CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin

职业：破译横贯南极山脉和威尔克斯冰下盆地的构造历史

• 批准号: 1148982
• 负责人: Samantha Hansen
• 金额: $ 71.46万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-15 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1148982&HistoricalAwards=false
• 关键词: CAREER; Deciphering; Tectonic; History; Transantarctic

Intellectual Merit: To understand Antarctica's geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF's PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI's supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.

知识价值：为了了解南极洲的地球动力学发展，必须确定南极横贯山脉（tam）和威尔克斯冰川下盆地（WSB）的起源。目前对tam和WSB下地壳厚度和地震速度结构的限制是有限的，这导致了解释它们形成的竞争性地质模型的不确定性。PI建议通过一个新的地震部署来扩大对该地区的调查，即横贯南极山脉北部网络（TAMNNET），这是一个跨越北部tam和WSB的15个站点阵列，将填补地震覆盖的主要空白。来自TAMNNET的数据将与其他以前和正在进行的地震活动的数据相结合，并将使用成熟的建模技术进行分析，以生成tam和WSB下方地震结构的详细图像。这些数据将用于测试三个基本假设：tam下面是加厚的地壳，WSB的特征是薄地壳和厚沉积层，以及tam下面沿走向普遍存在缓慢的地震速度。拟议研究的结果将提供有关南极大陆性质和形成的新信息，并将有助于增进我们对重要的全球过程的理解，如山脉形成和盆地形成。拟议的研究对南极科学的其他领域也有重要的影响。对于气候和冰盖模式来说，对热演化起源的限制是至关重要的，而获得的热演化和岩石圈结构变化的新信息将用于估算临界冰盖边界条件。更广泛的影响：本项目结合三项教育策略，促进教学与科研的融合。研究生将通过实地考察和数据分析技术进行南极构造和地震处理方面的培训。通过NSF的PolarTREC项目，PI将与K-12教育工作者合作。该项目将为阿拉巴马州少数族裔服务机构的应届高中毕业生和初入职场的本科生开发一个为期三周的暑期实地项目。教学材料和参与者的经验将通过课程网站与项目外的个人分享。夏季项目结束后，特别参与的参与者将获得实习机会，分析TAMNNET数据。在连续几年中，学生可以协助实地工作，并可以在PI的监督下被招募到研究生项目。最终，这个项目不仅可以教育本科生，还可以培养一批代表性不足的学生进入地球科学领域。