Captain’s Log # 8: Farewell

Murder in the Andes. What many thought was a cute little birdy turned out to be a vicious killer. Credit: XenoQuest Media

The camp is very quiet. Only nine of us are still here and most of the individual tents and a couple of domes are already down. I cannot believe how fast both Cristians, helped by David and Hernan, have started to stow away the scientific equipment as well. There is a mountain of bins lined up outside the dinning dome. They are waiting for…the mules (!) – maybe today or tomorrow.

I had another short night…Hard to sleep when a little someone I know who is sleeping on the cot next to mine continues to stubbornly wear his down-jacket in his sleeping bag and tosses and turns all night long. It sounds like scrubbing sand paper on dry paper. That ends up in some colorful dialogues in French between me and Edmond around 2:00 in the morning. I am not sure he heard half of what I said because his sleeping bag completely covers him and he is half-asleep anyway. Guess what? He simply turns around…and starts snoring! This is too much, this time, I can’t help and I start giggling.

I am tired, I am cold, and sleepless for another hour. As I finally start to doze off, an owl shows up next to our tent. She is probably right outside on that granite block and now she starts: Hoo-Hoo-Hoo, and then she derails. She might have a sore throat or something. That goes on for a good hour-and-a-half. She is lucky that I am too cold to get out, otherwise we would have owl’s ragout for breakfast. I am pretty sure that our cook David still has a few mushrooms left. If not, a bed of algae will do just fine. She finally goes quiet or leaves. A peaceful silence falls over the camp for a good…five minutes. Now, that’s the 5:00 am seagull. She has come every single morning, and every evening at 9:00 pm, on the clock. She is sometimes accompanied by geese and ducks, which normally I would love to hear, but right now, I just want to sleep. At least, this morning the seagull is alone. It seems that she is coming from El Yeso, the lake on the other side of the ridge, and her racket does not stop. Does she even breathe? I don’t know, but by 6:00 am, I have had it. I am getting out of the tent. Well, all is not lost. The sunrise is as spectacular as usual over Meson Alto and its glacier. I am in awe.

As the sun starts to warm up the air, the birds are also getting more active. By now, I have fully surrendered to the idea that my hope for sleep is over, and I fully enjoy watching and listening to them. Those are not much bigger than American robins. They are very colorful too. One of them has a bright yellow belly and an equally bright blue collar. Everything is more colorful here with the altitude. The flowers are amazing. I have never seen anything like them before. They look almost like miniature orchids but their stems and leaves are very different. They go from purple and yellow, to orange and yellow, blue, and white, and they beam across the white granite in ways that are unseen at lower elevation. For the small birds, while they look cute, we learned that they have a “dark” side. Gavin caught one of them killing a lizard a week or so ago. The lizard was not small at all. As luck had it, Gavin had his camera rolling at the time. That was the first time I saw this type of behavior. The bird actually held the lizard in his beak and, with repeated and swift motions, kept banging the head of the lizard against the granite block until it was dead. Then it swallowed the entire lizard in one gulp.

But this morning, I had the Mel Brooks version of the same…I went to the dinning dome and sat there for a while. I just had poured myself a coffee when one of these birds showed up and started hopping in the open space between the dome and the kitchen. It obviously had found something interesting on the ground that it had grabbed in its beak. That turned out to be a cooked spaghetti noodle that had fallen from one of the plates last night. For the next five minutes, I watched that bird kill the spaghetti, lizard-style. That changed my mood for the day!

I also have something else in mind that is lighting up my mood. Cristian is getting up early as well and has now joined me. The two of us have prepared a little surprise for Edmond. He knows nothing about it yet. He only knows that he needs to be up early following some unimaginative lie that we could come up with (e.g., we must take the tent down early). He has worked so hard to prepare his experiment in the past months…Unfortunately, the location of Station Lake on the Echaurren Valley and the dangerous access by Devil Slide has made it impossible for him to deploy it in person. He is 91 going on 92 strong, and climbs Mount Lassen without too much trouble. However, Devil’s Slide requires the kind of mobility and attention that is sometimes difficult to achieve even for people half his age. So, Chris had to deploy his experiment for him. Edmond is a trooper, and a very reasonable man. He understood the challenge and kept smiling all along, helping around the camp whenever needed, and also taking in full this landscape he told me reminded him so much of Switzerland where he was born and lived for a while.

The waters of Victoria’s Cascade, named by a team of Chileans who explored the Laguna Negra area 150 years ago, tumble into the northwest finger of the lake. Credit: Nathalie Cabrol

So, this morning, since pretty much everybody is gone and all objectives have been met and then some, Cristian and I have decided to take him on a tour of the lake, to show him in particular the Cave of the Amazons, Victoria’s Cascade. We will also take advantage of being on the northwest shore to take one last look at Planetary Lake Lander and its twin sonde, to make sure that everything is alright before we leave.

Edmond shows up at 7:00 am as planned. We still say nothing. The three of us have breakfast and then Cristian disappears for a while to take a couple of batteries to the Zodiac. Edmond and I follow a few minutes later and meet him at the beach, a.k.a. Base Camp Landing.Then we finally reveal the goal of this early morning outing. Someone has a huge smile pasted on his face as he dons the Mustang suit. We want to go early not only because we still have lots of work to do to break camp, but also because good conditions on the lake might not last more than a few hours.

