Climate change update
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The world is underestimating the geological consequences of global warming, which may trigger catastrophic earthquakes and tsunamis because Melting ice cap A leading geoscientist warned that it would reduce the weight of the crust below and trigger strong seismic activity.
Bill McGuire, professor of earth sciences at University College London, told the British Science Festival in the town of Chelmsford on Thursday that the biggest threat to the North Atlantic comes from the thinning of the Greenland ice sheet. He said that within a few decades, this could cause a huge undersea earthquake on the coast of Greenland, trigger a tsunami, and bring catastrophic consequences to North America and even Europe.
A possible precedent is the “Great Storega Tsunami” that destroyed the coasts of Scandinavia and the British Isles 8,200 years ago. An offshore earthquake triggered by the release of pressure after the melting of the northern European ice sheets triggered a huge landslide of the sediments under the Norwegian Sea. Geological evidence indicates that the resulting tsunami waves are 15 to 20 meters high in the Shetland Islands and 3 to 6 meters deeper in the North Sea.
“As the Greenland ice sheet melts, the uplift of the earth’s crust will trigger an earthquake,” McGuire said. “We don’t know much about the sediments off the coast of Greenland and cannot confidently predict what might happen there, but there is definitely a possibility of a tsunami across the North Atlantic within a few decades.”
He said its impact may be comparable to the 2004 Boxing Day tsunami that killed more than 200,000 people near the Indian Ocean.
Donald Slater, a glaciologist at the University of Edinburgh, said at the Science Festival that Greenland has lost 4 tons of ice through melting and disintegration of icebergs in the past 20 years, causing global sea levels to rise by about 1 cm. It will add another 10 centimeters to this century.
McGuire said ice loss from Greenland, Iceland and Svalbard is lifting up the crust around the North Atlantic. Sensitive GPS instruments on the coast around the ocean begin to detect this uplift, which occurs at a rate of a few millimeters to 2.5 centimeters per year.
“The entire central part of Greenland is below sea level and is weighed down by the weight of a 3-kilometer thick ice sheet, so the crust has a long way to rebound,” he said.
On the other side of the Arctic, Alaska—the most seismically active region in North America—has experienced more frequent earthquakes. On July 28, a magnitude 8.2 earthquake occurred near the southwest coast of Alaska. This was the strongest earthquake in the United States in 50 years.
“When it comes to the geological impact of climate change, Alaska can be seen as a canary in the coal mine,” McGuire said.
He denied alarmism. “When global temperatures may rise at the fastest rate in the history of the earth, I am proud to sound the alarm,” he said. “So far, almost all predictions about climate change have been underestimated.”