Volcanoes and Ice Ages I

Here is an article about using ice to examine the ends of ice ages. Ice ages are periods of time where the global temperature is lower and the continental ice sheets on the earth are expanding. The Earth does not always have ice present on its surface, these periods of time are called interglacial periods. By this definition, we are still in the ice age that began 2.6 million years ago at the start of the Pleistocene epoch, because the Greenland and Antarctic ice sheets still exist.

This article talks about what must have started the beginning of the end of our current ice age. 

"Once the cores have been processed in Denver, each university lab will get its slice of the ice for analysis, which will likely take a year, Cole-Dai said. His SDSU team will work on a section of ice from 17,500 years ago that offers clues as to why Earth began to emerge from the Ice Age.
At that point in history, Cole-Dai said, "something big happened -- a large volcanic eruption or a number of them." Others speculate that it might have been an object from outer space that struck Earth."

"By measuring the kinds and quantities of chemicals in the ice cores and determining how those change over time, scientists can study the events that lead to global climate change,"