Greenland, the world's largest island, is known for its vast ice sheet and frigid temperatures. But beneath the frozen surface, a surprising phenomenon is taking place: the land is rising, creating new islands and reshaping the country's landscape.
How Greenland's Bedrock is Elevating
The elevation of Greenland's bedrock is a result of two factors: the melting of the ice sheet and the rebound from the last ice age.
The ice sheet that covers most of Greenland is about 3 kilometers thick and weighs more than 2.5 million billion tons. As the ice melts due to global warming, it reduces the pressure on the underlying ground, allowing it to spring back up.
This process is called isostatic adjustment or post-glacial rebound.
According to a new study by the Technical University of Denmark (DTU Space), Greenland's bedrock has risen up to 20 centimeters over the past 10 years from 2013 to 2023, equivalent to 2 meters per century.
This uplift will continue in the coming years, driven partly by the melting of the ice sheet on top.
But the ice sheet is not the only factor that affects the land elevation. Greenland was also covered by a much larger ice sheet during the last ice age, which ended about 12,000 years ago.
The ice sheet was so heavy that it pushed the land down by hundreds of meters. Even after the ice sheet retreated, the land continued to rise slowly due to the elastic properties of the Earth's crust.
This process is called glacial isostatic adjustment or post-glacial rebound.
The combination of these two processes, isostatic adjustment and glacial isostatic adjustment, explains why Greenland is rising faster than the current sea level.
The researchers from DTU Space were able to distinguish between the movements from contemporary climate changes and ancient movements from the last ice age by using data from 61 GPS-based (GNSS) measuring stations scattered across Greenland.
How Greenland's New Islands are Emerging
The rising ground is not just a geological marvel; it is also an ecological and cultural phenomenon. As new land emerges from beneath the ice and the sea, new small islands and skerries are born over time.
These new land masses are not just geographical features; they are symbols of the Earth's dynamic and unpredictable nature.
One example of a new island is Uunartoq Qeqertaq, which means "warming island" in Greenlandic. It was discovered in 2005 by an American explorer, Dennis Schmitt, who noticed that what was once thought to be a peninsula was actually an island separated from the mainland by a narrow channel of water.
The island is about 13 kilometers long and 5 kilometers wide, and lies off the east coast of Greenland. It was formed by the retreat of the ice sheet and the rise of the land.
Another example is the island of Oodaaq, which is the world's northernmost point of land. It was first sighted in 1978 by a Danish expedition, but it disappeared and reappeared several times due to the shifting of sea ice and the rising of the land.
It is located about 700 kilometers north of the Arctic Circle, and measures only about 15 by 8 meters. It is made of gravel and boulders, and has no vegetation or wildlife. It is considered a skerry, a small rocky island that is often submerged by the sea.
These newly formed islands are not only of scientific interest, but also of political and cultural significance. They may affect the territorial claims and sovereignty of Greenland and Denmark, as well as the rights and identity of the indigenous people, the Inuit. They may also pose challenges and opportunities for navigation, tourism, and resource exploration.
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