Tag: #Earthquake

Remembering the Great Japan Earthquake and Tsunami of March 11, 2011 And Efforts to Reduce the Impact of a Similar Event in the Pacific Northwest

Monday, March 11th marks the 8th anniversary of the Great Japan Earthquake and Tsunami, (Sometimes called the Great Tōhoku Earthquake and Tsunami). The dramatic and startling images, covered on live television, are indelibly chiseled into the subconscious of everyone who watched the events unfold in real time, as the most disaster prepared country in the world, faced the wrath of a magnitude 9.1 earthquake, the 4th largest ever recorded and a series of massive tsunami waves.

Earthquake Early Warning

At 2:46 pm on Friday, March 11, 2011, the Japanese Earthquake Early Warning System received an indication of a major earthquake fault rupture, 45 miles east of the Tōhoku region and 231 miles northeast of Tokyo. Within seconds, the Earthquake Early Warning System transmitted a warning message to the people in and surrounding the Tohoku region of Japan, indicating a large earthquake had occurred. People began receiving the warning message, via a cell phone text message, as local television and radio stations began broadcasting the earthquake warning. As a result of the Early Earthquake Warning, elevators in Tokyo moved to the closest floor and opened to allow passengers to evacuate and take protective actions. Factory assembly lines were automatically shut down and the Tōhoku Shinkansen high-speed bullet trains, travelling nearly 200 mph, were automatically prompted to slow and stop, potentially saving thousands of passengers from injury. Just 5-15 seconds after the alert, coastal areas of the Tōhoku region closest to the rupture, began to violently shake, while a more devastating disaster was fast approaching – a series of massive tsunami waves.

The Impact

As of September 2018, data indicates 15,896 people were killed and 2,536 are still missing from the magnitude 9.1 earthquake and resulting tsunami. 58,000 of the coastal citizens who evacuated their homes remain evacuated 8 years later, while 5,623 still live in prefabricated temporary housing. The economic damage from the disaster event is estimated to be near $360 billion. As of Spring 2017, seven cities, towns and villages have been deemed “difficult to return” zones by the Japanese government because of increased radioactivity in those areas, due to the Fukushima Daiichi nuclear disaster that occurred during the tsunami.

Is Knowing What to Do Enough?

We can never be prepared enough for disaster, nor should we take any of them lightly. Any effort toward disaster preparation will help reduce the impact the event will have upon your family, business and community.

  • Families need to develop a Family Emergency Plan and discuss all types of disaster events (earthquake, flood, wildfire, tsunami, severe weather, etc.), with each other, to determine which actions to take, where you would evacuate to, shelter locations, and how to contact each other, should you become separated in a true emergency or disaster – then actually practice your plan at least once each year.
  • Each family should prepare Family Emergency Kits to be able to be on your own for a minimum of 2 weeks.
  • Make individual Go Kits for each member of the family, as well as your pets, to store in your home, in vehicles and at work, in the event you must evacuate in a hurry.
  • Sign up to receive emergency and disaster alerts and updates through the Emergency Notification System in your community, city and county.
  • Obtain an All Hazard ALERT Weather Radio for emergency and disaster notifications automatically.
  • Take a first aid and CPR class. You never know who might need assistance.
  • Learn protective actions be used during an earthquake to prevent injury, as well as learning, there may be aftershocks, and the possibility of tsunami in low lying coastal areas.
  • If in tsunami inundation areas, learn what to do and where to go while at home, at work and while shopping.
  • Get involved with local community groups that prepare for disaster such as a Community Emergency Response Teams (CERT).
  • Sign up for the Washington Shake Out and practice your disaster plans with your family.

Local, State and Federal Efforts to Reduce Disaster Impacts

Efforts are increasing in coastal communities to build Tsunami Vertical Evacuation Structures, like the Ocosta Elementary School, in Grays Harbor County and the planned Vertical Evacuation Tower, in Tokeland, by the Shoalwater Bay Indian Tribe.

Unreinforced Masonry Buildings are being identified throughout Washington as local governments are working with owners to assist in ways to retrofit the buildings, preserving the historic facades, while protecting people from an exterior wall collapse during earthquake.

Earthquake Early Warning is being developed and is becoming more robust throughout the Pacific Northwest and in Washington State. Pilot users are being sought in schools, business and industry to begin implementation of the ShakeAlert Earthquake Early Warning System. Currently Earthquake Early Warning messages cannot be sent to individuals, because the current process to send the warning to individual cell phones is far too slow. Work is ongoing, toward the development of a process that can transmit the warning to everyone, much more quickly and prior to the earthquake shaking at your location.

