Mount Erebus Spews 80 Grams of Gold Dust Daily Across 1,000 Kilometers

Q: What unique volcanic process forges perfect gold crystals in Antarctica, a mystery unsolved for decades?

No one knows for sure yet. After more than three decades of study, scientists still have not identified the exact process that lets Mount Erebus forge and eject its tiny, perfectly shaped gold crystals. The leading explanation is that gold escapes the magma in volatile chlorine-bearing gases. As those gases cool above Erebus’s persistent lava lake, the gold may crystallize into pure, faceted particles rather than irregular dust. But researchers say that model is hard to prove because the gas contains very little gold, making spontaneous crystal growth in the plume difficult to explain. A second hypothesis is that the crystals form more slowly on a crust at the surface of the lava lake, then get lifted into the air by rising volcanic gases. That could better account for the crystals’ geometric shapes, which are unlike the more common trace gold chemically detected at other volcanoes. What makes Erebus exceptional is not just that it emits gold, but that the particles are pure, crystalline, and sharply formed—some up to about 60 micrometers across—and are dispersed as far as 1,000 kilometers from the volcano. Researchers including Kimberly Meeker and Philip Kyle documented these particles in snow near the crater, in the gas plume, and in the Antarctic troposphere. So the mystery remains: Mount Erebus appears to create gold crystals either by gas-phase crystallization or by growth on the lava lake surface, but the precise mechanism is still unsolved.

Q: If an Antarctic volcano spews thousands of dollars in gold daily, why is this treasure left untouched?

The gold is left untouched because Antarctica’s legal regime bars commercial mining, and because Mount Erebus’s “treasure” is not a practical ore deposit anyway. Under the Antarctic Treaty System and the 1991 Madrid Protocol, Antarctica is reserved for peace and science, and activities related to mineral resources are prohibited except for scientific research. That means no company or country can legally mount a gold-recovery operation at Erebus. The protocol’s protections are designed to prevent industrial exploitation of one of the world’s most fragile environments. Even without the legal ban, the economics are poor. Erebus emits only about 80 grams of gold a day, and not as nuggets or veins that can be mined, but as microscopic crystals up to about 60 micrometers across. Those particles are dispersed in volcanic gas, snow and the atmosphere, sometimes as far as 1,000 kilometers away. Collecting enough of that dust to make a profit in Antarctica’s extreme conditions would be extraordinarily difficult and expensive. The setting adds another barrier. Erebus is an active volcano with a persistent lava lake, toxic gases, severe cold, ice-covered terrain and remote logistics. Any recovery effort would face major safety risks and high transport costs. So the “thousands of dollars in gold” makes for a striking headline, but in practice it is legally off-limits, scientifically more valuable than commercially useful, and physically too diffuse and dangerous to exploit.

3 articles · Updated · ScienceAlert · Jun 29

Scientists found Mount Erebus emits about 80 grams of microscopic crystalline gold each day, with particles detected in Antarctica as far as 1,000 kilometers from the volcano.
Samples from crater snow, the gas plume and the Antarctic troposphere all contained pure gold crystals—some up to 60 micrometers wide—making Erebus the only known volcano to eject elemental gold in crystalline form.
Researchers think the gold rides out in chlorine- or sulfur-bearing volcanic gases and crystallizes as those gases cool, though another model suggests it forms on the lava lake surface before being lofted upward.
The mechanism remains unresolved more than 30 years after the 1991 study, even though other volcanoes including Kilauea and Etna have shown chemically detectable gold in larger estimated daily amounts.