© Landsat Image Mosaic of Antarctica (LIMA)A 15-meter pan-sharpened Landsat 8 image of the Mount Takahe volcano rising more than 2,000 meters (1.2 miles) above the surrounding West Antarctic ice sheet in Marie Byrd Land, West Antarctica.
"Detailed chemical measurements in Antarctic ice cores show that massive, halogen-rich eruptions from the West Antarctic Mt. Takahe volcano coincided exactly with the onset of the most rapid, widespread climate change in the Southern Hemisphere during the end of the last ice age and the start of increasing global greenhouse gas concentrations," according to McConnell, who leads DRI's ultra-trace chemical ice core analytical laboratory.
Climate changes that began ~17,700 years ago included a sudden poleward shift in westerly winds encircling Antarctica with corresponding changes in sea ice extent, ocean circulation, and ventilation of the deep ocean. Evidence of these changes is found in many parts of the Southern Hemisphere and in different paleoclimate archives, but what prompted these changes has remained largely unexplained.
"We know that rapid climate change at this time was primed by changes in solar insolation and the Northern Hemisphere ice sheets," explained McConnell. "Glacial and interglacial cycles are driven by the sun and Earth orbital parameters that impact solar insolation (intensity of the sun's rays) as well as by changes in the continental ice sheets and greenhouse gas concentrations."
