Active volcanoes / Aktive vulkaner:

Turrialba, Costa Rica  

The summit crater complex of Turrialba volcano is seen here from the north, with the Central Valley of Costa Rica in the background.
Three well-defined craters can be seen at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE.

Photo by Federico Chavarria Kopper, 1999.

Located in southeast Costa Rica, Turrialba is a large, densely forested stratovolcano. The massive 3340-m-high
Turrialba, covers an area of 500 sq km, and is one of Costa Rica's most voluminous volcanoes. Three well-defined
craters occur at the upper SW end of a broad 800 x 2200 m wide summit depression that is breached to the NE.
The stratovolcano is 3,340 m (10,958 ft) high and is about 45 minutes from the Atlantic slope town of Turrialba.
The summit has three craters, one of which has fumaroles and sulfur pits.

The last major eruptions of Turrialba Volcano were from 1864 to 1868. Of its three craters, the central one is the
deepest and most active, presenting two conic structures with sulfuric steam and vapors.

probably not working all the time

Frioday, January 20th, 2012
Turrialba volcano is acting up lately, according to the Observatory (Ovsicori). On Wednesday, a little before 3 p.m.,
local time, the volcano emitted vapor, ash and gas into the air. Nearby residents reported seeing towering clouds of
ash over several communities.

An Ovsicori pilot flying over the area confirmed that a cloud reaching between 3.000 meters and 5.000 meters asl
came from the same area that had an eruption of ash and gas on January 12th. A report issued by the observatory
after that eruption indicated a new fumarole formed on the southeast flank of the volcano’s crater during the eruption,
but noted that the danger of a major eruption was small.

On Wednesday rumblings were stronger and threw more ash and gas into the atmosphere than on the 12th. A group
of volcanologists is working near the crater of Turrialba monitoring the activity.

January 13th, 2012
The Turrialba volcano entered yesterday a phase of gas and ash eruptions and the National Emergency Commission
(CNE) issued a yellow alert for the nearby cantons of Turrialba, Alvarado and Jiménez,. The national park was closed
and tourists were evacuated.

Experts from the National Seismological Network (RSN) confirmed the eruption and said that the fumes have
reached 200 feet high and are blown by the wind. Lava has not been seen.

Ashcloud from Web-cameria August 25th, 2010 at 06:03 local time

The Turrialba Volcano National Park was officially closed in August 2009 when increased volcanic
activity caused the CNE to issue a yellow alert for visitors. The volcano continued to emit gases and ash
throughout the final months of 2009, and the CNE and Costa Rican Red Cross held several meetings to prepare residents for evacuations in the town of Santa Cruz, located at the base of the volcano.

On Jan. 5, 2010, the Turrialba Volcano experienced its largest eruption in more than 140 years, spewing
ash, rocks, gases and helium into the air and covering Santa Cruz and surrounding communities in soot.
Forty residents were evacuated and moved into temporary shelters, while ash from the eruption was
carried as far as the San José neighborhood of Desamparados, about 40 kilometers away. Gases and
ash from the volcano covered nearby trees, turning them yellow

Increased degassing and resultant burned vegetation around Turrialba's W crater,
as illustrated in this photograph from June 2005.

Courtesy Eliécer Duarte, OVISCORI-UNA.

The January 5 eruption was the biggest since 1866, but it was not as dangerous or problematic.
The reason the ash was blown to San José was because of strong winds, not because the eruption
was particularly strong.

The National Park was re-opened in July, 2011.

Ashcloud from Web-camera August 25th, 2010

August 25th, 2010
Ashcloud visible, rising into the sky. No more information at the moment.

6 January-12 January 2010
OVSICORI-UNA reported that a phreatic eruption from Turrialba that began on 5 January was preceded by a
day of increased seismicity and about 30 minutes of almost constant tremor. Two events detected about 15 minutes
apart were followed by reports of ashfall as far away as 30 km. Field observations on 6 January revealed that
two small vents had opened and joined together on the SE inner wall of the SW crater. Gas emission temperatures
were more than 350 degrees Celsius. On 8 January seismic activity and gas emissions decreased. Observations
the next day revealed that the combined vent was about 25 m wide and 80 m long. Around 60 people had
evacuated from nearby farms.



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