Science reports on an Icelandic project going to a whole new level – they’re following the Krafla Volcano’s path and digging beyond the Earth’s crust into magma:
In 2009, drillers trying to tap hot water for geothermal energy here accidentally pierced a hidden magma chamber. After an outpouring of steam and glass shards from quenched magma, the borehole created the hottest geothermal well ever measured—until the casing failed.
Now, researchers are returning to penetrate the molten rock on purpose, using hardier equipment, to create the world’s only long-term magma observatory. “We’ve been to Mars. We’ve been to Venus,” says Paolo Papale, research director at Italy’s National Institute of Geophysics and Volcanology. “But we have never observed magma below the Earth’s surface.”
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Unable to study magma directly, volcanologists rely on surface measurements from seismometers, GPS sensors, and radar satellites to guess its movements. They can examine solidified magma chambers exhumed by Earth’s upheavals—but those remnants are incomplete, selectively depleted by ancient lava flows. They can study lava at the surface, but the samples have by then lost most of the trapped gases that drive eruptions and influence the magma’s original temperature, pressure, and composition. Crystals, inclusions, and bubbles in the hardened lava hold clues to its original state. But a sample from the Krafla chamber will tell researchers whether those estimates “are fictional or reliable,” says John Eichelberger, a volcanologist at Southern Methodist University and KMT leader.
Getting a sample will also reveal the true nature of the magma chamber. Most scientists reject the cartoonish view of magma chambers as hellish underground lakes. “We think of these systems as a mush”—small amounts of liquid between crystallized grains—“rather than a liquid balloon,” says Marie Edmonds, a petrologist at the University of Cambridge.
But Krafla, which last erupted in 1984, may be an exception. The glassy bits from the 2009 drilling campaign hinted that the magma was not only liquid, but also circulating, interacting with melt lower down. “That’s the most shocking thing from what little we’ve gleaned so far,” Eichelberger says. But little is known about the magma chamber’s size or how long it has persisted—questions KMT can help answer. “It’s seeing through a glass darkly, as it were,” Eichelberger says.
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KMT intends to collect multiple samples over time and embed sensors in and near the magma to measure heat, pressure, and even chemistry despite temperatures of more than 1000°C. “The technical challenges are formidable,” says Wendy Bohrson, a volcanologist at the Colorado School of Mines. KMT’s drilling partners are testing flexible couplings that can allow the steel liner of the well to expand and contract with extreme heat. And others are developing innovative electronics to withstand the heat and pressure, which could someday be used on Venus.
The technologies could also benefit Iceland’s many geothermal energy companies, which have shied away from the hottest rock.