The glacier is in Peru's Cordillera Blanca
Images taken from space are being used to monitor a potentially dangerous glacier in Peru.
A US space agency (Nasa) satellite is sending back data on a glacier that feeds Lake Palcacocha in the Andes.
Government officials and geologists are concerned that a large ice chunk could break off and fall into the lake.
They are monitoring the situation closely, in case it triggers a flood, threatening the city of Huaraz in the Rio Santa Valley below.
The images are being captured by a US/Japanese instrument on Nasa's Terra satellite.
Project scientist Dr Michael Abrams said remote sensing instruments like Aster (Advanced Spaceborne Thermal Emission and Reflection Radiometer) served a vital role in hazard management.
"In Huaraz, Peruvian authorities and scientists will incorporate Aster data along with data from ground-based monitoring techniques to better assess current conditions and take steps necessary to reduce risks to human lives and property," he said.
Glacial flood-bursts, known locally as "aluviones," occur when water is released suddenly from a lake within a glacier.
The burst of water can carry a stream of mud, rock boulders and blocks of ice through any settlement it encounters.
This has happened many times in the Rio Santa Valley since the 18th Century.
One particularly devastating event in 1941 killed an estimated 5,000 to 7,000 people.
Since then, the Peruvian Government has tried to control the water level in Lake Palcacocha and other potentially hazardous lakes in the region.
The efforts appear to have worked and there have been no destructive glacial floods since 1972.
But officials are monitoring the current situation closely in case emergency plans have to be implemented.