The water flowing from the Atlantic Ocean into the Arctic through the Fram Strait is warmer today than any time in the past 2,000 years. That’s what microscopic seabed deposits have told Robert Spielhagen of the Academy of Sciences, Humanities, and Literature in Mainz, Germany, and his colleagues. The scientists have shown that the average temperature of water flowing into the Arctic since 1890 is 2ºC higher than it has been on average in the previous two millennia. This sends a stark message about the prospects for the Northern polar region. “I am afraid that my children – now 14 and 17 years old – will be able to see a summer ice-free Arctic Ocean,” Spielhagen told Simple Climate.
On August 4, 2007 Spielhagen and his co-workers extracted the key deposits when they drilled a 46 cm long cylinder of rock from the sea bed. Such “sediment cores” had previously been used to look at temperature changes as far as 12,000 years into the past, but could only provide measurements for periods of a few hundred years at a time. That’s down to how much sediment settles to the sea bed, with too little deposition for high-resolution temperature measurements occurring where cores have been taken before. By contrast, Spielhagen’s team was able to give temperatures on a scale of 2-3 decades at a time. “We took our core in a place where a lot of fine-grained particles settle, due to diminished bottom currents,” he explained. “We were the first to find such a spot.” Read the rest of this entry »