Geoquímica glaciar: registro climático ambiental que se pierde

Abstract

There is alarming news about the disappearance of glaciers around the planet. In Mexico there are still two small bodies of ice (glaciers) in high mountains in the center of the country: Iztaccihuatl (5215 meters above sea level, m a. s. l.) and Citlaltépetl (5626 m a. s.l.). These glaciers, located at 19o north latitude and receiving precipitation (snow) from both the Pacific Ocean and the Gulf of Mexico (Atlantic Ocean), and very close to important urban and industrial areas, contain an environmental record of heavy metals of great interest for comparison with Andean, North American, Alpine and Himalayan regions. Since 2006, the Centro de Geociencias UNAM, Campus Juriquilla, has been working on the collection of snow and ice samples from these Mexican glaciers for chemical analysis of major elements and heavy metals. Currently, we have a database from 2006 to 2022 to evaluate 16 years of monitoring concentrations of metals and present the results in an international publication. A preliminary analysis shows considerable concentrations of V, Cr, Ni, Cu, Zn, Pb, and Hg in snow and glacier ice comparable with data from the Sajama glacier in Bolivia. The concentration increase goes from pre-industrial time (natural values) to higher concentrations in the last decades. In this article, we describe modern environmental glacial geochemistry techniques, present some preliminary data as examples, and describe current UNAM projects in this line of research.