Global Volcanism Program

Most Recent Bulletin Report: May 1991 (BGVN 16:05) Cite this Report

New fumarole field on upper S flank

A new fumarole field, 150 m below the rim on the S flank . . . was first observed in late February (figures 1 and 2). On 14 May, geologists from the Univ de Chile noted that the new activity was similar to that of earlier fumaroles associated with a small andesitic dome within the central crater.

Figure 1.Sketch of view looking E at the San José complex, 14 May 1991. Vapor rises from within the crater and from the February 1991 fumarole field. Courtesy of O. González-Ferrán.

Figure 2. Sketch map showing the summit region and craters of the San José complex, May 1991. Courtesy of O. González-Ferrán.

Although no earthquakes were detected at the volcano, an increase in seismicity was recorded by the Univ de Chile's seismic network throughout the roughly N-S fault zone that separates the Valle Central and the Cordillera Andina. Four events were recorded in February, 8 in March, 9 in April, and 14 in May, the largest (M 4.0 and M 3.5) on 8 and 11 April, respectively (figure 3).

Figure 3. Sketch showing the location of San José and the epicenters of two large earthquakes, April 1991. Courtesy of O. González-Ferrán.

Information Contacts: O. González-Ferrán, Univ de Chile; P. Acevedo, Univ de la Frontera, Temuco.

The Global Volcanism Program has no Weekly Reports available for San José.

Bulletin Reports - Index

Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

05/1991 (BGVN 16:05) New fumarole field on upper S flank

Information is preliminary and subject to change. All times are local (unless otherwise noted)

May 1991 (BGVN 16:05) Cite this Report

New fumarole field on upper S flank

A new fumarole field, 150 m below the rim on the S flank . . . was first observed in late February (figures 1 and 2). On 14 May, geologists from the Univ de Chile noted that the new activity was similar to that of earlier fumaroles associated with a small andesitic dome within the central crater.

Figure 1.Sketch of view looking E at the San José complex, 14 May 1991. Vapor rises from within the crater and from the February 1991 fumarole field. Courtesy of O. González-Ferrán.

Figure 2. Sketch map showing the summit region and craters of the San José complex, May 1991. Courtesy of O. González-Ferrán.

Although no earthquakes were detected at the volcano, an increase in seismicity was recorded by the Univ de Chile's seismic network throughout the roughly N-S fault zone that separates the Valle Central and the Cordillera Andina. Four events were recorded in February, 8 in March, 9 in April, and 14 in May, the largest (M 4.0 and M 3.5) on 8 and 11 April, respectively (figure 3).

Figure 3. Sketch showing the location of San José and the epicenters of two large earthquakes, April 1991. Courtesy of O. González-Ferrán.

Information Contacts: O. González-Ferrán, Univ de Chile; P. Acevedo, Univ de la Frontera, Temuco.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Synonyms

San Jose de Maipo | Maipo | Maipu

Cones

Feature Name

Feature Type

Elevation

Latitude

Longitude

Engorda, Volcán la

Stratovolcano

5692 m

33° 46' 0" S

69° 56' 0" W

Espíiritu Santo

Stratovolcano

Marmolejo

Stratovolcano

6070 m

33° 44' 0" S

69° 52' 34" W

Plantat

Pyroclastic cone

5740 m

33° 45' 0" S

69° 55' 0" W

San Jose

Stratovolcano

5856 m

33° 47' 21" S

69° 53' 43" W

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude

357020

1960 CE

6,070 m / 19,915 ft

33.789°S
69.895°W

Morphology

Volcano Landform
Composite

Volcano Types
Stratovolcano(es)
Pyroclastic cone(s)

