True North? Poles Become A Moving Target As They Shift From Climate Change
For those who imagine there's a True North, think again. Think of climate change and True North as a moving target. The North Pole is shifting due to the melting of glaciers and ice sheets from climate change. That finding could help scientists track global warming by monitoring the position of the pole.
A study by Jianli Chen, of the University of Texas at Austin, and his colleagues have found that greenhouse gas emissions are causing the ice caps to melt, which is contributing to pole shift, according to New Scientist. Chen presented the findings at the annual meeting of the American Geophysical Union held Dec. 9-3 in San Francisco.
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Scientists have observed the North Pole drifting 10 centimeters southward every year since measurements began in 1899. The drift is due to changes in the distribution of the Earth's mass, as the crust slowly rebounds after the end of the last ice age. But Chen and his colleagues found that since 2005, the southward drift changed and the pole began to shift more eastward.
Using data from NASA's GRACE (Gravity Recovery and Climate Experiment) satellite, which measures changes in the Earth's gravity field over time, Chen and his team calculated the redistribution of mass on the Earth's surface due to the melting of the Greenland and Antarctic ice sheets, and mountain glaciers and the resulting sea level rise. That matched up with changes measured in the Mean Pole Postiion or MPP, New Scientist reported.
"Ice melting and sea level change can explain 90 percent of the eastward shift," said Chen. "The driving force for the sudden change is climate change." Measuring the deviation of the Mean Pole Position is one way scientists can monitor climate change, said Jean Dickey of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who was not involved in the study.
The Earth's two geographic poles do not have a fixed location, according to a report by Subodh Varma, which was published in The Times of India in May. At the time, another study on pole shift was released. "As the distribution of snow, rain, and humidity changes every year, the poles, too, wobble around, usually in a circular manner," the article said.
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