Orosi Valley, Costa Rica
ERUPTION MAY 2016
As I write this, Turrialba Volcano has been erupting for several days. It appears to be its most serious activity in 150 years (since 1866). I am adding this page to the site to collect photos, maps, videos and information as I accumulate it. It is unlikely that any ash will fall on the Pondorosi because the prevailing trade winds blow in a west southwesterly direction, which will carry the ash toward San Jose, although the volcano is closer to the Orosi Valley, as the maps show.
Turrialba Volcano is not visible from the Pondorosi, but it comes into view on a clear day as we drive the short distance toward the village of Orosi. In February of 2008, when the Pondorosi was being built, we stayed at the Hotel Reventazón and I took this low quality video from our second story room.
Turrialba is at the southeastern end of a string of active volcanos stretching across Costa Rica. This string, in turn, is part of the Cental American Volcanic Arc. Note: Volcano Orosi is not in or even near the Orosi Valley. One time, years ago, on an extremely clear morning I was returning from dropping my wife off at the airport and was able to view all of Costa Rica's major peaks: Poás, Barva, Irazú, Turrialba and the highest mountain, Chirripó (which is not a volcano). I didn't have a camera and I soon moved along the autopista past my vantage point. I now realize what a rare sight I had beheld. Once, a few years later a saw the four volcanoes from a ridge above Cachí and I did have my camera, but was foiled by the haze.
This is an earlier view of the three craters of Turrialba looking south over the Reventazón Valley. It is the western one, on the right which is active.
Irazú (11,260 ft,) and Turrialba (10,958 ft) are the two highest volcanoes in Costa Rica and they are connected by a saddle. They are twin volcanoes because of their proximity and similarity. The photo below, taken from Orosi, shows Irazú on the left and Turrialba on the right sharing the same base. The Spaniards dubbed it Torre Alba (white tower) because it spewed white smoke. Previous known eruptions were in 1847, 1853, 1855, 1861 and 1866.
The most recent eruption of Irazú began in 1963 when JFK was visiting Costa Rica. Over the course of two years, it released enough steam and ash (but no lava) to cover San Jose and cause disastrous floodwaters and mudslides onto the city of Cartago.
These maps mostly show the pattern of the ashfall from previous Turrialba eruptions. They are consistent and indicate where future pyroclastic material will land...San Jose.