High-Resolution Younger Dryas Environmental Variability: A Comprehensive Assessment from Mid-North America Tree Rings

University Of Arizona, Tucson AZ

Investigators

Abstract

The goal of this award is to develop a high-resolution portrait of the Late Glacial-Early Holocene transition in middle North America using data from tree-rings. In this study, the environmental changes in middle North America will be investigated over several millennia (ca. 10,000 to 14,000 years ago) during the Late Glacial-Early Holocene transition, including the Younger Dryas (YD) interval. The warming from the Late Glacial to the Early Holocene was interrupted by an abrupt, millennial-length, cold climate excursion known as the YD event. The environmental effects of this climatic event seem to be widespread, but knowledge of the character of the YD in Europe far exceeds that of North America. North America has potential links with the physical mechanisms likely to have triggered the event in the middle North Atlantic Ocean such as shifting glacial meltwater outlets from the land to the ocean. The environmental changes during the YD (i.e., those related to temperature, water-use efficiency, and hydrologic cycle-related parameters of precipitation, relative humidity, and soil saturation) will be measured against those of the time periods immediately before and after, and with modern conditions. The results will improve our understanding of the environmental and faunal changes and responses in middle North America. This will help place such changes in the context of global environmental change during deglaciation.