Off we go. The lake and the air are still. Everything is perfect. We look at the transparent water, and the algae and blocks lurking from the depths. Ducks are giving us the right of way but they don’t seem to be that concerned by our presence. I have to say that considering our speed, they really have nothing to fear. If I had the ability to walk on water, I probably would have already made it to the other side, but that’s not the case and this is certainly not the right time for a metaphysical experiment just to prove a point. Beside, for once, I simply enjoy the slow pace.

We are at the Cave of the Amazons. Cristian proceeds even more slowly (…) to avoid some large blocks only partially submerged and also to give us time to observe carefully the richness of the environment. Only two days ago I was diving here. Hopefully, the movie will turn out to be good. We look up at the various springs shooting off the basalt cliff about 100 m higher up. The grass is definitely yellow around some of them. Those would be good candidates for testing water temperature next year. Hydrothermal systems could bring warmer and more acidic waters. That could explain the stains. Whether or not that’s the case here is a question to be answered by the next field campaign.

We continue on to the cascade. We are all amazed by its size and the roar of the water falling down from up high, especially Edmond who sees it for the first time. On our way, we just passed Lake Lander, now anchored about 100 m away. Everything checks out fine. Its twin sonde is a lot closer to the cascade. We are trying to see how different the waters from the lake and the runoff are. We will log data at least for the next three months with PLL. After that, the engineers will take it back home in the US to work on its “brain”. Meanwhile, its twin sonde will continue to log in.

We take our time touring the northwest shore. Now Edmond can see Devil’s Slide for himself. He seems impressed and has a connoisseur look on his face. Since the lake is still calm, we decide to take advantage of the good conditions to do a bit of a reconnaissance and hopefully find another way to access the perched Echaurren Valley. We go slowly with the Zodiac, which allows me to see more caves to be explored. We now pass near the promontory. The access is poor and dangerous everywhere. We even venture a bit into the northeast branch of the lake for the first time, not too far though, as it is soon time to turn around.

We enjoy the way back on a very still lake. By 9:30 am we are back at camp and the three of us are happy. Edmond has a smirk on his face, we all do. Time for a more serious breakfast. We go to the lake again this time for some morning bathing. Then, Edmond goes to the tent and starts his packing. I’ll wait until he is done to start mine. Meanwhile, I am giving a hand here and there, and when I am not, I spend some time discussing with Robert and Jeff about this, and other projects. This leads into lunch. My early afternoon is busy packing, taking the tent down, folding cots. By 2:30 am, we are all on our way to the trailhead, some on foot, and some by boat…Apparently Edmond had too much fun this morning and does not want to let go. He goes with Cristian. They are in Mariner 1 and they are towing Margaritaville, which is completely filled with bins. Actually, observing the scene from up high on the trail, it seems that someone let go of Margaritaville’s rope a bit too soon. A good thing that conditions are not too windy today. Still, Cristian and Edmond have to make a substantial swing away from the shore to get the escapee back.

Edmond Grin’s stream gauge experiment, placed at the outlet to Station Lake, will measure changes in the rate of outflow from the lake. Credit: Chris Haberle.

Once I see Margaritaville secured and towed by Mariner 1, I proceed up the trail. I stop a few times to look back at Meson Alto and Echaurren. What an incredible landscape. For the sheer beauty of it, if for nothing else, it pains me to think that the next generation will never know what these glaciers looked like, or maybe only on photographs. Our planet is experiencing incredible changes at a pace that we, humans, have never experienced before. Is this the price to pay for our civilization to enter its adulthood? This seems to be a very dear price, especially for the rest of the biosphere, which should not be held accountable for our own trials and errors. Yet, we are all in this together, as currently the climate is altered and biodiversity stressed by a process whose rapidity and impact on the ecosystem are being compared to major extinctions. This will not go away just because some prefer to ignore it. Within 50 years, this planet will be very different, even warmer. There will be more pressure on water resources than before: glaciers are not replenishing, aquifers are polluted in many countries, and the human population continues to expand without control.

We just cannot simply continue to look the other way, and act like scared children who cover their eyes hoping that what scares them will magically disappear. We are confronted with an issue on a global scale that will alter our way of life soon, definitely by the next generation. Not acting now would be a crime against our own kind. We might not have the keys or the answers yet, but some have started on the path of looking at the situation right in the eyes. The last two decades of efforts are starting to pay off. Clues are appearing here and there that may help us not only to find a solution one day, but also put us in the position of asking the right questions and prevent future damage. That will require from us to reassess our needs, our place, and our responsibility with respect to the biosphere. This will take a scientific process, and simply some good sense. Hopefully, the data we collect here will make a modest contribution to this process.

The drive back to Santiago can only be a reminder of where some of the issue lies. Our descent through the old glacial valley filled with moraines and blocks rounded by torrents seems already to be a distant memory. Santiago, like many active capitals of the world, is plagued with insane traffic. We left the peace of Laguna Negra at 2:30 pm. We reach our hotel four hours later when only less than 100 km separate the lake from the capital. As usual when coming back from an extended stay in the mountain, I have a difficult time adjusting with the noise and the crowd. The warm shower is good, though. We will stay only one night. No tourism this time around. Our plane takes off at 9:15 pm the following evening, and we are back in the US and home by 11:00 am on December 17. The morning air is clean and brisk, not unlike that of the lake, where for now, PLL is a reminder that we were there. It is logging data every hour and calling “home” (at NASA Ames) every evening, sharing more knowledge about melting glaciers and climate change. In a few months, it will be proactively monitoring the environment at Echaurren, as a precursor to what, maybe some day, another Lake Lander will do on Titan.

