Collaborative Research: EAGER: A Seismic Reflection Survey to Assess the Deep Drilling Potential of Laguna de Tota, Colombia

合作研究：EAGER：评估哥伦比亚拉古纳德托塔深钻潜力的地震反射调查

• 批准号: 1445662
• 负责人: Nigel Wattrus
• 金额: $ 4.28万
• 依托单位: University of Minnesota Duluth
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445662&HistoricalAwards=false
• 关键词: Collaborative; Research; EAGER; Seismic; Reflection

The proposed work would conduct a detailed geophysical survey of the Laguna de Tota, a large tectonic lake in the Eastern Cordillera of the Colombian Andes. The survey would determine the thickness and layout of the bottom sediment layers, and allow the researchers to better understand the type of materials available for a possible later expedition to extract samples by drilling for cores. The proposed geophysical work involves an international team of U.S. and Colombian geoscientists, which will strengthen international collaboration and provide training for U.S. and Colombian graduate students. Drs. Bird and Escobar will engage local communities that rely on Tota's water resources by giving lectures about the geophysical and drilling project at community centers. They will also speak at Colombian universities to increase awareness about Andean water resources and climate change. The location of the lake is important, because as South America's third largest lake, it is well removed to the North from the other two (Lakes Titicaca and Junin, in Bolivia and Peru). A sediment core from the Laguna de Tota could potentially contain climate data recording temperatures and lake process history over the last several hundred thousand years, and include several glacial/inter-glacial climate signals, including that of the South American Summer Monsoon, whose details are poorly understood.Using a small, high-resolution single-channel airgun seismic reflection system and a CHIRP sub-bottom profiler the team would map Tota's bathymetry, determine the thickness of lacustrine sedimentary sequences, locate depositional centers and identify lake-level transgression-regression sequences. Littoral sediment cores collected from Tota in 2013 suggest that the lake's sediment archive contains detailed climatic information, including evidence of past lake level changes. The team would characterize Tota's sediment archive and assess its potential for developing a long-term paleoclimate record. Despite near certainty that Tota's sediment archive spans at least several hundred thousand years, no known geophysical or paleoclimate work has been conducted on the lake previously. The proposed work therefore represents a unique opportunity to investigate a site that has tremendous potential for containing a long, continuous record of Northern Hemisphere South American Pleistocene climate. This work is in its initial phases, but has potential to transform our understanding of tropical climate change. As such, this work is appropriate for the EAGER funding mechanism that is designed to support "high risk-high pay off" exploratory work in its early stages.The funding is requested for ¾ of a summer month for the lead PI, 1 month for his graduate student, as well as travel for 3 PIs and 2 U.S. graduate students. Airfreight for the coring equipment from LacCore and its return, per diem in the Tota vicinity, and boat and truck rental are also requested.

拟议的工作将对哥伦比亚安第斯山脉东科迪勒拉的一个大型构造湖拉古纳德托塔进行详细的地球物理调查。该调查将确定底部沉积层的厚度和布局，并使研究人员能够更好地了解可用于以后可能的考察的材料类型，以便通过钻探岩心提取样品。拟议中的地球物理工作涉及一个由美国和哥伦比亚地球科学家组成的国际团队，该团队将加强国际合作，并为美国和哥伦比亚的研究生提供培训。伯德博士和埃斯科瓦尔博士将在社区中心举办有关地球物理和钻探项目的讲座，与依赖托塔水资源的当地社区接触。他们还将在哥伦比亚大学发表演讲，以提高人们对安第斯水资源和气候变化的认识。这个湖的位置很重要，因为作为南美洲第三大湖，它远离其他两个湖（秘鲁和玻利维亚的喀喀湖和朱宁湖）。来自托塔拉古纳的沉积物岩心可能包含过去几十万年来记录温度和湖泊过程历史的气候数据，并包括几个冰期/间冰期气候信号，包括南美夏季风的气候信号，其细节知之甚少。高分辨率单道气枪地震反射系统和CHIRP海底剖面仪，该小组将绘制Tota的水深测量图，确定湖泊沉积序列的厚度，定位沉积中心，识别湖平面海侵-海退序列。2013年从托塔收集的沿岸的沉积物岩心表明，该湖的沉积物档案包含详细的气候信息，包括过去湖平面变化的证据。该小组将描述托塔的沉积物档案，并评估其开发长期古气候记录的潜力。尽管几乎可以肯定托塔的沉积物档案跨越了至少几十万年，但以前没有对该湖进行过已知的地球物理或古气候研究。因此，拟议的工作代表了一个独特的机会，调查一个网站，有巨大的潜力，包含一个长期的，连续的记录北方半球南美更新世气候。这项工作处于初始阶段，但有可能改变我们对热带气候变化的理解。因此，这项工作适合于EAGER资助机制，该机制旨在支持早期阶段的“高风险-高回报”探索性工作。该资金要求为首席PI提供夏季月份的3/4，为他的研究生提供1个月，以及3名PI和2名美国研究生的旅行。还要求从LacCore空运取芯设备并将其运回，在托塔附近按日支付，并租用船只和卡车。