With debris from the Japanese tsunami expected to begin washing up on Hawaii shores in the next two years, scientists have placed buoys northwest of Midway in hopes of monitoring its arrival. 

The March tsunami produced about 25 million tons of debris, much of it being washed into the ocean. 

From Nikolai Maximenko: 

A team of scientists and conservationists from the University of Hawaii at Manoa and at Hilo, the Scripps Institution of Oceanography, and the Ocean Recovery Alliance conducted in December of 2011 a survey of the area northwest of Midway and Kure Atolls and deployed drifting buoys to monitor currents in the study area. At the time of the expedition, the oceanic front, formed 300-400 miles northwest of Midway, was found to separate the area, potentially containing tsunami debris, from Hawaiian Islands.

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