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Arenal Volcano Activity

Majestic colossus that start great volcanic eruption activity at 1968, and keeps continuously as active volcano.

Almost perfect conical shaped active Arenal Volcano is the youngest volcano in Costa Rica and until 2010 its most active. It have an double conical andesitic structure with 1670 m above that is located at the eastern shores of Lake Arenal (a natural lake that has been enlarged by a hydroelectric project in the early 70's). Arenal volcano lies along a volcanic chain formed sometime between 100 and 12 thousands of years ago and containing, in building up chronological order, Los Perdidos lava domes (giving place to beautiful Fortuna Waterfall), Chato inactive volcano (with its 500 m wide & lake-filled fantastic crater and about 12 thousands of years of antiquity) and finally the Arenal active Volcano. The earliest known eruptions of Arenal took place about 7,000 years ago, and it was active concurrently with Cerro Chato until the activity of this last ended about 3,500 years ago. Volcanic eruption activity of Arenal has been characterized by periodic major explosive eruptions (at intervals of several hundreds of years) and periods of lava effusion that armored the almost perfect cone.

The latest remarkable volcanic eruption stage, previous to current, was at the Christopher Columbus arrival to original indigenous Costa Rica land. After that, has followed approximately 400 years of dormancy, causing to be locally known as 'Cerro Arenal' (Mount Arenal) and not an active volcano. But Arenal's most recent volcanic activity period began with a major explosive eruption in July 29, 1968. Continuous explosive activity accompanied by slow lava effusion and the occasional emission of pyroclastic flows has occurred since that date, first from vents at the summit and on the upper western flank, and later only from the last one, giving place to the current active crater and surpassing the 1,633 m of the former cone. Because this uninterrupted volcanic eruption activity Arenal Volcano is worthy one of the current most active volcanoes in the world.

Constant volcanic activity and minimal endangerment as Arenal does, makes it an active volcano popular tourist destination, especially at night, because the lava and incandescent rocks make a very spectacular sight. [Arenal Volcano Hotel to get superb views] Lava eruption flows can be seen from almost any point at Hotel Los Lagos, that's the reason making it the better Arenal Volcano hotel. If during a clear night you have the opportunity to witness them, the absence of lights of the civilization will allow the total splendor of the stars (and the Milky Way inclusive), that with the red heat lava volcanic eruptions, one of the most sublime and unforgettable nature shows will take place.

For a closer view you surely will never forget the Arenal Volcano vantage point experience, where you can witness what impressive nature can be. Specially interesting is the presence of two Arenal Volcano lakes naturally formed by the blocking of springs by ancient lava flows, that features great beauty and emerald colored water. Hotel Los Lagos is named after these particular and beautiful lakes. The Arenal Volcano hike tour puts you in contact with the volcanic eruption rocks from more than 15 years ago and provides the full active volcano side view. Additionally, the tropical rainforest surroundings provides the chance for great and abundant bird watching, among others fauna possibilities like the howler monkey, the sloth or the coati.

Latest Arenal Volcano Eruption Activity Report

Most Recent Arenal Volcano strombolian eruption picture!It was taken from premium superior observatory-terrace at Los Lagos Hotel. After several failed attempts to catch a nocturnal Arenal eruption (like the classic pictures from 90's), that privilege was a spontaneous reality in the night of September 09, 2008 at 11:45 pm when Arenal Volcano threw to the air, in a firing spectacular way, some amount of red-hot lava. This happens in the forms of volcanic rocks that are thrown by the explosion of compressed gas. Because of the high red-hot temperature (more than 700º C), they register (in the camera sensor or film) an elliptic red path according to their parabolic movement while in the air, and erratic lines as rolling down on the volcano flanks.

At July 29, 1968 about 7:30 am Arenal Volcano initiates its current eruptive phase. After a phase of extraordinary eruptions and lava flows (one of which cross over the current road is dated about 1525) in the conquest period started by Columbus in Costa Rica, Arenal Volcano has gone over an inactive stage, such that in the first half of 20th century it has been called " Arenal Peak ". This peculiar peak of almost perfect conic shaped, warned with thundering and local trembling to inhabitants of two small villages near its base at northwest. In the morning of July 29 happened a furious volcanic eruption with a big explosion that released abruptly the amount of accumulated energy, precisely at the base of the cone al northwest and toward the villages, exterminating the people that was in home (mainly women and kids) by the cataclysmic bombing of huge rocks and the burning avalanches (pyroclastic flows). In such explosion, it has opened two holes, and one of them near the top, by the accumulation of continuously poured materials has shaped the main cone with the current active crater, that surpass the former cone and started to fill the old inactive crater.

July 2008: Strombolian Eruptions

Arenal Volcano delivers again its classic fireworks show. Archived picture (from 90's) of a strombolian eruption.In several days of July it has been reported volcanic eruptions of the strombolian type (lava is thrown up to the air by explosion), which apparently has not been photographed since more than 10 years ago (The illustrative picture is from 90's). Indeed, the author has been able to see one of them, from the premium superior area at Los Lagos Hotel, in the night of July 23, 2008, at 10:15 pm; unfortunately without the camera ready. With a powerful thundering, red heated rocks raised from the crater and fell down near top of volcano and rolled down, after a 10 seconds of air flight!

Arenal Volcano Pyroclastic Flow 2008-06-10June 10, 2008 at 7-8 am (13-14 GMT): Pyroclastic Flow Incandescent avalanche recurs (See Arenal Volcano Gallery for pics).

This event occurs again towards SW Arenal Volcano flank, in fact throughout the gutter caused in the flow of the past June 6. Again a cloud of thin ash has moved depositing material towards W and NW along an horizontal distance of 4 Km; because of that a partial closing of National Park was done. An activity of explosive eruption is discarded as a source for concern. Despite the fact that next to the cloud of materials a tall column of gas and steam was generated, this fact did not represent a direct threat to aviation. Even more the fall of solid materials is produced in a few tens of minutes and with light rain conditions, in less time. The unstable material (from summit to rest area) will keep descending. Fragments of big size, generated from the top or along the gutter can repeat this at anytime. The observatory zone at National Park neighborhood is still safe.

Source: OVSICORI. Arenal Volcano Pyroclastic Flow 2008-06-08June 6, 2008 at 9:15 am (15:15 GMT): Pyroclastic Flow Incandescent avalanche triggered by lava flow collapse. A hot avalanche rolled down the SW slopes of Arenal Volcano. An unestimated amount of blocky, andesitic lava that was accumulating, on the summit of Arenal Volcano, since March 2007, collapsed due to the extrusion of a lava flow. Even though fragments of such lava flow fell intermittently over these 14 months, it was until now that a mayor avalanche took place. The present collapse provoked a scar of some 800m long from the summit to the bottom. Lose, dry, incandescent material was canalized down the slope conforming a wide chaotic fan, at approx. 900m asl. Dust and fine ashes deposited in a small area W and NW of the active flank of volcano. Rain rapidly diluted the fine film that was deposited on vegetation. The affected sector does not offer a threat to visitors, park rangers or residents. On the contrary it is located in a safe remote sector of the volcano. Source: OVSICORI.

Don't forget that after an intense and active tour day you can enjoy relax in the natural hot springs hotel facilities and get relax, health and beauty at our Fangus Spa Resort.