DUSTWIND CAVE SERIES

Records of past dust fluxes can indicate changes in continental aridity, vegetation density or fine-grained sediment supply and can trace patterns of wind strength and direction. Why were glacial periods so dusty? Why study dust? Wind-borne mineral dust emitted from the world's drylands acts both as a passive tracer of continental conditions and atmospheric circulation and as an active player in Earth's climate system. Current and past projects include Mapping the North African dust plume during the onset and end of the African Humid Period Equatorial Pacific dust fluxes. Much of my work seeks to produce quantitative dust flux reconstructions in marine sediments using constant flux proxies. These deposits record much of the past 400,000 years, including the last 3 interglacials, promising new insights into the region's water balance during past warm periods. We are also developing complementary records from stalagmites from a high-elevation cave on the western edge of the basin. Beginning and end dates for the deposits precisely record the lake's rise and fall past each cave site, while stable isotope data provide high-resolution records of the basin's water balance.

DUSTWIND CAVE SERIES

We have identified lacustrine carbonates precipitated in a series of caves flooded by Lake Bonneville that are capable of being dated with great precision by both U-Th and 14C methods. Though Lake Bonneville's history has been studied for over a century, substantial uncertainties remain about the precise timing and rate of the lake's rise and fall and the lake's response to the abrupt climate changes of the last glacial period. The largest of these lakes was Lake Bonneville, a lake at the northeastern edge of the Great Basin that was approximately the size of modern Lake Michigan. Great Basin experienced much greater effective precipitation, allowing lakes to fill most of its subbasins. Kosmicki.ĭuring the last glacial period, the U.S. Paleorecords provide a key complement to models of future changes by characterizing the region's responses to a wide variety of initial conditions and forcings. In the U.S., there is particular interest in understanding controls on water availability in the Great Basin, a drought-prone region that has experienced substantial population growth over the last two decades. PaleohydrologyĬlimate models consistently predict that subtropical and midlatitude arid regions will become drier in response to greenhouse warming, but the magnitude and spatial distribution of this response are poorly understood. My current projects focus on the Late Pleistocene and fall into three main (sometimes overlapping) categories. Our work uses uranium and thorium isotopes to reconstruct and understand past climates, with a particular focus on reconstructing changes in atmospheric circulation and the balance of precipitation and evaporation.

Dustwind cave