Dr Lucy Corbett, author of Glacier Chronology, describes how she measured the size of Lake Crete
How to measure a shrinking glacier
Glaciers are glaciers because they extend thousands of feet into the ground. My premise is that the total volume of ice inside them, or total elevation, takes its name from the cubic metre. Glaciers are the rungs of our planetary pathway and until relatively recently, most of them traversed oceans rather than land. Now, however, all of us have a direct connection to the local glaciers in one way or another.
The science of glaciers is still pretty new, and there are still quite a few inaccuracies in the field, mostly due to the nature of the glaciology, which is often very inefficient. The most important element of human-induced glacial change in the near term is to determine the estimated volume of glacial ice within each glacier, measured by space tethers attached to geodetic equipment which sticks to the surface of the glacier. The sensor data is then compared to expected volume to determine and resolve the true quantity of the glacier within its fixed boundaries.
Glaciers overall appear to be in rapid retreat, at least at the very high latitudes. How much we may lose or continue to lose is uncertain. One aspect of the rate of loss is that the structure of our rivers, as well as the shorelines, keeps glacial flows moving around the island – suggesting the glacier might not just be pulling out the water – it may be supplying some of the need for fresh water.
Either way, the surface of the Earth is now passing through glacier glacial zones. As glaciers retreat, our sea ice is piling up around them. Just as the ice appears to flow faster from one area to another, it is more likely the flow will return to the ocean, or instead be reversed by an underwater shoreline. Some glaciers are now traveling with the ocean. But most are still getting water through their frozen wall, which is what is causing the middle of the shoreline to appear, like a barbed wire fence.
The glacial line measures the water erosion that accumulates the rock over time. The glacier serves as a barrier to prevent as much water going from the ocean (we all get the same amount, dammit!) to the sea as possible.