Jökulsárlón glacial lagoon has grown a great deal since it first appeared in the 1930s, when Vatnajökull glacier began retreating, Vísir reports. Since then, the glacier has continued retreating, at an increasingly fast rate. There is every indication that in the end, the lagoon, which is Iceland’s deepest, will become a long fjord.
In 1890, the glacier covering the lagoon was no more than 250 m (820 ft) from the ocean. Then, the lagoon first appeared in 1934 and has been growing ever since. At present, it reaches 7-8 km (4-5 mi) inland, but could eventually become 25 km (15.5 mi) long and 5 km (3 mi) wide.
According to Helgi Björnsson, geophysicist, the glacier has retreated exceptionally fast since 1995. It is a clear sign, he stated, of a warming climate in Iceland. Not only that, but at high tide, warm ocean water flows into the lagoon, melting the ice.
“What happens is that the glacier moves down to the lagoon, and parts of it constantly break off. The glacier can’t keep up with making up for what breaks off, which is why it retreats. All ice floes that break off float on the lagoon and eventually melt,” Helgi explained.
Here, you can watch a series of aerial images that show how the glacier has retreated since 1984.
Measurements indicate that from the bridge over Jökulsá river, the land under the glacier extends 200-300 m (650-980 ft) below sea level in a narrow fissure, 5 km wide and 25 km long.
“There will likely be a 25-km long fjord extending in there,” Helgi predicted, but added that it will likely be closed off from the ocean, as it is today.