GLACIERS ARE MELTING
The rate of melting of Russia’s Arctic Archipelago regions has accelerated, according to a study focusing on the region’s Arctic glaciers.
The glaciers of Novaya Zemlya Island, the Severnaya Zemlya Island Group, and the Frans Josef Land Island Group have melted twice as fast between 2010 and 2017 as in the previous ten years. Due to melting, the sea level rises by about 0.06 millimeters per year.
The study’s findings support other observations made about glaciers in the Arctic region, according to which the melting of glaciers has raised the sea level in recent decades.
The glaciers of Norway’s Svalbard are also melting faster than before. A study published in January comparing glacier images of the region from 1936 and 2010 predicts that the loss of glacier mass will double by the end of the century.
Even if the measures aimed at curbing climate change were all implemented, the glaciers of the Finnish Alps would still continue to melt at a rate at least 1.9 times higher than the melting that took place between 1936 and 2010. That would mean that the glacier is thinning by 67 centimeters every year. If emissions are not brought under control, as much as 92 centimeters of the thickness of the glacier will be lost every year.
Instead, the amount of snow was close to the 1981–2010 average. That’s important because winters with little snow combined with hot summers can cause the ice to melt at a tremendous rate.
The melting of the glaciers in the Arctic region is still slower than the glaciers that are outside the polar regions. In sub-Arctic regions, such as Alaska in the United States, glaciers shrink relatively faster, meaning that a greater proportion of their total mass is lost than in glaciers in the Arctic region.
The glaciers melt and it causes the sea level to rise – this is probably a familiar consequence of global warming. What is less well known is that the effects of melting are not distributed evenly across the oceans. It may seem contradictory to common sense that the sea level rise caused by melting is the greatest far from the melting glacier while melting in the vicinity of the glacier causes the sea level to fall. Why is this?
When the continental glacier melts, large amounts of meltwater are transferred from the glacier to the oceans. This movement of water mass from one place to another changes the Earth’s gravity field, the elevation relationships of the Earth’s crust, and even the Earth’s rotation. These secondary effects cause regional differences in how much the sea level rises.
Let’s take a closer look at the mechanisms. So the massive continental glacier also attracts seawater. The sea level is, therefore, higher in the areas near the glacier compared to the situation where there would be no glacier. As the glacier melts, this attraction weakens, reversing sea level rise in the vicinity of the melting glacier.
Second, the huge mass of the continental glacier presses the earth’s crust into the depression. As the glacier melts, it becomes lighter, and the land begins to rise under and near the melting glacier. The rise of the Earth’s crust partially offsets the sea level rise caused by the melting of the glacier.
There is enough ice in the current continental glaciers on Earth – in Greenland and Antarctica – that their melting can over time raise the sea level several meters above the current level if global warming is not controlled. Melting has already started in the peripheral areas of the glaciers. This can be seen, for example, from the observations of the GRACE satellites that measure the Earth’s gravity field.
The reduction of the ice cover, the increase of vegetation, and the melting of permafrost have already started a self-feeding cycle that accelerates climate change even more.
If the development continues, in the next few decades – i.e. in the lifetime of many of us – the summer will come when the ice will no longer be visible. In the Bering Strait, known from old seafaring stories, between Alaska and Russia, the melted sea has already extended far to its north in recent summers. IN MARCH 2017, NASA satellite images revealed an unprecedented collapse in the amount of ice in both Polar Regions during the 40-year measurement period. In the spring of 2018, the second lowest result in history was achieved. The two glaciers Thwaite and Pine Island located in the western Antarctic are also shrinking much faster than imagined or feared.