On March 11, 2011, the largest earthquake in Japanese history struck the northeast region of the island nation. The magnitude 9 earthquake created a tsunami that hit Japan and radiated out into the Pacific, threatening countless Pacific Islands and the entire west coast of the U.S.

Upon reports of the earthquake and ensuing tsunami, the Emergency Response Division (ERD) of NOAA OR&R quickly began relaying critical tsunami predictions to Coast Guard Sectors in Hawaii (Honolulu, Hilo), Guam, California (La Jolla, San Francisco, Crescent City), and Washington State (La Push).

Once the tsunami hit the continental U.S., the impacts were felt along the entire west coast, with a majority of the damage felt in Crescent City Harbor, where an estimated 50 vessels were left in critical condition, 11 sank, and many docks were damaged, with debris cluttering navigation channels. In Brookings, Oregon, OR&R supported the Coast Guard by providing trajectory analysis on a sunken Coast Guard auxiliary vessel that was discharging oil. OR&R would continue to aid the Coast Guard with tsunami damage response efforts throughout the west coast and Pacific Islands by providing oil spill trajectories and general scientific support, such as tide predictions and spot weather forecasts. 

Once the tsunami damage was accounted for in the continental U.S. and U.S. islands, the attention of OR&R shifted to radiological monitoring of the radioactive fallout from the damaged Fukushima Daiichi Nuclear Power Plant in Japan. The radiological monitoring focused on North American bound flights and vessels that originated from or passed through Japan. OR&R also provided trajectory estimations for the Japanese tsunami debris in the Pacific Ocean and where the debris could make landfall in the continental U.S. and U.S. Islands. Trajectory modeling of tsunami debris continued through September 2013.