Marine debris induced by the Great East Japan Earthquake and Tsunami: A multi-sensor remote sensing assessment

Using satellite remote sensing, we show the distribution, dominant type, and amounts of marine debris off the northeast coast of Japan after the Great East Japan Earthquake on 11 March 2011 and subsequent tsunami. Extensive marine debris was found on March 12, with the maximal amount found on March 13. The debris was found to be mainly wood (possibly lumber wood), with an estimated 1.5 million metric tons in an elongated water area of 6800 km2 (18 km E-W and 380 km N-S) near parallel to the coast between 36.75°N and 40.25°N. The amount decreased rapidly with time, with scattered debris patches captured in high-resolution satellite images up to April 6. These results provide new insights on the initial distribution of the Japanese Tsunami Marine Debris, which may be used to help find bottom deposition of debris and help refine numerical models to predict the debris trajectory and fate. Marine debris induced by the 2011 Great East Japan Earthquake and Tsunami is found to be mainly composed of wood and possibly lumber wood from constructions, with maximum amount on 13 March 2011 distributed within a narrow band of ∼18 km near parallel to the northeast coast of Japan between 36.75°N and 40.25°N. The Great East Japan Earthquake on 11 March 2011 caused a massive tsunami with a maximum height of 40.5 m. The tragic event caused thousands of lives, destroyed the Fukushima Daiichi Nuclear Power Plant, and damaged more than a million buildings. Here, we assess the distribution, dominant type, and amounts of marine debris off the northeast coast of Japan after the tsunami. The debris was found to be mainly wood (possibly lumber wood), with an estimated amount of ∼1.5 million metric tons captured in satellite imagery two days after the tsunami in an elongated water area of 6800 km2 (18 km E-W and 380 km N-S) near parallel to the coast between 36.75°N and 40.25°N. The amount decreased rapidly with time, with scattered debris patches captured in high-resolution satellite images up to 4 weeks after the tsunami. [Display omitted] •Multi-sensor remote sensing was used to map marine debris after the 2011 tsunami•The debris peaked on the second day after the tsunami, off the northeast Japan•With an aggregated area of 7.6 km2 on this day, the debris was mostly wood•Assuming an average thickness of 20 cm, the debris totaled 1.5 million metric tons•The debris lasted for 4 weeks, after which its size is below the detection limit