Online seminar by Elizabeth Olson from Post-Doctoral Research Fellow in Tropical Paleoclimatology at Union College
14 March 2025
KST 09:00
The Online seminar is being held in Room 1010 (Jasmin) – Integrated mechanical engineering building. Click here for the campus map.
Characterizing past hydroclimate variability in the tropics is key to improving future projections of water availability in these densely populated regions. Synchronicity between global ice volume and tropical glaciation over the past 700 thousand years was recently documented by the Lake Junin sediment core from the Andes in South America. Oxygen isotopes from Peruvian speleothems reflect changes in local rainfall amount, temperature, and the South American summer monsoon (SASM) strength upstream of our study site in the Andes mountains. High-resolution uranium/thorium dated composite speleothem records cover much of the past 450 thousand years. The glacial index from Junin Lake records changes in tropical glaciation controlled by local precipitation and temperature. We extract the upstream SASM strength over multiple glacial cycles by subtracting the lake glacial index from the speleothem oxygen isotope record. This reconstructed SASM Index is well correlated with a 230-thousand-year composite speleothem record from the core monsoon region in the western Amazon, supporting this multiproxy approach to climate reconstruction using lake and speleothem records. The changes in SASM strength over orbital periods are best explained by a shift in the mean latitude of the Atlantic Intertropical Convergence Zone (ITCZ) in response to precessional forcing.
Zoom link: https://pusan.zoom.us/j/87078906090?pwd=bSrKq329bSHt9x9AIn2j4mAJz0i7PG.1
Meeting ID: 870 7890 6090
Passcode: 784006
