GEOCHEMISTRY AND ISOTOPES OF GLACIER ICE CORES FROM MEXICAN MOUNTAINS

During the last decades continental and mountain glaciers are retreating all over the earth at an alarming rate. Mexico has three high mountains with altitudes above 5,000 m.a.s.l. (Popocatepetl, Iztaccihuatl and Pico de Orizaba) with small glaciers at their top. Popocatepetl is an active volcano and has lost all its glacier cap during the last 15 years. Glaciers on Iztaccihualt (5,286 m), and Pico de Orizaba (5,712 m), still exist with estimated thickness between 10 to 40 m, but retreating very rapidly. Physical glaciology studies have been done on these three mountains in Mexico (size of glaciers, movement of ice, accumulation vs. ablation zones, so on), but very little chemical and isotopic glaciology have been done in these Mexican glaciers. There is no other mountain glacier within 15º and 25º latitude north, but glaciers in Mexico. The closeness of a large metropolitan area (Mexico City) offers a good opportunity to analyze the anthropogenic impact in the atmospheric precipitation on the glaciers. Iztaccihuatl mountain (the closest to Mexico city) has two glaciers, one at 5,000 m altitute, and other at 5,280 m altitude. Pico de Orizaba has only one glacier from 5,712 to 5,000 m altitude. In this work we present preliminary geochemical and isotopic data from the first ice cores drilled in Iztaccihualt and Pico de Orizaba, and compare data between the two Mexican mountains and other mountain glaciers in the world. This project is currently under work and we propose to obtain more ice cores form these mountains and to compare the data with geochemical and isotopic data from glaciers all over the world. The geochemical analyzes is focussed on heavy metal content, delta-Deuterium and delta-18 Oxigen data from the ice cores.