Captain’s Log – Entry #7: Seeking Rock Glaciers

Nathalie Cabrol (r ) and Chris Haberle, during an earlier visit, make their way up the steep slopes above the northwest shore of Laguna Negra. Credit: XenoQuest Media

by Nathalie Cabrol

I was expecting to spend today packing. We are leaving Laguna Negra tomorrow. However, Robert (Jeff Moersch’s student) wants to go document rock glaciers from up close. This is the subject of his work with thermal imaging. He also wants to plan his next step for future investigations. I have to admit that I am tired and not really looking forward to ascending again the now-named “Devil’s Slide” ramp that separates the northwest shore from the perched Echaurren Valley. However, Robert does not have any experience in mountaineering and it would be unwise for him to find himself alone on that type of slope. So, last night, we organized a party of three to reach the foot of the rock glaciers we see on the satellite imagery. Interestingly, the thermal imagery from where we are on the south shore does not seem to show any substantial difference between the rest of the landscape and where we are expecting to see the rock glaciers. We will know more once we are there tomorrow…

We have an early breakfast at 7:00 am to take advantage of good conditions on the lake. Starting around 11:00 am, winds kick in and substantial waves form. The Zodiac is still a small, albeit excellent boat. Cristian will be our pilot today since Chris is leaving for Santiago with Liam, Sandy, and Gordon. Tonight, we will be only 9 at camp, which is a far cry from the 24 we started with.

The lake is quiet as we start our journey around 8:15 am. In addition to Cristian and Robert, Carlos – our doctor – is coming with us. He is a highly experienced mountaineer in the Andes. He will be additional support for Robert if need be, and also some assurance for our climbing party of three. Cristian stays on shore. He has a bad ankle.

Devil’s Slide…It did not get any better since the other day, but maybe I did! Despite the fatigue, it seems that going up on that slope wakes me up. I feel actually pretty good, steadily going up on the central dry gully, using blocks as stairs to gain ground. I am ahead of the guys by maybe 20 meters. I brought an empty Nalgene bottle that I fill with delight on the cascading waters about two-third of the way up.

Robert is doing an excellent job on his very first ascent. Carlos is not too far away from him and both advance with good assurance. Now comes the wall (well, let’s say the even-steeper-part-of-the-same-wall segment of that slope). I find my way in the wet ground, where my feet sink, giving me a bit more footing than on the slippery rocks.

Finally on top. It takes another 5 minutes for Robert and Carlos to join me. I give a high five to Robert who has a big smile pasted on his face. These are the kind of things that allow one to look back and have a sense of achievement. He will remember his first ascent, at least for the next 2-3 hours. I am very sure that this memory will be soon erased by the descent that is waiting for us on the way back. I do not mention it too much for now but he is a clever guy, and I am sure he already has a good sense of what’s in store for him from the effort he needed to put in to get up here.

Station Lake, a potential biological treasure-chest waiting to be opened. Credit: Nathalie Cabrol

The Echaurren Valley is as welcoming as last time. We stop near a small stream for a 10-minute break after our ascent. What is not to enjoy here? The banks of the little stream are covered in low, yellow and white flowers, whose smell fills the air. We have made good time, and that means that we will have time to reach at least the foot of the rock glaciers. We are on the move again. Geology lessons for Robert as we pass by striated rocks. I stop on the small promontory to show Station Lake to Robert and Carlos. It lies 100 m below us. While we are watching the stream cascading in and out of the lake, I am thinking about Edmond’s stream gauge that is now logging water speed and discharge. We leave.

The walk in the valley is comfortable. We have to climb a couple of low ridges, left behind by Echaurren when the ice descended that low. Reaching the top of the second ridge, we need to make a decision. According to the satellite imagery, we have two rock glaciers about 30 minutes away from us, one to the right, and one to the left. We head for the left one, which means gaining some elevation to avoid traversing a sea of large blocks. That still requires some effort. Walking in moraine material is not exactly the best way to make fast progress but for now we have no choice. The almost three weeks of heavy duty work and diving are starting to catch up with me, and Carlos and Robert need a break too. Time to stop for another breather, and for a good sip of that clear mountain water and whatever is on my food list. I am glad to see it is cheese.

We are now close to the foot of the promontory we wanted to reach and have time. The rock glacier should be somewhere near, in theory. We sit on rocks. Instinctively, I look down to evaluate the rock diversity that surrounds us. This is when I realize that something is different. On our way here, we have observed chalcopyrite, many other iron oxide minerals, mineralization on rocks but that is different. Scattered around us, pretty much everywhere my eyes can see on that basin are varve deposits. Yes, varves! Sedimentary layers. We found the sedimentary remains of an ancient lake…

The story unraveling in the book of stone carved in those deposits is telling. The lower (older) layers are on average substantially thicker, whereas the upper (more recent) layers are much thinner with still regularly spaced thicker layers. The discharge of whatever stream that entered that lake seem to have changed drastically over time, losing its ability to transport larger grains. The recent larger layers could be related to exceptional years but their regular spacing has me thinking that we are dealing with a cycle. It could be El Niño for instance, but this is pure speculation just looking at the sedimentary rocks. The only thing I can say is that apparently the competency of the water regularly got a bit higher than average. This is well in agreement with what is known of the climate history of the area. The varves also suggest that this lake must have been closely (spatially) connected to the Echaurren glacier.

