What is being learned from the High Lakes in South America?

The High-Lakes project researches the high lakes of South America to provide insight to Mars, as the area is considered analogous. Nathalie Cabrol, a Planetary Geologist, has been working on the High-Lakes project for several years. In previous blogs, we covered a director's colloquium that Cabrol recently gave at the center. In this blog, we will cover more of the details learned from the High Lakes Project project, which studies Licancabur, Aguas Calientes, Poquentica, Escalante, Laguna Verde and Laguna Blanca lakes.

This year, Cabrol led a team of divers, which collected samples in the Licancabur lake at close to 20,000 feet elevation, "We had a suspension system while diving because there is so much muck. We had floats that were used to give our location away because we dived with O2 (oxygen) rebreather instead of conventional diving gear and those systems do not produce bubbles."

The samples gathered this year are being compared to samples that were taken along the shore of the same lake in 2005. Also what was studied was the distribution of bacteria in the lake, comparing samples collected at very shallow depths to the higher depths. What was discovered is that there is less diversity of life than what you would find in rivers at sea level; also a significant portion of the samples have yet to be identified. Twelve to 17 percent of the samples brought back are unknown bacteria, so they are currently being analyzed.

The temperature, the relative humidity and the precipitation are all factors used to evaluate the evaporation rate from the Licancabur lake. Using these calculations, the team came to the conclusion that water loss from evaporation was 14 times higher than water gain from precipitation. "If we were just looking at those numbers, the Licancabur lake would be gone in 10 years," said Cabrol. However, there are several factors that play into this and prolong the lake's lifetime. The presence of an ice cover from April to September helps reduce that loss by 75 percent. While for several years Cabrol noticed the Licancabur lake decrease, this year the lake level was up 50 centimeters because of more abundant snow fall during the winter. Still, Licancabur lake should disappear in the next 15 to 20 years, if the climate trend persists.

Look forward to more blogs about the High Lakes project. Specifically, what ultraviolet light can tell us about organisms under water? [Source: http://center.arc.nasa.gov/ ]

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