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DOI	10.1029/2019JB019203
	Seismicity on Conjugate Faults in Ölfus, South Iceland: Case Study of the 1998 Hjalli-Ölfus Earthquake
	Parameswaran R.M.; Thorbjarnardóttir B.S.; Stefánsson R.; Bjarnason I.T.
发表日期	2020
ISSN	21699313
卷号	125 期号:8
英文摘要	The Ölfus seismic belt lies at the western end of the ~E-W sinistral transform shear zone in South Iceland, called the South Iceland Seismic Zone (SISZ), where most seismicity and surface faulting show ~N-S dextral slip. Unlike the rest of SISZ, seismicity in west Ölfus is predominantly along the ~ENE-WSW direction. Throughout recorded history, Ölfus has shown an interactive behavior with the Hengill volcanic system that lies northwest of the zone. For instance, the 13 November 1998 Mw 5.1 earthquake in the Hjalli area (west Ölfus) and its ~ENE trending aftershock sequence were likely triggered by the 4 June 1998 Mw 5.4 Hengill earthquake sequence. These events point to an interplay between conjugate ~N-S and ~ENE-WSW faults in the region. Relative relocations of earthquakes in Hjalli-Ölfus from July 1991 to December 1999 (Icelandic Meteorological Office, 2017) are chiefly limited to 4- to 8-km depth along the ~ENE direction with a few distributed on smaller ~N-S faults. The foreshocks of the November 1998 earthquake occurred on a ~N-S fault until a day prior to the mainshock when they shifted to the ~ENE direction. The subsequent aftershocks are also mainly restricted to the ~ENE direction. We find that the Mw 5.1 (Global Centroid Moment Tensor moment = 5.43 × 1016 N-m) Hjalli-Ölfus earthquake ruptured a near-vertical ~ENE fault area of 24–40 km2 with left-lateral average slip of 5–8 cm. Multiple relocations of the mainshock using various constraints indicate that the event likely occurred close to the junction of the conjugate ~ENE-WSW and ~N-S faults. ©2020. The Authors.
英文关键词	Conjugate faulting; Earthquake relocations; Hjalli-Ölfus; Iceland; Seismotectonics; South Iceland Seismic Zone
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187650
作者单位	Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland; Faculty of Business and Science, University of Akureyri, Akureyri, Iceland; Nordic Volcanological Center, Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland
推荐引用方式 GB/T 7714	Parameswaran R.M.,Thorbjarnardóttir B.S.,Stefánsson R.,et al. Seismicity on Conjugate Faults in Ölfus, South Iceland: Case Study of the 1998 Hjalli-Ölfus Earthquake[J],2020,125(8).
APA	Parameswaran R.M.,Thorbjarnardóttir B.S.,Stefánsson R.,&Bjarnason I.T..(2020).Seismicity on Conjugate Faults in Ölfus, South Iceland: Case Study of the 1998 Hjalli-Ölfus Earthquake.Journal of Geophysical Research: Solid Earth,125(8).
MLA	Parameswaran R.M.,et al."Seismicity on Conjugate Faults in Ölfus, South Iceland: Case Study of the 1998 Hjalli-Ölfus Earthquake".Journal of Geophysical Research: Solid Earth 125.8(2020).