While Carlos and Robert are looking at a large dead insect in a hole in a block of lava, I am scouting around. We should be on top of that rock glacier but all I can see are rocks and dust. No sign of interstitial ice, no indication that anything is here, no water. If anything was there, it is gone. The satellite image we looked at must have been a couple of years old at most. That confirms my finding on the other side a few days before. I still take Carlos and Robert there. On that side, though, streams are abundant, which  shows that there is flow below the rocks. We will have to climb higher to find the origin of those streams but that will be for next year’s field campaign. As I predicted, Robert didn’t fail to notice how hard the ascent of Devil’s Slide was and, wisely, wants to keep some energy for the descent. Thus, we start our way back. I choose to follow the stream cascading down to Station Lake as our guide to the central valley. When I see the moraine ridge, we head west and climb a 500-m wide pile of blocks. I cannot help looking down than forward. Minerals glitter in the sun. I find two very nice specimens that I pocket. Robert is laughing. We have known each other for only a few days and he tells me the same thing my grandma told me when I was a kid, or close to. He says: “My only photos of you are with your rocks”. My grandma was always saying that I was always either looking up at the stars or down at the rocks but never in front of me. Well, guess what? You were so right, grandma…

It is time to focus again. My right knee is bothering me. I suppose I cannot blame it too much. I dislocated it 15 years ago and Devil’s Slide was bound to revive that memory. I am taking a head start because I am planning to be slow on the way down. I am also opening the way. The secret is to block any dark ideas that can come up in one’s mind about being on a 50 or so degree incline, on slippery rocks, and with a temperamental knee. I know, that’s sounds like a lot, but in fact, it produces the right effect. I am taking my time and, although extremely difficult, this descent seems less overwhelming than last time. One step at a time. I regularly look up, higher in the slope. Carlos and Robert are making steady progress. I reach the beach and Cristian about 15 minutes before them. Robert has been stellar and when he finally gets to the shore I tell him that he is now officially a field geologist. He laughs again but I have to admit that this descent would be scary for any experienced mountaineer. He did extremely well.

We don the Mustang suits once again and we are on our way off the northwest cove with the Zodiac. As expected, the waves are now splashing around us and will until we pass the promontory. Something up there has caught a ray of sun, which gets my attention. This is our meteorological station. I can only think about what its wind gauge is showing right now…After the promontory, the lake is quieter but not calm. The journey back is a bit rough but eventless in the end, fortunately.

As the hours pass, we are getting closer to wrapping up our first field campaign. Our first encounter with the lakes and the glacier have led to more questions than answers, and this was to be expected. The glacier is retreating and the rock glaciers as well. This is worrisome. On the other hand, there is definitely an abundance of life in Laguna Negra. We still do not know about Station Lake. Does abundance translate into biodiversity? That is one of the key questions. The other one is how these organisms are adapting to a habitat that is changing so quickly. Hopefully the coming two years will bring some answers.

 

Captain’s Log – Entry #6: Underwater Caves and Alcoves

By Nathalie Cabrol

I have been watching them from the south shore for long enough and other activities have prevented me from exploring them earlier but today is the day. The west shore of Laguna Negra is characterized by a very large basalt exposure where underwater caves and alcoves are abundant. I am pretty sure those are being used as shelters by life, and possibly hold more biodiversity than we have observed so far. We leave early with Chris. The lake is a mirror, which makes the trip in Margaritaville (one of our boats) easy. While we head for our destination, Liam, Sandy, and Cristian pay a last visit to PLL on the northwest shore. Sandy did not have the chance yet to get on the lake and Cristian needs to learn how to maintain PLL while we will be away.

Ducks are flying away as we approach. The air is crisp but not cold. Every detail of the landscape is sharp. It does not take too long to reach our destination. Chris turns left into a hidden alcove and I discover a series of caves, not high enough to stand but close. We land at the largest one. From the report of the first exploration of Laguna Negra in March 1873 that the managers of Aguas Andinas gave me on December 16 when we met, I know that this cave is officially known as the Cave of the Amazons. The book is illustrated with amazing reproductions of photo plates 140 years old. If one is not paying attention too much, it could appear that time has stood still since then. Yet, the Echaurren glacier was lower than today. It is still very humbling to see that these shores were explored that long ago. The exploration party stayed for a week and came with horses and mules. That we shared…

Their camp was maybe 100 m to the west of ours. When I get back home and have time, I will put side by side their illustrations and ours: Two groups separated by almost one-and-half centuries but bound by the same interest, that of understanding what would be the future of their water resources. However, they came and left with a more optimistic vision than the one we have today. They returned to Santiago with the news of large reservoirs, and plans to build a dam that would supply water to the capital city, the dam of El Yeso, which is now standing less than two kilometers from where we are on the other side of the hill.

I start preparing my diving gear. I only have equipment for free diving so there will be no underwater cave exploration but rather a reconnaissance of where they are, and what type of organisms live there. Some of the caves are only partially submerged and have air pockets that will allow me to venture a bit farther.

It does not take me long to be ready. I had donned my suit before we left. I am wearing the dual GoPro camera system that allows 3D rendition of films. Hopefully, this time it will work without a glitch. The water is so transparent. As we were approaching, the bathymetric system was reading near 50 m depth and we still could see the huge granite blocks at the bottom. The cliffs are falling straight down into the water. There too, no real transition between the shore and the lake bottom. Just a small shelf and then… down. I still find a few blocks that allow me to enter the water without a problem, but more importantly, will give me a solid footing to get out.

