TY - JOUR
T1 - Tottori earthquakes and Daisen volcano
T2 - Effects of fluids, slab melting and hot mantle upwelling
AU - Zhao, Dapeng
AU - Liu, Xin
AU - Hua, Yuanyuan
N1 - Funding Information:
This work was partially supported by Grant-in-aid for Scientific Research ( Kiban-S 11050123 ) from the Japan Society for the Promotion of Science and MEXT (grant No. 26106005 ). Prof. An Yin (the editor) and two anonymous referees provided thoughtful review comments and suggestions which have improved this paper. Appendix A
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - We investigate the 3-D seismic structure of source areas of the 6 October 2000 Western Tottori earthquake (M 7.3) and the 21 October 2016 Central Tottori earthquake (M 6.6) which occurred near the Daisen volcano in SW Japan. The two large events took place in a high-velocity zone in the upper crust, whereas low-velocity (low-V) and high Poisson's ratio (high-σ) anomalies are revealed in the lower crust and upper mantle. Low-frequency micro-earthquakes (M 0.0–2.1) occur in or around the low-V and high-σ zones, which reflect upward migration of magmatic fluids from the upper mantle to the crust under the Daisen volcano. The nucleation of the Tottori earthquakes may be affected by the ascending fluids. The flat subducting Philippine Sea (PHS) slab has a younger lithosphere age and so a higher temperature beneath the Daisen and Tottori area, facilitating the PHS slab melting. It is also possible that a PHS slab window has formed along the extinct Shikoku Basin spreading ridge beneath SW Japan, and mantle materials below the PHS slab may ascend to the shallow area through the slab window. These results suggest that the Daisen adakite magma was affected by the PHS slab melting and upwelling flow in the upper mantle above the subducting Pacific slab.
AB - We investigate the 3-D seismic structure of source areas of the 6 October 2000 Western Tottori earthquake (M 7.3) and the 21 October 2016 Central Tottori earthquake (M 6.6) which occurred near the Daisen volcano in SW Japan. The two large events took place in a high-velocity zone in the upper crust, whereas low-velocity (low-V) and high Poisson's ratio (high-σ) anomalies are revealed in the lower crust and upper mantle. Low-frequency micro-earthquakes (M 0.0–2.1) occur in or around the low-V and high-σ zones, which reflect upward migration of magmatic fluids from the upper mantle to the crust under the Daisen volcano. The nucleation of the Tottori earthquakes may be affected by the ascending fluids. The flat subducting Philippine Sea (PHS) slab has a younger lithosphere age and so a higher temperature beneath the Daisen and Tottori area, facilitating the PHS slab melting. It is also possible that a PHS slab window has formed along the extinct Shikoku Basin spreading ridge beneath SW Japan, and mantle materials below the PHS slab may ascend to the shallow area through the slab window. These results suggest that the Daisen adakite magma was affected by the PHS slab melting and upwelling flow in the upper mantle above the subducting Pacific slab.
KW - Pacific slab
KW - Philippine Sea slab
KW - adakite
KW - earthquake
KW - slab melting
KW - volcano
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U2 - 10.1016/j.epsl.2017.12.040
DO - 10.1016/j.epsl.2017.12.040
M3 - Article
AN - SCOPUS:85044254561
VL - 485
SP - 121
EP - 129
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
ER -