Re-examination of the age of historical and paleo-tsunami deposits at Koyadori on the Sanriku Coast, Northeast Japan
Tóm tắt
High-accuracy age estimations of tsunami deposits are very important for tsunami deposit research because the recurrence interval and frequency of tsunami deposits allow us to assess the devastating impacts of tsunamis in a populated country such as Japan. The correlation of tsunami events between remote coastal areas further enables us to constrain tsunami scenarios and fault segmentation along a trench. Before the 2011 Tohoku-oki earthquake, the long-term tsunami history along the Sanriku Coast was not well known. Age data of the long-term tsunami history are essential to understand the mechanisms of tsunami generation and earthquakes and to assess the risks posed by them. This study re-examined the age of historical and paleo-tsunami deposits (E1 to E11 deposits) at Koyadori in the middle of the Sanriku Coast and estimated their ages with high accuracy by using continuous sediments since approximately 4 ka. Radiocarbon dating was conducted in combination with other radiometric dating methods (137Cs and excess 210Pb) to estimate the ages of the sediments. The resulting ages revealed the reliable ages of ten historical and paleo-tsunami deposits. The average recurrence interval of historical and paleo-tsunamis in the last 4 ka is 350–390 years, and each recurrence interval between the E4 and E11 deposits is similar despite the tsunami deposits having different characteristics. Moreover, far-field tsunamis do not seem to inundate this site based on the observed and documented records. The continuous and long-term data of tsunami deposits at Koyadori offer important constraints on the timing and frequency of near-field earthquakes (e.g., megathrust, outer-rise, and tsunami earthquakes) around the Japan Trench.
Tài liệu tham khảo
Earthquake Research Institute, the University of Tokyo (1934) Reports on the 3 March, Showa 8 Sanriku tsunami. Bull Earthq Res Inst Tokyo Univ, Suppl 1: 1–250
Earthquake Research Institute, the University of Tokyo (1989) New collection of material for the history of Japanese earthquakes, supplement. University of Tokyo Press, Tokyo
Goff J, Chagué-Goff C, Nichol S, Jaffe B, Dominey-Howes D (2012) Progress in palaeotsunami research. Sediment Geol 243–244:70–88
Goto T, Satake K, Sugai T, Ishibe T, Harada T, Murotani S (2015) Historical tsunami and storm deposits during the last five centuries on the Sanriku coast, Japan. Mar Geol 367:105-117
Hatori T (2009) Regional deviation of inundation heights due to the large Sanriku tsunamis. Hist Earthq 24:41–48
Imamura A (1934) Past tsunamis of the Sanriku District. Bull Earthq Res Inst Tokyo Univ 1:1–16
Ishimura D, Miyauchi T (2015) Historical and paleo-tsunami deposits during the last 4000 years and their correlations with historical tsunami events in Koyadori on the Sanriku Coast, northeastern Japan. Prog Earth Planet Sci 2:16. doi:10.1186/s40645-015-0047-4
Ishimura D, Ichihara T, Sakata T, Ohata M, Takada Y (2015) Continuity of tsunami deposits and their correlations based on close interval Handy Geoslicer survey: case study of Koyadori, Yamada Town, Iwate Prefecture, northeast Japan. Active Fault Res 43:53–60
Ishimura D, Yamada K, Miyauchi T, Hayase R (2014) Characteristics of tephras interbedded with the Holocene sediments in the Sanriku Coast, northeast Japan. J Geogr 123:671–697
Ishimura D, Miyauchi T, Hayase R, Ohara K, Yamaichi T (2016) Systematic age gap of radiocarbon dates between organic bulk sediment samples and fossil samples of animal and plant in Holocene core sediments and their causes. J Geogr 125:243–256
Nakata T, Shimazaki K (1997) Geo-slicer, a newly invented soil sample, for high-resolution active fault studies. J Geogr 106:59–69
Nanayama F, Satake K, Furukawa R, Shimokawa K, Atwater BF, Shigeno K, Yamaki S (2003) Unusually large earthquakes inferred from tsunami deposits along the Kuril trench. Nature 424:660–663
Ramsey BC (2008) Deposition models for chronological records. Quat Sci Rev 27:42–60
Ramsey BC (2009) Bayesian analysis of radiocarbon dates. Radiocarbon 51:337–360
Reimer PJ, Bard E, Bayliss A, Beck JW, Blackwell PG, Ramsey BC, Grootes PM, Guilderson TP, Haflidason H, Hajdas I, Hatte C, Heaton TJ, Hoffmann DL, Hogg AG, Hughen KA, Kaiser KF, Kromer B, Manning SW, Niu M, Reimer RW, Richards DA, Scott EM, Southon JR, Staff RA, Turney CSM, van der Plicht J (2013) IntCal13 and Marine13 radiocarbon age calibration curves 0–50,000 years cal BP. Radiocarbon 55:1869–1887
Satake K, Wang K, Atwater BF (2003) Fault slip and seismic moment of the 1700 Cascadia earthquake inferred from Japanese tsunami descriptions. J Geophys Res Solid Earth 108(B11):2535. doi:10.1029/2003JB002521
Sawai Y, Namegaya Y, Okamura Y (2012) Challenges of anticipating the 2011 Tohoku earthquake and tsunami using coastal geology. Geophys Res Lett 39:L21309
Takada K, Nakata T, Miyagi T, Haraguchi T, Nishitani Y (2002) Handy geoslicer—new soil sampler for quaternary geologist. Chishitsu News 579:12–18
The 2011 Tohoku Earthquake Tsunami Joint Survey Group (2012) Data from the 2011 Tohoku Earthquake Tsunami Joint Survey Group, release 20121229. http://www.coastal.jp/ttjt/. Accessed 12 Dec 2016
Tsuji Y, Ueda K (1995) Evaluation of AD 1611 Keicho, AD 1677 Enpou, AD 1763 Houreki, AD 1793 Kansei, and AD 1856 Ansei Sanriku tsunamis. Hist Earthq 11:75–106
Watanabe H (1998) Comprehensive list of tsunamis to hit the Japanese Islands, 2nd edn. University of Tokyo Press, Tokyo