Rock Types

Major
Andesite / Basaltic Andesite
Dacite

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km

194
616
15,963
6,615,248

Geological Summary

Volcán San José lies along the Chile-Argentina border at the southern end of a volcano group that includes the Pleistocene volcanoes of Marmolejo and Espíritu Santo. The glaciated 6070-m-high Marmolejo stratovolcano is truncated by a 4-km-wide caldera, breached to the NW, that has been the source of a massive debris avalanche. San José is a 5856-m-high stratovolcano of Pleistocene-Holocene age with a broad 2 km x 0.5 km summit region containing overlapping and nested craters, pyroclastic cones, and blocky lava flows. Volcán la Engorda and Volcán Plantat, located SW of Marmolejo and NW of San Jose, have also been active during the Holocene. An 8-km-long lava flow traveled to the SW from the 1-km-wide summit crater of Espíritu Santo volcano, which overlaps the southern slope of Marmolejo. Mild phreatomagmatic eruptions were recorded from San José in the 19th and 20th centuries.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

Casertano L, 1963. Chilean Continent. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 15: 1-55.

Gonzalez-Ferran O, 1995. Volcanes de Chile. Santiago: Instituto Geografico Militar, 635 p.

Hildreth W, Moorbath S, 1988. Crustal contribution to arc magmatism in the Andes of central Chile. Contr Mineral Petr, 98: 455-489.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior.

Moreno H, 1974. Airplane flight over active volcanoes of central-south Chile. Internatl Symp Volc Andean & Antarctic Volc Problems Guidebook, Excur D-3, 56 p.

Moreno H, Naranjo J A, 1991. The southern Andes volcanoes (33°-41° 30' S), Chile. 6th Geol Cong Chile, Excur PC-3, 26 p.

Eruptive History

There is data available for 7 confirmed Holocene eruptive periods.

1960 Jul 2 ± 182 days Confirmed Eruption VEI: 2

Episode 1 | Eruption

1960 Jul 2 ± 182 days - Unknown

Evidence from Observations: Reported

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Explosion
	1960	- - - -	VEI (Explosivity Index)

1959 Jul 2 ± 182 days Confirmed Eruption VEI: 2

Episode 1 | Eruption

1959 Jul 2 ± 182 days - Unknown

Evidence from Observations: Reported

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Explosion
	1959	- - - -	VEI (Explosivity Index)

[ 1941 ] Discredited Eruption

[ 1931 ] Discredited Eruption

1895 - 1897 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1895 - 1897

Evidence from Observations: Reported

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Explosion
	1895	- - - -	VEI (Explosivity Index)

1889 - 1890 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1889 - 1890

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Tephra
1889	- - - -	VEI (Explosivity Index)

1881 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1881 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type
- - - -	- - - -	Explosion
- - - -	- - - -	Tephra
1881	- - - -	VEI (Explosivity Index)

1838 Confirmed Eruption VEI: 1

Episode 1 | Eruption

1838 - Unknown

Evidence from Observations: Reported

List of 3 Events for Episode 1

Start Date	End Date	Event Type	Event Remarks
- - - -	- - - -	Phreatic activity
- - - -	- - - -	Ash	weak or small
1838	- - - -	VEI (Explosivity Index)

1822 Nov 19 - 1838 Confirmed Eruption VEI: 2

Episode 1 | Eruption

1822 Nov 19 - 1838

Evidence from Observations: Reported

List of 2 Events for Episode 1

	Start Date	End Date	Event Type	Event Remarks
	- - - -	- - - -	Explosion
	1822 Nov 19	- - - -	VEI (Explosivity Index)

Deformation History

There is no Deformation History data available for San José.

Emission History

There is no Emissions History data available for San José.

Photo Gallery

Volcán San José on the far left horizon rises to the north above ice pinnacles at the Nieves Negras pass on the Chile/Argentina border. The summit of San José is formed by a cluster of six Holocene craters, pyroclastic cones, and blocky lava flows that lie within a series of elongated, 0.5 x 2 km wide nested craters. Mild phreatomagmatic eruptions were recorded at San José in the 19th and 20th centuries.

Photo courtesy of Oscar González-Ferrán (University of Chile).

