Surface Water Isoscapes from NZ: Tools for Paleoclimatic Interpretation - ERI Seminar - May 2024

Stable isotopes of oxygen and hydrogen are powerful climatic variables with utility in climate science and paleoclimatology. Here, I show the climatic controls on the spatial variability in South Island river water oxygen isotope values. The strongest controls are winter temperature and physiography, including the influence of the high southern Alps. Isoscapes – maps of the stable isotopic composition of the river waters – have utility in paleoclimatology, climate dynamics, and other fields. A current campaign in 2024 will expand coverage to the North Island and with repeated sampling on the South Island, to better constrain remaining uncertainties.

Matthew Lachniet is a Professor of Geoscience at the University of Nevada Las Vegas, and a current Fulbright Scholar to Aoteoroa New Zealand in 2024. He is a Climate Scientist with a focus on Paleoclimatology: the study of climate variations over the last few hundred thousand years. He has field sites spanning from the Western United States, Central America, and New Zealand, among others. The main goals of his research are to understand why climate has experienced natural shifts in the past in precipitation amount and temperature, typically through stable isotopic geochemistry of natural hydroclimate archives. These data help us to understand how climate variations have affected human systems and history in the past and provide lessons for future adaptation to anthropogenic climate change.