Deep Inside a Lake

A team of scientists will embark on an expedition to a polar lake in Siberia, which should yield data that will provide the most detailed record of past Arctic climate to date.

Understanding the natural climatic variations of the Arctic--such as which aspects are cyclic and which are stable--will illuminate how the region evolved from a warm ecosystem blanketed in forest to a cold one covered in permafrost. And ultimately it could give scientists a glimpse at the Arctic of tomorrow, the researchers say.

The destination is Lake El'gygytgyn, a lake of roughly nine miles across that was formed when a meteorite hurtled into northeastern Siberia around 3.6 million years ago. Unlike much of the Arctic, this lake was never covered by glaciers or ice sheets and thus has received a steady accumulation of sediment since the time of impact. Scientists will collect deep cores of this sediment--cylindrical columns of dense muck that should provide a detailed narrative of the past climate of the Arctic.

Once the cores are extracted, the assemblage of pollen grains, algae and bacteria within the sediment will tell the scientists what was living in and around the lake throughout its history. The researchers will also read the cores for changes in geochemistry, the magnetic orientation of the muck's minerals and other parameters that capture what happened to the Arctic's climate since the time of impact. These data will be compared with cores taken from the north Atlantic and Pacific oceans, as well as tropical oceans, allowing scientists to address climate change questions on a broad scale.

---LiveScience Staff

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Credit: Julie Brigham-Grette/University of Massachusetts Amherst