As I often say, many volcanoes seem to have their own personalities. It seems over time they become anthropomorphized by the people who live around them as angry or benevolent..or both, depending on their appearance or how they erupt. It turns out this week’s virtual vacation destination is one such volcano. He is known by many names down in northwest Costa Rica, such as Volcán Río Frio (Frozen River Volcano), Volcán Costa Rica, Canaste, and my personal favourite, Pan de Azúcar (sugar bread), but officially he is called Arenal.
Arenal is Costa Rica’s youngest volcano and one of the most active of the country’s seven volcanoes. It is part of a chain of volcanoes where activity has migrated southeast to northwest. Arenal now stands a majestic 1,670 m high, towering more than 500 m over the crater-lake topped Cerro Chato (Flat Hill) stratovolcano to the southeast. Cerro Chato first erupted an estimated 38,000 years ago and was active alongside Arenal during his volcanic infancy, but went silent around 3,500 years ago. Chato’s 500 m wide summit crater is now filled by a green lake. Chato is a popular destination for the more skilled hikers, but the lake is said to be rich in the sorts of minerals that render it unsuitable for swimming.
Arenal’s eruptive history has been extrapolated through tephrochronology, radiocarbon dating and anthropology due to the fact that its modern scientific exploration only commenced in the 1930s. Major eruptions of unknown duration, mostly of VEI 4, seem to occur regularly with respited of one to three centuries in between. A smaller and brief eruption happened in 1922, but the one he is most known for is an eruption that began on 29 July 1968 and ended some time around mid December of 2010.
That eruption began in the morning with no recognized warning and over the next few days, depositing lava, ash and rocks over a 15 km area, burying three villages and taking 87 lives. It was reported that bombs weighing more than a ton were thrown a kilometer away by the explosions. Before then, the slopes of Arenal had been covered in vegetation, but the west and northwest flanks were laid bare by the eruption. Three new craters appeared on the west flank. For the next four decades, eruptive style went back and forth between effusive and vulcanian, and including all the landslides, pyroclastic flows and lava flows that such eruptions bring. Toward the end, his eruptions tended to be more of the degassing sort with strombolian activity and the occasional lava flow or avalanche.
But just as the mountain has his barren side and green side, the volcano as a neighbor is both feared and loved. His presence has made the surrounding soil fertile for agriculture, and his eruptive splendor and moutainous beauty have made him a tourist attraction. Arenal volcano, along with the large Arenal lake, are centerpieces of the Arenal Volcano National Park, established 6 November of 1991. The park includes wildlife refuges, waterfalls, thermal springs, natural spas and lots of hiking trails, though some parts of the volcano are still restricted. He is, after all, still a volcano.
Glenn was the only one who found me this week, and nobody picked up the bonus point. Thank you to all who play or follow along, and thank you for bearing with me and my missed deadlines. The Villa Volcanohead household has been experiencing the flu these two weeks, but hopefully things will return to normal soon. I hope to stay on schedule this coming week, so come back this Monday when I take off for new adventure on a new volcano.