Arenal Volcano Costa Rica

Change image 234
Arenal Volcano


"I always went very early in the morning to take food to my brothers working on the other side of Tabacon River: walking through the woods I always heard it. That day I heard the sound of what I thought was the plane but it was stronger, I thought I was late because I had not reached the place where I usually heard the plane, then I started to run so that my brothers did not get mad all me.
Arenal Volcano Costa Rica When I crossed Tabacon River it fell hotter than usual but I did not stop. Reaching the place where my brothers were working they told me that they were frightened, they asked if I knew something about the volcano since they direction. We all turned back and started running toward our house: everything was destroyed, were dead".

With these few words Jose Rafael Soto H. relates what happened that day in 1968 at Arenal Volcano."
Jorque Barquero H.

It has to be assumed that at the moment there was no monitoring of volcanoes in Costa Rica. Arenal as well as other volcanoes in our country had not been studied. For many years it was known as ARENAL PEAK. Recent studies suggest that Arenal's latest activity took place between 1200 and 1500 A.D.

People that had climbed to the summit years before the explosion reported that they could feel some heat between the rocks and see some fumaroles, they also said that the temperature in Tabacon River had increased. The night before the explosion the seismic activity was so intense that people from La Fortuna and El Castillo were scared; some survivors said that they felt earthquake all night long. Arenal, before the activity on 1968, was showing critical signs that would lead to the present activity that began at 07:30a.m.(local time) July 29.1968.

First explosion in Arenal

With the first explosion, 3 new craters were opened on the west flank of the volcano, they were named A, B and C, from [he lower 10 the upper flank respectively. Crater A was formed at 1000 meters above sea level (m. a.s.l.) and was the location where one or more pyroclastic flows originated. These flows devastated a 12 m2 area to the west of the volcanic edifice. A large amount of material was ejected: ash, lapilli, and bombs. Ash and laplli were carried west by the trade winds to Tilaran, Liberia and Santa Cruz in the Guanacaste Province.

Large blocks were deposited near crater A and some reached approximately 5Km from it: on impact they formed craters up to 20m wide and 2m deep. The temperature of gases emitted was so high that vegetation was instantaneously dehydrated and even carbonized. Eighty seven people were killed in the villages of Tabacon and Pueblo Nuevo. On July 31 a new pyroclastic flow occurred, this time 6 persons travelling in two vehicles were killed. One consequence of the devastation and deposition of large amounts of ash, heavy rain generated cold lahars in rivers and streams, mainly down in the Tabacon River valley.

Lava Flow

Late on September 19, the beginning of the first lava flow was observed flowing out of crater A, moving to the NW, this flow continued, until 1973. During 1973, activity migrated to crater C, localizing at approximately 1450 m. a.s.l. from this vent permanent emission of lavas, sporadic pyroclastic flows, constant emission of gas, and were occurring intermittent explosions emitting blocks and ash. Until June 1984 characteristic activity at Arenal included lava descending the different flanks of crater C with sporadic eruptions of pyroplastic material. Since that time strombolian activity has become more frequent.Due to the accumulation of materials around crater C, the height has increased and currently two cones occupy the summit, old crater (D) to the east and crater C to the west.

Pyroclastic flows, although not so large and constant as in 1968, have bean observed frequently: in July 1967 and March 1968 two flows traveled down the south and terminated 1 Km from the crater destroying all vegetation in their path. On August 28. 1993 the northern wall of crater C collapsed due to the pressure of the out pouring lava. For approximately the next 20 minutes tour glowing avalanches could be seen. "These flows traveled west approximately 1 Km and northeast to approximately 400 m from the road between Fortuna and Tilaran, several pyroclastic flows descended from crater C down the northwest flank. This activity kept on up to 7:00 p.m. A total of 23 flows were produced with distances averaging 1.5 km. On august 3th, 2000, at 10:15 a.m. the lava flow front descending from crater C, towards the ME collapsed forming a pyroclaslic flow. Three people that were ascending to see the lava were caught and gases at a high temperature, as a consequence a tour guide died later that night, at a hospital in San Jose and a little girl died days later In the U.S.

Pyroclastic flows continued later that day originating the most important flow at 1:47 p.m., materials deposited reached as far as the Cedeño Lake, devastating all vegetation. People continue to visit Arenal to hear the explosions and see the extrusion of lavas rolling down the flanks as well as to see the emission of gas and ash: phenomena that makes Arenal.


On July 31 a "nuee ardente" occurred travelling due north of crater A: several persons in two vehicles trying to help with the emergency were killed. Before the activity began in 1968, Arenal Volcano was covered by dense vegetation.

On June 29, 1968 about 07:30 am a very string eruption accurred; a ( a nuee ardente ) destroyed everything to the west of the volcano. All of vegetation was destroyed and a large number of impact craters were formed by blocks and bombs of different sizes.