For more information on Earthquake Early Warning and/or how to become a Pilot User of the ShakeAlert Earthquake Early Warning System, please contact:

Chuck Wallace – WA ShakeAlert EEW Coordinator, wallace@crew.org (360) 280-8278

Maximilian Dixon – WA State EMD Earthquake Program Manager, Maximilian.Dixon@mil.wa.gov (253) 512-7017

Bill Steele – PNSN, Director of Outreach & Information Services, wsteele@uw.edu (206) 685-5880

March 27th Marks the 50th Anniversary of the Great M9.2 Alaska Earthquake

50th Anniversary of the Great M9.2 Alaska Earthquake of March 27, 1964

March 27, 2014 marks the 50th anniversary of the great Alaska earthquake.   On March 27, 1964 at 5:36 pm local time a magnitude 9.2 earthquake began, ultimately breaking a fault about 400 miles long and a few 100 miles wide, rupturing from beyond the western edge of Kodiak Island to the eastern side of Prince William Sound and from well offshore inland to Upper Cook Inlet. The earthquake lasted approximately 4.5 minutes and is the largest earthquake in U.S. history and the second largest globally, next to the great 1960 M9.5 Chile earthquake.  The earthquake was felt in Dutch Harbor, 800 miles west of Anchorage, and in Seattle 1200 miles to the southeast of Anchorage.  Water well levels rose and fell in 47 states of the U.S.

Picture2Middleton Island, Alaska.  This rock platform was uplifted about 11 feet in tens of seconds by the 1964 Alaska earthquake. White specks are seagulls. Photo was taken near 7-foot tide stage on April 4, 1964. Figure 36, U.S. Geological Survey Professional paper 543-I; Figure 4-A, Circular 491.

As more recent great subduction zone earthquakes have demonstrated, the vast majority of the fatalities were caused by locally generated tsunamis; only 9 of the 129 fatalities attributed to the 1964 Alaska earthquake were caused directly by strong ground shaking. Property losses totaled $2.3 Billion in 2014 dollars.  Key practical scientific lessons were learned from the 1964 Alaska earthquake: 1) widespread liquefaction brought about the development of modern methods for assessing liquefaction hazard, 2) the potential for activation of large-scale secondary faulting became clear, and 3) the first direct evidence for how far-traveled tsunamis are generated led to a basic understanding of tectonic tsunami generation and inundation mapping around the globe.

Picture1The rails near the head of Turnagain Arm outside Anchorage were torn from their ties and buckled during the 1964 earthquake. Figure 24, U.S. Geological Survey Professional paper 541.

In the 50 years since 1964 economies and social structures from widespread States and countries have become much more intertwined, so a repeat of the great 1964 Alaska earthquake will likely have greater impacts on the Pacific Northwest and elsewhere.  The greatest far-flung impacts from the 1964 earthquake along  west coast of North America were due to its tsunami waves. In British Columbia communities along the southwest coast of Vancouver Island were hit hardest, with 21-foot waves damaging and flooding the cities of Alberni and Port Alberni.  Along the Washington coast, 5- to 6-foot tsunami waves struck Ocean City and collapsed the bridge over Copalis River.  Wave heights at Moclips, Sea View, La Push and Wreck Creek reached an estimated 11, 12, 5, 7, and 15 feet, respectively. In Oregon the tsunami took four lives. Seaside, struck by a 10-foot wave, was the hardest hit. Tsunami wave heights reached 10 to 11.5 feet at Depoe Bay, Newport, Florence, Reedsport, Brookings, and 14 feet at Coos Bay. Four people died at Beverly Beach State Park.  California lost 12 people to the tsunami. 10 of these fatalities occurred in inundation-prone Crescent City, which was struck by an unusually large 21-foot wave owing to the shape of the ocean bottom just offshore. Cities all the way to San Diego experienced significant tsunami waves, with one fatality in Los Angeles occurring when the 6-foot tsunami surge struck the Cerritos Channel.

Many institutions are commemorating the 1964 Alaska earthquake by taking stock of preparations and practicing future earthquakes.  The State of Alaska is conducting the Alaska Shield Exercise, which simulates the ground shaking and tsunami effects that occurred during the 1964 earthquake and exercises today’s response plans capabilities.  The Alaska Shield scenario is the centerpiece of the FEMA National Exercise Program Capstone Exercise for 2014, which has participants from across the U.S.

 

For lots more information check out http://earthquake.usgs.gov/earthquakes/events/alaska1964/. Additional information includes 1964 Alaska Earthquake Fact Sheet and a Online Resources Handout