Lake Mysteries from the World’s Roof: Part Four

Astrobiologists Probe the Mysteries of the Highest Lake in the World

Licancabur Expedition Journal: Part IV

Click here for larger image. Expedition leader Nathalie Cabrol with Edmond Grin, the current record-holder for the oldest person ever to summit Licancabur.
Credit: Seth Shostak

This is the fourth and final article about a scientific expedition that just returned from studying 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. Although buffeted by harsh weather, the scientists did reach the summit and were able to collect samples from the lake for future study.

Astrobiology News editor Henry Bortman conducted interviews on Monday, November 4th, with expedition leader Nathalie Cabrol, who works for the SETI Institute at NASA Ames Research Center in Mountain View, CA.

Astrobiology News: So you made it all the way to the summit lake?

Nathalie Cabrol: Yes, we did. We reached the summit yesterday at 2:15 PM local time and it was really cold.

Everyone made it to the top. Edmond [Grin, an 82-year-old member of the expedition team,] was second to arrive. Only the guide got there before him. And he is now the record-holder for the oldest person ever to summit Licancabur. The previous record was set by a 70-year-old. The whole team reached the summit, which includes people from 24 to 82 years old.

Then we had only an hour to do the science. So we rushed to the lake. The lake was emerald green – just magnificent. And most of all, it was unfrozen. We had wondered if it would be because, with the wind chill we had, I guess the temperature had been down at times to minus 20 or minus 25 C (minus 4 to minus 14 F).

So we did all the science we could. We weren’t able to dive, because the conditions were too dangerous and we were risking hypothermia and had too little time to go down, so we took a safe approach. But we recovered samples of water, samples of sediment. We deposited data loggers. We deployed our UV experiment. And we filmed some underwater footage with the underwater camera.

Something which is extremely puzzling is that while I was dragging the sample bottle along the bottom of the lake using a rope, while I was getting the bottle out of the water, there was water in the sample bottle. And when I closed the bottle, the water was still liquid – but the rope was completely frozen. Andy measured the surface temperature of the lake up there at 6 degrees C (42 F).

AN: Did you see any thermal springs there?

NC: No. We didn’t see any on the crater, but we would need to look in the lake itself. If I had to choose a place, it would be just where we see the green stuff, but unfortunately this time we were not able to get to it. That will be for next year.

AN: Were you able to get any sense from the physical layout there of how the lake is maintained?

NC: What is interesting is that there are shorelines. So it means that this lake has been varying with time. We took some samples from the shore and we’ll have to study them to see if we see any layers, any signs that we have cycles here.

laguna_blanca
Ten days prior to this interview, the Licancabur team placed UV filtering plates in Laguna Blanca (above) to study how the UV affects the lake’s biology.
Credit: geo.umass.edu

The Inca, when they were living in the area (500 years ago), were holding celebrations at the lake. So if this is the same lake, it is not a very large body of water and this raises many questions. In my mind, there must be another source than the yearly snow because, although there is some snow on the crater itself, to me the watershed is not enough to keep that lake alive for 500 years.

AN: Were you able to tell how deep the lake is?

NC: No, we couldn’t deploy [the bathymetry, or depth-measurement, instruments] because of the conditions.

AN: From visual inspection, what could you tell about the life in the lake?

NC: It was very difficult because the shores of the lake seem pretty lifeless. But towards the middle of the lake it was more green, so this is where we would like to know better about what is going on there. It was difficult for us to reach. We tried some contingency science by throwing bottles with a rope, so we’ll have to see what’s in those bottles. Right now I can’t tell you what’s there. It will have to be analyzed.

After that, we rushed back up to the summit and it was a madman race to get all the way back down the mountain in time. The conditions here are extremely tough. The wind is blowing all the time, and when you are at 6,000 meters, believe me, it’s really tough.

AN: Have you heard a report yet from the Hungarian biologists about what types of organisms are living in the lower lakes, where you took samples a couple of weeks ago?

NC: All I can tell you right now is that they have observed a very large diversity of organisms there. They have taken the samples with them [to Hungary and will be doing further analysis later].

AN: What do you have planned for the rest of the expedition?

NC: While I’m talking to you I can see from where I am three of our team members. Today they are retrieving material from underneath the [UV filtering] plates we placed [in Laguna Blanca] ten days ago to study how the UV interacts with the biology and how the organisms defend themselves against the UV radiation here. The plates will be left in the water for an additional year, but we wanted to have some preliminary results, so we are going to bring back this sample with us.

We are leaving tomorrow at the end of the day. We will be doing some dives tomorrow morning in Laguna Blanca [to collect more samples].

AN: Well, congratulations on your achievement and thank you for taking the time to talk with us.

NC: Thank you.


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
Hot Springs in the Andes (Licancabut Expedition Journal: Part III)