Tsunami in Northwest Islands Highlights Need for Emergency, Climate Change Plans

posted in: May 2011 | 0

“I’m sure there will be a next time,” said David Swatland of the Papahanaumokuakea Marine National Monument. 

At last month’s meeting of the Northwestern Hawaiian Islands (NWHI) Marine Ecosystem Reserve Advisory Council, Swatland described some of the lessons learned from the March 11 tsunami event that killed some 110,000 Laysan albatross chicks on Midway atoll alone.

For one thing, the modeling that determines the run-up of tsunami waves may need some improvement. The waves that hit Laysan atoll ran 20 feet up the beach, which was higher than expected, he said.

“There’s a lot more information we can get on modeling impacts on atolls and islands. … We were lucky this time. We had a little bit of time to prepare. If it happens off the Big Island, we’re not going to have much time to prepare at all,” he told the council.

Swatland said there needs to be a monument emergency response plan and his office is looking to hire an outside contractor to develop one.

One area that may need special attention is communication. Swatland said that during the event, there was an information overload. 

“There were a lot of extra communications that could have been avoided,” he said. Cell phones were not very reliable and only one third of the monument staff has a land line. Although email helped, Swatland said the lines of communication weren’t as direct as they should have been. 

“I was getting updates from Washington DC about what’s going on” in the Northwestern Hawaiian Islands, he said.

Reducing other stresses on the environment so that it can be more resilient is another goal, he said.

A number of researchers and managers have said that the effects in the NWHI seen from the tsunami are similar to what might be expected from climate change.

On Midway, planes could not land for a whole day because tsunami waves had inundated the runway with debris, said Ray Born of the U.S. Fish and Wildlife Service. He also said the atoll’s breakwater and seawalls were breached and waves reached Midway’s water and fuel tanks.

“Infrastructure protection at Midway is a big deal for the Fish and Wildlife Service,” he said. “The run-up we’re seeing from this event gives us an idea of the impacts of the three-to-five feet rise [in sea level] expected in the coming century,” Born said.

Dan Polhemus, also with the FWS, pointed out that sea level at Midway is currently rising five millimeters a year, three times as fast as it is at O`ahu. 

“We probably ought to plan for at least a three-foot scenario. A lot of our proposed translocation zones ended up being inundated. It was a good wakeup call of the potential vulnerability of those sites,” he said. 

The Intergovernmental Panel on Climate Change keeps revising its models, he added. Sea level rise was initially project to be three feet, but “we keep pushing the upper end of the carbon envelope. … There is a school of thought that five feet might be more likely,” he said.

Polhemus also noted that the tsunami inundation of the uncapped, PCB-contaminated dump on Kure could happen on Midway and French Frigate Shoals, which also have dumps.

Restoration costs from the March event are likely to be between 55 million and 60 million dollars, Born said.

At some point, climate change may make some Northwestern Hawaiian Islands too dangerous to host researchers. 

“That’s a risk management decision,” Swatland said. “If these things [storms and high waves] become very frequent, we’re going to have to decide if it’s worth the danger to these folks.”

On Midway, for example, if trees hadn’t caught the debris swept in by the tsunami, it would have gone right through the FWS camp, Born said.

— Teresa Dawson

Volume 21, Number 11 May 2011

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