PIRE: LIFE ON A TECTONICALLY-ACTIVE DELTA: CONVERGENCE OF EARTH SCIENCE AND GEOHAZARD RESEARCH IN BANGLADESH WITH EDUCATION AND CAPACITY BUILDING

该项目汇集了一个由美国、孟加拉国、印度、德国和意大利科学家组成的国际团队，以加深我们对世界上最大的恒河-雅鲁藏布江-梅格纳三角洲(GBMD)的动态的了解。这个三角洲以从喜马拉雅山脉和缅甸山脉流入的三条大河命名，涵盖了孟加拉国的大部分地区。除了它的规模，这个三角洲值得注意的是，它位于三个构造板块的活跃交界处，每年从三大河流接收超过10亿吨的泥沙。只有大约三分之一的沉积物留在三角洲，因为三角洲下沉得如此之快。这一组合保存了大量的喜马拉雅侵蚀过程的地层档案，包括建造GBMD的基于河流的过程，它所覆盖的活动板块边界的构造，以及这些过程之间的相互作用。这一记录在很大程度上是未被探索的，人们对这种规模的沉积和构造之间的基本相互作用知之甚少。该团队将使用一套广泛的学科和技术，共同研究沉积和水文过程、构造学、构造地质学和地震学，这些都是揭示GBMD动力学所必需的。帝国团队将首先使用先进的技术和当地的人工方法相结合的方法来创建三角洲的地层结构记录。该项目的核心领域包括：1)确定被沉积掩埋的构造板块边界；2)确定未来地震的潜在来源；3)调查较长期影响(如泥沙负荷、构造和压实)与较短期影响(如地震和人为干预)造成的沉降率的相对原因；4)调查恒河和雅鲁藏布江的快速河道转换；以及5)通过将构造和水文过程相结合，并通过将长期稳定过程与突发性的短期事件联系起来，对三角洲动力学作出全面、完整的记录。孟加拉国是一个发展中国家，面积相当于爱荷华州，但人口是爱荷华州的50倍，人口近1.6亿。这个贫穷的国家极易受到与三角洲体系的活力有关的自然灾害的影响。这些危险包括大范围的季节性洪水、河流侵蚀和河道改道、海平面上升造成的永久性土地损失、地下水中自然产生的砷、反复出现的气旋和季风、山体滑坡和大地震。由于人们对这种罕见的地质事件知之甚少，因此几乎没有长期规划来应对动态的GBMD地貌变化的时间尺度，从而使越来越多的人口面临风险。因此，可靠的地质过程知识是孟加拉国进行有效的基础设施设计、降低风险和优化资源的先决条件。该项目为所有参与者提供了一个令人信服的国际教育机会，让他们共同参与一个重要的基本问题的研究，其结果可以减少未来与三角洲有关的危害的影响。它将通过国际实地考察、实验室实验和分析以及建模，培训下一代美国地球和环境科学家在全球范围内工作。来自该机构的研究生和本科生将能够在孟加拉国开展研究，并在那里注册跨学科的实地课程；来自不直接参与该机构研究努力的机构的学生将可以参加更多的研究旅行和实地学校。该项目还将扩大各机构的参与，并加强在明尼苏达大学教授的孟加拉国水问题跨学科课程的地球科学层面。帝国项目将使美国机构能够建立其参与国际事务的能力。它将加强和联系孟加拉国在几个校园的长期正在进行的研究。它将把美国的机构组成一个由欧洲和南亚的三角洲专家组成的国际网络。该项目的成员还将利用国家地球表面动力学中心(NCED)独特的“实验地球景观”和计算设施，NCED是明尼苏达大学由NSF资助的科学和技术中心。与NCED的联系支持了许多研究人员研究密西西比河三角洲，这意味着这个帝国有可能对全国产生重大影响，因为它提供了对三角洲系统行为的基本新见解。该奖项还将通过与三角洲研究中心(DSC)和达卡大学地球天文台(DUEO)在达卡大学(DU)的合作，帮助孟加拉国建设研究能力和基础设施。该项目应有助于将DSC和DUEO定位为三角洲沉积和构造过程的卓越中心，并将它们确立为GMBD研究的焦点，拥有强大的教师队伍、存档的沉积数据以及对关键地震和GPS网络的监督。美国的合作机构是哥伦比亚大学(NY)、范德比尔特大学(TN)、明尼苏达大学和纽约城市大学皇后学院。合作的外国机构是达卡大学(孟加拉国)、不来梅大学(德国)、物理研究实验室(印度)、孟加拉工程和科学大学(印度)和国家地质科学研究所(意大利)。该项目由美国国家科学基金会国际科学与工程办公室和地球科学部共同资助。

This PIRE project brings together an international team of U.S., Bangladeshi, Indian, German, and Italian scientists to further our understanding of the dynamics of the world's largest delta, the Ganges-Brahmaputra-Meghna Delta (GBMD). This delta, named for the three large rivers that flow into it from the Himalayan and Burmese Ranges, encompasses most of Bangladesh. In addition to its size, this delta is notable because it is at the active juncture of three tectonic plates and receives over one gigaton of sediment annually from the three large rivers. Only about one-third of this sediment remains in the delta because the delta is sinking so rapidly. This combination preserves a tremendous stratigraphic archive of erosional processes in the Himalaya, the river-based processes that are building the GBMD, the tectonics of the active plate boundaries it overlies, and the interactions among these processes. This record is largely unexplored and little is known about the fundamental interactions between sedimentation and tectonics at this scale. This PIRE team will use a broad suite of disciplines and techniques to collectively study the sedimentary and hydrological processes, tectonics, structural geology, and seismology essential to unravelling GBMD dynamics. The PIRE team will first create a record of the stratigraphic architecture of the delta using a mixture of advanced technical and local manual methods. Core areas of the project include: 1) defining the tectonic plate boundaries that are buried by sedimentation; 2) identifying potential sources of future earthquakes; 3) investigating the relative causes of subsidence rates due to longer term effects (e.g., sediment loading, tectonics, and compaction) vs. shorter term effects (e.g., earthquakes and human interventions); 4) investigating rapid channel switches of the Ganges and Brahmaputra rivers; and 5) assembling a comprehensive, integrated record of delta dynamics by coupling