New York Times Features Desert Research Institute: Ancient Rome Was Teetering. Then a Volcano Erupted 6,000 Miles Away.
Excerpt from the article:
Scientists have linked historical political instability to a number of volcanic events, the latest involving an eruption in the Aleutian Islands.
Roughly 1,500 volcanoes are potentially active right now, meaning that they’ve erupted at some point in the last 10,000 years. While scientists today have sophisticated tools to monitor volcanoes, the vast majority of historical eruptions have gone unrecorded, at least by modern scientific instruments. Sussing out those eruptions requires patience and ingenuity, and a willingness to manage a lot of ice.
At the Desert Research Institute in Reno, Nev., it’s not unusual to find researchers in puffy parkas and wool hats handling chunks of ice in a minus 4 Fahrenheit “cold room.” Ice cores, typically drilled vertically from glaciers, hide bits of volcanic material that rained down from long-ago eruptions within their layers.
Joseph McConnell, a climate scientist at the institute, and his collaborators are in the business of looking for that debris. Using an instrument they designed and built, they melt the ice and pipe the water into an array of sensors. With hundreds of feet of tubing, the setup looks downright chaotic, but it’s exquisitely sensitive. The sensors pinpoint many substances, including about 30 different elements, and they do so by catching just tiny whiffs.
“They have sensitivities of parts per quadrillion,” Dr. McConnell said.
Volcanic ash, more generally known as tephra, sometimes hides in ice. It’s a special find because it can be geochemically tied to a specific volcano. “The tephra comes from the magma itself,” said Michael Sigl, a chemist at the University of Bern in Switzerland who collaborates with Dr. McConnell. “It carries the composition of the rocks.”
Sulfur is also indicative of a past eruption. Sulfur dioxide, a gas commonly belched by erupting volcanoes, reacts with water in the atmosphere to create sulfate aerosols. These tiny particles can linger in the stratosphere for years, riding wind currents, but they, like tephra, eventually fall back to Earth.
The ice also carries a time stamp. Dr. McConnell and his colleagues look for variations in elements like sodium, which is found in sea spray that’s seasonally blown inland. By simply counting annual variations in these elements, it’s possible to trace the passage of time, Dr. McConnell said. “It’s like a tree-ring record.”
Dr. McConnell and his collaborators recently analyzed six ice cores drilled in the Arctic. In layers of ice corresponding to the early months of 43 B.C., they spotted large upticks in sulfur and, crucially, bits of material that were probably tephra. The timing caught the scientists’ attention.
Read the full article from the New York Times here.