Learning about past climate conditions in the High Arctic|
by Darlene Lim
One method of retrieving long-term past climate data in the High Arctic involves tapping into the wealth of information trapped in the sediment record at the bottom of the existing (e.g. Sapphire Lake in Haughton Crater) and extinct lakes (e.g. Haughton Crater which became a lake post-impact, but has since drained out) found on Devon Island and other High Arctic sites. Essentially the sediment reads like the pages of a great climate book, since through time organic and inorganic fallout from within and around the lake accumulates and provides a historical climate record that would otherwise be unattainable. By taking a sediment core of the lake we can acquire this precious information. This type of research, aimed at the study of lake history, is termed paleolimnology.
The biological remains of diatoms, for example, found within these sediment cores, can be used as biological mechanism to track andunderstand past climate change. Diatoms are unicellular algae with glass (siliceous) cell walls, and are used as biological indicators of past climate change, since their populations will shift as their environment shifts, thus allowing us to infer changes in a lakeís climate history. They preserve exceptionally well in the sediment record, and their remains can be incredibly ornate and beautiful (see Feb 1999 National Geographic for more info).
The High Arctic is a beautiful and pristine region, and through further paleolimnological studies we hope to better understand its climate history as a tool for predicting and managing future climate change in this sensitive area.