توپوگرافی لایه های مرزی در منطقه گذاراز گوشته بالایی به گوشته پایینی در خاورمیانه با استفاده از داده های تابع گیرنده
عنوان دوره: هجدهمین کنفرانس ژئوفیزیک ایران
کد مقاله : 1204-NIGS
نویسندگان
چکیده
We use a dense seismic data set to provide an image of the mantle transition zone (MTZ) beneath the Middle East. We applied Common Conversion Point (CCP) stacking of P-wave receiver functions to study the topography on the 410-km and 660-km discontinuities defining the upper and lower boundaries of the MTZ. Our results show significant topography on the MTZ discontinuities and corresponding variations in the MTZ thickness. The MTZ topography is broadly consistent with seismic tomography implying the presence of both cold thermal anomalies imparted by detached Tethyan slabs and lithospheric segments and hot thermal anomalies induced by upwelling of lower mantle material. The MTZ topography in the northern Middle East is dominated by the presence of segments of cold material that are intermittently separated by regions of ‘hot’ to ‘normal’ MTZ. Our results suggest that the Tethyan slab in the Middle East is segmented. The southern Middle East is dominated by the mantle upwelling beneath the Afar depression. Our results imply that the lower mantle material enters the MTZ beneath the Afar depression and then spreads out northeastward beneath the western Arabia flowing within the MTZ and in the upper mantle.
کلیدواژه ها
Title
Topography of Mantle Transition Zone beneath the Middle East by Receiver function stacking
Authors
Abstract
We use a dense seismic data set to provide an image of the mantle transition zone (MTZ) beneath the Middle East. We applied Common Conversion Point (CCP) stacking of P-wave receiver functions to study the topography on the 410-km and 660-km discontinuities defining the upper and lower boundaries of the MTZ. Our results show significant topography on the MTZ discontinuities and corresponding variations in the MTZ thickness. The MTZ topography is broadly consistent with seismic tomography implying the presence of both cold thermal anomalies imparted by detached Tethyan slabs and lithospheric segments and hot thermal anomalies induced by upwelling of lower mantle material. The MTZ topography in the northern Middle East is dominated by the presence of segments of cold material that are intermittently separated by regions of ‘hot’ to ‘normal’ MTZ. Our results suggest that the Tethyan slab in the Middle East is segmented. The southern Middle East is dominated by the mantle upwelling beneath the Afar depression. Our results imply that the lower mantle material enters the MTZ beneath the Afar depression and then spreads out northeastward beneath the western Arabia flowing within the MTZ and in the upper mantle.
Keywords
Tethyan Slab, Mantle Transition Zone, Receiver function