TY - JOUR
T1 - Geochemical characteristics of paleotsunami deposits from the Shizuoka plain on the Pacific coast of middle Japan
AU - Watanabe, Takahiro
AU - Tsuchiya, Noriyoshi
AU - Kitamura, Akihisa
AU - Yamasaki, Shin Ichi
AU - Nara, Fumiko W.
N1 - Funding Information:
Acknowledgments—We thank the members of the Shizuoka University and Tohoku University for the preservation, division and preparation of the boring cores and other geological samples. Y. Asahara and two anonymous reviewers are acknowledged for their helpful comments and suggestions for improving the manuscript. This work was partly supported by a Grant-in-Aid from JST/RISTEX, Japan, to N.T. (FY2011, 2012-2015) and a Grant-in-Aid for Scientific Research to T.W. (17K06989) from JSPS, Japan.
Funding Information:
We thank the members of the Shizuoka University and Tohoku University for the preservation, division and preparation of the boring cores and other geological samples. Y. Asahara and two anonymous reviewers are acknowledged for their helpful comments and suggestions for improving the manuscript. This work was partly supported by a Grant-in-Aid from JST/RISTEX, Japan, to N.T. (FY2011, 2012-2015) and a Grant-in-Aid for Scientific Research to T.W. (17K06989) from JSPS, Japan.
Publisher Copyright:
Copyright © 2021 by The Geochemical Society of Japan.
PY - 2021
Y1 - 2021
N2 - The Pacific coast of Japan has repeatedly suffered earthquakes with magnitudes greater than Mw 8 and accompanying tsunami on coastal areas. Estimating the inundation area of paleotsunami using event deposits in sediment layers can inform and reduce possible damages from future earthquakes and tsunami. In addition to geological and sedimentological analyses, the geochemical signature of sediments can be an effective proxy for identifying event deposits in many cases. However, few geochemical analyses have been applied to study the Pacific coast of middle Japan. Therefore, the geochemical characteristics of paleotsunami deposits (~1000, 3500, and 4000 cal BP) were assessed for core samples from the Shizuoka plain (Oya lowland) on the Pacific coast of middle Japan. In a ternary diagram for (Na2O+CaO)-Al2O3-(Cr+Ni), our data from the paleotsunami deposits from the Shizuoka plain plotted between those of the beach core samples (shoreface and dune deposits) and mud layers in the back marsh deposits. Additionally, vertical and horizontal distributions of titanium normalized values (Na/Ti, Sr/Ti, Ba/Ti, and Cr/Ti atomic ratios) and Si/Al atomic ratios in the cores from the Shizuoka plain provided important clues for discrimination of the paleotsunami deposits from other layers, such as flood deposits from river overflow and mud layers that settled in calm environments. Based on the cluster analysis, the data from the paleotsunami deposits (~3500 cal BP) were discriminated from those of other layers in our case.
AB - The Pacific coast of Japan has repeatedly suffered earthquakes with magnitudes greater than Mw 8 and accompanying tsunami on coastal areas. Estimating the inundation area of paleotsunami using event deposits in sediment layers can inform and reduce possible damages from future earthquakes and tsunami. In addition to geological and sedimentological analyses, the geochemical signature of sediments can be an effective proxy for identifying event deposits in many cases. However, few geochemical analyses have been applied to study the Pacific coast of middle Japan. Therefore, the geochemical characteristics of paleotsunami deposits (~1000, 3500, and 4000 cal BP) were assessed for core samples from the Shizuoka plain (Oya lowland) on the Pacific coast of middle Japan. In a ternary diagram for (Na2O+CaO)-Al2O3-(Cr+Ni), our data from the paleotsunami deposits from the Shizuoka plain plotted between those of the beach core samples (shoreface and dune deposits) and mud layers in the back marsh deposits. Additionally, vertical and horizontal distributions of titanium normalized values (Na/Ti, Sr/Ti, Ba/Ti, and Cr/Ti atomic ratios) and Si/Al atomic ratios in the cores from the Shizuoka plain provided important clues for discrimination of the paleotsunami deposits from other layers, such as flood deposits from river overflow and mud layers that settled in calm environments. Based on the cluster analysis, the data from the paleotsunami deposits (~3500 cal BP) were discriminated from those of other layers in our case.
KW - Cluster analysis
KW - Geochemical signatures
KW - Shizuoka plain
KW - Titanium normalized values
KW - Tsunami deposits
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U2 - 10.2343/geochemj.2.0641
DO - 10.2343/geochemj.2.0641
M3 - Article
AN - SCOPUS:85120790156
SN - 0016-7002
VL - 5
SP - 325
EP - 340
JO - Geochemical Journal
JF - Geochemical Journal
IS - 6
ER -