Hot Springs High in the Andes

Licancabur Expedition Journal: Part III

Andy Hock of UCLA (left) and David Fike of MIT (right) spoke to Astrobiology News editor Henry Bortman from "the Refuge," a stopover point near the base of Licancabur.
Credit: NASA

This is the third in a series of four articles about a scientific expedition currently under way to explore the highest lake in the world. The lake lies inside the crater of Licancabur, a dormant volcano that straddles the border between Chile and Bolivia. The expedition hopes to learn how the organisms that live in the lake have adapted to the thin atmosphere and damaging high-UV environment there.

Astrobiology News editor Henry Bortman conducted interviews on Tuesday, October 29th, with expedition team members Andy Hock and David Fike. Both are graduate students intrigued by the intersection of geology and biology.

Hock, who studies at UCLA, focuses more on geophysics, specifically on the habitability of geothermal environments. Fike is at MIT. He uses DNA analysis to understand what microorganisms inhabit an environment.

Hock and Fike spoke to Astrobiology Magazine from a stopover point known as "the Refuge," located 4200 meters (13,800 feet) above sea level, near the base of Licancabur. They and the other team members have spent the past week exploring the hydrothermal environment of the nearby lakes.

Astrobiology News: Can you set the scene for those of us who aren’t fortunate enough to be there with you?

Andy Hock: Right now the sun has just set. On the horizon you have these gigantic and beautiful volcanoes and the sky is fading from a sort of pinkish purple to a light blue, and out in front of me is a sign that says, "Este es mi tierra, Bolivia. Bienvenidos. (This is my land, Bolivia. Welcome.)" And beyond that is Laguna Blanca and a couple of remaining hungry flamingos.

AN: How has the expedition been going so far?

AH: So far the experience has been tremendous. It’s been physically challenging. We summitted a volcano called Tres Cumbres as a training exercise yesterday. That was a real challenge.

So was our first climb up Licancabur. We went to the middle camp, about 600 or 700 meters (1970 to 2200 feet) short of the summit, to the place where we’re going to spend one night. And that experience was not only physical, like Tres Cumbres, but also a very spiritual and emotional one. I’ve always thought of outdoors as being my chapel. And getting out on Licancabur for the first time a couple of days ago was really spectacular.

David Fike of MIT describes a small spring on the northern side of Laguna Verde (shown above) that is rich in algae and microbial life.
Image Credit: EOS, Duke University

And of course it’s been absolutely intellectually stimulating. We just end up developing more and more questions as time goes on. I guess that’s the way science works – you keep having more and more questions and the answers come in time.

The thing that’s been most interesting to me as a geophysicist is how this gigantic geothermal reservoir associated with all these volcanoes, this gigantic heat reservoir, how it plays into the biology of the area.

The higher lake that I’m looking out on now [Laguna Blanca] is about a kilometer or two in length, maybe a half a kilometer in width and only about a meter deep at its deepest point. And it’s full of flamingos.

I guess it would be probably 5 or 6 miles (8 or 9 kilometers) around. I’ve walked around nearly the whole thing; it takes the better part of an afternoon to walk around. But everywhere I walk around, there’s thermal water input.

The lake is about 13 to 15 degrees C (55 to 59 F) on the whole, and these little spring outlets are maybe 15 to 22 degrees C (59 to 72 F). So all around the lake there’s these little springs, and right by those springs, there’s a tremendous amount of biomass: algae, bacteria.

I came here with a big, big interest in the summit lake. But without even having been there yet, we’ve already discovered tremendous scientific potential with these lagunas.

AN: David, can you describe some of these microbial environments?

David Fike: At the hot springs where water comes up at about 37 Celsius, roughly body temperature (98.6 F), you have rich mats of bacteria and algae that are photosynthesizing and producing oxygen like crazy. And at other places we have cold springs, where water comes up at from 20 Celsius (68 F) to 15 Celsius (59 F), which is approximately the temperature of the lake, and you have much different communities of bacteria there, and almost no algae. Each spring seems to have its own different microbial community, based on visual inspection, which is incredibly fascinating. It would take years to try and actually understand it.

AN: Have you been able to identify any of the organisms?

DF: Not yet. We’ve been looking at some soil and water samples, but it’s too soon to get any real data out of them. I’ll have to wait till I get back to MIT to do some lab work before I can really understand them. It’s really interesting to be here and to see the immense diversity of environments, but it’s frustrating because I don’t have the tools here with me to actually understand what those visual differences actually relate to in terms of microbial diversity.

Some of the members of Team B are coming back on Wednesday and hopefully they’ll be able to present the first analysis of the data they collected with us on their last visits. [Team B is working in a laboratory in Antofagasta, a city on the Chilean coast.]

Laguna Colorado, shown above, is red and white due to seaweed growth and white borax deposits.
Image Credit: EOS, Duke University

AN: What about Laguna Verde?

DF: I haven’t really had a chance to get over to Laguna Verde. It has much more mineral content to it. And it seems to have almost a uniform lack of algae and rich bacterial communities except for one area on its northern side where there’s a small spring that feeds into the laguna, that’s characterized by a rich algal and microbial community.

AH: People say there’s a high content of arsenic, copper sulfate, which is what I would guess would give it its aquamarine tint. But it’s clearly very mineralized.

The Inca legend goes that these lagunas were right along one of the prime Inca trade routes. And when you ask people around here why Laguna Verde is so mineralized, it’s because when the Incas were traveling along this trade route with their pack animals and their gold and their sliver, and their copper, when the pack animals died, when they couldn’t make the trip, they would always bury the pack animals with their burden. And so, the story goes around here – and for all we know, it may be true – that Laguna Verde is so mineralized because there’s a whole bunch of old Inca metals, valuable metals, at the bottom.

AN: There’s also another lake not too far away, Laguna Colorado.

AH: We visited there today. It’s blood red with white borax mineral deposits, so it’s a stark contrast of red and white. It’s an extraordinary sight. Tons and tons of flamingos. Our driver told us today that they did a census on flamingos at Laguna Colorado and there were over 32,000. That’s going to be a place we’re going to really want to go back to.

AN: What’s been the most surprising thing being there?

DF: The fact that everywhere I turn there’s something interesting. In terms of science, there are areas of the lake, springs I don’t understand, there’s paleo shorelines that don’t make any sense, there’s weird rock formations I’m trying to analyze, but also I’m here on the border of Chile and Bolivia and I’m exposed to new cultures and it’s really a broadening experience.

AH: I think for me it would be the amount of thermal water that I see. I’ve never been to a place like this before, where you walk around the lake and every 10 meters or less you see a little spring outlet and biomass around it.

I look around and I see what I think are old shorelines and what looks like a gigantic lake basin. And so the picture starts coming together of how this place used to have a much larger body of water and how there’s evidence for hydrothermal alteration all over the place. So there’s this picture that comes together of water, heat and life in this place that is otherwise the driest desert in the world and subject to huge UV flux and otherwise pretty harsh.

So working together with the other members of the science team and sitting down after dinner and talking over the day’s observations – we’re pulling together this picture from all of our observations. That’s been the most surprising thing so far – that’s been really great, especially for me as a young scientist.

Related Web Pages

Licancabur Expedition Home

Michael Endl’s Journey to Licancabur

What’s Living in the World’s Highest Lake? (Licancabur Expedition Journal: Part I)

Licancabur Expedition Journal: Part II