With the first explosion of July 29, 1968 a crater was formed on the west side of the Volcano at an elevation of 1000m. This was named crater A. On September of the same year, the first lava flow was seen coming out the crater A. This activity was continuous until 1973 when a lava dome formed in crater A due to the high viscosity of the lava and very low effusion rate.
* The author (Jorque Barquero H.) is foundering member of OVSICORI-UNA, institute that carryes on the monitoring of Costa Rica volcanoes.

18 Responses to "Arenal Volcano" | Add a comment
  • Peter S said: December 14, 2012 (Denmark)

    During my stay the volcano was very clear. It's relaxing taking a cup of coffee from your room while admiring the volcano.

  • Christie said: January 02, 2012 (United States)

    this is a great website but i have 1 simple question im sure you can answer:

    What type of eruption occured in 1968?

    i have checked with ppl. who study this volcano day and night and they dont even know!

    please email if you may or may not have the answer


  • Oscar said: December 26, 2011 (Costa Rica)

    the volcano does not present any activity since October 2010,I live in fortuna since May 2010 and is no more than a little smoke, if you travel to see the erupting volcano Forget it, there is something that tourists have to know is that before 1968 was off by 400 years, vulcanologist and scientists claim that is being repeated.

  • Zehavh said: July 13, 2011 (Israel)

    Is it true that the Arenal Volcano is not active anymore from Oct 2010?

  • rikhav123 said: May 27, 2011 (Costa Rica)

    This is really the best information shared with us , this information about the arenal valcano, attracts many tourists to visit this adventures place in the world, also the precautions given while visiting this are makes simple to avoid the any strange or harm .

    <a href="">arenal volcano</a>

  • arenal volcano said: May 27, 2011 (India)

    This is really the best information shared with us , this information about the arenal valcano, attracts many tourists to visit this adventures place in the world, also the precautions given while visiting this are makes simple to avoid the any strange or harm .

  • jack said: March 08, 2011 (Russia)


  • Eric Logan said: February 15, 2011 (United States)

    A question. When I was in Costa Rica in 1975, someone told me that La Fortuna was so named because the town had been destroyed several times by eruptions, and rebuilt. Living there was trusting in good fortune. Is that accurate?

  • David Smith said: May 28, 2010 (United States)

    Dear Olivia, I think it's better to stay in Arenal and then in Monteverde. But if you have not enough time you can take the Monteverde One day tour as well.

  • Olivia said: April 09, 2010 (United States)

    May 9- overnight flight to San Jose, CR

    May 10- Arrival-transfer to Hotel Grano de Oro

    May 11- Morning visit to National Theater or National Museum

    Afternoon transfer to Arenal

    May 11-14 Arenal—Hotel Nayara

    River Rafting/Wildlife Refuge/Hot Springs

    May 14-16 Transfer & overnight Tortuguero Nat park

    May 16- 18 Transfer & overnight Manuel Antonio

    May 18- Transfer to San Jose & overnight

    May 19- Depart to NY

    Question? Is it worth cutting Arenal a day short and going to Monteverde or can we take a day trip from Arenal?

    Thanks for any advice or help!

  • jackson said: March 05, 2010 (Sweden)


  • Lynn said: February 16, 2010 (United States)

    We just returned from La Fortuna yesterday. Gilda, there are plenty of places to stay on the side of the volcano where you can see the eruptions, but you will pay between $200 and $600 per night. Stay in La Fortuna. We stayed at Cabinas Los Buho just a few blocks from the center of town and paid $10 per person. It has private baths and a balcony from which you can clearly see the volcano and smoke plumes (best time is at sunrise), although you cannot see any lava from there. Take tours to see the lava flows but ONLY from certified tour guides. They are trained in all the flora and fauna of the area and will make your trip one to remember.

  • gilda said: January 24, 2010 (United States)

    where is the BEST place to stay and see the lava flow? Should I stay in La Fortuna or El Castillo? Which direction is the laval flowing Today?!

    Thank you

  • Gracie said: October 31, 2009 (United States)

    I am doing a report for Spanish Class on Volcanoes in Costa Rica. It is so boring! Any idea where I can find more info?

  • Sonya said: October 12, 2009 (New Zealand)

    Camped under Arenal for 3 nights in 1992 - ash covered our tent - one day - hiked right up to the hottest spots - and it erupted - had ash and massive rocks splattering all around us - incredible - no restrictions in place or tours etc in those days - wondering what it is like now - have fantastic photos from the experience both day and night

  • Valerie said: September 24, 2009 (United States)

    Skip I am leaving for Arenal on Saturday you said it was wild how great was it?

  • skip G said: July 23, 2009 (United States)

    was at arenal last week the wildest thing i have ever seen

  • Toure Amadou Ali said: May 17, 2009 (Morocco)

    HI i'll like to visit costa rica .i don't know that your company can make the invitation latter vor making the visa to me .

Leave a comment

(Will not be published)

* Required fields

More hotels in La Fortuna Costa Rica
USA & Canada Toll Free1 800 540 0395
Local Phone Costa Rica2479 7242
Send Us an
Arenal Volcano Hotels - Arenal Volcano Tours - Arenal Volcano Hot Springs - Arenal Volcano Packages - Arenal Volcano Transportation - Costa Rica All Inclusive