EAR-PF: The role of temperature of the crust and lithosphere in the magnitude and style of far-field deformation: EarthScope Transportable Array in Interior Alaska

Jenny Nakai博士已获得NSF博士后奖学金，在新墨西哥州大学开展研究和教育活动。来自美国国家科学基金会资助的阿拉斯加和加拿大西北部的可移动阵列的地震数据正在被用来研究远离板块边界的大陆的变形是如何受到地壳和上地幔的物质特性控制的。目前正在探索温度以及地壳和上地幔强度对阿拉斯加山脉以北阿拉斯加内陆地形和一个大的（2 000公里长）、可能较弱的大陆断层的影响。分析地壳和上地幔的温度将有助于更好地理解为什么走滑断层会在主要大陆边界的内陆形成。来自地球科学领域代表性不足的少数民族的本科生正在参与这项研究。 PI正在与阿拉斯加原住民科学和工程项目以及阿尔伯克基美洲原住民社区学院和本科生进行外联，以传播成果并使学生接触到活跃的地球物理学和地震学研究。众所周知，岩石圈的温度会影响主要板块边界内陆的变形方式（例如，在西藏），但在这些环境中的大陆规模的数据集是罕见的。阿拉斯加和加拿大西北部移动式阵列的出现为研究地壳和岩石圈的强度剖面提供了机会。主要方法将包括使用Pn地震速度来限制上地幔岩性和外推上地幔热流，以及使用当地地震来研究地震能量衰减，以推断地壳和上地幔的温度。由此产生的岩性和温度限制将与当地地质信息相结合，以恢复地壳和岩石圈的强度分布。这些剖面将被内插，以生成整个阿拉斯加内陆地壳和上地幔强度的3D地图，由于无法进入，地震学界对该地区知之甚少。结果将与现有的地球物理数据共同解释，以确定流变学和温度在大陆远场变形中的作用，并因此确定阿拉斯加内陆的地震危险。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

Dr. Jenny Nakai has been granted an NSF EAR Postdoctoral fellowship to carry out research and education activities at the University of New Mexico. Seismic data from the NSF-funded Transportable Array in Alaska and northwestern Canada are being utilized to investigate how deformation of a continent far from a plate boundary is controlled by the material properties of the Earth's crust and upper mantle. The influence of temperature, and therefore the strength, of the crust and upper mantle on topography of Interior Alaska north of the Alaska Range and a large (2000 km long), potentially weak continental fault are being explored. Analyzing the temperature of the crust and upper mantle will lead to improved understanding of why strike-slip faults form inland of major continental boundaries. Undergraduate students from underrepresented minorities in earth science are participating in the research. The PI is engaging in outreach to the Alaska Native Science and Engineering Program and Albuquerque Native American community college and undergraduate students in order to disseminate results and expose students to active Geophysics and Seismology research.Temperature of the lithosphere is known to influence the style of deformation inland of a major plate boundary (for example, in Tibet), but data sets on a continental scale in these environments are rare. The advent of the Transportable Array in Alaska and northwestern Canada provides the opportunity to investigate the strength profile of the crust and lithosphere. Key methodologies will include using Pn seismic velocities to constrain upper mantle lithologies and extrapolate upper mantle heat flow and investigating seismic energy attenuation using local earthquakes to infer temperature of the crust and upper mantle. The resulting lithologic and temperature constraints will be combined with local geologic information to recover strength profiles of the crust and lithosphere. The profiles will be interpolated to produce a 3D map of crustal and upper mantle strength throughout Interior Alaska, a region which the seismological community knows little about due to its inaccessibility. Results will be jointly interpreted with existing geophysical data to determine the role of rheology and temperature in the far-field deformation of the continent, and as a consequence, earthquake hazard in Interior Alaska.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.