Arenal Volcano General Information
Arenal Volcano is a 1,633 meter (5,300 feet) high mountain, which is perfectly conically shaped with a crater of 140 meters. Arenal Volcano is geologically considered a young volcano and its age is estimated to be less than 3,000 years. Local residents also refer to the Arenal Volcano as "Arenal Peak" , "Pan de Azúcar", "The Canaste Volcano", "The Costa Rica", "Río Frío Volcano" or "The Guatusos Peak".
The volcano was asleep for hundreds of years and exhibited a single crater at its summit, with minor fumaroles activity, covered by dense vegetation. In 1968 it had an eruption that destroyed the small town of Tabacón. Due to the eruption three more craters were created on the western flanks of the volcano but only one of them exists at present.
Arenal is considered one of Costa Rica's most active volcanoes and has been studied by seismologists from around the world for many years, and although the activity nowadays is less pronounced, you can still see daily columns of ash emanating from the crater of this majestic conically shaped behemoth. The volcano is located in the northern zone of the country, fifteen kilometers southwest of La Fortuna in San Carlos. The temperature varies between 16 degrees Celsius (60.8 degrees Fahrenheit) in higher altitudes to 24 degrees Celsius (75.2 degrees Fahrenheit) in the lower altitudes and the annually rainfall is around 5,000 mm (195 inches).
The Arenal Volcano area is an important watershed for the Arenal Lake Reservoir. Water from the Arenal Lake is used for hydroelectric power, with the purpose of satisfying the electricity demands of the inter-connected national system and the Guanacaste irrigation projects.
Although the main attraction is the Arenal Volcano; the area offers much more. Next to the volcano is the Arenal Volcano National Park with a wide variety of flora and fauna and a great view of the volcano. Furthermore there is La Fortuna, which is the nearest town to the Arenal Volcano. In addition, there are several other activities and interesting places that can be visited in the area.
First of all, the main attraction; as mentioned above, is the Arenal Volcano. One can often be treated to breathtaking views, including the opportunity to watch the volcano in action, with plumes of smoke emanating from its´ crater.
For a scenic hiking trail and views of the volcano, you can visit the Arenal Volcano National Park. There is an observatory site located in the park from where you have a spectacular view of both the volcano and the Arenal Lake. There are also several hiking trails which you can explore on your own. La Fortuna, as mentioned above, the nearest town to the Arenal Volcano is very user friendly as it is ever more focused on satisfying the needs of the visitors of the Arenal Volcano. In this town you will find ATMs, supermarkets, a post office and internet cafes. You can also find restaurants and hotels of all price ranges.
If you want to do something more adventurous or you want to see other places of interest in the area, you can go on one of the many half day and full day trips that are being offered. These range from adventurous rafting and horseback adventure tours to a relaxing visit to the Caño Negro Wildlife Refuge or the La Fortuna Waterfall. In short, there is enough to see and to do in this fascinating and beautiful region to keep you coming back for more.000
Arenal Volcano Historic Dates
July 29, 1968: At about 7.30 am a powerful eruption took place and destroyed the area west of the volcano. A big quantity of impact craters were formed by blocks and projectiles of different sizes.
June 1975: Between June 17, and 21, 1975 several glowing avalanches, composed of extremely hot rocks and debris rolled down 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 miles).
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 in the form of a V and was approximately 60 meters deep and 100 meters wide. Within this V-shape the lava started to flow again.
March 1994: Flows started to fill the V-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 different types of gases. This type of activity went on until May 5, 1998.
May 5, 1998: Arenal Volcano experienced a series of large eruptions on Tuesday afternoon. The first eruption was recorded at 1.05 pm when part of the northwest wall of the crater fell apart. Large amounts of lava, rock and ash were expelled from the volcano during this explosion. Another eruption took place at 2.20 pm with material emerging from the same part of the volcano.
A specialist from the Costa Rica Volcanic and Seismic Observatory explained that this type of activity is not 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 distributed therein. The activity was so pronounced that it triggered a landslide (avalanche) as part of the crater wall fell apart on the northwest side of the volcano. This phenomenon had occurred sporadically in the past, however, this time the consequences were far greater than usual in terms of the avalanche.
As a normal precaution, authorities declared a red alert, closed the road between La Fortuna and Tilarán, which traverses the north side of the volcano, and evacuated approximately 450 people (mostly tourists) from the immediate area including several hotels and tourism related businesses. There were no reports of injuries caused by the volcanic activity; however authorities decide to err on the side of caution.
At 5.20 pm on Tuesday the volcano was still discharging material, but activity had decreased significantly. (The information provided is based on reports in the Costa Rican daily newspaper, La Nación.)
May 7, 1998The 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 opened up in the wall of the crater and all the material slid down the side of the volcano. During this day, May 7, 1998, there were a total of 23 eruptions, between 1.05 pm and 7 pm, and shortly thereafter the volcano returned to its normal state. Authorities reported no unusual behavior and the Arenal Volcano National Park was reopened the same week. Local seismologists investigated the activity of the volcano and park rangers continue to vigorously enforce the safety perimeter.
UFO sighting over Cote Lagoon near the Arenal Volcano, picture was taken around 1978 approximately, by topographers. More recently there have been sighting reported by visitors to the area, such as the one reported to ufoweek, an online magazine on September 15, 2010 where a traveler claims that when in the Arenal Vocano area, he and his friends saw a UFO come from the north from the Arenal Lake area. The author also noted that NASA has a hanger at the Juan Sanatmaria International Airport (the main airport in San Jose, Costa Rica) which they installed in the 90´s, coincidentally at around the time that a UFO report was filed in San Jose, the capital.