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 Published by the American Geological Institute
Newsmagazine of the Earth Sciences

August 2000


Bushwacking in the Galápagos

Fraser Goff

A Galapágos tortoise observes Jim Stimac backpacking to the rim of Alcedo caldera. All photos courtesy of Fraser Goff.


In early 1995, colleagues and I ventured to the Galápagos for six weeks in search of magmatic tritium. Extensive analysis on gases from two of the volcanoes in the archipelago was part of a long-term research project that looked at more than 10 volcanoes world wide to find evidence (or non-evidence) for cold fusion in the deep Earth.

Isabela, the largest island, consists of six coalesced basaltic shields resembling upside-down soup bowls 30 to 60 kilometers across and more than one kilometer high. Two of these shields, Sierra Negra and Alcedo, are noted for their vigorous fumarolic activity. We were the first to sample for tritium in the Galápagos and also the first to determine if the fumaroles were volcanic or geothermal. Although sampling the gases of these fumaroles was our main objective, our trip became a goat-eating, burro-sacrificing, volcano-exploring adventure.

The Galápagos islands are remote and their special ecology, geology and history are preserved as an Ecuadorian national park. The climate is hot, people are scarce and drinking water is scarcer. While most tourists stay within one or two kilometers of the ocean, my colleagues Gary M. McMurtry of the University of Hawaii, Alfredo Roldán-Manzo of Instituto Nacional de Energia in Guatemala and then post-doc Jim A. Stimac of Los Alamos and I planned to camp on the caldera rims and make day trips to intracaldera sites.

On Sunday, Jan. 22, we boarded a fishing boat from Santa Cruz for an overnight voyage to Villamil, the only village on Isabela. We were greeted the next morning with a typical tropical island view: palm trees, waves breaking on black lava, a few sandy beaches and a dark, distant volcano draped in green. We horse-packed through a rainstorm to the southwest rim of Sierra Negra and set up camp. The next several days we spent hiking into the caldera to the fumarole field of Mina Azufral (a sulfur mine). We donned gas masks and stood several hours in clouds of acid gases sampling fumaroles as hot as 210 degrees Celsius. These true volcanic emissions contained steam, CO2, SO2, H2S, HCl and minor trace components. Sulfur, white mineral incrustations, altered basalt and small flows of molten sulfur occurred everywhere. After 10 days at Sierra Negra, we boarded a small boat sailing north toward Alcedo Volcano. The next morning we disembarked on a dry and desolate coast with our gear, three guides and 25 plastic jugs — each filled with five gallons of water. The captain stated he’d be back in 11 days and sailed away on his boat El Pirate.
The northwest flank of Alcedo is blanketed with white pumice erupted from small rhyolite vents inside the caldera. Backpacking to the crater rim took us most of the day. Halfway up, we saw our first giant Galápagos tortoise grazing peacefully on grass. Although tortoises frequented sporadic mud holes, there were no springs or streams. The guides hauled the jugs of water from the beach, but it was not always enough. The hot and humid days made us incredibly thirsty.

During our visit, Ecuador and Peru were at war, and when our Ecuadorian guides caught a burro they named him Fujimori after Peru’s president Alberto Fujimori. One guide carried a rifle to shoot goats, and the meat greatly improved our freeze-dried meals.

The team standing on Alcedo caldera rim. Left to right: Alfredo, Pepi (with rifle), Giovanni, Eduardo, Gary, Fraser and Jim.

Gary McMurtry and Fraser Goff sample gas from a fumarole in Alcedo caldera. Two new fumaroles steam in the background.
We camped on the southeast rim and again made long day trips to fumaroles distributed along a fault zone inside the western caldera. Surprisingly, these fumaroles were extremely water-rich and discharged at the boiling point. Some were also very noisy and issued from phreatic explosion craters. We didn’t need gas masks. The gases contained minor CO2 and H2S, but virtually no SO2 or HCl. Hydrothermally altered rocks, incrustation and sulfur deposits were comparatively minor. These were geothermal fumaroles, not volcanic fumaroles, so we had come a long way to sample the wrong kinds of features for our project.

After returning to the beach for pick-up, our guides dispatched Fujimori with a bullet. The boat showed up as planned and the captain brought us cold beer. On the voyage back to Santa Cruz, the captain landed a yellow-fin tuna and sliced thick strips of sashimi from the back of its neck.

Did we find tritium? Our samples contained minor amounts of tritium, but all of meteoric origin (rain, snow or groundwater). We found no magmatic tritium in Sierra Negro and Alcedo volcanoes. But since the fluids of these Galápagos volcanoes have never been extensively sampled, in June we published a comparison of their hydrothermal characteristics (Goff, F., et al., 2000, Bulletin of  Volcanology, v. 62, p. 34-52).

Magmatic Tritium

The magmatic tritium project originated from the “cold fusion” controversy of the late 1980s. One of the more legitimate proponents of the theory that cold fusion occurs in Earth’s interior was Steve Jones of Brigham Young University. Jones postulated that one consequence of cold fusion in Earth’s interior might be excess tritium coming out of the deep earth in volcanic emissions. I had made a few measurements of tritium in magmatic fluids at Mount St. Helens, and Jones soon contacted me to pursue the study.

The tritium I had sampled merely showed contamination of magmatic fluids with young meteoric water (rain, snow or groundwater). Still, the U.S. Department of Energy granted a small amount of seed money Gary M. McMurtry of the University of Hawaii and me to further investigate anomalous tritium in magmatic fluids at St. Helens and Kilauea. Early results from investigations at these two volcanoes were ambiguous and attempts to publish preliminary results were shut down by scientific journals.

We then obtained additional funding through a proposal from Los Alamos’ Laboratory of Directed Research and Development to enlarge the scope of the project. I argued that consistent results were required from several volcanoes of different compositions and tectonic environments to settle the issue. Using these funds, McMurtry and I visited several more volcanoes from 1992 to 1996 collecting high-temperature magmatic fluids and analyzing them for tritium and other isotope and chemical constituents.

We found that tritium in such fluids was derived from mixing with meteoric waters or, in some cases, from seawater. Generally speaking, tritium content is inversely correlated with increasing temperature and geochemical constituents enriched in magmatic fluids (Goff, F., McMurtry, G.M. 2000, Tritium and stable isotopes in magmatic waters: JVGR, 97, 347-396).

Fraser Goff

Goff is a research geologist and geochemist who has worked on volcanic and geothermal projects throughout the world for the last 22 years at the Los Alamos National Laboratory in New Mexico.

Other Activity

Mount Oyama, which sits in the center of the small island of Miyakejima about 200 kilometers south-southwest of Tokyo, apparently became active June 27 following all-night evacuations of 2,500 residents. Scientists suspected an eruption on the west flank of the island, but discolored seawater and steam indicated an eruption on the submarine west flank about 1.8 kilometers from the coast.

An afternoon earthquake on July 1 of magnitude 6.1 jarred the Izu islands south of Japan and left one person dead from a landslide. The quake was centered 15 kilometers below the surface near Kozushima island.

Homemade hot air balloons in Brazil, used illegally during June festivals, ignited 16 separate fires that destroyed at least 88 acres of Rio’s rapidly diminishing Atlantic Rainforest — the largest single loss in the past two decades, said Major Fabio Meirelles, deputy commander of Rio’s Rainforest Firefighting Group. Hot air from burning, fuel-soaked cotton propels the balloons, which are traditionally used to honor Catholic saints and often carry hanging lanterns or fireworks.


Associate Editor Christina Reed compiles Geophenomena.