Researchers led by Yuko Motizuki from the Astro-Glaciology Laboratory at the RIKEN Nishina Center in Japan have developed a new laser-based sampling system for studying the composition of ice cores taken from glaciers.
Researchers led by Yuko Motizuki from the Astro-Glaciology Laboratory at the RIKEN Nishina Center in Japan have developed a new laser-based sampling system for studying the composition of ice cores taken from glaciers. The new system has a 3-mm depth-resolution—about 3 times smaller than what is currently available—meaning that it can detect temperature variations that occurred over much smaller periods of time in the past. The new laser melting sampler, or LMS, is expected to help reconstruct continuous annual temperature changes that occurred thousands to hundreds of thousands of years ago, which will help scientists understand climate change in the past and present. The study was published in the Journal of Glaciology on Sep 19.
Tree rings can tell us how old a tree is, and the color and width of the rings can tell us a little about the local climate during those years. Yearly growth of glaciers can tell us a similar story, but over a much longer period of time. Scientists are studying past changes in climate by analyzing cylindrical ice cores removed from glaciers. By taking samples at regular intervals along the cores, researchers can reconstruct continuous temperature profiles. However, this is impossible with samples taken from deep locations, where annual accumulation has often been compressed to sub-centimeters.
Currently there are two standard methods for sampling ice cores. One has a depth-precision of about 1 cm, which means that data from years with less than 1 cm accumulation are lost, and any one-time events that acutely altered climate would be missed. The other method has good depth-precision, but it destroys the part of the sample needed to analyze the water content – the primary way in which scientists calculate past temperatures. The new laser melting sampler overcomes both these problems; it has high depth-precision and does not destroy the critical oxygen and hydrogen isotopes found in water, which are needed to infer past temperature.
Read more at RIKEN
Photo Credit: ThierryBEUVE via Pixabay
