When not doing fieldwork in the Bolivian Andes, Simon Lamb lectures at the University of Oxford. His paper on why high mountain ranges occur, which suggests a link between climate and tectonics, appeared in Nature last year (vol 425, p 792). His book, Devil in the Mountain: A search for the origin of the Andes, is published by Princeton University Press in May.
Do you have a favourite rock?
A piece of granite – this one here from the Bolivian Andes. It’s such a beautiful granite, the crystals are so fresh and clean. In some ways it symbolises what a wonderful place the Andes is to work. The rocks are so pristine and have so much to tell you.
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What does it feel like to spend all that time in the mountains?
It is extreme. The altitude is a problem. You have half as much oxygen as at sea level and that is stressful because you never feel completely well. It is hard work to move around, you have to force yourself.
The other problem is that there is little infrastructure there. If your vehicle breaks down or somebody gets ill you quickly go from a situation where everything is fine to one that is life-threatening. You might have your breakfast and plan to do something, then by lunchtime you are fighting for your life. It takes a while to recover from that.
Eventually, it takes it out of you psychologically. You become more reluctant to take risks – that becomes the biggest problem. When I first went to Bolivia we were adventurous, because we didn’t know what could go wrong. We did an awful lot of things that later on in the project I wouldn’t have dreamed of doing.
What sort of things go wrong?
There was one time when we wanted desperately to get to the summit of a volcano to sample some gases, but we couldn’t see a way to get there. Then a miner said he knew how to take a party of people up the volcano. In fact he was humouring us: he didn’t know the way at all. First he took us up the wrong volcano, so we ended up having to climb two volcanoes instead of one.
After all this effort we were determined to get the gas sample. It got dark, the guide panicked. He knew he was in trouble and he more or less abandoned us. We were floundering around in the dark trying to feel our way down. We were at our limit. I was pig in the middle between the guide far in the distance and the other two people in our team behind. I was using a flashlight to signal to them where I was, while keeping an eye on the guide and shouting to him. It was a close thing.
What about other kinds of hazard?
These volcanoes are on the border with Chile, which is a militarily sensitive area. One time we were on this border, travelling north. There was this flattish, sandy area beside the road, a good place for lunch. We just drove over, parked the car and started to eat. While we were sitting there someone noticed a piece of wood sticking out of the plain not far away. It was a sign saying, “minefields”. I can tell you, we reversed absolutely on our wheel marks. I have never gone out of a place so carefully. We weren’t going to deviate one inch.
You are often in most danger when you don’t know it. In Bolivia, there is the danger of climbing a volcano or a high mountain at the limit of your abilities. And then there are the political dangers.
The country has become much less stable: it has been close to civil war. The most dangerous situations are where there is a conflict between the local people and the army, because then people get carried away. The Bolivian campesinos have slings, and when they are rioting they catapult stones at people. A lot of people have been killed that way. Death is always around the corner.
How did you end up in the Andes, and in Bolivia in particular?
I was offered a job by John Dewey, the professor of geology at Oxford, who had set up a project on the origin of the Andes. I was hesitant because I felt that I knew nothing about South America. Then everybody I spoke to told me I’d be mad not to take the job. I began to see it as a fantastic opportunity. But when I phoned the Foreign Office to ask for advice about working in South America, I was horrified when they counselled me against going to almost any country there. There was a guerrilla war in Columbia and Ecuador: they had big problems with drugs. No western scientists were going to Peru because the government had lost control of the country. I thought, this is completely hopeless. Then almost as a throwaway, they said, why don’t you think about going to Bolivia?
What are you looking for when you are out on a field trip?
If you spend a lot of time working in a particular area, you want to know more and more about what went on there. The joy of the science I do is going out into the real world to get the answers, trying to reconstruct what happened at some distant period in the earth’s history. The other question in your mind is: why did it happen like that? I’m trying to work out what the important process or phenomenon is that led to the rise of the Andes. Why is it that this mountain range appeared in the past 40 million years? In terms of the history of the earth, that’s yesterday.
