Lahar-hazard zonation for San Miguel volcano, El Salvador
Links
- More information: USGS Index Page (html)
- Document: Report
- Plate: Plate 1 (pdf)
- Download citation as: RIS | Dublin Core
Abstract
San Miguel volcano, also known as Chaparrastique, is one of many volcanoes along the volcanic arc in El Salvador. The volcano, located in the eastern part of the country, rises to an altitude of about 2130 meters and towers above the communities of San Miguel, El Transito, San Rafael Oriente, and San Jorge. In addition to the larger communities that surround the volcano, several smaller communities and coffee plantations are located on or around the flanks of the volcano, and the PanAmerican and coastal highways cross the lowermost northern and southern flanks of the volcano. The population density around San Miguel volcano coupled with the proximity of major transportation routes increases the risk that even small volcano-related events, like landslides or eruptions, may have significant impact on people and infrastructure.
San Miguel volcano is one of the most active volcanoes in El Salvador; it has erupted at least 29 times since 1699. Historical eruptions of the volcano consisted mainly of relatively quiescent emplacement of lava flows or minor explosions that generated modest tephra falls (erupted fragments of microscopic ash to meter sized blocks that are dispersed into the atmosphere and fall to the ground). Little is known, however, about prehistoric eruptions of the volcano. Chemical analyses of prehistoric lava flows and thin tephra falls from San Miguel volcano indicate that the volcano is composed dominantly of basalt (rock having silica content <53%), similar to the lava erupted by Hawaiian volcanoes. The chemical composition of eruptive products and the lack of evidence of large cataclysmic eruptions suggests that prehistoric eruptions probably were similar in nature to the historical eruptions. Unlike San Salvador and San Vicente volcanoes, San Miguel volcano does not appear to have had a history of violent explosive eruptions.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Lahar-hazard zonation for San Miguel volcano, El Salvador |
| Series title | Open-File Report |
| Series number | 2001-395 |
| DOI | 10.3133/ofr01395 |
| Year Published | 2001 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Vancouver, WA |
| Contributing office(s) | Cascades Volcano Observatory, Volcano Science Center |
| Description | Report: 14 p.; Plate: 32.68 x 24.10 inches |
| Country | El Salvador |
| City | El Transito;San Jorge;San Miguel;San Rafael Oriente |
| Other Geospatial | San Miguel Volcano |
| Datum | North American 1927 |
| Projection | Universal Transverse Mercator projection |
| Scale | 50000 |
| Additional Online Files (Y/N) | Y |
| Google Analytic Metrics | Metrics page |