麻豆传媒

When visits a volcano he鈥檚 after two things 鈥� a whiff of ultra-fresh volcanic gas and samples of brand new lava. That means climbing into craters and getting uncomfortably close to bubbling lava lakes and noxious gases. Sims admits to Stephanie Pain that he loves adventure, but insists it鈥檚 the data he craves, not the danger

Isn鈥檛 molten lava too hot to get close to?

You only feel the heat when you鈥檙e very close or if the wind is blowing over the lava towards you. In some places collecting lava is easy. In Hawaii, for instance, there are breakouts and you can just reach down with your hammer and scoop up one of the little dribbles. In explosive types of volcano like Stromboli and Mount Erebus, it鈥檚 hard to approach the lava because there can be a big splatter which can kill you if it hits you. So you wait for an eruptive event and then run over, collect the lava bomb and run away. On Mount Etna I have had to wear a fireman鈥檚 suit to sample active lava flows 鈥� but once, when the wind shifted so the heat was blowing towards me the helmet started to burn. If you鈥檙e after gas samples, though, it鈥檚 helpful to have the wind blow it your way.

Is it really necessary to get so close?

It鈥檚 the only way to get the data I need. As a geochemist, I use radioactive clocks to understand volcanic processes 鈥� for instance, how magmas and gases form and how fast they travel to the surface. The answers to these types of questions are important for our basic understanding of volcanoes and are also essential for assessing the risk of eruptions.

I鈥檓 especially interested in radon. By analysing radon isotopes we can work out how long it takes magma to reach the surface and to recharge a volcano鈥檚 magma chamber. But radon is extremely dilute and to get true magmatic radon measurements you need to get as close to the active vent as possible.

What else do you look for?

I also collect trace metals in the gases to measure back in the lab. These provide evidence of past volcanic events and help in understanding mass extinctions. Many trace metal measurements can be made from the top of the volcano, but the concentrations are much higher inside, so we get better data.

This is some change from your original career.

When I left school I intended to be a mountain guide and professional climber. I went to work for Eastern Mountain Sports in New Hampshire teaching people how to rock climb and ice climb. I started guiding in the Peruvian Andes and in Alaska and put up first ascents in wild places like the Black Canyon of the Gunnison National Park in Colorado. Later I got a bit tired of just climbing and guiding so I started working at the , which runs a 鈥淗oods in the Woods鈥� programme. I took juvenile delinquents and penitentiary inmates on 20-day trips, backpacking and mountaineering.

Did you ever feel threatened out in the wild with a group of offenders?

Only once. We had ice axes for snow travel and one particularly violent kid was threatening another with his axe and I stepped between them. The kid took a swing with his axe, and as it swung through the air I must admit I was a bit concerned 鈥� but he threw it in the ground. We worked with both teenagers and adults, but I preferred the kids. I liked their energy. Many just needed some direction and for them . When I was young I鈥檇 also been a troublemaker and climbing had turned me around.

What made you switch to science?

I decided I wanted to go to school and some influential friends encouraged me. So I went to Colorado College, a small liberal arts college. I found I just loved geology.

How did you come to be climbing into volcanoes?

During my masters and later during my PhD I worked as a field guide in Antarctica for a month or two each summer. While I was there I climbed into Mount Erebus. That was the first volcano I climbed into using ropes. But it was really only in 2002 that I climbed into a volcano for scientific reasons. A colleague and I wanted to collect radon and the obvious place to go was Masaya volcano in Nicaragua. It鈥檚 perfect for our radon measurements because you can get right over the magma conduit where the gas is coming out. There鈥檚 even a bit of an overhang so you can get very close to sample the gas.

Is it more dangerous than mountain climbing?

Technically the climbing is much easier but I often hang two ropes because volcanic rock is sharp and glassy and if the rope you are on cuts then you are clipped into another safety line. Also, if you ever need to get out in a hurry two of you can go up at the same time. I鈥檝e been into at least 10 craters but only three where I had to rope up and abseil in 鈥� Erebus, Masaya and Nyiragongo in the Democratic Republic of the Congo (DRC).

Is there a risk you might get caught in an eruption?

I only climb into volcanoes that are continuously monitored. I want degassing volcanoes, not exploding ones. There are dangers, especially from falling rocks and collapses. Things change very quickly inside craters. One day in Masaya the magma conduit doubled in size. On that same trip there鈥檚 a photo of me sitting on the edge of the inner crater above the conduit, sampling gas. Three days after we left, a large section of the terrace we were sitting on collapsed.

鈥淎fter we left, the section of terrace we鈥檇 been sitting on collapsed鈥�

What about the danger from gas and molten lava?

At the first whiff of sulphur, I put on my gas mask. I have known people to camp in volcanic craters, but I would never do that. The air is very acidic. It鈥檚 not good for your lungs. It鈥檚 not good for anything 鈥� your gear degrades very quickly. Some volcanoes produce a lot of carbon dioxide. Get into a pocket of that and you can die pretty quickly.

Lava bombs can also be dangerous. There鈥檚 a lava lake in Erebus and the lava is very viscous and big bubbles form deep down. When they break the surface there鈥檚 a loud boom, which makes your heart skip a beat. When you hear that you have to keep your wits about you because when bubbles burst they send bombs through the air. Most of the time they don鈥檛 come near you, but you need to stay focused to watch where they are going.

Does one volcano stand out from the rest?

Nyiragongo is the most spectacular I鈥檝e seen. The crater is humungous. It鈥檚 got the biggest lava lake in the world and gases stream out of it. If you camp on the rim and look down at night it鈥檚 mesmerising. Erebus has beautiful ice caves carved out of the glacier by the heat from the volcano. Stromboli is spectacular at night: you sit around in the late afternoon waiting for the wind to shift and blow gases your way, then it鈥檚 a 20-minute walk down the scree to town, a nice bottle of wine and some of the best Sicilian food I鈥檝e ever had. Masaya stands out because you can get right over the conduit where the gas comes out 鈥� so it鈥檚 the best for my science.

These are all volcanoes on land. If you are studying Earth鈥檚 plumbing system, doesn鈥檛 that include eruptions on the seabed too?

No one has ever seen a lava eruption on the ocean floor. To understand what鈥檚 happening at mid-ocean ridges we collect lavas to determine their ages. In 2004, I collected some from the East Pacific Rise. That meant going down in a submersible, which is a whole different experience from climbing.

Are there any volcanoes you still want to sample?

One of my aims is to build up a global inventory of gases from volcanoes. That doesn鈥檛 mean sampling every volcano, but ones representative of different tectonic settings 鈥� volcanic arcs, continental rifts, ocean island basalts and so forth. I have the whole range, but to really complete the inventory I鈥檇 like to go to Reunion in the Indian Ocean, Villarrica in Chile and Puu Oo on Kilauea, Hawaii. I鈥檝e also got money to go back to Nyiragongo in the DRC, but the civil war means that will have to wait.

How do you respond to those who accuse you of being more of a thrill-seeker than a scientist?

I can鈥檛 deny I鈥檓 an adrenaline junkie, but I wouldn鈥檛 be going into volcanoes if it wasn鈥檛 for a good reason. I have a wife and daughter and I鈥檓 extremely safety conscious. None of this would be much use if you can鈥檛 also sit down at a desk and work hard and think about the data. The research I do fulfils all my needs 鈥� pursuing something intellectual, pursuing adventure and seeing the world. But if I want thrills, I鈥檒l go climbing.