But even though the Taupo diatom shells are pristine, Theriot is doubtful any diatoms lived through the eruptions. Instead, he suspects diatom resting spores could travel the atmospheric currents, dropping out and colonizing new ecosystems. Diatoms fashion spores to ride out inhospitable changes in their environment. Two years ago, Danish researchers revived 100-year-old resting spores from muck in a local fjord. Resting spores have been found in clouds. The eruption could have launched spores from the lake bottom into the atmosphere, Theriot said.
"I and many others have joked about Yellowstone blowing up again and dispersing the diatomite that is being created at the bottom of Yellowstone Lake," Theriot said. "This is the most thoroughly studied and best documented example of this phenomenon, and so it really says maybe we can add volcanoes to the list of possibilities (of how diatoms spread). And volcanoes would be particularly effective." (Infographic: The Geology of Yellowstone)
Van Eaton hopes the discovery will prompt other scientists to search for microscopic life in "wet eruptions," where magma hit water.
"This is potentially another tool to pinpoint where ash deposits come from," Van Eaton said. "If the work is done to characterize the kinds of microbes that are unique to an area, then it could give you a biogenic fingerprint for your eruption deposits. This has likely been going on in modern eruptions, but no one has taken the time to look for them."
Ash travels hundreds of miles, but once it's far from its source, linking a few inches of glass back to a single volcano becomes difficult, particularly in regions like the South Pacific, where volcanoes pop off all the time.
But Theriot is skeptical that diatoms will prove to be a useful tool for tracking volcanic ash. Diatoms are so global that endemic species — known only to one place — are hard to find, he said. "If you found diatoms in ash deposits in a bog in Ohio, you would have no idea if it was from Yellowstone or from that bog," Theriot said. "It would take a really extraordinary set of circumstances, like this New Zealand (diatom) that is clearly out of place, to be convincing that the diatoms had blown in with the ash."
Email Becky Oskin or follow her @beckyoskin. Follow us @OAPlanet, Facebook & Google+. Original article on LiveScience's OurAmazingPlanet.
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