The Martian Chronicles
Arctic Special - Issue 7, Autumn 2000

Learning about past climate conditions in the High Arctic
by Darlene Lim

Darlene and Marianne extracting a sediment core.

Darlene and Marianne extracting a sediment core.
(click for larger image)

The Canadian High Arctic is a distinct region of our planet in the way that it supports life, responds to shifts in the climate, and affects the environments of the rest of the globe. Investigation of High Arctic climate and environmental change is needed to better understand their global effects and to monitor this pristine and sensitive region. This necessitates an understanding of the regionís natural variability and of how it has changed through time. Given the remote and isolated nature of this area, it is not surprising that this past climate data from the High Arctic is sparse. However, through a recent increase in scientific activities geared at understanding High Arctic climate change, this is slowly changing.

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.