HR: 0800h
AN: V51A-06    [Abstracts]
TI: Use of GPR to Determine Thickness and Volcanic Stratigraphy: Case Study Parícutin Volcano (Mexico)
AU: * Villanueva Inchaurregui, Z C
EM: inchaurregui@gmail.com
AF: Instituto de Geofísca, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, México, DF 04510, Mexico
AU: Delgado Granados, H
EM: hugo@tonatiuh.igeofcu.unam.mx
AF: Instituto de Geofísca, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, México, DF 04510, Mexico
AU: Cabral Cano, E
EM: ecabral@geofisica.unam.mx
AF: Instituto de Geofísca, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, México, DF 04510, Mexico
AU: Díaz Molina, O
EM: oscard@geofisica.unam.mx
AF: Instituto de Geofísca, Universidad Nacional Autónoma de México, Av. Universidad 3000, Coyoacán, México, DF 04510, Mexico
AB: Parícutin is a monogenetic volcano born on February 20, 1943 in the middle of a cornfield in Michoacán, Mexico. During and after the end of its activity, several studies were carried out about the volcano and the surrounding area. However, additional detailed studies on its tephra deposits have not been performed since 1946 (Segerstrom, 1950). Recent studies have been carried out re-visiting this volcano and its deposits. Michoacán is a region where erosive processes are intense thus, the volume and distribution of tephra was expected to have changed accordingly. In parallel with direct studies observing the tephra sequences, Ground Penetrating Radar (GPR) surveys using 40, 70 and 200 MHz antennas were performed in close proximity to several selected stratigraphic sections observed at trenches. This allowed a precise calibration of propagation velocities and other acquisition parameters that were later used for surveying a wider area. This allowed us to map and laterally correlate the extent and thickness of several tephra units using a much faster GPR based method. We present several examples where we can confirm the dramatically tephra-thickness changes since Segerstrom's study sixty year ago. We also show that the use of GPR techniques can be very useful to improve the detail and resolution for tephra thickness mapping while at the same time making much more efficient field work efforts.
DE: 8404 Volcanoclastic deposits
DE: 8428 Explosive volcanism
DE: 8486 Field relationships (1090, 3690)
DE: 8494 Instruments and techniques
DE: 8499 General or miscellaneous
SC: Volcanology, Geochemistry, and Petrology [V]
MN: 2007 Joint Assembly