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U.S. Tsunami Preparedness
The tragic earthquake and ensuing tsunami that devastated large portions of the northeastern coastline of Japan have renewed questions relating to the preparedness of U.S. West Coast states for a similar type of catastrophe. And there is little question that public safety first responders will be at the center of any response efforts.
Tsunami protection is of a particular concern on the West Coast where the threat of the tsunami nearly 6,000 miles away off the coast of Japan brought warnings to low-lying areas in Washington, Oregon and California with the expectation of waves as high as four to six feet. The state of Washington actively ramped up its tsunami protection efforts just after the start of the 21st century once researchers from the University of Washington discovered new research relating to the Cascadia Subduction Zone about 300 miles off the Washington/Oregon coastline in the Pacific, said Washington Emergency Management Division Public Information Officer Rob Harper.
Geologists and geophysicists took samples, pulled carbon dating samples from the trees along the coastline, and spoke with Native American historians to learn that a large tsunami had impacted the Washington coastline in 1700, even using scientific evidence and written records to pinpoint the exact date.
Simply put, there is repeated evidence of sand and ground displacement as a result of multiple earthquakes off the Pacific coast and within Puget Sound, Harper said. “There was a real emphasis placed on this evidence following the Indian Ocean tsunami that impacted Indonesia in 2004,” Harper said. “When you take what happened there and recently in Japan, it is very conceivable that we could also see waves of 20 to 30 feet in some areas and waves coming several miles inland. There are several earthquake faults in and around Puget Sound where land rises or falls four or five feet.”
So for more than a decade, Washington has taken steps to prepare for a possible tsunami, given that history shows a large earthquake and tsunami is likely to impact the region every 300-500 years. Emergency speakers have been added to nearly 50 sites along the Washington coastline to warn residents of a tsunami warning.
Two areas in particular are at a severe danger because they lie just above sea level: Ocean Shores and Long Beach near the mouth of the Columbia River, Harper said. Some of these areas might have as little as 20-30 minutes warning time from when an earthquake is detected to when tsunami waves might crash ashore. “We have worked with local law enforcement, public safety and communities on really educating them what to do,” Harper said. “We want them to prepare routes and get to higher ground immediately. Don’t wait for confirmation.”
One specific plan that is in process has been called Project Safe Haven, a process of vertical evacuation where communities with the greatest risk would construct burns or towers 30-40 feet high in the air that would be built with reinforced materials and could whether such massive waves. These towers could hold hundreds or perhaps thousands of people. As is the case with most emergency plans, money is the biggest issue as each burn or tower would likely cost between $500,000-$1 million to build. The state is currently researching money sources. “We would build them by ball fields and other common gathering places that could be easier for residents along the coastline to get to,” Harper said. “It’s not realistic to think that in the case of a tsunami many of the two-lane highways along the coast would be passable so in some cases this may be the best way to (reduce fatalities).”
Tsunami emergency preparation is not new along other parts of the coast either. Emergency managers, coastal authorities and officials with the Oregon Department of Geology and Mineral Industries have sought to educate coastal communities of the potential dangers. There have been initial inundation maps drawn that outlined the danger zones, and evacuation routes have been identified. Reverse 9-1-1 systems and sirens are also in place.
In Tillamook County, Ore., an incident command team was activated in the minutes following the earthquake off the coast of japan. Word was communicated to first responders about eventual evacuations which occurred a few hours later since the waves from the tsunami didn’t hit the Oregon coast for more than nine hours. That gave Emergency Manager Gordon McCaw and his team time to review the available information provided by the National Weather Service, the Alaska Tsunami Center and other resources to make decisions. “We evacuated 300-400 people who lived in low-lying areas near the beach and evacuated about one-half mile out which gave us a nice buffer zone,” McCaw said.
If local officials had less time to prepare for a possible tsunami, such as three to four hours, they would have made decisions more quickly but the process would have been similar, McCaw said.
Representatives from sheriff’s departments, the American Red Cross, the Salvation Army, Oregon Department of Transportation and many other agencies were onsite at the county’s incident command center in Tillamook and in counties along the Oregon coastline. But McCaw and his staff caution local residents all the time that there is no one single method of communications that residents should rely on for tsunami warnings. That is important because the latest warning revealed some defective sirens and improvements that were needed in using the reverse 911 phone system to inform nearly 7,000 residents that may be at risk by phone. “There are many elements within our toolbox that we use to get the word out,” McCaw said. “We did want to get people to shelters and other high points and while everything worked well, we did learn a few things.”
