Title: SISAL the speleothem and cave monitoring database: enabling modern karst water estimates to understanding past rapid climate changes

Authors: PAGES-SISAL Working Group

presented by Nikita Kaushal
Earth and Planetary Sciences Department
American Museum of Natural History
New York, United States of America

Preferred email
address: nikitageologist@gmail.com / sisal.sc2@gmail.com

Abstract: Global distribution, precise age control through absolute chronologies and multiple proxies for climatic and environmental parameters make speleothems an excellent natural archive for understanding climate changes. Researchers using the speleothem archive have made significant advancements in recent years. These include estimating temperatures that cause permafrost melting using U-Pb dating, gaining a deeper understanding of under-investigated Southern Hemisphere climate changes, reconstructing absolute rainfall amounts in the Holocene using recently developed calcium-isotope proxies, increasing the understanding of atmospheric dynamics during past Terminations and millennial events enabled by speleothem database, enhancing our comprehension of proxies for paleo-fires and development of models for karst water estimations. These achievements have been made possible by advances in multiple tools and techniques. Significant development has been made in the ‘length’ of speleothem records through the addition of the U-Pb dating technique. Tighter control on the time period of events has been facilitated by age-depth model standardisation and layer counting using confocal and trace element methods. Big data methods enabled by the SISAL speleothem database are improving isotope (δ18O,δ13C, Sr isotopes, 234/238U) and trace element (Sr/Ca, Mg/Ca, Ba/Ca, U/Ca) proxy interpretations through systematic reviews, isotope-enabled model data comparisons and the use of geostatistical tools like isoscapes. An increased focus on present-day cave monitoring (rain and drip water oxygen isotopes, modern carbonate) allows us to evaluate and use karst models, proxy system models and process models for semi-quantitative to quantitative reconstructions of modern karst water estimates and past climate and vegetation changes. In this presentation, we highlight some of these recent achievements of the field as well as provide a perspective on ongoing community research and future directions.

Biography: Nikita Kaushal is a trained Geologist from India. She works in the fields of paleoclimate and biogeochemistry on a range of spatial and temporal scales, ranging from regional to global, and centuries to half a million years. She uses natural archives such as speleothems and corals, and multiple approaches including field and lab work, and database techniques. Her goal is to understand the drivers, pathways and responses of the climate and carbon cycles during different climate states in order to, ultimately, inform our understanding of future changes.