The magma that fed the eruption of Costa Rica’s Irazú volcano traveled from the deep earth to the surface in mere months, says a new study in Nature. (Rafael Golan)
Nature, scientists suggest that the 1960s eruption of Costa Rica’s largest stratovolcano was triggered by magma rising from the mantle over a few short months, rather than thousands of years or more, as many scientists have thought. The study is the latest to suggest that deep, hot magma can set off an eruption fairly quickly, potentially providing an extra tool for detecting an oncoming volcanic disaster.
, a volcanologist at Columbia University’s
Lamont-Doherty Earth Observatory
. “We could have had an early warning of months, instead of days or weeks.”
Towering more than 10,000 feet and covering almost 200 square miles, Irazú erupts about every 20 years or less, with varying degrees of damage. When it awakened in 1963, it erupted for two years, killing at least
and burying hundreds of homes in mud and ash. Its last eruption, in 1994, did little damage.
Volcanologist Philipp Ruprecht analyzed crystals formed as Irazú’s magma cooled to establish how fast it traveled. (Kim Martineau)
, a geochemist at Lamont-Doherty. “We like to call it the highway from hell.”
to magma rising from the mantle-crust boundary. In 2010, a chain of eruptions at Iceland’s Eyjafjallajökull volcano that caused widespread flight cancellations also indicated that some magma was coming from down deep. Small earthquakes set off by the eruptions suggested that the magma in Eyjafjallajökull’s last two explosions originated 12 miles and 15 miles below the surface, according to
a 2012 study
by University of Cambridge researcher Jon Tarasewicz in Geophysical Research Letters.
with saving as many as 20,000 lives.
Spikes of nickel in the crystals indicated the magma was still relatively fresh. (Kim Martineau)
for Wired magazine. “In volcanic hazards you have very few shots to get people to leave.”
Nature study also provides a real-world constraint for modeling how fast magma travels to the surface. “If this interpretation is correct, you start having a speed limit that your models of magma transport have to catch,” said Tom Sisson, a USGS volcanologist based at Menlo Park, Calif.
, whose ideas inspired the study. “It’s clearly not a local phenomenon,” she said. The researchers are currently analyzing crystals from past volcanic eruptions in Alaska’s Aleutian Islands, Chile and Tonga, but are unsure how many will bear Irazú’s fast-rising magma signature. “Some may be capable of producing highways from hell and some may not,” said Ruprecht.