ARENAL VOLCANO AND TENORIO VOLCANO NATIONAL PARKS
Arenal Volcano National Park was set up in 1994 over 12,124 hectares of land and Tenorio Volcano National Park in 1995 on 12,871 hectares. Both of these more or less adjoining parks are part of the Arenal-Tilarán Conservation Area, and both have obvious examples of volcanic activity.
The three most representative volcanic features of these two national parks are Arenal Volcano, an almost perfect 1,633-meter- high active cone, whose explosive eruptions and emissions of very viscous lava, mainly at nighttime, provide an extraordinary spectacle; Chato Volcano, south-east of Arenal Volcano, a truncated cone with an explosion crater in its upper part occupied by a lagoon with bluey green water, and Tenorio Volcano, at 1,916 m which exhibits a lot of geothermal and solfataric activity.
Arenal is a very recently formed conical stratovolcano, which in 1968 started erupting again with a loud Plinian-type explosion that formed a crater in half of the cone. Tenorio consists of four volcanic cones, other domes and pyroclastic cones and two twin craters identified as Montezuma Volcano. It now has fumaroles on the north-east flank, 965 meters high in the place known as Las Quemadas. There are also thermal sites in the place known as La Casa and on the banks of the River Roble. At the foot of these parks that protect many drainage basins there is the large Arenal Lagoon where over 40% of all the electricity consumed in Costa Rica is generated.
The two parks are covered in very moist premontane forest, which in the case of the slopes of Arenal have been much altered due to the and western sides of Tenorio still have extensive primary forests. Some of the most representative species in these forests are the yellow milk (Pouteria con gestifolia), wild atta (Sloanea fagihea), freijo (Cordia alliodora), which is very numerous and the stone (Coccoloba tuerckheimii). One botanical curiosity on Tenorio Volcano is the jícaro danto (Parmenteria valerii) whose fruits resemble large cucumbers and grow directly out of the trunk. On Chato Volcano there are lots of orchids. Over 3,450 plant species have been identified in both parks.
Thirty five species of freshwater fish have been recorded, one, the olomina (Priapichtys annectens), being endemic. Among the 78 amphibian species the endemic and extinct golden toad of Monteverde (Bufo periglenes) is worth a special mention. There are 135 known species of reptiles, including the oropel snake (Bothrops schi agelii). The 453 bird species that have been recorded represent over 50% of the total birdlife in the country. They include the resplendent quetzal (Pharomachrus macinfo), three-waif fed bellbird (Procnias tricarunculata), sunbittern (Europygas helias), great green macaw (Are ambigua), bare- necked umbrellabird (Cephalopterus glabncollis) and coppery-headed
emerald hummingbird (Elvira cupreiceps). One hundred and thirty one mammal species have been identified in both protected areas, including three of the most threatened species in Costa Rica: Baird’s tapir (Tapirus bairdii), the giant anteater (Myrmecophaga tridactyla) and jaguar (Panthera onca). There are also pumas (Felis concolor), white-tail deer (Odocoileus virginianus) and three species of monkey: namely the mantled howler monkey (Alouafta palliata), white-faced capuchin monkey (Cebus capucinus) and Central American spider monkey (Ateles geoffroyi).
PRACTICAL INFORMATION
• Location: both volcanoes are part of the Cordillera de Guanacaste and are located in the provinces of Guanacaste and Alajuela. Arenal Volcano is on the eastern edge of Arenal Lagoon and Tenorio Volcano to the north-west of that lagoon.
• Access: access to Arenal Volcano National Park is via San Jose-Ciudad Quesada-Fortuna administration office (128 km) via an asphalted road. Access to Tenorio Volcano National Park is via the Pan-American Highway from San José to Cañas From there; take the road north to Upala. There are bus services and taxis San José-La Fortuna and Ciudad Quesada-La Fortuna.
• Service: the administration offices of Arenal Volcano park have a car park, toilets and a visitor center with an auditorium. The El Principal Las Heliconias, Las Coladas, Los Tucanes, La Catarata de a Fortuna and Los Miradores trails start from there. The Tenorio Volcano National Park offices are in Pilon de Bijagua.
1968’s great explosion, Arenal Volcano
After 500 years the Arenal left its latent state and awoke in July of 1968 to one of the most regrettable chapters of our recent history, as far as natural calamities.
Until 1968, the Arenal was considered to be a peaceful volcano. There is no evidence of activity during the colonial time or later years. It wasn’t until the 30’s, when an expeditionary group climbed to the top of the mountain and discovered fumaroles activity.
The Monday morning of July the 29th of 1968, the former called Hill of Arenal revealed all its volcanic nature and with a huge explosion in its west flank, ended abruptly with over a hundred human lives, at the same time that floated with ashes, gas and lava harvests’, villages and farms. Huge amounts of hot stone, burning gases and tons of ashes ended with what was formerly known as a hill.
In the wets flank three craters were opened from the explosion: crater A with 1050 meters height, crater B with 1175 meters height and crater C with approximately 1460 meters height. Aside from these three craters that were opened during 1968, there was a crater D with 1633 meters height that already existed since before the eruptive period. One of these craters provoked an explosion of hot steams that destroyed 12 km2, destroying the villages of Pueblo Nuevo and Tabacón and causing the death of 87 people.
In the last ten years this volcano has remain the most active in Costa Rica. But the tragedy however, helped to turn the area in one of the most visited places of the country, for both local and foreign visitors; the majestic sight of a volcano in constant activity that hasn’t stopped being active for the past 30 years and the exuberant nature along with the flavor of a Costa Rican rural area that stills holds on to the old fashion features.
Despite the natural invasion first, and second the visitors’ invasion, the people from La Fortuna, Tabacón and other communities of the area managed to remember the people who fell on July 1968 sharing mass every year. The lava flows are very common in the Arenal Volcano.
Other explosions made by the Volcano are:
May 5th, 1998´s eruption caused the breaking of one of the wall of the mountain and a big flow of hot stone and ashes that threaten nearby villages and some tourist’s establishments such as Tabacón that at the moment had 200 people in it, among visitors and employees.
Nowadays authorities are very alert due to the fact that this Volcano is one of the most dangerous and active in the country.
In the present the Arenal Volcano remains active all the time without representing any real danger to the visitors and giving the opportunity of enjoying the great scenic resources of the area, such as the Arenal Lagoon and the Arenal National Park; hot springs can also be access in the area.