Aracar

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  • Argentina
  • South America
  • Stratovolcano
  • Unknown - Evidence Credible
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 24.29°S
  • 67.783°W

  • 6095 m
    19992 ft

  • 355160
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: April 1993 (BGVN 18:04) Cite this Report


Ash column reported

A steam plume was observed rising above Arácar on 28 March. Viewed from the town of Tolar Grande, 50 km SE, the plume persisted throughout the clear day. At least twice during the day, a large ash column slowly rose 2,000 m above the summit. The following day clouds prevented a clear view of the volcano, but an "ashy haze" in the sky was noted. A local observer indicated that the activity was not unusual.

Arácar has a base 10 km in diameter. It is located just E of the Argentina-Chile border, ~ 100 km S of Lascar and 80 km NE of Llullaillaco volcanoes. No historical eruptions have been recorded. Moyra Gardeweg provided the following background. "It is clearly younger than the surrounding Miocene volcanoes. Its steep conical edifice has been cut by some deep gorges and an uncovered alteration zone lies close to its summit on the NE flank. It has a well-developed and well-preserved summit crater (1-1.5 km diameter) that contains a tiny lake. Lava flows are well preserved at the base of the cone (below 4,500-m elev), a common feature of Pliocene-to-Quaternary volcanoes in the Central Andes. I have no information about its exact age, but the good preservation of the summit crater and lava flows suggest that it could be Quaternary, although I can only assume it is Pliocene or younger."

Information Contacts: R. Trujillo, Colorado, USA; M. Gardeweg, SERNAGEOMIN, Santiago.

The Global Volcanism Program has no Weekly Reports available for Aracar.

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.

04/1993 (BGVN 18:04) Ash column reported




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


April 1993 (BGVN 18:04) Cite this Report


Ash column reported

A steam plume was observed rising above Arácar on 28 March. Viewed from the town of Tolar Grande, 50 km SE, the plume persisted throughout the clear day. At least twice during the day, a large ash column slowly rose 2,000 m above the summit. The following day clouds prevented a clear view of the volcano, but an "ashy haze" in the sky was noted. A local observer indicated that the activity was not unusual.

Arácar has a base 10 km in diameter. It is located just E of the Argentina-Chile border, ~ 100 km S of Lascar and 80 km NE of Llullaillaco volcanoes. No historical eruptions have been recorded. Moyra Gardeweg provided the following background. "It is clearly younger than the surrounding Miocene volcanoes. Its steep conical edifice has been cut by some deep gorges and an uncovered alteration zone lies close to its summit on the NE flank. It has a well-developed and well-preserved summit crater (1-1.5 km diameter) that contains a tiny lake. Lava flows are well preserved at the base of the cone (below 4,500-m elev), a common feature of Pliocene-to-Quaternary volcanoes in the Central Andes. I have no information about its exact age, but the good preservation of the summit crater and lava flows suggest that it could be Quaternary, although I can only assume it is Pliocene or younger."

Information Contacts: R. Trujillo, Colorado, USA; M. Gardeweg, SERNAGEOMIN, Santiago.

Basic Data

Volcano Number

Last Known Eruption

Elevation

Latitude
Longitude
355160

Unknown - Evidence Credible

6095 m / 19992 ft

24.29°S
67.783°W

Volcano Types

Stratovolcano

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
0
0
94
4,803

Geological Summary

Aracar is a steep-sided stratovolcano with a youthful-looking summit crater 1-1.5 km in diameter that contains a small lake. It is located just east of the Argentina-Chile border. The volcano was constructed during three eruptive cycles dating back to the Pliocene. The andesitic stratovolcano overlies dacitic lava domes. Lava flows found at the base of the volcano below 4500 m elevation are relatively well preserved, but upper-flank lavas, often an indication of youthful activity, are not present (de Silva, 2007 pers. comm.). There were reports of possible ash columns from the summit in 1993, but it is not known whether these were rockfall dust or eruption plumes.

References

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

de Silva S L, 2007. (pers. comm.).

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

Smithsonian Institution-GVN, 1990-. [Monthly event reports]. Bull Global Volc Network, v 15-33.

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1993 Mar 28 ] [ Unknown ] Uncertain 2  

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.


Cones

Feature Name Feature Type Elevation Latitude Longitude
Aracar Stratovolcano

Photo Gallery


Steep-sided Aracar stratovolcano rises to 6028 m just east of the Argentina-Chile border. The light-colored Salar de Pular and Sala de Incahuasi appear at the upper left and right, respectively, in this NASA Space Shuttle image with north to the upper right. Well-preserved lava flows are visible on the lower flanks below 4500 m elevation, and several satellitic cones are found at the base of the volcano. Prior to a report of possible ash columns from the summit in 1993, the volcano was not known to be active.

NASA Space Shuttle image ISS006-E-13813, 2003 (http://eol.jsc.nasa.gov/).

Smithsonian Sample Collections Database


A listing of samples from the Smithsonian collections will be available soon.

Affiliated Sites

Large Eruptions of Aracar 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).
WOVOdat 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.
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).
MODVOLC - HIGP MODIS Thermal Alert System 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.
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.