Photo courtesy Michael Smith

"Yesterday, was a walk in the park compared to today."

Intro to Irazu by David Hilton

Take a look around the edge of the crater

Volcan Irazu, at an elevation of 3,400 meters (about 11,100 feet), is the highest  volcano  in Costa Rica. It last erupted in 1963, coincidentally during U.S. President Kennedy's historic visit to the nearby capital of San Jose. The presidential entourage was showered with ash, as was the entire city's population, which subsequently suffered from a number of year's activity. The hazards  of Irazu's proximity  to one of Central America's principal population centers soon led to a movement  toward mitigation. Solutions were proposed ranging from science to science fiction. One proposal was the use of an atomic bomb to fight back at the erupting mountain. Another proposed flooding the crater with water, thereby extinguishing the fire within. Obviously, little was understood at the time by proponents of this ambitious scheme about the power of the Earth's primordial forces. A third proposal was to drill a tunnel into the offending mountain in an attempt  to drain it of its power. When none of these preposterous schemes proved tractable, prayer was a last resort. But, as volcanoes are wont to do, Irazu entered a period of dormancy that continues to this day. However, dormancy is a relative concept, as today's field report by Scripps graduate student Alison Shaw attests:

Yesterday was a walk in the park compared to today. At a certain point I debated whether the samples were really worth it. We started our trek through the cloud forest along a nicely marked path and then scrambled up the cliff face to begin our journey across the so-called "Ridge of Death." Upon reaching the ridge, with cliffs on both sides, to the left we could see an emerald green lake about 200 meters below in Irazu's crater, and to the right there were fresh landslides. Our guide's words of caution were:  "Be careful and don't walk too closely together, as anything can trigger a landslide."

In the crater lake bubbling springs were visible; however, these gases could only be sampled by rappelling down the cliff and boating over to the site. This may be an option for a future expedition.

We scrambled down the back of the volcano in search of fumarole sites. A landslide in 1996 made these sites less accessible. After two hours climbing up, down, and sideways over slippery gullies and ridges, we came upon a large crack in the outer wall of the volcano. I could hear the fumaroles roaring from the crack before I could actually see them. Bright yellow sulphur deposits rimmed the crack and gas was pouring out. We managed to take several gas samples and one fluid sample. Success!

As you can probably imagine, the hike back up to the crater rim was even more tortuous. And all this time, I was wondering what Dave was up to..