The period when the Andes, and the Himalayas, rose rapidly does seem to be synchronised with the way the planet’s climate has cooled down. I am not the first to say that, but it suggests a link between what happens deep in the earth and the atmosphere. We are heating up the planet with global warming, so it’s important to understand what can cool it down.
Maybe the rise of a mountain belt can cool the planet. But in the Andes it also seems to be the other way round: a cooling climate can help push up a mountain belt. That seems absurd, doesn’t it? It seems like the tail wagging the dog. How could that happen? Yet every part of the earth is so interlinked that small things can have a big effect.
You have likened the Andes to a wedding cake. It seems like an odd comparison…
The huge forces at work inside the earth cause the surface to move around. Sometimes it gets squeezed and pushes up big mountain ranges. You’ve got a stiff, solid outside that sits on something much more squishy. Wedding cakes always come to mind. As you cut a wedding cake, the icing cracks. You get these great slabs of marzipan and icing, then the rich soft cake bit. Something stiff and brittle that can crack sitting on something that is gooey and runny.
So mountains are more than chunks of rock?
I see mountains as almost living organisms, as dynamic things. They grow. If the whole history of the earth was speeded up, you would see its surface almost pulsing. Take the Andes: 40 or 50 million years ago there was no mountain range at all. One way of thinking about it is to take a million years of geological time and say that is equivalent to one year of our time. A typical life of a mountain range is about 70 million years – call that 70 years. If something geological happens in a million years, that’s fast.
The Andes are probably in middle age, in their 40s, with plenty of life ahead of them and lots of experiences behind them. They have been late developers because they hung around for a long time without growing much, then suddenly rocketed up and doubled in height. If I couldn’t think of the mountains this way I wouldn’t be so interested in them. They would turn into great lumps of inert rock, which is how I think most people see them.
When you are in the mountains, does anything distract you from your geology?
Definitely. You suddenly step back and say this is an incredible place to be. We have seen herds of vicuna, and foxes. You can be driving through Bolivia’s Alto Plano, come over a hill and see a huge lake covered in flamingos, and they all suddenly rise up. There can be moments of immense beauty, especially late in the day when you get this wonderful low evening light – a rich light, it has a lot of orange in it – and the landscape becomes almost like a painting. It’s fantastically beautiful.
You do fantasise that you want to get back to civilisation, you want a hot shower, a meal at a restaurant, you want to pamper yourself. But when you get to the city it comes as quite a shock. You immediately regret being back, and straight away you are looking forward to going away again. That’s the great thing about these long field trips: you always have the thought that you’ll be off again in a week and a new adventure will start. I feel privileged to have experienced all that.
Do you need to be a scientist to appreciate the work you do?
I think everybody is in some sense a scientist at heart. Everyone wants to know the answers to the same questions that drive scientists. Whenever I meet people when I’m travelling, when I tell them what I’m doing they are always asking me: Why is it like this? Why do we have mountains? Why did they form? My audience is anybody who has an interest in the world around them. The most difficult questions to answer are the ones from people who are not scientists. You cover up, you put up a smokescreen, but often their questions trigger a line of thought. It inspires you.
What’s the “devil in the mountain” of your book title?
The Bolivians are descended from the Incas, who saw the earth as being ruled by spirits. Different domains of the earth have different spirits, and there is a spirit in the underworld, the bedrock of our world.
When the Spanish came to South America, the locals created a hybrid, mixing their traditional beliefs with the Christian ideas. The devil from Spanish Catholicism got mixed up with this spirit of the underworld. The Spanish were pretty cruel about getting the peoples of the Andean countries to extract gold: the hardship in those mines was unbelievable. So the spirit of the underworld became a formidable character, a devil.
Today if you are a miner you make a pact with the devil, otherwise you are in big trouble. If you go into any mine in Bolivia, there’s a big effigy of the devil close to the entrance. They give it presents in the hope everything will be all right. For me, as a geologist, the devil in the mountain is the nature of the bedrock, what has happened there, all the stories locked up in it.