Stable Isotopes of Lake Surface Water Along the Western Side of Southern South America.
Abstract
The present-day hydroclimate in southern Chile is dominated by the Southern Westerly Winds (SWW). The SWW are the strongest time-averaged winds on Earth and are related to several significant climatic features, including the Antarctic circumpolar current and sea surface temperature and pressure gradients in the southern Pacific Ocean. The SWW shift northward and weaken in austral winter, and conversely shift southward and intensify during austral summer. Paleolimnological pollen studies indicate that during the late Holocene, the core of the SWW was weak, and the northernmost margin of the SWW was strong, similar to the present-day austral winter seasonality of the SWW. To further understand the possible moisture source conditions and intensities of the SWW, and if lake water is a reasonable analogue for local meteoric water, we sampled and measured the stable isotope composition of surface water from 34 lakes in southern Chile. The locations of the lakes cover approximately 10° of latitude and varying climate regimes and elevations ranging from near sea level to ~ 2000 m. Results indicate that most of the lakes are recording meteoric water with very little evaporative effect, which is favorable for generating paleohydroclimatic reconstructions based on isotopic proxies from biomarkers in lacustrine sediment. The entire region presents an exceptional opportunity to study not only the SWW, but also to understand the spatial properties of meteoric water in this region.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP23E1698S
- Keywords:
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- 3344 Paleoclimatology;
- ATMOSPHERIC PROCESSES;
- 1041 Stable isotope geochemistry;
- GEOCHEMISTRY;
- 1655 Water cycles;
- GLOBAL CHANGE;
- 1833 Hydroclimatology;
- HYDROLOGY