Here we go. The GoPro is on. Laguna Negra has this uncanny ability to envelop you as soon as you get in. It is a deep blue blanket that surrounds you immediately. Over the past few dives, I have learned not to be spooked by it anymore. In fact, I am sort of expecting it now and it finally feels comfortable. Looking around me, I am surrounded by giant blocks, and yes, a flotilla of small trout. They look at me with curiosity but no fear.

I start with a quick reconnaissance of the near shore morphology. Macrophytes are still present in abundance but other types of algae are there too that I do not recognize. Those actually almost look like stalactites. They are hanging downward in the water and can grow several meters long. Looking closer at the macrophytes, I see something I did not see on those of the southern shore. They are encased by a whitish, translucent, almost gooey material, which I mistake for a moment for fish eggs. At closer look, it seems to be some sort of envelope that contains millions of air bubbles. I have seen the same process taking place in the High Andes at Laguna Blanca. Those algae produce billions of oxygen bubbles every day. This is how our planet’s atmosphere changed drastically a few billion years ago, although this theory has started to be challenged.

If this is really the scenario that played out, that was one of the first real ecological disasters, killing most life that could not adapt to a O2 atmosphere. I often wonder if this is why we are taking such poor care of our environment. After all, if we are the result of an ecological disaster, maybe, very deep inside, it is rooted in us that messing with the environment is a good thing…Going beyond cynicism, watching these algae doing what their ancestors have done for billions of years gives a direct connection to our evolution, to where we are coming from, and it is also a warning. We live in a natural system of many components. Destabilizing one or more leads to feedback mechanisms and loops we have poor or no control over and very little ability to correct.

I move on. I pass by many similar alcoves and then, I am surrounded by a sea of red, literally. The time to adjust my vision, I recognize these tiny (0.5-1 mm) organisms, their long antennae floating in the water. They are old friends of mine from many prior lakes in the High Andes. Their morphology is easily recognizable. Millions of copepods are surrounding me in a very large swarm. I slowly move my hand to see them swim around and away. That was unexpected. A week ago, Ruben was mentioning that he was surprised by their low number in the south shore. Well, I guess they are here. Also, if I am not mistaken, the water seems slightly warmer. With all this fractured basalt, the springs, and an active volcano (Tupungato) not too far away, I would not be surprised if a number of springs that enter Laguna Negra were actually hydrothermal. In fact, coming by boat, we could see patches of grass stained yellow, as if burned by acidic waters. The other possibility is that I am getting really used to this cold water…

The copepods are red, very red. That surprises me a little. The water is highly transparent, that’s a fact. However, they have so much water column to work with and we are not that high in elevation, so although I have not checked the UV here, I would expect it to be substantially lower than at Licancabur, which is located about 3300 m higher. I might be wrong and these are still tiny organisms needing protection against an abundance of UV. Besides, they are apparently very close to the surface too and we are about one hour away from solar noon. Maybe they share the same behavior as those of Licancabur and Laguna Blanca (5,914 m and 4,340 m elevation, respectively). We saw them swimming at solar noon at the surface while the UV index was scarily between 24 and 29. Maybe they do not care about the short UVB that is irradiating them. Who knows. The biologists will have to help us unravel that part of the story. The experience gained with the High Lakes Project in the past nine years will be very helpful here.

I leave the copepods to go back south. I have to be careful not to venture too much farther away from where the boat landed. The water is cold and I do not want to be caught starting to get chills in an area where there is no place to get on shore. I pass by the main cave where Chris is sitting, patiently waiting for me, and keeping one eye on me and one on possible rock glaciers on the other shore. I sign that everything is fine. The area allows me to get into a partially submerged cave. I have room to breath. I sneak up on a very large fish who is obviously sleeping. It does not move. I am standing right on top of it, maybe a meter or so above, no more. This time the camera is rolling and I am making sure to capture its image. It completely ignores me until I start moving on. At this time, it realizes that it is not the largest fish in that lake and darts away from me. In the time I will spend near and in those alcoves, I will see a total of 3 large fishes (30-50 cm long). The others are medium to small-size trouts.

As I proceed with my reconnaissance, I noticed that the walls of the cliff that plunges into the deep of the lake are also covered in algae, very low profile and light ones. They, too, are producing oxygen. I play for a moment with the bubbles and move on again. This underwater landscape is amazing: bright algae lit-up by the sun are dancing in the current with, in the background, the dark blue of the depth, which, where I am reaches over 100 m. I will have to come back with a rebreather next year. For today, it is a shallow depth investigation, 5 m deep maximum.

I pass through the macrophytes and then venture farther away from the shore. Bubbles are coming straight up in a column in front of me. I look below and see no fish or algae. Maybe there is a spring. Strangely, the bubbles stop. Weird. Time to go back. I spot my landing made of a few blocks conveniently arranged in a staircase-like fashion. There is so much work to be done here next year, so much sampling to do. We will have to go through these alcoves and small caves one by one. And they are only the beginning. There are many more of those not only on the other side of the northwest branch of Laguna Negra, but on the northeast branch as well. We will need more diving flexibility.

