Removal of a short core
Regional climate changes can be very rapid. A German-British team of geoscientists now reports that such a rapid climate change occurred in different regions with a time difference of 120 years. Investigation in the west German Eifel region and in southern Norway demonstrated that at the end of the last glaciation about 12,240 years before present climate became warmer, first recognised in the Eifel region and 120 years later in southern Norway. Nonetheless, the warming was equally rapid in both regions.
The team around Christine Lane (Oxford University) and Achim Brauer from the GFZ German Research Centre for Geosciences reports in the latest volume of Geology
(vol 41, no 12, p. 1251 - 1254) that within the younger Dryas, the last about 1100-year long cold phase at the end of the last ice age, a rapid warming first was measured in the Eifel region. Sediment cores from the Meerfelder Maar lake depict a typical deposition pattern, which was also found in the sediments of Lake Krakenes in southern Norway, but with a time lag of 120 years.
But how did the researcher reveale such a accurate time marking? "12 140 years ago a major eruption of the Katla volcano occurred on Iceland" explains Achim Brauer. "The volcanic ash was distributed by strong winds over large parts of northern and central Europe and we can find them with new technologies as tiny ash particles in the sediment deposits of lakes. Through counting of annual bands in these sediments we could precisely determine the age of this volcanic ash." Therefore, this ash material reflects a distinct time marker in the sediments of the lakes in the Eifel and in Norway.