2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM
Paper No. 141-30
Presentation Time: 8:00 AM-4:45 PM

Geochemistry of Ice and Ground Penetrating Radar Profiles in Mexican Glaciers

CARRILLO-CHÁVEZ, Alejandro1, CARREON-FREYRE, Dora2, PONCE, Gabriela3, TANER, Martin2, JOSE, Perez1, ORITZ, Lorenzo1, and LEVRESSE, Gilles2, (1) Centro de Geociencias, UNAM, Carr. Qro-SLP, km 15, Juriquilla, Queretaro, 76230, Mexico, ambiente@geociencias.unam.mx, (2) Geociencias, UNAM, Campus Juriquilla, Queretaro, 76230, Mexico, (3) Depto. Geologia, Univ. de Guanajuato, Guanajuato, 76230, Mexico

During the last 15 to 20 years the glaciated Mexican high mountains have lost some 30% or more of their glacier ice. Geologically these glaciers are important because they are the only mountain glaciers between Ecuador and Canada, and the only worldwide at 19° north latitude. We have drilled three shallow ice cores in the glaciers for chemical and isotopes analyze (two at Pico de Orizaba and one at Iztaccihuatl). A Ground Penetrating Radar (GPR) profile was archived using a 900 MHz antenna in order to asses the ice internal structure and thickness at the border of Jamapa Glacier at Pico de Orizaba. We used a GPR system Zond 12 C (by Radar Systems Inc). The GPR profile was oriented S20W and had a total length of 175 m. It was composed by 7 sections of 25 m length. According to the slope of the recorded diffraction hyperbolas the estimated velocity of propagation of electromagnetic waves was about 10.6 cm /ns (corresponding to a dielectric constant of 8). A coherent reflector was recorded approximately at 2.5 m depth that could be related to the frozen water depth. Moreover irregularities in the ground, cavities related to blocks and other slope deposits were also recorded for the first 2 m of depth. Such as those recorded between 5 to 10 m from the start of the GPR profile. Ice chemistry indicates some concentrations of Cl, NO3, SO4, Fe, Ni Cu, Zn, Pb and As, very likely from aerosols and atmospheric dust. We present correlations between this compounds and elements in the Iztaccihualt ice (relatively close to Mexico City atmospheric influence) and Pico de Orizaba ice (relatively far from any big city).

2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM
General Information for this Meeting
Session No. 141--Booth# 30
Geochemistry; Geochemistry, Organic (Posters)
George R. Brown Convention Center: Exhibit Hall E
8:00 AM-4:45 PM, Sunday, 5 October 2008

Geological Society of America Abstracts with Programs, Vol. 40, No. 6, p. 134

© Copyright 2008 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.