Cave Records Provide Clues to Climate Change

If you have ever been in a cave, you know how beautiful they are and are familiar with the different formations such as stalagmites. But to scientists from Georgia Tech, caves are a trip back into the ancient past that can give an insight into what caused climate changes in the past.

Led by Georgia Tech Assistant Professor Kim Cobb and graduate student Jud Partin, they explored the caves on the Pacific island of Borneo and found some of the keys that would unlock the mysteries about how the climate changed again and again over the period of 25,000 years. They studied the stalagmites, which are the formations that resemble pillars coming up from the ground of the caves. From the stalagmites, they were able to produce a high resolution, continuous record of the climate over this area.

Each layer in the stalagmites contains traces of chemicals that show what was going on in the climate at different times in history, just like has been done by other scientists who have studied ice cores that they drilled from either Greenland or Antarctica.

They picked the tropical Pacific area to study because of the role that it plays in the variations of climate around the world. For instance it is the place where el Nino is formed. But very little has been done to study the climate changes in the past in this area and they wanted to see if it played a major roll back then as well.

The ice cores that have been taken from the Northern Hemisphere in Greenland and the Southern Hemisphere in Antarctica each has a different pattern of climate change and they are hoping that the results from the Pacific will provide a link between the two.

Getting an understanding of how the climate changed in the past is an important factor in understanding the trends in today's climate.

They cut open each one of the stalagmites and took a total of 1,300 measurements of the chemical content in order to determine the relative level of moisture in the climate at various periods of time, starting from the oldest on the bottom to the present day on the top.