I do not know what the biodiversity of Laguna Negra is. It is hard for me to assess. This is not my area of expertise. I have learned to be cautious in the High Andes where certainly life is abundant in the altitude lakes but cladograms show it is not so diverse. Is it the case here too? We will see in the future. What I do notice from this reconnaissance is that life occupies every possible niche we have explored so far. It will be interesting to compare what biodiversity characterizes Laguna Negra, already in stage 2 of deglaciation, with Station Lake in the Echaurren valley, which is still in stage 1.

As I resurface, I can see Mariner 1 (the Zodiac) about 1 km away next to PLL, near the opposite shore. About 50 meters from it, and close to Victoria’s Cascade, a tiny orange dot shows the emplacement of the buoy that holds its twin sonde located where the waters from Station Lake cascade down into those of Laguna Negra. I smile because this summarizes in many ways what has been accomplished in these 17 days: PLL is now sending back data to the US. With its twin sonde, they are like a time machine recording the changes that occur when glaciers disappear, a space-for-time substitution experiment of sorts. It is up to us to understand what they mean. I am sure Ruben will like it. That could make a very informative comparison with his own study in the Alps.

Time to come back to camp. Margaritaville does very well, helped by almost no wind. The camera was still recording as I was coming out of the water. This time, unless something went terribly wrong, I am pretty sure we have 45 minutes of underwater documentation. Jeff (Moersch), who loaned me the camera for this dive and the previous, will process the movie. The 3D should definitely, and most literally, add a dimension to it. Hopefully, it should help the biologists for the planning of next year field campaign, and that is also something I really like about our investigation so far. Our bathymetric mapping (plus the scientific rationale provided by the rest of the team) has helped the engineers decide on where to moor PLL. This underwater documentation will help future planning for bio-sampling. This team is working as one, the data from one group helping the others farther their research; brought together, they give a unique view of the richness and evolution of the Laguna Negra system. After our “mule days” of the beginning, I cannot help but think we came together very strongly and made this first field campaign a success. For now, I let Chris take us back “home,” toward the white domes on the south shore I can see straight ahead. My only ambition at the moment: a large bowl of David’s warm soup. I might get used to it but the waters of Laguna Negra are still cold…

Captain’s Log – Entry #5: South Shore

PLL Principal Investigator Nathalie Cabrol prepares to investigate the shallow waters along the southeast shore of Laguna Negra. Credit: XenoQuest Media

by Nathalie Cabrol

More underwater exploration of the lake today. Gordon and I leave from “Launch Point” and head towards the southwest shore. At the beginning, the landscape is very similar to that explored in previous days. We see long macrophytes grouped in a forest that runs in a belt along the shore, and then the shelf plunges into the deep of the lake. As we are approaching “Base Camp Landing”, things suddenly change. The macrophytes become longer and denser, but also more fishes are present. Generally, the water is deeper close to the beach. I spend some time passing through the algae. It is floating with the current. The wind has picked up on the surface and the algae seem to be dancing in a well-choreographed ballet. Many are covered with sediment but when exposed, they range from a bright to a dark green. They offer a strong contrast with the dark blue of the depth. I make my way through them, pushing them aside as I advance. Gordon is not too far. I take advantage of him fixing his camera on the shore for an instant to wander in a deeper part of the lake. This time, I do not have the same feeling of being lost in the twilight zone. I can still see huge granite boulders at the bottom. Time to head back towards Gordon, and I do well. I surface and he is looking for me. We proceed.

The shore is turning south again. To my amazement, I see a channel, not a natural channel, a man-made one. The rocks that were used to build it are now covered in algae but it is obviously artificial. It was part of the pipe system to release the waters of Laguna Negra into those of Lo Encañado during overspill times. That has not happened for a long time. We enter the channel. It is maybe 5-10 m wide. It is hard to say from our perspective. It is deep, probably 10 m, and quite long (50 m?). We proceed with caution. The center is filled with very long and dense macrophytes. Algae are also growing from the side. The last thing I want is to get my fins entangled while I am free diving. So, extra caution…

I opt to swim on the left side of the channel, which is clear of natural obstacles. And this is when I see it. Huge… Since we have been here, we only have observed trout of moderate size. The fish that just popped up in front of me, maybe two meters below me, is enormous. It is not a trout. It is about 50 cm long but the width of its back is what strikes me most. It has a very thick back. This fish could easily weigh 10 kilos. It is dark to dark blue, with some lighter patterns on its back, possibly including light pink. It is not a salmon either, its head is round. He is keeping an eye on me. He looks as astonished by my presence as I am by his. Strange encounter in a very foreign environment. I hand-signal the position of the fish to Gordon who joins me on the left side. The arrival of another strange creature in a yellow dry suit is too much for the fish, which disappears among the algae. Gordon does not have time to capture it with the camera.

Nathalie explores the underwater world of Laguna Negra. Credit: XenoQuest Media

We advance in this long channel. A wall of macrophytes now makes an impassable obstacle. I surface to get an idea of the extent of the obstacle. It goes to the end of the channel, about 15 meters away. We will have to stop here. Interestingly enough, there is also a small tunnel down below us. That’s probably part of the piping. I bet this is where the big fish hides. That would make a terrific habitat. Since I am just free diving, I will not go down there to check it out. Besides, I am starting to feel the cold that surrounds me. We have been in the water about one hour and half now. Time to retreat.

We go back down the same way we came. The color of the water fades from sky blue to deep blue depending on depth. This channel is amazing. It is very much like walking in a hallway. I am not clear as to why the dense forest of macrophytes grows only in the center.

