کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4727781 1356394 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Lithospheric deformation under pre- and post-seismic stress fields along the Nicobar–Sumatra subduction margin during 2004 Sumatra mega-event and its tectonic implications
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Lithospheric deformation under pre- and post-seismic stress fields along the Nicobar–Sumatra subduction margin during 2004 Sumatra mega-event and its tectonic implications
چکیده انگلیسی

A high-resolution study was carried out under pre-seismic (i.e., static) and post-seismic stress fields (i.e., dynamic) in a space–time frame along the Nicobar–Sumatra margin. The study reveals that the descending lithosphere records minimum stress obliquity, predominant thrust movement, and down-dip least compressive stress axis under static stress field in northwest Sumatra (sector III). The imbalance between down-dip component of slab pull force and viscous resistive force possibly caused cyclic stress loading in compressive field around the flexing zone (∼ 25 km), and that undergone brittle failure through generation of mega-thrust event on 26th December' 2004. A sharp decrease in stress obliquity towards north (sector II), redressing of least compressive stress axes from horizontal to down-dip direction, and increasing thrust movements under dynamic stress field account for continued upward shortening of the lithosphere. The weak thinner zone (i.e., between ∼ 159 and ∼ 217 km depth), an age-discontinuity portion, possibly was collapsed through rapid enhancement of stress-induced weakening and strain localization following the 2004 Sumatra mega-shock. It is also well appreciated in the literature that such shallow disruption of the lithosphere is inevitable in the upper mantle, if the slab is weakened or broken there, and this phenomenon is not uncommon below the Sumatra.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gondwana Research - Volume 12, Issue 4, November 2007, Pages 468–475
نویسندگان
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