History of Arenal Volcano, Costa Rica

 The earliest known eruptions of Arenal took place about 7,000 years ago, and it was active concurrently with Cerro Chato until the activity of this last ended about 3,500 years ago.

A perfect conical shaped peak that became thundering... By the year of 1951, when the first of these pictures was taken, there was not much activity in the region; and the Arenal Peak, as the Arenal Volcano was called, was a mountain with thermal emanations that was witnessed by some explorers who dared to climb and even camp at the summit, since the year of 1937. Then they lowered narrating histories of resounding and vapors coming from the bowel of the earth...

But the period of most recent volcanic activity of Arenal began with a big lateral explosive eruption which thrown its destructive power towards the west in the morning of 29 July 1968; unfortunately there were two little settlements into the scope of the 15 km² of devastated area, "Tabacón" and "Pueblo Nuevo".

Arenal Volcano History

Most Recent 2012 Eruptions & Activity Report!
Location: La Fortuna, San Carlos. Costa Rica.
10°27'48"N, 84°42'12"W
(around 90 km north-west of San José)
Volcanic Activity: 42 years of continuous eruption activity from 1968 to 2010.
Height: 1,720 m ASL (5,643 feet) approx.
Age: More than 7,000 years (according to the most up-to-date earliest volcanic eruption evidence)
Type: Andesitic Stratovolcano
*Arenal Volcano eruption activity appreciation is possible with properly safety guidelines applied by tour operator guides and Arenal Volcano National Park authorities, so follow it carefully.

Arenal Volcano from La Fortuna at 1951. (© Courtesy of Olger Aragón). Arenal Volcano from La Fortuna. (© 60's. Olger Aragón). Arenal Volcano from La Fortuna while the church was building. (© 1960-1964, Olger Aragón). Arenal Volcano from La Fortuna Church. (© 1998, Olger Aragón). Deposit of volcanic rocks after the pyroclastic flow July 29, 1968 from the W flank base. (© 1968 Clint & Juanita, Courtesy of Olger Aragón). Arenal Volcano classic strombolian eruption from La Fortuna. (© 1995, Olger Aragón). Arenal Volcano Pyroclastic Flow (May 5, 1998; 1pm). (© Olger Aragón). Arenal Volcano Pyroclastic Flow, another angle (May 5, 1998; 1pm). (© Olger Aragón).

 Arenal Volcano is part of a volcanic chain formed between 100 and 12 thousands of years ago which contains, in chronological order according to its formation, the lava domes "Los Perdidos" (whose erosion had gave place to the beautiful Fortuna Waterfall), the currently inactive and about 12 thousands of years old "Chato" volcano (whose crater becomes filled with water and host now a 500 m wide fantastic lake) and finally the spectacular active Arenal Volcano. About 7,000 years ago have taken place the first known eruptions of Arenal, and it was active concurrently with Chato Volcano until this last ended its activity about 3,500 years ago. Throughout the time the volcanic activity of Arenal features periodic major explosive eruptions (at intervals of several hundreds of years) and periods of lava effusion that have built the volcanic cone.

Previously to current volcanic eruption phase, the latest remarkable was at the epoch of arrival of Christopher Columbus to the original indigenous Costa Rica region. After this, followed approximately 450 years of inactivity, which causes to be locally known as "Cerro Arenal" (Arenal Peak) and not as an dangerous active volcano. But the period of most recent volcanic activity of Arenal began with a big lateral explosive eruption which thrown its destructive power towards the west in the morning of 29 July 1968; unfortunately there were two little settlements into the scope of the 15 km² of devastated area, "Tabacón" and "Pueblo Nuevo" (as an ironic unfortunate fact, both communities were located at the very boundaries of that area).