Volcanoes

Costa Rica volcanoes (specially Arenal volcano)

Arenal was very active in 2010. The photo shows a 30 second exposure taken on May 28, 2010 by Tucker Comstock

Volcanoes – nature’s safety valve

Arenal is the newest in the chain of active volcanoes forming the main spine of Costa Rica. Arenal was constructed by successive eruptions of the older Chato volcano, which now has a beautiful lake filling its calderas (the cone in the top of an extinct volcano). This is a popular, albeit very rugged, hiking place, with great views of active Arenal nearby.

No lava has been seen from Arenal since October, 2010. They there are no prediction on when/if lava will again start to flow again. The earliest eruptions of Arenal took place about 7,000 years ago, with a cyclic period of eruption and dormancy. Arenal’s current eruptive period began with major explosive eruption in 1968 which took everyone by surprise, and killed 78 people in the village of Arenal.

Eruptions are truly not predictable. When they happen, pyroclastic flow (ash and vaporized metals) flow down the slopes at speeds exceeding 60 miles/hour.

Arenal was very active in 2010. The photo shows a 30 second exposure taken on May 28, 2010 by Tucker Comstock.

Serendipity’s staff have a very healthy respect for all volcanoes’ power. Large volcanic eruptions are truly huge explosions which create a very high speed, very hot gas “river” which races more than 60 miles/hour down the mountainside. This pyroclastic flow, rather than lava itself, is the real danger being near an active volcano. The most recent fatalities, in 2001, were from pyroclastic flow.

There are a few volcanoes in different parts of Costa Rica that are National Parks and that we may visit to learn more about volcanology. The Turrialba volcano has been more active since 2010, spewing gases, and also ashes in various occasions. Therefor we are not allowed to go anywhere near the crater as of the time being, but during the day you can see from a distance how the peak is emitting visible steam.

Map of the high risk for pyroclastic flow, OVSICORI UNA

This map above shows the danger zone of Arenal volcano as determined by the Observatorio Vulcanológico y Sismológico de Costa Rica. Note that the hot springs areas (Tabacon, Eco Termales, Baldi) are in the extreme tips of the high risk area..