COLLABORATIVE: EAGER: Seismic Survey of Lake Junin, Peru in Preparation for Deep Drilling

合作：EAGER：秘鲁胡宁湖地震勘测，为深钻做准备

• 批准号: 1128166
• 负责人: Steven Colman
• 金额: $ 4.22万
• 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: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1128166&HistoricalAwards=false
• 关键词: COLLABORATIVE; EAGER; Seismic; Survey; Lake

This grant will generate critical site survey information for planned deep drilling of Lake Junin (Peru). The team will carry out an airgun seismic survey of Lake Junin in order to estimate the sediment thickness, and to provide the spatial resolution needed for selection of the best deep drilling sites. The work would be completed in a short (~two week) field season, with results made available for an International Continental Drilling Program (ICDP) drilling workshop.Lake Junin contains a sediment record that likely spans multiple glacial cycles?perhaps covering many hundreds of thousands of years, and it contains carbonates that can provide isotopic records of lake hydrology and regional climate with sub-decadal resolution. Numerous faculty and students spanning four decades have contributed to an extensive database on the lake and its watershed. However, Lake Junin has never been cored in its most deep sedimented areas, and has never been cored with a mechanical corer capable of penetrating the thick sedimentary sequences that lie under the center of the lake.The Scientific Advisory Group of the ICDP has agreed that Lake Junin is indeed worthy of a deep drilling effort, and has funded up to US $40,000 for an in-country workshop to develop a science team for a deep drilling project. This workshop, which will be held in Peru, will bring together about two dozen scientists from the U.S., Canada, Germany and other ICDP countries. Although the Scientific Advisory Group of ICDP has expressed their enthusiasm for potential deep drilling of Lake Junin, they have also noted that improved seismic imaging of the Lake Junin basin is a prerequisite for ICDP drilling approval.Expected results include a more complete understanding of the thickness and distribution of lacustrine sediment and intercalated glaciogenic sediment in the Junin basin, which will provide essential guidance for selection of appropriate coring equipment and drilling sites, and will enable estimates to be made of the length of sediment core that will need to be processed for any future deep drilling project.The intellectual merit of the proposed work is grounded in the fact that an improved seismic survey of Lake Junin is a prerequisite for deep drilling, which, in turn, will yield sediment cores that can address several fundamental issues regarding tropical climate change during the late Quaternary. These include: 1) the degree of synchrony between the last several glacial cycles in the tropics and those in higher latitude regions of both hemispheres, 2) the degree of hydroclimatic stability that prevailed during interglacial and interstadial intervals, 3) the long-term evolution of ENSO during interglacial intervals, and 4) the relative roles of temperature and precipitation in governing glacier mass balances in the tropical Andes over multiple glacial, deglacial, and interglacial intervals.The broader significance of the proposed research will depend on the successful development of a deep drilling project on Lake Junin. Such a project would provide an ideal platform for training numerous undergraduate and graduate students, and for promoting climate change research by our Peruvian colleagues.

这笔赠款将为计划中的朱宁湖（秘鲁）深钻提供关键的现场调查信息。该小组将对Junin湖进行气枪地震调查，以估计沉积物厚度，并提供选择最佳深层钻探地点所需的空间分辨率。该工作将在短时间内（约两周）完成，其结果将提供给国际大陆钻井计划（ICDP）钻井研讨会。Junin湖包含了可能跨越多个冰川旋回的沉积物记录？可能覆盖了数十万年，它含有碳酸盐，可以提供湖泊水文和区域气候的同位素记录，具有亚年代际分辨率。四十年来，许多教师和学生为这个湖及其流域的广泛数据库做出了贡献。然而，Junin湖从未在其最深处的沉积区进行过取芯，也从未使用能够穿透位于湖中心的厚沉积层的机械覆盖层进行过取芯。ICDP的科学咨询小组已经同意Junin湖确实值得进行深钻工作，并且已经为一个国内讲习班提供了高达4万美元的资金，以发展一个深钻项目的科学小组。这次研讨会将在秘鲁举行，来自美国、加拿大、德国和其他ICDP国家的20多名科学家将参加。尽管ICDP的科学咨询小组对Junin湖的潜在深层钻探表达了他们的热情，但他们也注意到，提高Junin湖盆地的地震成像是ICDP钻探批准的先决条件。预期的结果包括更全面地了解君宁盆地湖泊沉积物和间冰期沉积物的厚度和分布，这将为选择适当的取心设备和钻孔地点提供必要的指导，并将使人们能够估计今后任何深钻孔项目需要处理的沉积物岩心的长度。所提议的工作的知识价值是基于这样一个事实，即改进的Junin湖地震调查是深钻的先决条件，而深钻又将产生沉积物岩心，可以解决有关晚第四纪热带气候变化的几个基本问题。这些包括:1)热带地区最后几个冰期旋回与两个半球高纬度地区的冰期旋回的同步程度；2)间冰期和间冰期的水文气候稳定程度；3)间冰期ENSO的长期演化；4)在多个冰期、去冰期和间冰期，温度和降水在控制热带安第斯山脉冰川物质平衡中的相对作用。拟议研究的更广泛意义将取决于朱宁湖深钻项目的成功开发。这样一个项目将为培训众多本科生和研究生提供一个理想的平台，并促进我们秘鲁同事的气候变化研究。