Science - japan-tsunami

Apr

2013

3:07pm, EDT

Japan tsunami debris confirmed in California

Redwood Coast Tsunami Working Group

Examining the Japanese skiff that washed up near Crescent City, Calif., on April 7, 2013. This is the first verified item from the Japan tsunami to appear in California.

By Douglas Main
LiveScience

A small skiff recently washed ashore near Crescent City, Calif. But this was no ordinary ship — it floated there all the way from Japan, dislodged from its native land more than 25 months ago by a monster tsunami, government scientists have confirmed.

It's the first confirmed piece of debris to wash up in the state of California from the Tohoku earthquake and tsunami that hit Japan on March 11, 2011, according to the National Oceanic and Atmospheric Administration (NOAA).

The Coast Guard and local sheriff's office removed the ship after it was spotted, and staff at Humboldt State University in northwestern California helped translate the Japanese writing on the boat. Officials then traced the boat to Takata High School, located in Japan's Iwate prefecture, an area devastated by the tsunami, NOAA reported.

The 20-foot (6 meters) skiff was covered in gooseneck barnacles, a common type of filter feeder that makes itself at home on stuff that floats in the open ocean. It wasn't immediately clear whether this boat carried invasive species, which had been seen with other pieces of Japanese tsunami debris that have washed up on the West Coast.

One ship that recently washed onto the shore in Long Beach, Wash., for example, contained an estimated 30 to 50 species of plants and animals, including potential invasive species. In a sealed compartment in the back of that ship, scientists found five live striped beakfish — “a species native to coral reefs mainly in Japanese waters (and) sometimes found in Hawaii, but certainly not in the cold waters of the Pacific Northwest coast," NOAA reported.

To date, 26 other pieces of Japanese debris have washed up in Oregon, Washington, Hawaii, Alaska and British Columbia.

The tsunami dragged some 5 million tons of debris into the Pacific Ocean, according to Japanese government estimates. Much of it likely sunk shortly thereafter, but about 1.5 million tons floated away from Japan's coast, and this tsunami debris is still washing up far afield.

Email Douglas Main or follow him @Douglas_Main. Follow us @OAPlanet, Facebook or Google+. Original article on LiveScience's OurAmazingPlanet.

Mar

2013

11:44am, EDT

Japan tsunami debris still washing ashore 2 years later

Kevin Head

In this photo released by NOAA, a boat lost in the Japanese tsunami of 2011 sits onshore on a remote Canadian island. The boat was discovered Aug. 9, 2012.

By Stephanie Pappas
LiveScience

Two years after a deadly tsunami swept ashore in Japan, killing more than 15,000 people, solemn reminders of the disaster are still washing ashore in Hawaii and along the Pacific coast of North America.

The tsunami debris, sometimes identifiable by serial numbers, includes boats, docks, appliance parts and fishing buoys. Though harder to trace back to a particular source, an uptick in Styrofoam and housing materials may also originate from the March 2011 wave.

"This has been a very unprecedented event," said Nancy Wallace, the director of the marine debris program at the National Oceanic and Atmospheric Administration (NOAA). The agency has been tracking the debris, which can pose a navigation hazard to boats and an entanglement or choking hazard to wildlife. The process has given scientists a better understanding of how debris travels, Wallace told LiveScience, but no one knows how much is yet to come ashore.

"We just don't know how much debris is still floating in the water," Wallace said. "We don't know how much has sunk. What we're trying to be as focused on as possible is trying to prepare for it as best we can."

Unusual debris
So far, NOAA has confirmed 21 pieces of debris from the Japan tsunami on U.S. shores. The most recent piece, confirmed by the Consulate of Japan on Feb. 5, was a large, yellow buoy found off the Hawaiian island of Kauai. (The agency has received more than 1,000 debris reports, but many items cannot be definitively linked to the tsunami.)

Nicholas Mallos

This framed insulation measures about four feet by four feet (1.2 meters). The piece washed ashore on Ki'l Dunes Beach in Oahu after being set adrift by the Japan tsunami.

Other confirmed items that have washed up include a soccer ball in Washington state, a 35-foot (11 meters) steel tank in British Columbia and multiple small, derelict boats.

Two floating docks beached themselves in Washington and Oregon, both harboring massive amounts of marine life and requiring decontamination to prevent invasive species from establishing themselves on the U.S. coastline. [Images: Beached Japanese Dock]

Sometimes, a sudden influx of a particular item strongly suggests that it is tsunami-related, even in the absence of other evidence. Styrofoam and other housing materials, for example, have been showing up in bulk in Alaska and Hawaii, said Nicholas Mallos, an ocean debris specialist at the non-profit Ocean Conservancy.

"Styrofoam has shown up in some places in quantities 30 times historical abundances," Mallos told LiveScience.

Tracking the debris
The debris slowly making its way across the Pacific to North America is only a fraction of the estimated 5 million tons of rubble and other materials swept into the sea by the tsunami, according to Japanese government estimates. About 70 percent of the debris sank off of Japan's coast, leaving 1.5 million tons to float across the ocean. How much of that is still floating is anybody's guess. [Tracking Tsunami Debris (Infographic)]

NOAA works with fishing vessels and commercial shippers, relying on eyewitness reports of debris in the open ocean. Early on, Wallace said, the agency tried to monitor the debris by satellite, but soon found that the material wasn't visible for very long. As the debris fields dispersed and some of it sank, the remaining pieces were too small to see from orbit.

Models of debris flow have proved more useful, though the motion of the matter depends heavily on wind and water currents. Using historical climate data, scientists can make an approximation, Wallace said, but the models were greatly improved when researchers put the real-world current and wind conditions into the system. Unfortunately, that means that while researchers are good at telling where the debris is likely located now, they're not as clear on where it's going.

"There's a large amount of uncertainty," Wallace said.

Humans dump massive amounts of debris into the ocean on a regular basis, the Ocean Conservancy's Mallos said. There are no good numbers on what percentage of the debris currently in the sea comes from the tsunami versus from everyday garbage and abandoned fishing gear. Working to reduce this everyday junk, by decreasing consumer waste, for example, will make the oceans more resilient in the face of unavoidable debris disasters like tsunamis, Mallos said.

Another thing researchers don't know: the impact of all that debris that may never reach shore.

"Very little research has been done at midwater depths, and particularly on the seafloor, as to what extent of debris abundance is there and what particular ecological impacts debris has on those marine environments," Mallos said.

Meanwhile, experts expect trickles of tsunami debris to continue to wash onto American shores for the next few years.

"Things can get caught up in eddies and gyres for a while and then get spit out, so it could really be years that the debris is out there," Wallace said. "We hope that we've seen most of it, but it's just so hard to tell."

Follow Stephanie Pappas @sipappas. Follow us on Twitter @livescience, Facebook or Google+. Original article on LiveScience.com.