Collaborative Research: Seismic Investigation of Slab Structure and Back Arc Volcanism in the Sea of Japan Region

GSTDTAP

项目编号	1547228
	Collaborative Research: Seismic Investigation of Slab Structure and Back Arc Volcanism in the Sea of Japan Region
	Fenglin Niu
主持机构	William Marsh Rice University
项目开始年	2015
	2015-12-15
项目结束日期	2018-11-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	57592(USD)
国家	美国
语种	英语
英文摘要	We propose to develop a seismic image of the crust and mantle beneath Northeast China, Korea, and Japan with unprecedented resolution. This region is tectonically active and includes a subduction zone beneath Japan that has produced large devastating earthquakes (for example the 2011 Tohoku event), active volcanoes both in Japan as well as in Northeast China, and a history of extension in Northeast China that has resulted in a sedimentary basin rich in natural resources such as coal and oil. Current seismic images of the region will be improved through recent increased data coverage in the region as well as using a new numerical inversion technique that will fit seismic waveforms as well as travel times. The ultimate goal of developing the new seismic models is to better understand the physical processes in the deep Earth in this complicated region and how they relate to the surface tectonic activity. The inversion will utilize 3D spectral element methods to model wave propagation. Adjoint sources will be used in combination with linear optimization methods to invert observed waveforms for seismic velocity. Through waveform inversion we will model triplicated waveforms as well as multipathed seismic arrivals. This type of information has not been used in previous tomographic imaging of the region and thus will result in far higher resolution images than was previously attainable. We will use the crosscorrelation between data and synthetics as an objective function rather than time delays. This is ideal for modeling data that consist of multiple arrivals interfering within short time windows but at the same time it is insensitive to the absolute amplitude of the data. Although this project is essentially seismic in nature, the resulting high resolution images will place constraints on a number of important tectonic processes and questions such as: 1. Can all slab subducted beneath Japan for the past 50 Ma be accounted for as seismically fast anomalies? 2. Are there stagnant slabs in the deep upper mantle that are detached from the current subducting Pacific plate? If we find segmentation in slabs beneath eastern Asia, can they be associated with the opening of the Japan Sea, as well as Cenozoic magmatism in NE China? 3. Is there a warm upwelling coming from beneath stagnant slabs feeding Changbaishan volcano? Are there plumes rising from above the slab feeding volcanic activity in NE China? 4. Is there a slab gap associated with the deep seismicity gap beneath the Japan Sea? If so, can this gap be related to the ?hole? observed in the stagnant slabs beneath NE China? 5. Can metastable phases be imaged within subducting slab? Can low velocity structures likely associated with water transport into the mantle be imaged?
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/69013
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Fenglin Niu.Collaborative Research: Seismic Investigation of Slab Structure and Back Arc Volcanism in the Sea of Japan Region.2015.