Drifting Japan Tsunami Debris: NOAA Models Where It May Have Been and Where It May Be Now (NOS's Response and Restoration Blog)
Marine Debris — Diving Deeper audio podcast
Ongoing efforts to update and refine computer models with wind speed and ocean current data is leading to a better understanding of how fast tsunami-generated debris may travel across the Pacific. Visit NOAA's Marine Debris Program for the latest information and modeling maps.
Audio Podcast: The powerful Japanese earthquake and resulting tsunami in March, 2011, washed untold tons of marine debris into the Pacific Ocean. Carey Morishige, Pacific Islands Regional Coordinator for the NOAA Marine Debris Program, explains where this debris may be, where it's heading, what's being done about it, and what you can do to help.
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Debris from the tsunami that devastated Japan in March 2011 could continue washing ashore in the United States for many years, according to predictions by NOAA scientists. However, they warn there is still a large amount of uncertainty over exactly what is still floating, where it's located, where it will go, and when it will arrive. Responders now have a challenging, if not impossible situation on their hands: How do you deal with debris that could now impact U.S. shores, but is difficult to find?
To learn more about the tsunami debris, NOAA researchers have been working with federal and state partners to collect data, assess the debris, and reduce possible impacts to natural resources and coastal communities.
NOAA and its partners have also drafted interagency response plans to address the wide-range of potential scenarios and threats posed by the debris. In December 2012, the Government of Japan generously provided the United States, through NOAA, $5 million to support response and removal efforts.
“We’re preparing for the best and worst case scenarios—and everything in between,” says Nancy Wallace, director for the NOAA Marine Debris Program.
As the tsunami surge receded, it washed much of what was in the coastal inundation zone into the ocean. Boats, pieces of smashed buildings, appliances, and plastic, metal, and rubber objects of all shapes and sizes washed into the water—either sinking near the shore or floating out to sea. The refuse formed large debris fields captured by satellite imagery and aerial photos of the coastal waters.
The Japanese government estimated that the tsunami swept 5 million tons of rubble into the ocean, and that 70 percent sank immediately. There is no clear understanding of exactly how much debris remains afloat today.
The debris fields seen immediately after the disaster no longer exist. Winds and ocean currents scattered items in the massive North Pacific Ocean to the point where debris is no longer visible from low-resolution satellite.
NOAA is coordinating interagency reporting and monitoring efforts that provide critical information on the location of the marine debris generated by the tsunami. Ships and beach-goers can report significant debris sightings to DisasterDebris@noaa.gov.
To date, NOAA has received hundreds of debris reports, which are mapped for the public. Several of these items have been definitively traced back to the tsunami, typically by registration number or some other unique marking. However, marine debris is an everyday problem and not all debris found is from Japan.
Computer models run by NOAA show some fast-moving debris, such as foam, washed ashore on U.S. coastlines in winter 2011-2012. Debris continued arriving throughout 2012, and models show it could continue for many years as it travels through the Pacific Ocean. Debris may also get caught in existing “garbage patches” and never make landfall.
Researchers caution that models are only predictions based on location of debris when it went into the water, combined with historical ocean currents and wind speeds.
Conditions in the ocean constantly change, and items can sink, break down, and disperse across a huge area. Because it is not known what remains in the water column nor where, scientists can’t determine with certainty if any debris will wash ashore.
Marine debris typically has far-reaching impacts, but they are sometimes made worse by natural disasters. Heavy objects could wash ashore in sensitive areas, damage natural resources or habitats, or interfere with navigation. In some cases, marine species attached to structures immersed in seawater, like docks and buoys, can hitch a ride across entire oceans and become invasive in new habitats. Responders have included guidance in regional marine debris plans for mitigating some of these threats.
Many efforts are underway within federal agencies to respond to the debris. NOAA is collecting at-sea observation data from aircraft, satellite, and vessels. Officials are also modeling the debris movement, conducting outreach to communities, and monitoring baseline debris accumulations.
For the latest information, visit www.marinedebris.noaa.gov/tsunamidebris.