Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

What has happened to the tsunami debris from Japan?

21.02.2014
Outcomes from synthesis of model and observations

The amount of debris in the ocean is growing exponentially, becoming more and more hazardous and harmful to marine life and therefore also to our ocean food source. Measuring and tracking the movements of such debris are still in their infancy. The driftage generated by the tragic 2011 tsunami in Japan gave scientists Nikolai Maximenko and Jan Hafner a unique chance to learn about the effects of the ocean and wind on floating materials as they move across the North Pacific Ocean.


This is an image of location of different types of tsunami driftage on Feb. 20, 2014. Orange regions show where items of high boyancy, or high windage, may be found. Dark blue to purple show regions where objects of low windage, lying low in the water may be found. The animation is at http://iprc.soest.hawaii.edu/users/hafner/PUBLIC/
TSUNAMI_DEBRIS/WINDAGE_03/ANIMATION_1/
movie_windages.gif.

Credit: Nikolai Maximenko and Jan Hafner, International Pacific Research Center, University of Hawaii

Shortly after the tsunami struck, Maximenko and Hafner used the IPRC Ocean Drift Model to predict where the debris from the tsunami would go. Their computer model is based on trajectories of real satellite-tracked drifting buoys and satellite-measured winds.

The model has now been charting the possible paths of the tsunami driftage for nearly 3 years. The scientists have made a major improvement to the initial model: it now accommodates objects of different shapes and buoyancies that expose different amounts of surface to the wind and travel at different speeds and different trajectories. The model therefore now includes different levels of wind-forcing, simulating the movement of different types of floating debris.

No formal marine debris observing systems exist to verify the model simulations. The model paths for tsunami debris, however, agree with reports of such debris washing up on the shores of Oregon, Washington, Alaska, and the Hawaiian Islands, as well as with observations by sailors crossing the North Pacific.

The first physical evidence of tsunami driftage far from the coasts of Japan, for example, came in September 2011 from the Russian sail training ship Pallada. The captain had been forewarned that the ship might run into a tsunami debris field on its voyage from Honolulu to Vladivostok. Sailors, alerted and on the lookout, sighted much debris just northwest of Midway, and picked up a little fishing boat later confirmed lost in the tsunami.

The model predicted both the timing and the type of material that has washed up along windward shores of Hawaii: the first tsunami driftage came in August – September 2012, about 1½ years after the tragedy. These were very buoyant pieces, for example, oyster buoys, crates, small fishing boats like the one picked up by Pallada, and parts of small refrigerators.

Then 2½ years after the tsunami, materials sitting lower in the water and less buoyant than the previous driftage arrived: poles and beams with mortise and tenon features. Experts on lumber, who have analyzed cross-cuts of several of these wood pieces, agree that it is Sugi, a species of cypress endemic to Japan. One piece of wood is of very old timber and must have been cut 100 or more years ago.

The IPRC Ocean Drift Model has recently shown to be useful in another dramatic event at sea: validating the El Salvadoran castaway's ordeal. In January 2014, Jose Salvador Alvarenga washed ashore in the Marshall Islands after enduring a 13-month journey from the shores of southern Mexico. The paths of floating objects in the IPRC Ocean Drift model, driven with the currents and wind conditions, lend strong support to this rather improbable odyssey. Details are at http://iprc.soest.hawaii.edu/news/marine_and_tsunami_debris/2014/14_02_Maximenko_fisherman.pdf.

Hafner, J.; Maximenko, N.; STORY OF MARINE DEBRIS FROM THE 2011 TSUNAMI IN JAPAN IN MODEL SIMULATIONS AND OBSERVATIONAL REPORTS
(Abstract ID: 13323)
Oral presentation
Session #:140
Date: 2/24/2014
Time: 08:00
Location: 316 B
http://www.sgmeet.com/osm2014/viewabstract.asp?AbstractID=13323
Scientist Contacts
Jan Hafner - email: jhafner@hawaii.edu
Nikolai Maximenko – email: maximenk@hawaii.edu
Outreach
Gisela Speidel, International Pacific Research Center Outreach – email: gspeidel@hawaii.edu

Gisela Speidel | EurekAlert!
Further information:
http://www.hawaii.edu

More articles from Earth Sciences:

nachricht Earth Day: Disease spread among species is predictable
24.04.2015 | National Science Foundation

nachricht Warming climate may release vast amounts of carbon from long-frozen Arctic soils
24.04.2015 | University of Georgia

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles

KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.

Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...

Im Focus: NOAA, Tulane identify second possible specimen of 'pocket shark' ever found

Pocket sharks are among the world's rarest finds

A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...

Im Focus: Drexel materials scientists putting a new spin on computing memory

Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.

Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...

Im Focus: Exploding stars help to understand thunderclouds on Earth

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...

Im Focus: On the trail of a trace gas

Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.

In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HHL Energy Conference on May 11/12, 2015: Students Discuss about Decentralized Energy

23.04.2015 | Event News

“Developing our cities, preserving our planet”: Nobel Laureates gather for the first time in Asia

23.04.2015 | Event News

HHL's Entrepreneurship Conference on FinTech

13.04.2015 | Event News

 
Latest News

Electrons Move Like Light in Three-Dimensional Solid

24.04.2015 | Materials Sciences

Connecting Three Atomic Layers Puts Semiconducting Science on Its Edge

24.04.2015 | Materials Sciences

Understanding the Body’s Response to Worms and Allergies

24.04.2015 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>