气候变化领域集成服务门户(CCPortal): Seismicity and seismotectonics of Madagascar revealed by the 2011–2013 deployment of the island-wide MACOMO broadband seismic array

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DOI	10.1016/j.tecto.2020.228547
	Seismicity and seismotectonics of Madagascar revealed by the 2011–2013 deployment of the island-wide MACOMO broadband seismic array
	Rakotondraibe T.; Nyblade A.A.; Wysession M.E.; Durrheim R.J.; Rambolamanana G.; Aleqabi G.I.; Shore P.J.; Pratt M.J.; Andriampenomanana F.; Rümpker G.; Rindraharisaona E.
发表日期	2020
ISSN	00401951
卷号	790
英文摘要	The seismicity and seismotectonics of Madagascar have been studied using an island-wide distribution of broadband seismic stations. The 28-station MAdagascar-COmoros-MOzambique (MACOMO) array was deployed for a 23-month period between 2011 and 2013. MACOMO data were supplemented by seven temporary stations from the Seismological Signatures in the Lithosphere/Asthenosphere system of Southern Madagascar (SELASOMA) project, ten temporary stations from the Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel project (RHUM-RUM), and 11 permanent stations. A total of 695 earthquakes with magnitudes between ML1 and ML5.3 located within Madagascar were recorded, a new local magnitude scale was developed, and focal mechanisms were determined for 23 well-recorded events. Most of the seismicity is clustered within central Madagascar, forming NW-SE trends in the Ankaratra region and NE-SW trends in the Alaotra and Ankay regions that roughly align with extensional tectonic features. The northern and southern parts of Madagascar also show seismicity clusters that align parallel to existing tectonic features, primarily Precambrian shear zones. Focal mechanisms exhibit a wide orientation of nodal planes, show predominantly normal faulting throughout Madagascar, and provide no evidence for a sharp east-west striking plate boundary between the Lwandle and Somalian plates in the middle of the island. However, a diffuse plate boundary cannot be excluded. We suggest that topographically-generated extensional stresses is the cause of most seismicity, given that significantly fewer earthquakes are located in the lower elevation areas of the island compared to regions of higher elevations. The frequency-magnitude distribution has a b-value of ~1.2 and indicates that events with magnitude ML5 or greater should occur with an average repeat time of ~1.4 years. However, no earthquake exceeding ML6 has been recorded in the last century, suggesting that the frequency-magnitude distribution could be truncated. © 2020
英文关键词	Faulting; Broad-band seismic stations; Diffuse plate boundaries; Extensional stress; Extensional tectonics; Frequency-magnitude distribution; Normal faulting; Plate boundaries; Tectonic features; Earthquakes; broadband data; earthquake magnitude; focal mechanism; geophysical array; seismic method; seismicity; seismotectonics; Madagascar
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207856
作者单位	School of Geosciences, University of the Witwatersrand, Private Bag 3, Wits, Johannesburg, 2050, South Africa; Department of Geosciences, Penn State University, University Park, PA 16802, United States; Department of Earth and Planetary Sciences, Washington University in St. Louis, Campus Box 1169, 1 Brookings Drive, Saint Louis, MO 63130-4899, United States; Institut et Observatoire de Géophysique d'Antananarivo, Université d'Antananarivo, Ambohidempona - B. P 3843, Antananarivo, 101, Madagascar; Institute of Geosciences, Goethe-University Frankfurt, Altenhöferallee 1, Frankfurt, 60438, Germany; GeoForschungs Zentrum (GFZ), Telegrafenberg, Potsdam, 14473, Germany
推荐引用方式 GB/T 7714	Rakotondraibe T.,Nyblade A.A.,Wysession M.E.,等. Seismicity and seismotectonics of Madagascar revealed by the 2011–2013 deployment of the island-wide MACOMO broadband seismic array[J],2020,790.
APA	Rakotondraibe T..,Nyblade A.A..,Wysession M.E..,Durrheim R.J..,Rambolamanana G..,...&Rindraharisaona E..(2020).Seismicity and seismotectonics of Madagascar revealed by the 2011–2013 deployment of the island-wide MACOMO broadband seismic array.Tectonophysics,790.
MLA	Rakotondraibe T.,et al."Seismicity and seismotectonics of Madagascar revealed by the 2011–2013 deployment of the island-wide MACOMO broadband seismic array".Tectonophysics 790(2020).