World Library  
Flag as Inappropriate
Email this Article

Arenal Volcano

Arenal in November 2006
Elevation 1,670 m (5,480 ft)[1]
Arenal is located in Costa Rica
Costa Rica
Location Alajuela Province, Costa Rica
Type Stratovolcano
Age of rock 7,000 years old
Last eruption 1968 to 2010

Arenal Volcano, in Spanish Volcán Arenal, is an active andesitic stratovolcano in north-western Costa Rica around 90 km northwest of San José, in the province of Alajuela, canton of San Carlos, and district of La Fortuna. The Arenal volcano measures at least 1,633 metres (5,358 ft).[2] It is conically shaped with a crater spanning 140 metres (460 ft). Geologically, Arenal is considered a young volcano and the age is estimated to be less than 7,500 years.[3] It is also known as "Pan de Azúcar", "Canaste", "Volcan Costa Rica", "Volcan Río Frío" or "Guatusos Peak".[1]

The volcano was dormant for hundreds of years and exhibited a single crater at its summit, with minor fumaroles activity, covered by dense vegetation. In 1968 it erupted unexpectedly, destroying the small town of Tabacón. Due to the eruption three more craters were created on the western flanks but only one of them still exists today. Since October 2010, Arenal has become dormant,[4] with no explosions since December 2010.[5]


  • Geographic setting and description 1
  • Geologic history 2
    • July 29, 1968 2.1
    • June 1975 2.2
    • June 1984 2.3
    • August 1993 2.4
    • March 1994 2.5
    • March 1996 2.6
    • May 5, 1998 2.7
    • May 7, 1998 2.8
  • See also 3
  • References 4
  • External links 5

Geographic setting and description

Arenal is one of seven historically active Costa Rican volcanoes along with Poás, Irazú, Miravalles, Orosí, Rincón de la Vieja complex, and Turrialba. It was Costa Rica's most active volcano until 2010, and one of the ten most active volcanoes in the world. It has been studied by seismologists for many years.

The volcano is located at the center of Arenal Volcano National Park in the northern zone of the country, 15 kilometres (9.3 mi) southwest of the La Fortuna district in San Carlos (canton), Costa Rica.[6] The temperature varies from 9 °C (48 °F) in the high areas to 89 °C (192 °F) in the low areas and the annual rainfall is around 349 centimetres (137 in).

Arenal Volcano area is an important watershed for the Arenal Lake Reservoir. The reservoir's water is used for hydroelectric power. It is also connected to the national system.[7]

Arenal has a good number of eruptive vents.[8] Chato is a dormant stratovolcanic cone. It is believed Chato first erupted 38,000 years ago during the Pleistocene period and last erupted about 3,500 years ago.[3] Chatito is a lava dome with an elevation of 1,100 metres (3,609 ft). Espina is another lava dome.[1]

Arenal Volcano with Lake Arenal on the left.

Geologic history

Arenal is the youngest and most active of all the volcanoes in Costa Rica. Scientists have been able to date its activity back to more than 7000 years ago. The area remained largely unexplored until 1937, when a documented expedition took place to reach the summit.[9] It has been considered eruptive since 1968.[10]

Arenal in 2014, viewed from the old 1968 lava flow.

July 29, 1968

On Monday, July 29, 1968 at 7:30 AM, the Arenal Volcano suddenly and violently erupted. The eruptions continued unabated for several days, burying over 15 square kilometers with rocks, lava and ash. When it was finally over, the eruptions had killed 87 people and buried 3 small villages – Tabacón, Pueblo Nuevo and San Luís – and affected more than 232 square kilometers of land. Crops were spoiled, property was ruined, and large amounts of livestock were killed.[11]

At the height of its ferocious activity, the volcano flung giant rocks – some weighing several tons – more than a kilometer away at a rate of 600 meters per second. These explosions would go on to form three new active craters.

As the three towns were destroyed on the western side of the volcano, a town by the name of El Borio on the east side was untouched and unharmed . After the volcano ceased to erupt, El Borio was renamed La Fortuna, which means "the fortunate", referring to its luckiness that the volcano erupted to the west and not the east.