Nathalie checks out some underwater plumbing, part of the system installed many years ago to deliver Laguna Negra water to the six million inhabitants of Santiago, Chile. Credit: XenoQuest Media

Cold. I am moving forward. What was just a feeling a few moments ago has turned into a distraction and is now a deep feeling of discomfort. I need to get out. My hands are getting a bit numb. My core temperature is affected. So, I bail out as soon as we get out of the channel. That’s probably the sharpest right turn I have ever made to shore. I still need to find a good spot to land on that shelf. I am wearing a GoPro camera and I do not want to damage it against the rock. Jeff (Moersch), who arrived yesterday and loaned me the camera, would not be too happy.

I am on land now, shivering a little. Gordon surfaces soon after. We take a moment to remove masks and fins and initiate the return to camp. Well, it is only a kilometer away (…) through huge rocks that we carefully navigate in our diving boots. Actually, they are gripping pretty well. I forgot to mention that I am still wearing my lead belt. It is only 3 kg of lead, so not much of a hassle to carry around. I do not need much more in this lake. The 4-kg belt sent me by the bottom a bit too fast two days ago. Adjustments were needed.

We walk through the magnificent flowers now on white gravel. Their colors are amazing: bright purple, yellow, blue, pink. Birds and lizards everywhere…Yesterday, a fox came within 50 meters of camp. It did not look too afraid. He most likely smelled the trout Hernan was cooking. I am pretty sure I heard him the night before roaming into camp as well.

We are at camp now. Cristian unstraps my GoPro, somebody else takes the lead belt away. It seems that I have an army of ants around me. When they are done, I barely have my diving suit still on. :) I am still fairly cold so I go change. I will wear my down jacket for an hour to get some warmth back, which is very strange in a 20C afternoon. Finally, I will end up sleeping part of the afternoon to get back some of the energy I spent. Considering what we saw and documented today during this dive, it was well worth the trouble.

Captain’s Log – Entry #4: Base Camp, This Is Echaurren Valley

by Nathalie Cabrol

In contrast to the arid south shore where PLL Base Camp is located, the northwest shore of Laguna Negra, just below the Echaurren glacier, has running streams and this cascade. Credit: Liam Pedersen

It has been taunting us for so many days now and the time has come to pay a visit to the Echaurren Valley. The work with the Lake Lander is proceeding as planned, helped by the presence of two engineers from YSI, Fred and Jim, who spent three days with us. The sonde is calibrated, and we have data. The webcam has been installed on the probe, which means that it is spying back on us in camp, sending us the first image of our domes. The biologists have collected and processed a large number of samples. The project is running as smoothly as possible, therefore I can grant myself a day of pure exploration.

Early Friday morning, I leave with Chris and Gordon (who wants to film us). After donning our Mustang suits, we get into the Zodiac. We are towing Margaritaville – that’s the name of our second boat, which is loaded with equipment. The boat’s name is inherited from the fact that its propeller speed would probably make it appropriate only to stir a Margarita. The lake is calm. Because we can only use an electric engine, the expected time to travel the ~ 4km that separate us from the northwest shore is about 45 minutes. That gives us plenty of time to admire the landscape, including the majestic glacial valley of Echaurren that enters Laguna Negra.

As we are nearing our landing site, we can see underwater caves to the east, and the roar of a cascade becomes more present each moment on the west side. I have the feeling of entering the “Lost World.” This feeling will become even more real as soon as we get to shore. What an amazing landscape. From the boat, we can see cascades flowing over thick moss, cutting the fractured and fragile volcanic rock. There are numerous dikes, caves, and strange erosion patterns. Even stranger though is the apparent lack of glacial erosion marks. The shape of the valley is evidence that the glacier came through here. Yet, its marks have faded away, possibly erased by the abundance of water that flows here, and post-glacial fill.

Our landing is tricky: on one side, there are too many macrophytes for our propeller, and on the other, too many large blocks for comfort. Finally Chris, who is piloting the boat, squeezes the Zodiac in between two blocks and we are on shore. There are large blocks everywhere, but this is not really what captures my attention most. From the satellite image and DEMs, I suspected that the ascent to the upper plateau would be “interesting.” I was right. In front of us, we have a wall about 100 m high, whose slope starts around 42-45 degrees. In the last third of the ascent, it turns into an almost 50-degree overhang. Going up is not so much of an issue. I am used to Andean volcanoes whose slopes are comparable. Here, you forget the notion of slope of equilibrium and you just focus on the goal, the summit. As we go up, we encounter lush cascades of fresh water pouring over thick moss. This is the best water I have drunk in a long time. Flowers of all kinds are arranged in a multi-colored carpet. This is simply amazing.

Nathalie Cabrol and Chris Haberle ascend the steep slope of the northwest shore. Credit: XenoQuest Media

We make it to the top. The valley floor is typical of glacial valleys. There are still morainic bars left and the valley floor is made of light-toned, very fine material. Finally, as we reach the opposite side of the promontory, I see the first block that clearly shows glacial striations. We have only a short hike to the top of a small hill. From there, we see it: Station Lake. I gave the lake this name when I was still at Ames looking at satellite images and trying to identify potential sites for the deployment of our experiments.  The bad news is that it lies about 100 m below us. The excellent news is that it is obviously a lake that is still very much connected with the Echaurren glacier. Its color is milky blue. From the moment I see it, I know that we are going to stay at Laguna Negra for the rest of the project.

