Swiss and Italian researchers are digging near the summit of Monte Rosa on the Italian border in search of secrets locked deep within the ice.
They hope to reveal what sort of pollution the Romans caused and how the climate has changed over the past 10,000 years.
Ice is a natural archive that can store a wealth of information about the past: volcanic eruptions, Sahara sand storms and nuclear tests carried out on the other side of the world.
“Anything that is emitted into the air will ultimately be captured in the ice as a result of precipitation,” says Professor Heinz Gäggeler of the Paul Scherrer Institute (PSI), one of the top scientific research institutions in Switzerland.
“The quality and consistency of the various glacial layers can take you back to the climatic situation of any given era.”
For some time now, the PSI has been exploring glaciers all over the world: in Chile, Siberia, Argentina, Ecuador, the Antarctic and even in Switzerland. But never before have its researchers analysed a glacier more than 500 years old.
On the Monte Rosa’s Colle Gnifetti, at 4,452 metres above sea level, researchers hope to find ice that is at least 10,000 years old.
“It’s a perfect place,” says Heinz Gäggeler, as the helicopter pilot battles the wind to reach the Colle.
“High altitude, limited precipitation, fairly flat terrain – these are ideal conditions for a glacier to grow in a steady but contained manner while conserving its secrets."
It is a sea of ice that has been known about and studied for some time. A team of six researchers from the PSI and the University of Venice recently spent nearly a week here.
The working conditions are harsh: intense cold, gusting winds and altitude-related problems, such as disturbed sleeping patterns.
The plan is to drill through the ice down to the bedrock, hundreds of metres below, and to take samples about 70cm long from the ice core.
The deeper the team digs, the further they go back in time. Laboratory analysis will be conducted over the next few months to determine exactly how far.
Lead from Roman times
Paolo Gabrielli, a PhD student at the University of Venice, is one of those studying on the Colle.
Sheltering in a wind-swept tent over the drilling hole, in temperatures of minus 30 degrees Celsius, he explains the hopes of the mission.
“We'd like to find data covering the 10,000 years since the last Ice Age,” he says.
“It would be a record for an Alpine glacier. It could also confirm what we saw in a glacier in Greenland: major emissions of lead or copper dating back to the ancient Greeks and Romans.”
Both civilizations mined metals on a large scale. The noxious emissions into the atmosphere would have left traces in the environment that can still be examined today.
Ice thus acts as an archive of past events; but it is a threatened archive, at the mercy of global warming, which is steadily reducing the mass and volume of the ice.
“And this is precisely why we are seeking every opportunity to study a glacier,” says Heinz Gäggeler. “We wouldn't want to lose ancient data before we can record it.”
swissinfo, Marzio Pescia, Colle Gnifetti-Zermatt
Ice is a natural archive - past volcanic eruptions, Sahara sand storms and nuclear tests can be detected in its layers.
Analyses of ice in Greenland suggest that the Romans and Greeks were prolific polluters.
Global warming is steadily reducing the mass and volume of the ice, threatening to deprive science of this valuable archive.