ANOTHER worrying sign that Greenland’s ice may be vanishing fast comes from an increase in the number of glacial “earthquakes” recorded on the island.
Göran Ekström, a seismologist at Harvard University, says the rapid melting causes water to collect under the ice faster than it can drain away. This makes the glaciers slip faster into the sea, which causes more quakes.
Ekström discovered glacial quakes three years ago after noticing that some signals picked up by seismic monitors contained fewer high-frequency waves than is normal for an earthquake. He traced their source to slips within ice sheets. Most…
