People in northern climates who have been looking south and shaking their heads sadly over the plight of people living in the path of Atlantic hurricanes and Pacific tsunamis had better get ready for a few seismic events of their own, according to a growing number of prominent geologists.
Less Glacial Pressure, More Earthquakes and Volcanic Eruptions
Ice is extremely heavyweighing about one ton per cubic meterand glaciers are massive sheets of ice. When they are intact, glaciers exert enormous pressure on the portion of the Earths surface they cover. When glaciers begin to meltas they are doing now at an increasingly rapid rate due to global warmingthat pressure is reduced and eventually released.
Geologists say releasing that pressure on the Earths surface will cause all sorts of geologic reactions, such as earthquakes, tsunamis (caused by undersea earthquakes) and volcanic eruptions.
"What happens is the weight of this thick ice puts a lot of stress on the earth," said Patrick Wu, a geologist at the University of Alberta in Canada, in an interview with the Canadian Press. "The weight sort of suppresses the earthquakes, but when you melt the ice the earthquakes get triggered."
Global Warming Accelerating Geologic Rebound
Wu offered the analogy of pressing a thumb against a soccer ball. When the thumb is removed and the pressure released, the ball resumes its original shape. When the ball is a planet, the rebound happens slowly, but just as surely.
Wu said many of the earthquakes that occur in Canada today are related to the ongoing rebound effect that started with the end of the last ice age 10,000 years ago. But with global warming accelerating climate changes and causing glaciers to melt more quickly, Wu said the inevitable rebound is expected to happen much faster this time around.
New Seismic Events Already Happening
Wu said melting ice in Antarctica is already triggering earthquakes and underwater landslides. These events arent getting much attention, but they are early warnings of the more serious events that scientists believe are coming. According to Wu, global warming will create lots of earthquakes.
Professor Wu is not alone in his assessment.
Writing in New Scientist magazine, Bill McGuire, professor of geological hazards at University College in London, said: "All over the world evidence is stacking up that changes in global climate can and do affect the frequencies of earthquakes, volcanic eruptions and catastrophic sea-floor landslides. Not only has this happened several times throughout Earth's history, the evidence suggests it is happening again."