Photo courtesy of David Noone

The National Science Foundation Ice Core Facility holds records so old, they make those at the Library of Congress, the University of Cambridge, and the Vatican Apostolic Archive seem like new releases. Instead of manuscripts, though, the “documents” at this U.S. Geological Survey–managed warehouse in Lakewood, the only one of its kind in the country, are archaic pieces of frozen matter. Scientists drill the samples, called ice cores, from deep within glaciers and ship them to this facility, where they’re stored in meter-long chunks at minus 36 degrees Celsius. (The suburb is convenient because it’s near a major airport and the low humidity here minimizes pesky frost buildup.) Preserved within the cores are accounts of Earth’s climate from long before humans were around to record data. The chilly ledgers exist thanks to the way glaciers form: New snowfall lands atop old, compressing over time into striated ice formations. “Just about anything that went into the atmosphere is recorded in the ice,” says Geoffrey Hargreaves, head curator at the facility—meaning researchers can glean past concentrations of greenhouse gases and better guide policies such as the Paris Agreement. This month, the repository will receive a roughly 2.5-million-year-old specimen from Antarctica, the oldest core ever drilled. Groups can view the ancient ice during free tours of the facility (make an appointment several months in advance at Just bring your curiosity—and a warm coat.

Hard Core History

Three important samples at Lakewood’s National Science Foundation Ice Core Facility.

The First: Camp Century Core

After three years of drilling, the last piece of the 1,390-meter Camp Century Core was extracted from Greenland’s ice sheet in 1966. The first core ever recovered and a chronicle of the past 100,000 years, it allowed Danish scientist Willi Dansgaard to chart changes in historical temperatures, birthing modern climate science.

Photo courtesy of Jim West/Alamy Stock Photo

The (Second) Longest: West Antarctic Ice Sheet (WAIS) Divide Core

At longer than two miles, WAIS is the lengthiest sample extracted by a U.S. team. Pulled from near the South Pole in 2012 and going back 68,000 years, its segments record volcanic eruptions such as the 1815 blast at Indonesia’s Mt. Tambora, which triggered climate cooling and global famine.

The Most Recent: South Pole Ice Core (SPICE)

Scientists drilled the newest continuous* core from 2014 to 2016. Its layers reveal (only) the past 50,000 years or so. Its youthfulness may help us understand why the South Pole has shown little to no warming over the past few decades, unlike the rest of Antarctica.

*A continuous ice core includes layers that formed around the time drilling began.