Suitable indicators to determine tsunami impact on coastal areas in Northern Japan, Aomori Prefecture

Environmental Monitoring and Assessment, vol. 194, pp. 385

Abstract

The 2011 Tohoku-oki tsunami released and mobilized many anthropogenic and natural organic compounds and, hereby, left a clear signature in its sedimentary remnants. In this study, a wide variety of organic marker substances were analyzed in 15 sediment profiles from the Aomori coast (Northern Japan). Total organic carbon (TOC) and fine grain fraction normalization have been tested with the wide dataset, and the already more frequently used TOC normalization was proven to be the more suitable one. Concentration profiles and specific ratios have been interpreted using two different approaches. Differentiation of marine and terrestrial matter characterized mixing processes due to the tsunami impact. Linking constituents to anthropogenic emission sources pointed not only to pollution revealed by the tsunami damages but also to dispersion processes, in particular erosion, transport, mixing and redeposition of particle-associated contaminants. Both approaches have been proved to identify unambiguously tsunamites in sedimentary archives and to reveal detailed insights into the tsunami-driven dispersion of particle-associated organic matter. Generally, the organic geochemical proxies as tested in this study can be reliably used to identify and characterize tsunami deposits in the sedimentary record. Finally, this strategy can be transferred to other locations affected by tsunamis for an in-depth characterization of the destruction and environmental changes induced by tsunami events.

Authors 7

1. Mike Frenken Aachen Neotectonics and Natural Hazards Group Institute for Geology and Geochemistry of Petroleum and Coal

   RWTH Aachen University

   Affiliation as printed

   Institute for Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany

   Neotectonics and Natural Hazards Group, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany

2. Piero Bellanova Aachen Neotectonics and Natural Hazards Group Institute for Geology and Geochemistry of Petroleum and Coal

   RWTH Aachen University

   Affiliation as printed

   Institute for Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany

   Neotectonics and Natural Hazards Group, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany

3. Yu. Nishimura

   Hokkaido University

   Affiliation as printed

   Institute of Seismology and Volcanology, Hokkaido University, Kita-10, Nishi-8, Kita-ku, Sapporo, 060-0810, Japan

4. Philipp Schulte Aachen Department of Geography

   RWTH Aachen University

   Affiliation as printed

   Department of Geography, RWTH Aachen University, Wüllnerstrasse 5B, 52056, Aachen, Germany

5. Frank Lehmkuhl Aachen Department of Geography

   RWTH Aachen University

   Affiliation as printed

   Department of Geography, RWTH Aachen University, Wüllnerstrasse 5B, 52056, Aachen, Germany

6. Klaus R. Reicherter Aachen Neotectonics and Natural Hazards Group

   RWTH Aachen University

   Affiliation as printed

   Neotectonics and Natural Hazards Group, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany

7. Jan Schwarzbauer corresponding Aachen Institute for Geology and Geochemistry of Petroleum and Coal

   RWTH Aachen University

   Affiliation as printed

   Institute for Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstrasse 4-20, 52056, Aachen, Germany