Indonesia’s towering Puncak Jaya mountain straddles one of the world’s richest and most inaccessible gold and copper mines. But the scientists currently prospecting on the 16,000-ft peak are digging for a different kind of treasure: fragile ice cores that can yield clues to the climatic past and give pointers on the future.
Jutting up from the island of New Guinea, which is split between the Indonesian province of Papua and the independent nation of Papua New Guinea, the mountain’s slopes hold some of the only tropical glaciers in the world. Scientists study ice cores as a proxy for climatic data stretching back thousands of years. The data can be used for climate modeling to understand how natural cycles work and to predict the impact on manmade warming on temperature and precipitation.
For Lonnie Thompson, an alpine glaciologist at Ohio State University and a leading authority in the field, climbing Puncak Jaya completes a longtime ambition. Speaking Friday by phone from the expedition’s campsite 120 meters below the peak, he said it was a race against time as a warming planet was already taking its toll on the ice.
“It’s melting and retreating very quickly. We want to capture its history while it’s still possible,” he says.
The six-person expedition team includes Indonesian oceanographer Dwi Susanto of Columbia University’s Lamont-Doherty Earth Observatory (LDEO), who studies the Pacific Ocean and the El Nino system that brings either drought or rainfall to Indonesia. The ice-core data can complement other proxies of oceanic temperature oscillations such as seabed samples and tree rings.
Thompson says the team, which arrived last month in Indonesia and scaled the peak earlier this week, had drilled down 16 meters on the first day. Over the weekend they hoped to dig as deep as 40 meters, using extendable drill bits only 100 mm thick, and to wrap up their expedition by the end of the month. (Follow the team’s expedition on its blog.)
The extracted ice cores are laid flat in three customized freezers, to be airlifted out later by helicopters provided by Freeport McMoRan, the US-based company that operates the nearby Grasberg mine and is assisting the team. The expedition is also supported by Indonesia’s Meteorological, Climatological and Geophysical Agency. The expedition was delayed for a week when several pieces of equipment were left behind at customs in Jakarta, including essential drill bits.
The final challenge for Mr. Thompson, who led a similar expedition last year to the Peruvian Andes, will be to ship them back from equatorial Indonesia to Ohio State where they will be stored at -30 degrees C. His other samples include ice from peaks in China, Peru, and Kenya’s Mount Kilimanjaro, another tropical glacier.
Puncak Jaya is blanketed daily in fog and rain, as well as lightning storms that pose a risk to the drillers. Thompson says he wanted to stay as long as it takes to get the best samples, probably a few more days. The cores extracted Friday contain compacted animal and plant matter and other substances that record atmospheric changes, as well as the isotopes of the frozen water, all essential to reconstructing the complex climatic patterns of the western Pacific.
“This is the first time [drilling Puncak Jaya], and I guess it will be the last time,” he says, referring to the shrinking ice cover.