POINTS OF VIEW:
Gordon Hamilton, University of Maine
That would start to collapse the ice sheet very rapidly in ways that we don’t yet aren’t don’t yet appreciate and that could remove a large amount of the Greenland ice sheet quite quickly.
Jason Box, Byrd Polar Research Center
I didn’t expect the temperature trends to manifest themselves this clearly in ice sheet acceleration. We know that the temperatures have gone up but to see this rapid response has been a surprise to the science community.
Greenland is an island nation locked in what seems like a never changing state of deep freeze. However, scientists recently discovered that this polar ecosystem is changing, and at a pace that is sounding alarm bells around the world.
|Scientists setting up camp on glacier
It happened during a recent expedition to the southeastern coast of Greenland. When their research ship arrives, glaciologists load equipment onto a helicopter and set off in search of a staple landing area to setup camp. Their destination is the Kangerdlugssuaq glacier. At almost five miles across and over three thousand feet thick, this is one of Greenland's largest ice fields.
When the scientists reach the glacier they begin installing a series of GPS sensors. Their mission is to measure the movement of the glacier, as it transports frozen water from the ice sheet to the ocean. Although it's almost impossible to see glacial movement with the naked eye, when time-lapse photography compresses eight hours into a few seconds, it becomes more apparent.
Once back aboard the ship the scientists begin calculating the glacier’s speed. They discover that it's moving at the rate of nine miles per year, 125 feet per day. Everyone is stunned. The speed of the glacier's march to the sea has tripled in just ten years. The implications are shocking. Once a glacier picks up speed, it's almost impossible to slow it down.
|Scientists explore melt-water lakes
The speed of the glacier's march to the sea has tripled in just ten years.
But there still remains one unsolved mystery. What is causing the glaciers to speed up? Some believe the answer is tied to the melt-water lakes that form on the ice sheet during the summer months. The team begins to investigate one of the larger lakes. It's just under a mile in diameter.
They decide to take a closer look. Though melt lakes forming in the warmer months is not new phenomenon, they are now developing more frequently and at higher elevations. This is clearly a sign of global warming.
The glaciologists then uncover the connection they were looking for, the relationship between the lakes and the racing behavior of the glaciers. They discover that many of the lakes empty into rivers that feed into deep cracks in the ice. From there the water falls straight down.
Scientists believe that when the water from the lakes reaches the bottom, it lubricates the flow of the glacier over the bedrock. This speeds up the movement of the glacier, increasing the volume of ice falling into the ocean. The problem is, every time glacial ice falls into the sea, it contributes to global sea-level rise. If global temperatures continue to rise, more melt-water lakes will form, and more ice will speed its way to sea.
Scientists now estimate that one third of global sea level rise comes from the Greenland ice sheet. If the entire ice sheet should melt the oceans of the world would rise by a catastrophic 23 feet. Fortunately, scientists tell us that the possibility of the disappearance of Greenland's entire ice sheet is centuries away. But, at the current rate of melting, within a few decades rising seas will have profound effect on the low-lying countries of the world.
Read more about The State of the Planet's Oceans:
Introduction | Aveiro | Belize | Calcutta
| Dry Tortugas
| Greenland | Lima | New Bedford