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

There are no samples for San José in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites

Copernicus Browser

The Copernicus Browser replaced the Sentinel Hub Playground browser in 2023, to provide access to Earth observation archives from the Copernicus Data Space Ecosystem, the main distribution platform for data from the EU Copernicus missions.

MIROVA

Middle InfraRed Observation of Volcanic Activity (MIROVA) is a near real time volcanic hot-spot detection system based on the analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) data. In particular, MIROVA uses the Middle InfraRed Radiation (MIR), measured over target volcanoes, in order to detect, locate and measure the heat radiation sourced from volcanic activity.

MODVOLC Thermal Alerts

Using infrared satellite Moderate Resolution Imaging Spectroradiometer (MODIS) data, scientists at the Hawai'i Institute of Geophysics and Planetology, University of Hawai'i, developed an automated system called MODVOLC to map thermal hot-spots in near real time. For each MODIS image, the algorithm automatically scans each 1 km pixel within it to check for high-temperature hot-spots. When one is found the date, time, location, and intensity are recorded. MODIS looks at every square km of the Earth every 48 hours, once during the day and once during the night, and the presence of two MODIS sensors in space allows at least four hot-spot observations every two days. Each day updated global maps are compiled to display the locations of all hot spots detected in the previous 24 hours. There is a drop-down list with volcano names which allow users to 'zoom-in' and examine the distribution of hot-spots at a variety of spatial scales.

WOVOdat
   Single Volcano View
   Temporal Evolution of Unrest
   Side by Side Volcanoes

WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.

GVMID Data on Volcano Monitoring Infrastructure The Global Volcano Monitoring Infrastructure Database GVMID, is aimed at documenting and improving capabilities of volcano monitoring from the ground and space. GVMID should provide a snapshot and baseline view of the techniques and instrumentation that are in place at various volcanoes, which can be use by volcano observatories as reference to setup new monitoring system or improving networks at a specific volcano. These data will allow identification of what monitoring gaps exist, which can be then targeted by remote sensing infrastructure and future instrument deployments.

Volcanic Hazard Maps

The IAVCEI Commission on Volcanic Hazards and Risk has a Volcanic Hazard Maps database designed to serve as a resource for hazard mappers (or other interested parties) to explore how common issues in hazard map development have been addressed at different volcanoes, in different countries, for different hazards, and for different intended audiences. In addition to the comprehensive, searchable Volcanic Hazard Maps Database, this website contains information about diversity of volcanic hazard maps, illustrated using examples from the database. This site is for educational purposes related to volcanic hazard maps. Hazard maps found on this website should not be used for emergency purposes. For the most recent, official hazard map for a particular volcano, please seek out the proper institutional authorities on the matter.

IRIS seismic stations/networks

Incorporated Research Institutions for Seismology (IRIS) Data Services map showing the location of seismic stations from all available networks (permanent or temporary) within a radius of 0.18° (about 20 km at mid-latitudes) from the given location of San José. Users can customize a variety of filters and options in the left panel. Note that if there are no stations are known the map will default to show the entire world with a "No data matched request" error notice.

UNAVCO GPS/GNSS stations

Geodetic Data Services map from UNAVCO showing the location of GPS/GNSS stations from all available networks (permanent or temporary) within a radius of 20 km from the given location of San José. Users can customize the data search based on station or network names, location, and time window. Requires Adobe Flash Player.

DECADE Data

The DECADE portal, still in the developmental stage, serves as an example of the proposed interoperability between The Smithsonian Institution's Global Volcanism Program, the Mapping Gas Emissions (MaGa) Database, and the EarthChem Geochemical Portal. The Deep Earth Carbon Degassing (DECADE) initiative seeks to use new and established technologies to determine accurate global fluxes of volcanic CO₂ to the atmosphere, but installing CO₂ monitoring networks on 20 of the world's 150 most actively degassing volcanoes. The group uses related laboratory-based studies (direct gas sampling and analysis, melt inclusions) to provide new data for direct degassing of deep earth carbon to the atmosphere.

Large Eruptions of San José

Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

EarthChem

EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).