tectonics and hydrological processes, and by linking long-term steady processes with abrupt, short-term events. Bangladesh is a developing country that is the size of Iowa, but with a 50-fold greater population of almost 160 million people. This impoverished nation is extremely vulnerable to natural hazards related to the dynamism of the delta system. Such hazards include widespread seasonal flooding, river erosion and channel redirections, permanent land loss from sea level rise, naturally-occurring arsenic in groundwater, recurrent cyclones and monsoons, landslides, and huge earthquakes. Because such infrequent geologic events are poorly understood, there is little long-term planning to address the timescales at which the dynamic GBMD landscape is changing, leaving a growing population at risk. Reliable knowledge of geologic processes is therefore a prerequisite for effective infrastructure design, risk-reduction and resource optimization in Bangladesh. The PIRE project provides a compelling international education opportunity for all participants by collaboratively engaging them in research on an important fundamental problem, the results of which could reduce the impact of future delta-related hazards. It will train the next generation of U.S. earth and environmental scientists to work globally via international fieldwork, laboratory experiments and analysis, and modelling. Graduate students and undergraduates from PIRE institutions will be able to conduct research in Bangladesh and enroll in interdisciplinary field courses there; additional research trips and field schools will be open to students from institutions not directly involved in the PIRE research efforts. The project will also broaden participation across PIRE institutions and strengthen the geosciences dimensions of an interdisciplinary course on water issues in Bangladesh taught at the University of Minnesota. The PIRE project will allow the U.S. institutions to build their capacity for international engagement. It will strengthen and link longstanding ongoing research involvement in Bangladesh on several campuses. It will couple the U.S. institutions in an international network of delta experts in Europe and South Asia. Members of the project will also take advantage of the unique "Experimental Earthscape" and computational facilities at the National Center for Earth-surface Dynamics (NCED), an NSF-funded Science and Technology Center at the University of Minnesota. Linkage to NCED, which supports many researchers studying the Mississippi River delta, means this PIRE has the potential to have a large national impact by providing fundamental new insights into the behavior of delta systems. This award will also help build Bangladeshi research capacity and infrastructure via the collaboration with the Delta Study Centre (DSC) and Dhaka University Earth Obseratory (DUEO) at Dhaka University (DU). The project should help position DSC and DUEO as centers of excellence on deltaic sedimentary and tectonic processes and establish them as a focal points for GMBD research with strong faculty, archived sedimentary data, and oversight of critical seismic and GPS networks. The collaborating institutions in the U.S. are Columbia University (NY), Vanderbilt University (TN), the University of Minnesota, and City University of New York, Queens College. Collaborating foreign institutions are the University of Dhaka (Bangladesh), Bremen University (Germany), Physical Research Laboratory (India), the Bengal Engineering and Science University (India), and Istituto Nazionale di Geofisica e Vulcanologia (Italy). This project is cofunded by NSF's Office of International Science and Engineering and the Division of Earth Sciences.