Our concern with Laguna Negra was its great transparency. With Station Lake, we now have a complete system for our project: The Echaurren glacier, its downstream part composed of a debris-covered glacier, then a rock glacier, melt water coming from underneath the rock glacier base that channels into the valley. This water ponds into the 200-m large basin that forms Station Lake. The outlet flows downstream into another small basin, and then falls into Laguna Negra in the cascade we saw while arriving on the boat. The mixing between the waters from Station Lake and Laguna Negra is characterized by the same milky blue water over a relatively small area, and this water is rapidly diluted into the larger transparent lake.

A view looking down onto the milky, turquoise-blue Station Lake. Credit: Nathalie Cabrol

We decide to split up. Chris will go to the lake and leave the boxes containing the stream gauge experiment he will deploy on Sunday. Meanwhile, I will make my way to the base of the rock glacier about 30 minutes away and deeper into the Echaurren Valley. I want to collect water. A few days ago, we had a discussion with Ruben who studies the impact of deglaciation in the Alps. He told me that the water from the rock glaciers there is characterized by a high abundance of nickel, regardless of geological formation. Sampling here is therefore very important. If we were to find similar results, we could hypothesize that we are confronted to an issue of possibly global, rather than regional scale. As I move up the slope, the algae and vegetation in and around the stream look healthy, though. This is a contrast with what Ruben was showing on some of his slides. Hopefully, we won’t find any nickel anomaly here.

It is really a pity that our time is limited. We have to keep an eye on the weather. For the past three days, we had afternoon thunderstorms starting 4:00 pm and winds descending over the lake. We need to leave the northwest shore at 2:00 pm at the latest. I still cannot help it. I look on the ground, which is glittering with minerals reflecting the sun. There is an abundance of hematite, for sure. I have to move up. I reach the base of the rock glacier shortly before 1:00 pm. Water surges underneath the rocks in intricate ways. There are probably many underground channels below those rocks.

A loud rumbling freezes me. By reflex, I look up. This sound is not good news. There is an avalanche higher up. I am well protected where I am, so I wait. I contact Chris by radio. He heard it too. It is “wait and see” for a few seconds. I still have in mind this meter-sized boulder that came at me at day-break on the slope of Shasta 10 years ago in the Californian Cascades. I still can see it turning on its axis several times per second. I had to wait the last second to duck as it was tumbling down erratically on the slope. I have been really scared only a few times in my life, but that was one of them. So, I duck and wait. The sound dissipates. It is safe to continue. I have my samples and I know that I am running late. Chris is already at our meeting point on the promontory. I tell him to descend and prepare the boat. Clouds start to accumulate. The water samples make my backpack heavier, but overall, the way back to the promontory is short enough. Now, I am on the overhang valley, looking down 100 m to the landing where Chris and the boats are waiting. Going up a couple of hours before was not such a big deal despite the slope. Going down is suicidal.

I have to forget about the insane gradient and focus on where to put my feet. My poles have become an impediment so I keep them in one hand. The load in my backpack is pulling me backward. That’s not good news. This descent is simply dangerous, and I know what dangerous slope means. I had plenty of those on the volcanoes. This one is nasty between sheer rocks made slippery by the cascading water, the loose blocks, and the very fine material where rodents have made their burrows. It takes me almost 20 minutes and a few close calls to finally get to the boat. At this point, I am pretty much exhausted. Still, I am there in one piece and this is all that counts. Chris also had some adventures going down, sliding on slippery rocks. I tell him that there is no shame going down on our butt. It is always better than to go head first. On that, we agree.

We don our mustang suits and are back in the Zodiac. I cannot believe the size of the waves this lake can generate. We have a very rough departure from shore and for about 20 minutes, it seems that our little electric engine cannot do much against the wind and the waves, especially with Margaritaville in tow. We are being seriously splashed in the Zodiac. And then, as soon as we pass the promontory, things completely change. The lake is almost a mirror again and the water calms down.

Making our way to our camp landing, we are acquiring bathymetry. For now, our deepest point is close to 290 m. The bathymetric map is coming together. We still have a lot to cover, but for now, most importantly, we have documented the region where Planetary Lake Lander should be deployed. This data will help the engineers decide on a mooring point in an area of scientific significance for the project.

It takes us about an hour to reach “Base Camp Landing,” our landing area near camp. The rest of the crew is waiting for us on the small beach and helps us unload the boat. We have samples and photographs. The reconnaissance of the Echaurren Valley, and the discovery of the glacial sediment load in Station lake has helped us to reach a major decision for the project. We have everything we need in the Laguna Negra region to achieve our science objectives, and will stay here in the coming years. I am also thinking about moving camp from the south shore to the Echaurren valley next year. That will require yet another level of logistics, and most definitely a helicopter.

The mood is upbeat tonight at camp. After dinner, we discuss the plans for the last week at Laguna Negra. That includes the “need list” and the “wish list.” Considering our progress, I am confident that we will be able to complete our wish list as well. After dinner, I meet the engineers in the “Robo Dome.” We line up the science objectives, possible mooring points, and the bathymetry. After weighing the pros and cons of several locations, we come up with the operation site for Planetary Lake Lander and its twin sonde for the next three months. The transfer of PLL from Launch Point to its mooring position should happen tomorrow, and will mark a great achievement for this year’s deployment, as well as a phenomenal achievement on the part of the engineering team.