Tsunami Debris: Halloween Arrival

Drifts of large hypothetical buoys set free by the tsunami as simulated by Jim Ingraham using OSCURS. Six buoy tracks begin off the tsunami coast on March 11, 2011. Using US Navy data and windage parameters from the drift of the Ginoza buoy (see inset), the tracks progress day by day across the Pacific Ocean until October 31, 2011, the last day that data were available. By Halloween, OSCURS indicates that five buoys (one headed into the Garbage Patch) had arrived in America from Washington north to Southeast Alaska. Inset: Kathy stands beside the buoy that drifted from Ginoza, Japan, to Copalis, Washington. At 30 feet long overall, the cylindrical part measures 11 feet long by 47 inches in diameter, and the mast is 7 feet long. The waterline indicates that it sailed rapidly before the wind, at a speed of 20 miles per day as indicated by OSCURS. Photo by John Mcaulay, Ocean Shores Interpretive Center.

by Curtis C. Ebbesmeyer

On March 11, 2011, a magnitude 9.0 earthquake devastated northern Japan. The subsequent tsunami inundated hundreds of miles of coastline. As the tsunami receded from the land, it carried millions of tons of flotsam into the coastal ocean, forming a debris field which, at present, is drifting across the North Pacific Ocean.

On November 2, 2011, Jim Ingraham and I described the Japanese tsunami debris to sixty people at the Best Western Hotel, Ocean Shores, Washington. Based on historical debris which previously drifted from Japan to North America, Jim’s OSCURS (Ocean Surface CURrent Simulator) computations showed the locations of the debris field as of October 31, 2011. OSCURS utilizes daily weather data supplied by the US Navy to estimate the track of individual flotsam.

I’d just returned from the Sea Bean Symposium in Cocoa Beach, Florida, and immediately prepared a PowerPoint slide show. Media had been inquiring as to dates of debris arrival. The presentation would give me a chance to collect my thoughts and Alert beachcombers to report tsunami debris. OSCURS, as well as independent simulations from the University of Hawaii, showed the debris field stretched over an area the size of the state of California. Winds and currents had pushed the leading edge of the debris field, the flotsam closest to America, half way across the Pacific to a position north of Hawaii.

At Ocean Shores, Kathy Klee reminded me of the Fish Attraction Buoy (FAD) moored off Ginoza, a village on Okinawa. On April 9, 2007, Kathy reported the buoy off Copalis, Washington (see Beachcombers’ Alert, July-September, 2008). Detective work showed that super typhoon Saomai had torn the buoy free from its anchor eight months earlier on August 9, 2006. OSCURS revealed it had floated north off the tsunami coast, then directly across the Pacific to Copalis Beach. Because much of it floated above the water, the winds sailed the buoy at twenty miles per day, three times faster than surface water and typical of tsunami flotsam.

After my talk, I thought back over many historical flotsam (mostly small craft like a Boston Whaler) exposed above the waterline such that the winds sailed them twenty miles per day, about the same speed as exhibited by the Ginoza buoy. It seemed reasonable that amongst the millions of tons of tsunami debris some of these high-windage drifters would be floating across the Pacific, including boats, FAD buoys and houses.

Soon as we returned from Ocean Shores, I looked up the Ginoza buoy’s drift track in the July 2008 Beachcombers’ Alert newsletter. In eight months, it had crossed the Pacific from the tsunami coast to Washington state. The eight-month transpacific crossing, added to the tsunami date of March 11, 2011, equaled November 11, about the time I spoke at Ocean Shores. To understand where flotsam might have arrived, Jim set free six hypothetical Ginoza buoys along the tsunami coast. OSCURS showed high-windage flotsam arriving on Halloween 2011 at locations scattered from Washington state north into Southeast Alaska.

Hiro Tojo, Consulate General of Japan in Seattle was so intrigued the buoy had crossed the Pacific Ocean from a town the size of Ginoza, that he and Hidehiro Hosaka, senior consul, decided to see it for themselves. In November 2007, representatives from the Japanese Consulate visited twice more, as well as the Mayor and two fishermen from Ginoza. If a fishing buoy could generate this much international attention, I wondered at the impact of thousands of items in the huge debris field coming to America.

During November and December, I conducted numerous media interviews, asking beachcombers to report the large debris which I thought should now be on American shores. By Pearl Harbor Day, none had been reported. Nonetheless, on December 5, 2011, Gene Woodwick and I met with representatives at the Japanese Consulate in Seattle seeking to develop a plan to deal with the immense debris field. Five stages came to mind: 1. Treat debris as a crash scene; 2. Call the police, check radioactivity; 3. Remove debris to safe sites; 4. Inspect debris for mementoes; and 5. Notify loved ones in Japan.