Debris fields, some reaching 70 miles long, are moving slowly across the Pacific in the clockwise rotating basin-scale subtropical oceanic gyre. The debris aggregations will take several years to come ashore along the U.S. and Canadian west coast, although some of the material will likely get entrained into the interior of the gyre in the North Pacific garbage patch. In the meantime, they pose a maritime navigation hazard that the U.S. Navy has been monitoring.
Colleagues at the University of Hawaii who have previously worked on characterizing the plastic garbage patch in the Pacific, seeded a model of the Pacific based on drifting buoy data to map the trajectory of the present debris field. Some of their results are described here. It will be important to track the composition of the debris and alert Pacific-going vessels about these data. By some estimates, 70,000-200,000 buildings were washed away from coastal Japan by the massive tsunami. Structures like houses would be expected to disintegrate somewhat in the passage across the Pacific, but boats and other items might make it across more or less intact.
“It’s very challenging to move through these to consider these boats run on propellers and that these fishing nets or other debris can be dangerous to the vessels that are actually trying to do the work,” Ensign Vernon Dennis of the U.S. Navy’s 7th Fleet reported to ABC News. (Arresting video and photos in the ABC News report.)