Deep Drilling of Lake Junin, Peru: Continuous Tropical Records of Glaciation, Climate Change and Magnetic Field Variations Spanning the Late Quaternary

The ability to understand the full complexity of climate change and forecast future regional trends requires that we extend the available instrumental records into the geologic past. Over the past several decades paleoclimatologists have developed myriad proxy indicators of past regional climate that are recorded in natural archives such as ice cores, cave deposits, and lake sediment, among many other archives. Proxy paleoclimate records from the tropics are particularly important because this region is the ?heat engine? of Earth. Long- and short-term changes in ocean-atmosphere circulation that are manifested in such phenomenon as the El Nino Southern Oscillation (ENSO), the mean position of the Intertropical Convergence Zone, and the response of the tropics to high latitude climatic ?events? are critical to understand because these phenomena can have a profound impact on regional water balance, which directly affects potable water supplies, hydroelectricity generation, and agricultural productivity.

The longest continuous records of climate change in the tropics are limited to those derived from the relatively few old lake basins in the region. Lake Junin, the largest lake located entirely within Peru, is among the oldest lake basins in South America. It contains a sediment record that is at least 200 m long that may extend more than 250,000 years. Lake Junin is exceptional in the length of record that it contains, but also in the climate signals that it records. Considerable prior research has documented that Lake Junin records the waxing and waning of nearby alpine glaciers and changes in regional water balance through the isotope geochemistry of calcium carbonate deposited on the lake bottom at a rate of approximately 0.2 to 1.0 mm/yr. This research will develop these and other proxy climate records for the full length of recovered core; the records generated will comprise one of the longest continuous records of climate and environmental change from the inner tropics.

The Lake Junin Drilling Project has several broader impacts. These include the joint renovation of an abandoned lodge for future shared use as the first shoreline outpost for officials of the Junin National Reserve, as a visitor center, and as a lake access point for ecotourism. Capacity building activities in the Junin Project include collaboration with Peruvian universities, training of geoscientists, as well as Peruvian and American student training. A specific team will be responsible for the organization of lectures at villages in the region to inform citizens about the significance of the drilling, and will work closely with the national park service to instruct the rangers on how to use the science to promote conservation efforts around the lake. During the drilling, a team will facilitate interactions with local and international media. The team expect to involve U.S. and Peruvian students in all aspects of Junin drilling, and much of the paleoecological research related to the Junin cores will be conducted by graduate students. Training opportunities during the drilling phase of operations are also planned for geoscientists from Peruvian universities. Numerous U.S. undergraduate and graduate students, and one postdoctoral fellow will be involved in all phases of the proposed research. The material collected during this project will set the stage for significant future research. LacCore, the National Lacustrine Core Facility at the University of Minnesota, will facilitate this by overseeing the long-term storage, curation, and access to data and samples obtained in this project.