Editor’s Note: Today’s caption is the answer to Earth Observatory’s January puzzler.
If you were a plant, the Oobloyah Valley on Ellesmere Island would probably not be the first place you'd want to set down roots. The island in Canada’s Nunavut territory is located at the same latitude as northern Greenland, so air and soil temperatures are frigid on good days. During the warmest month—July—temperatures average 3.3°C (37.9°F); during the cold and dark of February, the average plunges to -38°C (-36°F). Don’t expect much snow or rain either. Like much of the High Arctic, Ellesmere Island is a polar desert, receiving just 64 millimeters (2.5 inches) of precipitation per year.
The valley does have some upsides. Multiple retreating glaciers—including the Nukapingwa, Arklio, Perkeo, and Midget—flow into the valley from the Krieger Mountains and provide melt water during the summer. The landscape also has escaped scouring by ice for thousands of years. While sheets of ice covered much of Ellesmere during the last glacial maximum, Oobloyah Valley remained ice free. And while it is very difficult for most plants to eke out a living in the High Arctic, once a species is established, there is very little competition for space.
This unique combination of climatic and geological conditions has drawn groups of Japanese ecologists to the area to study how plants survive and spread. Terminal moraines—the heaps of rock, gravel, and sand deposited near the snout of glaciers—offer an ideal natural laboratory for studying which plant species can colonize the recently exposed terrain.
A team of researchers led by Yokohama National University’s Akira Mori focused their search for Arctic plants on the moraine created by Arklio Glacier, the second to the left in the image above. The Advanced Land Imager (ALI) acquired this image of the glacier on June 19, 2012. The moraine, which formed during the Little Ice Age, appears as a lobe-shaped bulge around the end of glacier. The light brown feature south of the moraine is a stream bed.
They found two dominant pioneer species living on the rocky, virtually soil-free moraine, according to a study published in October 2013. The first is Epilobium latifolium, a flowering plant in the evening primrose family known as Dwarf fireweed. The second is Salix arctic, a type of creeping willow.
Visit our Earth Matters blog to see an image of these two pioneer species, as well as a view of the moraine from the ground.
- Mori, A. et al (2013, October 9) Non-stochastic colonization by pioneer plants after deglaciation in a polar oasis of the Canadian High Arctic. Polar Science, 7 (3-4), 278-287.
- Okitsu, S. et al (2004, August 25) Vegetation development on the glacier moraines on Oobloyah Valley, Ellesmere Island, high arctic Canada. Polar Bioscience, 17, 83-93.
NASA Earth Observatory image by Jesse Allen and Robert Simmon, using EO-1 ALI data from the NASA EO-1 team. Caption by Adam Voiland. Congratulations to Dillion and Eric J.F. Kelijssen for solving the puzzler the fastest.
- EO-1 - ALI