Replacing the outdated sirens could cost Tillamook County $200,000, meaning it may not be an immediate fix so maintenance personnel have been working to create other solutions to ensure all the sirens work, McCaw said. Social media is also used to update nearly 3,000 followers via Twitter and Facebook pages. Education, though, will need to continue, particularly during the summer months when the seasonal population can grow exponentially during vacation season or summer holidays. McCaw said.
Educational efforts continue to be shared with hotels, motels, beach homes, restaurants and more. In some cases there are local ordinances that require certain businesses and rentals to contain tsunami warning and preparation information. Of course there may be little that can be done if the worst-case scenario occurs and an earthquake along the Cascadia Subduction fault line causes a tsunami that could arrive on the coast within 20 minutes, McCaw said. At that point, the upfront education and planning that individual communities and households make would be critical. “We tell them that if you feel the ground shaking get to high ground immediately – don’t wait to find your belongings,” McCaw said.
And there are misconceptions about tsunamis that residents need to be aware of, said Prof. Scott Burns, a Geology professor at Portland State University. Law enforcement officials can help educate coastal residents about these dangers in advance. The most prominent misconception is that after the first surge of the tsunami comes, it is then safe to go onto the beach. “We had 11 people in 1964 and 2 this year killed in Crescent City, Calif. when they went onto the beach as the water went out after the first tsunami. Emergency managers have to keep people off of the beaches and away from docks in the bays for 5-6 hours after the distant tsunamis first hit,” Burns said.
The tragic Japan tsunami already proved a type of case study for communities along the West Coast. Once the tsunami was detected, statewide emergency response teams, scientists and other personnel were on the phones all night discussing the latest in available information and low-lying areas were evacuated. Harper was a part of those late-night calls for several hours leading up to the estimated 7 a.m. arrival time of the first wave in southern Washington state.
As a home-rule state, local municipalities and emergency response teams were charged with setting direction in Washington, Harper said. Most of the emergency communications were run through local sheriff’s offices but there was a large amount of ongoing communications between such agencies as the Western State Seismic Council and state agencies about the likely impact.
Schools and administrators and teachers have also been educated about emergency procedures. “We had hourly updates with coastal counties and state agencies and by 3:30 a.m. we felt that some evacuations were needed from localized areas,” Harper said. “It was a clear, concise decision and was impressive. We had good information and acted upon it. We had scientific data that was translated to good, hard information that could be shared with first responders.”
Although Washington is a home-rule state, sheriff’s departments were in touch with officials from Oregon, a state that allows for more executive control over such matters, Harper said. At the end of the day, residents that live and business owners located along the Pacific coastline need to be aware of the potential for catastrophic conditions if and when a tsunami does occur.
The powerful photos and video coming out of Japan are evidence of the danger. Community, public safety and local governmental preparation will certainly help to save some lives even as enhancements to safety policies are made. But it is up to each individual
There are two types of tsunamis that West Coast residents need to be prepared for, said Scott Burns, Professor of Geology at Portland State University. Distant tsunamis could be developed from distance earthquakes such as what was experienced in Japan this year, Chile in 2010 and Alaska in 1964. “We have many hours to prepare for them (at least 6-8 hours) so we can be prepared. If an earthquake over 6.5 occurs in the Pacific Basin, a tsunami watch is issued for the whole basin. If a real tsunami is seen or recorded on land of by the buoys in the ocean, then it might be upgraded to a tsunami warning at which time all areas along the coast in the Tsunami Hazard Zone (elevations from 0-40 feet elevation) are asked to get to higher ground.
In that scenario law enforcement officials would be needed to get all people off of the beaches and away from docks in harbors along the coast for 4-5 hours after the first impact, Burns said. Wave heights from these far away tsunamis might get to 6-8 feet high. Even at that height they can be destructive, especially in harbors like Crescent City and Santa Cruz California and Depoe Bay and Brookings, Oregon last week.
Local tsunamis come from local subduction zone earthquakes along the Cascadia Margin that occur every 500 years, Burns said. The last one was in 1700 on Jan. 26. The shaking lasted over 2-3 minutes and the tsunami arrived within 20 minutes.
When these huge quakes happen, everyone must head to higher ground – at least 50 feet elevation. “I tell people who live along the coast, if you are knocked to the ground by a large quake and it last for 2 plus minutes, you have 20 minutes to get to high ground - have your place picked out. Each town on the coast has signs for the tsunami hazard zones and also in those areas has tsunami evacuation routes. Visitors must have then memorized. These tsunamis mostly will be in the range of 10-20 ft high, but there is past evidence of a few as high as 40 feet high.
Mike Scott has contributed to more than 70 newspapers, magazines and Web sites. He lives in Waterford, Mich., and can be reached at Mas1774@yahoo.com.
Published in Public Safety IT, Nov/Dec 2011
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