This deep-blue iceberg was beached at Jökulsárlón Strandur in Iceland shortly before midnight in midsummer. Encircled by gentle waves during low tide, it awaits its fate as the rising waters of the Atlantic return.
These icebergs originate in the tidal proglacial lagoon of Jökulsárlón at the margin of the Vatnajökull ice cap. Because ice is less dense than water, about 90 percent of a floating iceberg’s volume remains below the water surface. As a result, the largest icebergs become grounded at low tide on large boulders that form part of the rocky barrier and terminal moraines damming the tidal lagoon.
The narrow Jökulsá channel connects the Atlantic Ocean with the glacial lagoon and reverses its flow direction twice a day. As the tide rises, seawater flows into the lagoon, raising the water level and freeing the grounded icebergs. They begin to rotate in large circles across the lagoon, revealing the currents in the water. As the tide falls again, the Jökulsá reverses direction and carries an entire armada of icebergs out toward the Atlantic. There, they are immediately battered by the waves, which crush them into smaller fragments amid spectacular sounds. Only the largest icebergs survive long enough to return to the shore and become temporarily stranded along the Jökulsárlón coastline at low tide. The spectacle repeats itself twice every day.
This particular iceberg rises 2.5 meters (8 feet) above the water. Its deep-blue color results from the preferential scattering of short blue wavelengths of light within the densely compressed ice. This ice formed from snow that fell on the Vatnajökull ice cap about 1,000 years ago. The fractured structure reveals the immense pressure and tension the ice endured while still part of the glacier. These zones of weakness eventually cause the iceberg to break apart rapidly in the surf.
Every beached iceberg is unique, and the scenery is so ephemeral that within just a few hours, the rising tide can erase all trace of these fleeting beauties.
