Volcanic hazards zonation of the Nevado de Toluca Volcano,Central Mexico |
| |
Authors: | José Fernando Aceves Quesada Ana Lillian Martin Del Pozzo Jorge López Blanco |
| |
Institution: | (1) Instituto de Geofisica, Circuito Institutos, Cuidad Universitaria México, UNAM, C.P. 04510, Mexico city, Mexico;(2) Instituto de Geografia, Circuito Institutos, Cuidad Universitaria México, UNAM, C.P. 04510, Mexico city, Mexico |
| |
Abstract: | Nevado de Toluca Volcano (NTV), located in central Mexico, is a large stratovolcano, with an explosive history. The area is
one of the most important developing centers (>2 millions) in Mexico and in the last 30 yrs large population growth and expansion
have increased the potential risk in case of a reactivation of the volcano. As part of a study to assess volcanic risk, this
paper presents the results of the volcanic hazard analysis for the NTV. A total of 150 stratigraphic sections were made in
the field and three new ages were obtained. Eruptions from NTV produced a complex sequence of pyroclastic deposits that have
affected the area at least 18 times during the last 100,000 yrs. Eight vulcanian, four plinian and one-ultraplinian eruptions
as well as the destruction of at least three domes occurred in the last 42,000 yr BP as well as two sector collapses in the
last 100,000 yrs. Isopach and isopleth maps for the main ulraplinian eruption were also made. The original cone height (5,080 m.a.s.l)
was reconstructed through geomorphologic methods. The maximum distance calculated with the energy line for the block and ash
flows was 41 km, 35 km for pumice flows and 45 km for debris avalanches. The dominant wind direction at altitudes of 20–30 km
is to the east-northeast from November to March, west-northwest in April and west from May to October. Five hazards maps (block
and ash flows, pumice flows, ash fall, debris avalanches, and lahars) were made for the NTV. The pyroclastic flows and lahars
represent very high to medium hazard for Toluca, Villa Guerrero, Coatepec, Tianguistengo, Metepec, Tenango, Lerma and Zinacantepec.
A new debris avalanche would probably affect the south and northeast because of active faulting (E–W and NW–SE) and existing
topographic differences in height. |
| |
Keywords: | Volcanic hazards Pyroclastic flows Energy line Nevado de Toluca Volcano Toluca Basin Volcanic stratigraphy Volcanic hazard zonation maps |
本文献已被 SpringerLink 等数据库收录! |
|