Journey to Mount Doom

By Bill Harby

By the time you get this magazine, Brian Kastl ’07 will be off on his trek to towering “Mount Doom” of Lord of the Rings fame. Though he won’t be going to fling the dangerous One Ring into the volcano’s maw, Kastl will clearly be helping the forces of good. He is visiting Mount Ruapehu—the New Zealand volcano that played the part of Mount Doom for close-up shots in the famous film trilogy—to research the potentially deadly volcanic phenomenon known as a “lahar.”

A lahar is a fast-moving volcanic mudflow that can be “tremendously violent,” says Kastl, whose Ruapehu research is for his Ph.D. in volcanology at the University of Hawaii at Manoa. The avalanche of sludge normally builds as it races down the mountain, scooping up everything from house-sized boulders to fine silt. In Colombia, the 1985 eruption of Nevado del Ruiz caused lahars that buried a city and killed some 23,000 people.

Kastl hopes the field research he is set to conduct in January and February, focused on a Ruapehu lahar that took place a year earlier, will help avoid such tragedy. He and his adviser from the University of Hawaii will lug instruments and gear up cinder roads and trails to collect samples. By hammering away at rock samples and analyzing them, gathering GPS topography data of the mudflow, they will formulate computer models they hope will predict lahars—their path, volume, velocity and reach—not just on Mount Doom, but at other volcanoes.

Mount Ruapehu—at 9,174 feet, the tallest mountain on New Zealand’s North Island—commonly sees lahars during its frequent eruptions (46 since 1861, says Kastl, who, of course, is hoping for 47 while he’s there). The lahars are caused by an active vent beneath a crater lake near the snowy summit. When Kastl is perched there gathering data, he won’t be tempted to warm up by jumping into the lake. It contains sulfuric acid.

Growing up in Washington state, Kastl visited Mount St. Helens when he was about 12. It was a “pivotal experience,” he says. “You could look right into the guts of this volcano.”

His mechanical engineer father gave him an early appreciation for science. His mother, a teacher and native of Switzerland, gave him a thirst for different cultures.

As a geology undergrad at Pomona, Kastl went to Cape Town, South Africa, for six months to study non-volcanic debris flows not unlike lahars, and to teach disadvantaged township students about geography, an experience he found inspiring.

He has also studied volcanology in Kamchatka, Russia, and later, Mongolia. “Talk about a cool field excursion—we traveled for three days over treacherous roads, then would hike in three hours every single day just to get to our site, collecting samples to do this geo-chemistry research later in the lab.”

Kastl points out that his lahar research on Ruapehu wouldn’t be possible if it weren’t for the native Maori people. “A lot of volcanologists have pushed to eliminate this [lahar] hazard entirely by draining the crater lake on top of Ruapehu. But they’ve been unsuccessful because the Maori are opposed to that, as it messes with Mother Nature. And that’s understandable. Even scientifically speaking, they’re right. You shouldn’t divert them; you really need to let them carry out their natural course so the landscape can reach a state of equilibrium.”

Kastl’s only experience with an actively erupting volcano was last year during his first semester at the University of Hawaii. In a helicopter with other students, he flew low over the fiery lava flows from Kilauea volcano on Hawaii Island. It was a drop-jaw experience, but not the sort of thing he expects to see often. “Most of the volcanoes I’m interested in are explosive in nature, not effusive like the eruptions you get at Kilauea.”

Soon Hawaii will be half a world away for this grad student, and he’s not likely to be back for a year. That’s because, after he finishes his lahar work at Ruapehu, he will go on leave of absence from University of Hawaii, as planned, and hook up with another adviser at the University of Auckland for a master’s project—a year’s research thanks to a Fulbright grant.

Kastl’s Fulbright is one of a record 25 of the prestigious grants awarded to Pomona College students last year—more than any other liberal arts college in the country.

His project is on Mount Tongariro, just a couple miles from Ruapehu. He will analyze a particular lava flow that’s a mere 10,000 years old—a blink of an eye in geologic history. There, he and his professor will look at “eruption triggering mechanisms” in hopes they can “recreate” that eruption to predict future ones.

The research consists of collecting samples of ash deposits and lava rock from violent pyroclastic flows (fast-moving torrents of super-hot gas and rock), then determining in the lab the mineral composition of the various samples.

“Each lava has its own little genetic code,” says Kastl, “and you can identify the different types of magma based on the assemblages of these minerals.” From this information he’ll be able to determine the source of the flow, the depth of the magma chamber, even the ascent rate. “It’s pretty remarkable,” he says.

Like Kastl’s work with lahars on Mount Doom, his year of Tongariro research may save lives one day. “If we can better understand what activity precedes eruptions, we will be more successful in deciphering whether something like a low-frequency earthquake is just background noise or if it means a catastrophic eruption is imminent.”

While in New Zealand, Kastl is also excited about volunteering to mentor high school students, as he did in Cape Town. “It’s fun and easy to get students excited about the incredible forces of nature,” he says. He even knows several ways to mimic
mini-volcanic eruptions in the classroom.

Should be a blast.