气候变化领域集成服务门户(CCPortal): 3-D thermal regime and dehydration processes around the regions of slow earthquakes along the Ryukyu Trench

CCPortal

DOI	10.1038/s41598-021-90199-2
	3-D thermal regime and dehydration processes around the regions of slow earthquakes along the Ryukyu Trench
	Suenaga, Nobuaki; Yoshioka, Shoichi; Ji, Yingfeng
通讯作者	Suenaga, N (通讯作者)
发表日期	2021
ISSN	2045-2322
卷号	11 期号:1
英文摘要	Several interplate seismic events, such as short-term slow slip events (S-SSEs) and low-frequency earthquakes (LFEs), have been identified in the Ryukyu Trench, southwestern Japan. As one of the specific characteristics of this seismicity, the depths at which S-SSEs occur at the plate interface beneath Okinawa Island are approximately 5-10 km shallower than those beneath the Yaeyama Islands. To elucidate the cause of this difference in depth, we constructed a three-dimensional, Cartesian thermomechanical subduction model and applied the subduction history of the Philippine Sea (PHS) plate in the model region. As a result, the interplate temperatures at which S-SSEs take place were estimated to range from 350 to 450 degrees C beneath Okinawa Island and from 500 to 600 degrees C beneath the Yaeyama Islands. The former temperature range is consistent with previous thermal modelling studies for the occurrence of slow earthquakes, but the latter temperature range is by approximately 150 degrees C higher than the former. Therefore, explaining how the depth difference in S-SSEs could be caused from the aspect of only the thermal regime is difficult. Using phase diagrams for hydrous minerals in the oceanic crust and mantle wedge, we also estimated the water content distribution on and above the plate interface of the PHS plate. Near the S-SSE fault planes, almost the same amount of dehydration associated with phase transformations of hydrous minerals from blueschist to amphibolite and from amphibolite to amphibole eclogite within the oceanic crust were inferred along Okinawa Island and the Yaeyama Islands, respectively. On the other hand, the phase transformations within the mantle wedge were inferred only beneath the Yaeyama Islands, whereas no specific phase transformation was inferred beneath Okinawa Island around the S-SSE occurrence region. Therefore, we conclude that dehydrated fluid derived from the oceanic crust at the plate interface would play a key role in the occurrence of S-SSEs.
关键词	SUBDUCTION ZONE JAPAN DYNAMICS GEOMETRY TREMOR
语种	英语
WOS研究方向	Science & Technology - Other Topics
WOS类目	Multidisciplinary Sciences
WOS记录号	WOS:000658391200081
来源期刊	SCIENTIFIC REPORTS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/260148
推荐引用方式 GB/T 7714	Suenaga, Nobuaki,Yoshioka, Shoichi,Ji, Yingfeng. 3-D thermal regime and dehydration processes around the regions of slow earthquakes along the Ryukyu Trench[J]. 中国科学院青藏高原研究所,2021,11(1).
APA	Suenaga, Nobuaki,Yoshioka, Shoichi,&Ji, Yingfeng.(2021).3-D thermal regime and dehydration processes around the regions of slow earthquakes along the Ryukyu Trench.SCIENTIFIC REPORTS,11(1).
MLA	Suenaga, Nobuaki,et al."3-D thermal regime and dehydration processes around the regions of slow earthquakes along the Ryukyu Trench".SCIENTIFIC REPORTS 11.1(2021).