| JaLCDOI |
10.18926/ESR/63515
|
| Title Alternative |
FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model
|
| FullText URL |
esr_028_027_103.pdf
|
| Author |
Okunaka, Tatsuya |
Komatsu, Masanao|
Takenaka, Hiroshi|
Yoshimi, Masayuki|
Nakamura, Takeshi|
Okamoto, Taro|
|
| Abstract |
Oita prefecture is located in northeastern part of Kyushu Island which is characterized by active subduction of the Philippine Sea plate (PHS) beneath the Eurasian plate and several active volcanoes along with the volcanic front. Oita area has frequently been damaged by large earthquakes and tsunamis since ancient times. From the point of view of disaster prevention, it is important to investigate the feasibility of strong ground motion prediction using realistic structural models. In this paper we use a land-ocean unified 3D (three-dimensional) structure model around Oita prefecture, which includes land and sea-floor topography and a seawater layer as well as subsurface structures of the arc side and the PHS slab to conduct the FDM (finite-difference method) simulations of strong ground motion in land and ocean areas for the 2015 Southern Oita, Japan, earthquake (MJMA5.7) whose hypocenter is located in the PHS slab. The simulated long-period (2–20 s) ground motions reproducing observed records demonstrate substantial contributions of thick low-velocity sediment layers in and around Beppu Bay and Oita basin to development of the motions. We also examine the topographic effects on the seismic motion by analyzing the simulation results to show the strong enhancement of the later phases.
|
| Keywords |
strong motion
Oita
the 2015 Southern Oita earthquake
long-period ground motion
simulation
finite-difference method
topography
|
| Publication Title |
Okayama University Earth Science Report
|
| Published Date |
2022-03-31
|
| Volume |
volume28
|
| Issue |
issue1
|
| Start Page |
27
|
| End Page |
103
|
| ISSN |
1340-7414
|
| language |
Japanese
|
| Copyright Holders |
© 2022 by Okayama University Earth Science Reports Editorial Committee All Rights Reserved
|
| File Version |
publisher
|