June 1975

Between the 17th and the 21st of June 1975 several avalanches went down from one of the craters. The vegetation along Tabacon River was destroyed and a great amount of material was deposited on the riverbed. Four strong explosions also blew large amounts of ash into the sky. The ash was spread within a distance of 26 kilometers (16 mi).

June 1984

After a period of high effusive activity of intermittent lava flows, a new explosive phase began with 3 to 20 explosions per day of low to moderate magnitude. These explosions of steam, water, gases and ash reached altitudes of up to 5 kilometers where winds again carried the material across the Arenal reservoir (Lake Arenal) and over the town of Tilarán.

August 1993

A northwest wall of one of the craters collapsed and generated several pyroclastic flows. The collapsed crater wall was shaped as a V, about 60 meters deep and 100 meters wide. In this V-shaped crater the lava started to flow again.

March 1994

Flows started to fill the U-shaped crater and deposited materials around the crater.

March 1996

At this time the volcano started to produce regular lava flows, accompanied by intermittent explosions of gases. This was the regular activity of the volcano until May 5, 1998.

May 5, 1998

The Arenal Volcano experienced a series of large eruptions on Tuesday afternoon, May 5, 1998. The first eruption was recorded at 1:05 p.m. when part of the northwest wall of the crater fell apart. Large amounts of lava, rocks and ash flew out of the volcano during this explosion. Another eruption took place at 2:20 p.m. with material emerging from the same part of the volcano.

A specialist from the Costa Rica Volcanic and Seismic Observatory explained that the happening is nothing unusual for the volcano. Nevertheless, during this occasion the amount of lava within the crater was significantly greater than normal and therefore more material was poured out. This time a landslide (avalanche) took place, too, as a part of the crater wall fell apart on the northwest side. The phenomenon occurs sporadically, although this time the consequences were greater than usual.

As a normal precaution, authorities declared a red alert, closed the road between La Fortuna and Tilarán, which runs around the north side of the volcano, and evacuated approximately 450 people (mostly tourists) from the immediate area including several hotels and tourism oriented businesses. There were no reports of injuries caused by the volcanic activity.

At 5:20 p.m. on Tuesday the volcano was still discharging material, but activity had decreased significantly.

May 7, 1998

The eruptions of May 7, 1998 damaged two square kilometers and destroyed a 400 by 100 meter area of green forest in the vicinity of Arenal Volcano. A fissure, 500 meters long and 10 meters deep, was opened up in the wall of the crater and all the material slid down the side of the volcano.

During this day 23 eruptions were reported, between 1:05 p.m. and 7:00 p.m., and thereafter the volcano returned to its normal state. Authorities reported no unusual behavior and the national park was reopened the same week. Local seismologists investigate the activity of the volcano and park rangers continue to vigorously enforce the safety perimeter.

See also


  1. ^ a b c "Arenal - Synonyms and Subfeatures".  
  2. ^ "Arenal" (in Spanish). Costa Rican Vulcanologic and Seismologic Observatory. Retrieved 2009-10-11. 
  3. ^ a b "Arenal".  
  4. ^ "Arenal Volcano". Retrieved 2015-10-14. 
  5. ^ "Arenal Volcano". Retrieved 2015-10-14. 
  6. ^ "Arenal Volcano Costa Rica overview". Retrieved 2015-06-19. 
  7. ^ "Lake Arenal Dam - Costa Rica". Retrieved 2015-06-19. 
  8. ^ "Arenal | Volcano World | Oregon State University". 1968-07-29. Retrieved 2015-06-19. 
  9. ^ "Arenal Volcano, Costa Rica. Recent Eruption & Activity 2012, 2010". Retrieved 2015-06-19. 
  10. ^ "Arenal - Eruptive History".  
  11. ^ "Arenal Volcano 1968 eruption". Retrieved 2015-06-19. 

External links

  • MTU Volcanoes Page: Arenal
  • Updated (and detailed) information and images about Arenal and its recent activity
  • Most recent pictures of Arenal eruptions
  • Jorque Barquero's Personal Account of the 1968 Eruption
  • Fortuna (Costa Rica) travel guide from Wikivoyage
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.