Image: Laurence Dyke

Satellites have changed how we see the world. That includes being able to watch climate change overrun everything beautiful in agonizing detail.

Behold, the Petermann Glacier, a wending trail of ice that descends from Greenland’s ice sheet down to an icy tongue sticking out over a fjord on the island’s northwest edge. The animation above, a recently-released time lapse from spring to fall 2016, shows the seasonal shifts on one of Greenland’s most important pieces of ice.

Because of its direct link between the ice sheet and open water, Petermann Glacier is a crucial doorstop. If it disappears or shrinks, more land ice can flow into the ocean, which in turn raises sea levels. The Greenland ice sheet contains enough ice to raise sea levels by 20 feet.

While losing Petermann Glacier wouldn’t unleash all that ice into the ocean, its connection to the interior ice sheet means monitoring it is crucial to understanding what comes next for coastal communities. Satellite data from the Landsat 8 and Sentinel-2 satellites owned by the U.S. and European Union respectively are one way for researchers to keep an eye on one of the most remote corners of the world.

Laurence Dyke, a postdoctoral researcher at The Geological Survey of Denmark and Greenland, used the amazing wealth of imagery Landsat 8 sends back each day to show six months of the glacier’s life.

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They were an eventful six months. The animated map shows growing cracks visible on the left side of the ice. Those cracks will eventually spread across the entire face of the glacier, unleashing a massive iceberg.

The glacier has had two other recent major calving events, one in 2010 and another in 2012, that reshaped its face. When that happens, the glacier will be at its smallest size in recorded history.

The glacier did calve a fairly hefty chunk of ice this summer. Satellite imagery from July shows that the cracks have clearly expanded since Dyke’s animation and new ones have formed, but they have yet to fully reshape the glacier’s outlet.

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The animation paints an ominous picture of climate change being realized, but it’s also easy to get lost in the beauty of the changing landscape. Far from being a completely frozen wasteland, Greenland’s landscape is remarkably dynamic.

Shadows ebb and flow as the seasons change. Sea ice melts away, turquoise blue melt ponds appear, and snow disappears from the peaks rising more than 3,000 feet above the cold waters below with summer’s arrival.

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While climate change won’t alter Earth’s orbit around the sun, the animation reveals the other natural processes that climate change is slowly messing up in Greenland. And each tweak to Greenland’s ice will eventually end up on the shores of coasts much closer to home.

[EGU Blogs]