TY - JOUR
T1 - Numerical simulation of tsunamis generated by caldera collapse during the 7.3 ka Kikai eruption, Kyushu, Japan
AU - Maeno, Fukashi
AU - Imamura, Fumihiko
AU - Taniguchi, Hiromitsu
N1 - Funding Information:
Acknowledgments. The authors would like to thank K. Minoura, T. Kobayashi, H. Naruo, and N. Geshi for critical discussion, and are grateful to A. Goto, T. Miyamoto, and M. Ichihara for logistical advice. We also thank Y. Shigihara and N. Okajima for helpful with mesh-forming and cording, and are grateful to JODC and GSI for providing digital geographical data. We appreciate constructive reviews and comments from B. Keating, C, Mader and Y. Nishimura, and thank the editor A. Takada for efforts in handling the manuscript. This research was supported by a Grant-in-aid for Scientific Research entitled ‘Dynamics of Volcanic Explosion’ from the Ministry of Education, Culture, Sports, Science and Technology, Japan (No. 14080203).
PY - 2006
Y1 - 2006
N2 - The relationship between tsunamis and scales of caldera collapse during a 7.3 ka eruption of the Kikai volcano were numerically investigated, and a hypothetical caldera collapse scale was established. Wave height, arrival time, and run-up height and distance were determined at some locations along the coastline around Kikai caldera, using non-linear long-wave equations and caldera collapse models using parameters showing the difference in geometry between pre- and post-collapse and the collapse duration. Whether tsunamis become large and inundations occur in coasts is estimated by the dimensionless collapse speed. Computed tsunamis were then compared with geological characteristics found in coasts. The lack of evidence of tsunami inundation at Nejime, 65 km from the caldera, suggests that any tsunamis were small; indicating that the upper limit of dimensionless caldera collapse speed was 0.01. On the other hand, on the coast of the Satsuma Peninsula, 50 km from the caldera, geological characteristics suggests that tsunamis did not inundate, or that even if tsunamis inundated the area, the traces of a tsunami have been eroded by a climactic pyroclastic flow or the tsunami itself and they have not been left. In numerical computations, when a dimensionless caldera collapse speed is more than 0.003, tsunami can inundate this area.
AB - The relationship between tsunamis and scales of caldera collapse during a 7.3 ka eruption of the Kikai volcano were numerically investigated, and a hypothetical caldera collapse scale was established. Wave height, arrival time, and run-up height and distance were determined at some locations along the coastline around Kikai caldera, using non-linear long-wave equations and caldera collapse models using parameters showing the difference in geometry between pre- and post-collapse and the collapse duration. Whether tsunamis become large and inundations occur in coasts is estimated by the dimensionless collapse speed. Computed tsunamis were then compared with geological characteristics found in coasts. The lack of evidence of tsunami inundation at Nejime, 65 km from the caldera, suggests that any tsunamis were small; indicating that the upper limit of dimensionless caldera collapse speed was 0.01. On the other hand, on the coast of the Satsuma Peninsula, 50 km from the caldera, geological characteristics suggests that tsunamis did not inundate, or that even if tsunamis inundated the area, the traces of a tsunami have been eroded by a climactic pyroclastic flow or the tsunami itself and they have not been left. In numerical computations, when a dimensionless caldera collapse speed is more than 0.003, tsunami can inundate this area.
KW - Caldera collapse
KW - Caldera-forming eruption
KW - Kikai caldera
KW - Numerical simulation
KW - Tsunami
UR - http://www.scopus.com/inward/record.url?scp=33750200660&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33750200660&partnerID=8YFLogxK
U2 - 10.1186/BF03352606
DO - 10.1186/BF03352606
M3 - Article
AN - SCOPUS:33750200660
VL - 58
SP - 1013
EP - 1024
JO - Earth, Planets and Space
JF - Earth, Planets and Space
SN - 1343-8832
IS - 8
ER -