Collaborative Research: The Burma Arc from Collision Kinematics to Subduction Tectonics as Observed from a Passive seismic experiment (BACKSTOP)

合作研究：被动地震实验观察到的从碰撞运动学到俯冲构造的缅甸弧（BACKSTOP）

• 批准号: 1928786
• 负责人: James Ni
• 金额: $ 20.71万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1928786&HistoricalAwards=false
• 关键词: Collaborative; Research; Burma; Arc; Collision

When two tectonic plates collide, one may slide underneath the other. This process, called subduction, often occurs when an oceanic plate meets a continental plate. The subducting oceanic plate, or subducting slab, sinks into the Earth's mantle affecting the regional mantle flow. This often generates mountain building and volcanic activity on land, like in Cascadia and Andean mountains. The volcanos may form along a curved chain called an arc. Colliding continental plates also build mountain ranges, like the Alps and the Himalayas. These processes are responsible for large earthquakes and volcanic eruptions threatening human lives and activity. Here, the researchers study a plate boundary coupling subduction with continental collision. Subduction of the Indian oceanic plate occurs along the Indo-Burma arc. It transitions to collision along the Himalayan Mountains. The scientists leverage on an international collaboration between five countries and the U.S. They use seismology, the study of seismic waves propagating through the Earth, to image in 3D mantle and crustal structures. Deploying 24 seismic stations in key locations in Myanmar, they analyze data from these instruments and ~900 other stations in surrounding India, Bangladesh and China. A primary objective is to unveil the processes responsible for the growth of the southeastern Tibetan Plateau. Another one is to quantify the effect of the Indian slab geometry on the mantle flow. The project improves the understanding of the regional tectonics. Its outcomes have strong implications for seismic and volcanic hazard assessment in Myanmar; a region which faces large dramatic events. The project provides support for two graduate students in Missouri and New Mexico, as well as the development of scientific collaborations in Myanmar. The three-year award was co-funded by NSF Prediction of and Resilience against Extreme Events (PREEVENTS) program. Here, the team investigates the role of the Indian slab beneath Burma as a "backstop" to the mantle flow around the eastern Himalayas. They also study how this impacts the growth of the southeastern Tibetan Plateau. The project consists of two components: (1) data collection from a temporary seismic array that links large arrays in India/Bangladesh and China; (2) the synthesis of data from a large number of existing stations across the region. The data acquisition component consists of 24 temporary broad-band stations deployed in key regions lacking any seismic instruments. The second component is a collaborative effort with scientists from Myanmar, India, Singapore, China, and Germany. The combined seismic network of over 900 stations spans an area of 1800 km by 2000 km. It completely covers the entire Indo-Burma Arc. The scientists use 3-D seismic tomography and anisotropic surface wave tomography to image the Indian slab beneath the Indo-Burma subduction zone. This enables them to compare flow and lithospheric deformation around eastern Himalayas and in the Indo-Burma back-arc. The project outcomes constrain the dynamics of the deformation associated with the Indian collision and subduction, and how the transition from subduction to continental collision occurs. The gained insight into the regional tectonics, as well as crustal attenuation, is key to improve seismic and volcanic hazard forecasting in Myanmar and surrounding regions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当两个构造板碰撞时，一个可能会滑到另一个构造板。当海洋板遇到大陆板时，这种过程称为俯冲。俯冲的海洋板或俯冲平板沉入地球的地幔中，影响了区域地幔流。这通常会在陆地上产生山区建筑和火山活动，例如卡斯卡迪亚和安第斯山脉。火山可能沿着称为弧的弯曲链形成。碰撞的大陆盘子还建造了山脉，例如阿尔卑斯山和喜马拉雅山。这些过程造成了大地震和火山喷发，威胁人类的生命和活动。在这里，研究人员研究了与大陆碰撞的板边界耦合俯冲。印度海洋板的俯冲发生在印度 - 伯马弧线。它过渡到沿喜马拉雅山脉的碰撞。科学家利用他们使用地震学的五个国家和美国之间的国际合作，对在地球传播的地震浪进行研究，以3D地幔和地壳结构形象形象。他们在缅甸的主要地点部署了24个地震台，他们分析了这些工具的数据，以及在印度，孟加拉国和中国周围的其他〜900个车站。一个主要目标是揭示负责东南藏族高原增长的过程。另一个是量化印度平板几何形状对地幔流的影响。该项目提高了对区域构造学的理解。它的结果对缅甸的地震和火山危害评估具有很大的影响。面临大型戏剧性事件的地区。该项目为密苏里州和新墨西哥州的两名研究生以及缅甸的科学合作发展提供了支持。 NSF对极端事件（PREEVENTS）计划的NSF预测和弹性共同资助了三年奖励。 在这里，该小组调查了缅甸下面的印度平板的角色，作为在喜马拉雅山脉东部的地幔流的“后台”。他们还研究了这如何影响藏东高原的增长。该项目由两个组成部分组成：（1）来自临时地震阵列的数据收集，该阵列将印度/孟加拉国和中国的大型阵列连接起来； （2）来自该地区许多现有站点的数据合成。数据采集​​组件由缺乏任何地震仪器的关键区域中的24个临时宽带站组成。第二部分是与缅甸，印度，新加坡，中国和德国的科学家的合作努力。超过900个电台的联合地震网络跨越了2000公里的1800公里。它完全覆盖了整个印度伯马弧。科学家使用3-D地震断层扫描和各向异性表面波断层扫描图像印度 - 伯马俯冲带下的印度平板。这使他们能够比较东部喜马拉雅山脉和印度伯马后弧周围的流动和岩石圈变形。该项目结果限制了与印度碰撞和俯冲相关的变形的动力学，以及从俯冲到大陆碰撞的过渡如何发生。对区域构造的洞察力以及地壳衰减，是改善缅甸及周边地区的地震和火山危险预测的关键。该奖项反映了NSF的法定任务，并认为通过使用该基金会的知识分子和更广泛的影响，可以通过评估来进行评估。