalis River bridge

Large waves generated by the 9.2 magnitude Alaskan earthquake in 1964 destroyed this bridge in Washington State.

Yesterday (while we were intently focused on the aftermath of Whidbey Island landslide), was the anniversary of the March 27, 1964, earthquake in south-central Alaska that caused about 143 deaths. The magnitude 9.2 earthquake lasted for almost three minutes and caused widespread destruction to buildings, bridges and other infrastructure. In addition to hitting many  Alaskan coastal communities, tsunami waves generated by the earthquake took lives and destroyed property in British Columbia, Oregon and California, including 12 people in Crescent City, California, and four at Beverly Beach State Park in Oregon.

Here’s more information about earthquakes in Washington.

The Washington Emergency Management Division says the best way to survive any type of disaster is to have a plankeep informed, and have a mobile survival kit. Find out if you are in a tsunami inundation zone. Download a tsunami evacuation brochure for your community. DNR worked with local governments to produce these brochures.

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Deadly Solomon Island tsunami highlights need for tsunami awareness here

February 6, 2013

tsunami hazard zone signIn the news today are reports that magnitude 8 earthquake hit near the Solomon Islands, generating a tsunami that is reported to have damaged dozens of homes in the South Pacific island chain. At least five people were killed.

The location of the quake is in the region of the boundary of two major tectonic plates, the Australia and Pacific plates — the Australia plate is being forced (subducted) beneath the Pacific plate. For background, see today’s scientific summary report from the USGS

Another major subduction, known as the Cascadia Subduction Zone, lies just off the coast of Washington state, which is why tsunami awareness is a focus of natural hazards planning efforts here. DNR and its Geology and Earth Resources Division work with federal agencies and local governments to prepare maps of recommended tsunami evacuation routes for many coastal Washington communities. We also map earthquake faults and hazards. Local and state emergency officials rely on these maps, in addition to data and estimates prepared by DNR’s geologists and other sources to plan their responses to earthquakes, tsunamis and other natural disasters.

DNR’s interactive web portal also offers Washington State tsunami evacuation maps. We also co-developed a smartphone application that shows the danger zones and evacuation routes (in the future we hope to update the app. to provide alerts and other information).

More DNR tsunami safety resources…

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