TY - JOUR
T1 - Vertical tectonic crustal movements along the Japanese coastlines inferred from late Quaternary and recent relative sea-level changes
AU - Okuno, Jun'ichi
AU - Nakada, Masao
AU - Ishii, Masayoshi
AU - Miura, Hideki
N1 - Funding Information:
We acknowledge Kurt Lambeck for kindly providing the ice sheet chronology of the ANU ice model, and an anonymous reviewer and the editor (C.V. Murray–Wallace) for their constructive comments. This work was basically motivated by the geomorphological studies of the late Nobuyuki Yonekura, who made a great contribution to research of the Quaternary sea-level change and tectonics in Japan. This work was partially supported by the Japanese Ministry of Education, Science and Culture (Grand-in-Aid for Scientific Research No. 21253001 , 22540440 , 23501255 , and 25400455 ).
PY - 2014/5/1
Y1 - 2014/5/1
N2 - Observed relative sea-level (RSL) changes during the past ~130kyr make it possible to evaluate the vertical crustal movement due to several tectonic processes such as the subduction of oceanic plates. Here we infer average rates of tectonic crustal movement along the Japanese coastlines on three typical timescales of ~50yr, ~6kyr and ~125kyr based on tide gauge and Holocene RSL observations and the altitudes of marine terraces formed at the Last Interglacial (LIG) phase at ~125ka. The rates on a timescale of ~50yr are derived from tide gauge data, thermosteric sea-level changes due to thermal expansion of the oceans and predictions due to the glacio-hydro isostatic adjustment (GIA) for the last deglaciation and also recent melting of the mountain glaciers and Greenland and Antarctic ice sheets. Those for ~6kyr and ~125kyr are based on the RSL observations and the predictions by GIA modelling, considering uncertainties for temporal changes in eustatic sea-level for the mid- to late-Holocene and LIG phase. The inferred rates for ~50yr are significantly different from those for ~125kyr in most sites, particularly for sites along the coastline from eastern Hokkaido to northeastern Japan, Shikoku and south Kyushu facing the Pacific Ocean. In these regions, the rates for ~125kyr and ~50yr are positive (uplift) and negative (subsidence), respectively. Also, the observed RSL changes at ~6ka are consistent with the inferred RSL changes using the rates for ~125kyr and GIA-predictions in many sites, but inconsistent with those for ~50yr in most sites except for a few sites. These results suggest that the rates on a timescale of ~50yr are not representative of the tectonic crustal movements for timescales longer than ~6kyr in most sites along the Japanese coastlines. However, the inferred rates on these timescales may be useful in discussing the recurrence of megathrust earthquake with its interval of ~1kyr such as the 2011 earthquake off the Pacific coast of Tohoku.
AB - Observed relative sea-level (RSL) changes during the past ~130kyr make it possible to evaluate the vertical crustal movement due to several tectonic processes such as the subduction of oceanic plates. Here we infer average rates of tectonic crustal movement along the Japanese coastlines on three typical timescales of ~50yr, ~6kyr and ~125kyr based on tide gauge and Holocene RSL observations and the altitudes of marine terraces formed at the Last Interglacial (LIG) phase at ~125ka. The rates on a timescale of ~50yr are derived from tide gauge data, thermosteric sea-level changes due to thermal expansion of the oceans and predictions due to the glacio-hydro isostatic adjustment (GIA) for the last deglaciation and also recent melting of the mountain glaciers and Greenland and Antarctic ice sheets. Those for ~6kyr and ~125kyr are based on the RSL observations and the predictions by GIA modelling, considering uncertainties for temporal changes in eustatic sea-level for the mid- to late-Holocene and LIG phase. The inferred rates for ~50yr are significantly different from those for ~125kyr in most sites, particularly for sites along the coastline from eastern Hokkaido to northeastern Japan, Shikoku and south Kyushu facing the Pacific Ocean. In these regions, the rates for ~125kyr and ~50yr are positive (uplift) and negative (subsidence), respectively. Also, the observed RSL changes at ~6ka are consistent with the inferred RSL changes using the rates for ~125kyr and GIA-predictions in many sites, but inconsistent with those for ~50yr in most sites except for a few sites. These results suggest that the rates on a timescale of ~50yr are not representative of the tectonic crustal movements for timescales longer than ~6kyr in most sites along the Japanese coastlines. However, the inferred rates on these timescales may be useful in discussing the recurrence of megathrust earthquake with its interval of ~1kyr such as the 2011 earthquake off the Pacific coast of Tohoku.
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U2 - 10.1016/j.quascirev.2014.03.010
DO - 10.1016/j.quascirev.2014.03.010
M3 - Article
AN - SCOPUS:84898655660
SN - 0277-3791
VL - 91
SP - 42
EP - 61
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
ER -
