Geochemical tracers to establish the significance and timing of gas hydrate induced slide failure in the Hikurangi margin, as a component of the SLAMZ project

GSTDTAP

项目编号	1557519
	Geochemical tracers to establish the significance and timing of gas hydrate induced slide failure in the Hikurangi margin, as a component of the SLAMZ project
	Marta Torres
主持机构	Oregon State University
项目开始年	2016
	2016-04-01
项目结束日期	2018-03-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	298363(USD)
国家	美国
语种	英语
英文摘要	This project investigates the relationship between landslides and gas hydrate formation on the northeastern Hikurangi margin of New Zealand. Submarine landslides pose a significant socio-economic hazard, not only because they may destabilize offshore installations (e.g. underwater cables), but more significantly because the tsunamis generated by such slope failures have caused significant human fatalities and destruction of coastal infrastructure. The Hikurangi margin off New Zealand is ideally suited to study the various processes known to act as drivers/preconditioners for slope failure. The project will assess the importance of many factors on slope stability including gas hydrates and sediment composition and diagenesis (e.g., what makes a particular sedimentary layer weak); tectonic stress and geometry (e.g., slope steepening); and margin hydrogeology (e.g., transient pore pressure changes associated with climate and faulting). The geochemical component of this project complements a large, international, multi-year German-led project termed Slide Activity on the Hikurangi Margin, New Zealand (SLAMZ). Results from this study will serve to test various current ideas on the role of gas hydrate on slope stability, and will also address issues such as the water and carbon budgets along the margin and the presence and extent of fluid flow within the sediments. The results will thus have a broader relevance in the context of our understanding of the hydrogeology, element cycling, and earthquake generation in subduction zones worldwide. The project includes the training of an undergraduate student as well as mentoring of a postdoctoral investigator. Submarine slope failure is a major sedimentary process along ocean margins worldwide, with consequences that include margin architecture, hydrogeology and tsunamogenesis. Numerous studies have proposed that gas hydrates play a major role in controlling slope failure initiation and mass-movement processes, including a new hypothesis that postulates that gas hydrate itself may lead to seafloor weakening through plastic, very slow (creeping) deformation similar to rock glaciers in the terrestrial environment. In contrast to the extensive geophysical and near-seafloor data sets available for the Hikurangi margin, there is a lack of deep core geochemical data to address the interdependence of fluid, temperature, and gas hydrate dynamics in slope stability. This project aims at generating the first data set on geochemical parameters that complements ongoing geophysical, petrophysical and modeling efforts to unravel the role of gas hydrate in slope stability of the Hikurangi Margin in a partnership with scientists from Germany and New Zealand. The SLAMZ program (led by the University of Bremen) will use a seafloor to sample sediment at eight locations with contrasting tectonic settings and geometries, depth of gas hydrate stability, slump characteristics and fluid flow. The geochemical component of this large international project will generate and analyze pore fluid data that are key to: 1) Establish distribution and concentration of gas hydrate; 2) Evaluate postulated changes in gas hydrate stability associated with seamount subduction; 3) Constrain transients associated with gas hydrate and sediment slumping processes; and 4) Detect and characterize the nature and sources of fluid flow. Our results will contribute to our understanding of the geochemical, and geomechanical transformations in gas-hydrate bearing subduction zones, with implications to the societally-relevant processes that contribute to slope instability.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/69330
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Marta Torres.Geochemical tracers to establish the significance and timing of gas hydrate induced slide failure in the Hikurangi margin, as a component of the SLAMZ project.2016.