SGER: Exploratory seismic reflection and gravity coring survey of Lakes Mantano and Towuti, Indonesia

这项探索性研究小额赠款（SGER）支持对印度尼西亚苏拉威西岛的两个大型构造湖（Mantano湖和Towuti湖）进行地震反射和重力取芯调查。尽管湖泊和气象数据表明，这两个湖泊应该对厄尔尼诺-南方涛动（ENSO）驱动的气候变化敏感，但实际上对湖泊的沉积及其环境历史一无所知。该研究将利用加拿大和印度尼西亚的科学合作伙伴和工业界的支持，利用地震反射和重力取芯方法探索这两个湖泊在古气候研究方面的潜力。总体目标是通过在印度尼西亚进行基于湖泊的气候重建，获得对ENSO更新世和全新世历史的新见解。这项探索性研究代表了实现这一目标的第一步：对印度尼西亚曼塔诺湖和托乌提湖的考察。该小组将收集约500公里的高分辨率和中分辨率地震反射数据，以及一套重力岩心和抓取样本，并开展一个小型实验室项目，调查两个湖泊的沉积物样本和沉积环境。具体而言，地震资料和岩心样品将用于：1)识别侵蚀不整合面和其他可以指示主要湖泊水位变化深度的地层表面；2)研究湖泊的现代沉积模式，以确定有希望进行长活塞取心的地点，为未来的建议提供支持；3)校准地球化学和有机地球化学代理；4)建立两个湖泊近期环境变化的初步记录。虽然具有高度的探索性，但这项工作应该催化利用湖泊沉积物对印度尼西亚气候和环境历史的重要未来研究。知识优势：ENSO是一种全球关注的现象，但我们对ENSO在几十年到几千年时间尺度上的变化的理解很差。这项研究将为印度尼西亚的湖泊低洼和干旱提供初步但极有价值的记录，为美国气候变化科学计划特别强调的几个领域做出贡献。此外，该研究代表了印度尼西亚大型湖泊的第一个系统的古气候研究，Mantano湖和Towuti湖最终可能提供印度尼西亚气候历史和ENSO变率的无与伦比的记录。更广泛的影响：这项研究将促进美国、印度尼西亚和加拿大科学家在印度尼西亚湖泊研究方面的广泛国际合作。收集到的重力岩心将成为布朗大学高级研究论文的基础，并将为重建由enso引起的印度尼西亚干旱提供基础，这对于评估世界上人口最稠密的国家之一的农业和水电利用的水资源至关重要。

This Small Grant for Exploratory Research (SGER) supports a seismic reflection and gravity coring survey of two large tectonic lakes on the island of Sulawesi, Indonesia: Lakes Mantano and Towuti. Although limnologic and meterologic data suggest that both lakes should be sensitive to El Nino Southern Oscillation-driven (ENSO) climate changes, virtually nothing is known about sedimentation in the lakes nor their environmental histories. The research will explore the potential of the two lakes for paleoclimate research using seismic reflection and gravity coring methods, leveraging support from Canadian and Indonesian scientific partners and industry. The overarching goal is to gain new insight into the Pleistocene and Holocene history of ENSO using lake-based climate reconstruction in Indonesia. This exploratory research represents a first step toward that goal: an expedition to Lakes Mantano and Towuti, Indonesia. The team will collect about 500 km of high- and intermediate-resolution seismic reflection data and a suite of gravity core and grab samples, and conduct a small laboratory program to investigate sediment samples and sedimentary environments in the two lakes. Specifically, seismic data and core samples will be used to:1) Identify erosional unconformities and other stratigraphic surfaces that could indicate the depthof major lake level changes2) Investigate modern patterns of sedimentation in the lakes to identify promising sites for longpiston coring to be supported by future proposals3) Calibrate geochemical and organic geochemical proxies4) Develop preliminary records of recent environmental changes in the two lakes. Although highly exploratory, the work should catalyze significant future research on Indonesian climate and environmental history using lake sediments.Intellectual merits: ENSO is a phenomenon of global interest, but our understanding of ENSO variability at timescales of decades to millennia is poor. This study will provide a preliminary but extremely valuable record of lake lowstands and drought from Indonesia, contributing to several areas of special emphasis within the US Climate Change Science Program. Moreover, this research represents the first systematic paleoclimate study of Indonesian large lakes, and Lakes Mantano and Towuti could eventually provide unparalleled records of Indonesian climate history and ENSO variability.Broader Impacts: This study will promote a broad, international collaboration between US, Indonesian, and Canadian scientists working on Indonesian lakes. Gravity cores collected will form the basis for senior research theses at Brown University, and will provide a basis for reconstructing ENSO-driven drought in Indonesia, critical to evaluating water resources for agriculture and hydroelectric utilization in one of the most densely populated countries in the world.