See photos of a Swiss glacier melting in the heat of climate change

RHONE GLACIER, Switzerland — Drip, drip. Trickle, trickle.

That's the sound of water seeping from a sunbaked and slushy Swiss glacier that geoscientists are monitoring for signs of continued retreat by the majestic masses of ice under the heat of global warming.

In recent years, glaciologists like Matthias Huss of the Federal Institute of Technology in Zurich, known as ETHZ, and others have turned to dramatic measures to help protect glaciers like the Rhone Glacier, which feeds into the river of the same name that runs through Switzerland and France.

One of those desperate steps involves using giant sheets to cover the ice like blankets to slow the melt.

Switzerland is continental Europe's glacier capital, with some 1,400 that provide drinking water, irrigation for farmland in many parts of Europe including French wine country, and hydropower that generates most of the country's electricity.

The number has been dwindling. The Alpine country has already lost up to 1,000 small glaciers, and the bigger ones are increasingly at risk.

Drilling into glaciers to track what's happening inside

Huss hosted The Associated Press for a visit to the sprawling glacier this month, as he carried out his first monitoring mission as summer temperatures accelerate the thaw. Under normal conditions, glaciers can regenerate in the winter, but climate change is threatening that.

''I always say glaciers are the ambassadors of climate change because they can spread this message in a very understandable way," Huss said. "They also cause good feelings because glaciers are beautiful. We know them from our holidays.''

The vast expanse of blue, gray and white ice is riddled with cracks and grooves, and Huss says his teams at the Swiss GLAMOS glacier monitoring group have spotted a new phenomenon in Switzerland: holes appearing beneath the surface that at times widen so much that the ice above collapses.

Huss uses an auger to bore into the ice, sending frosty chips upward as if from a gushing fountain. It's part of a process that involves using stakes and poles to track ice loss from melting.

A better understanding of glacier melt

Huss monitors melting not just at the top but also from the base of glaciers.

''Normally glaciers melt from the top because of the warm air, because of their radiation from the sun. But in recent years we realized at several sites that there is a substantive melt from the bottom,'' Huss said. ''If there are some channels in the ice through which air is circulating, this can excavate big holes under the ice.''

The Alps were covered with ice 20,000 years ago, but no more. It's the same story elsewhere. Experts have warned that some two-thirds of the world's glaciers are set to disappear by the end of this century

Huss says only humans can help save them.

''It's difficult to save this very glacier because it could only be saved — or at least made to retreat slower — by bringing down CO2 emissions," he said. 'But everybody can contribute on their own to reduce CO2 emissions as far as possible."

''This will not help this glacier immediately, but it will help all glaciers in the long range,'' he added. "This is the important thing that we should think of if we see this melting ice and this big retreat — that it's time to act now.''

A glacier gives way, and a village is destroyed

The concerns about Switzerland's glaciers intensified recently after the southwestern village of Blatten, tucked near the Birch Glacier, was largely destroyed by a slide of rock and glacier ice in May. The village had been evacuated ahead of the slide, which covered dozens of homes and buildings and left just a few rooftops visible.

A review of data showed that the Birch Glacier was a rarity in that it has been advancing while most glaciers have been receding. And its advance had been increasing in recent years, to the point that it was flowing at about 10 meters (about 30 feet) per day shortly before the collapse — a rate Huss called ''completely unsustainable.''

Huss said the landslide was triggered by rocks piling onto the glacier, though he also called Birch's advance a ''precursor."

The main takeaway from the Birch Glacier collapse, Huss says, is that ''unexpected things happen.''

''If you ask me, like three weeks ago, nobody would have guessed that the whole village is going to be destroyed,'' he said. "I think this is the main lesson to be learned, that we need to be prepared.''

___

AP journalist Jamey Keaten in Geneva contributed to this report.

___

The Associated Press' climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP's standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.