Promising drilling expedition on Lake Towuti

Geologist Hendrik Vogel works with sediment cores. They come from lakes from all over the world, and provide information about climate and the environment far back in time. He has recently joined the management team of an international deep drilling project on Sulawesi, Indonesia.

A lake in the tropics, a simple wooden hut built on a boat and all sorts of expedition equipment: the photo that geologist Hendrik Vogel gets out for his visitors shows an image of fieldwork that could hardly be more romantic. Many young researchers dream of such missions.

And the post doc in the Oeschger Centre's group for Quaternary Geology and Paleoclimatology is also drawn to field work. "I like the variety in my job. Sometimes you are out in the field, and then other times you are back in the laboratory making analyses." But Hendrik Vogel spends most of his working days sitting at the computer in his office. "It's worth it for the other 20 per cent," he laughs.

Hendrik Vogel, who took his first degree at the University of Leipzig, likes adventure - but not all the time. In fact at one point he saw himself working for large mining companies as a contract geologist prospecting for raw materials, which is why he took classes at Stellenbosch University in South Africa in economic geology. But then he realised that he could not really imagine spending his entire working life in the most remote spots on the planet.

Back in Germany, and later in Sweden, he began to get interested in studying lake sediments as climate archives. "As a geologist, I wanted to better understand sedimentation processes in lakes. I am interested in where the sediments came from, transport processes, and how weathering of the bedrock and how chemical processes after deposition have affected sediment composition ."

Surprises from the drill pipe

Vogel subsequently wrote his MA thesis at the University of Umeå in Sweden about quick and low-cost ways to carry out a geochemical analysis of lake sediment cores. Later he wrote a dissertation at the University of Cologne about new methodological approaches to the analysis of drilling cores, for which he also worked on the history of the climate and environment in the northern Mediterranean region. So Hendrik Vogel has had a sustained in the potential of lake sediments in climate research. "I am interested in how a climate signal is stored in the lake," he explains. "Every lake is different, and you cannot always work with the same parameters: first of all you have to try to understand the lake as a system." That means that the geologist can never be certain what surprises a sediment core might produce on the day. He describes it as like "unwrapping a present."

The places where Hendrik Vogel has unwrapped scientific presents include Sweden, Antarctica, Macedonia and Albania as well as Siberia and Indonesia. Here on Lake Towuti in Sulawesi he is currently planning his most important field campaign to date. A test bore carried out in 2010, of which the photo with the improvised expedition boat is a souvenir, demonstrated the lake's potential as a climate archive - in a very important geographical area for the climate system. Lake Towuti is located at the centre of the so-called Indo-Pacific Warm Pool, whose characteristic feature is the unusually high temperatures of the ocean surface. Above this warm zone is the planet's biggest convection cell, one of the engines of atmospheric circulation. "If there is any change here, the knock-on effects are felt worldwide," says Vogel.

Traces on the sea bed

The aim of the drilling planned for 2015 is to bring up cores going right through the 250 metre thick layer of sediment down to the bedrock. It is hoped that analysis of this material will provide first class information in high temporal resolution about the climate history of the past 600,000 years. The focus will be on the hydrology and changes in precipitation over the course of time. These have left traces on the lake bed, since depending on how heavily and how much it rained, different elements like titanium or aluminium as a component of clay minerals would be washed in from the lake's drainage basin. And the newly installed X-ray fluorescence spectrometer in the lab in Bern enables Hendrik Vogel to detect their presence in the sediment layers with millimetre accuracy.

But one challenge remains: how can the various inputs be dated? To a certain extent Hendrik Vogel and his colleagues are placing their hopes, apart from established dating methods such as paleomagnetics, in a lucky break. It would be extremely helpful if they were to discover further datable layers of ash from known volcanic eruptions in addition to those already found.

International research consortium

Drilling in Lake Towuti is a major project involving some 40 researchers from seven countries. The reason for this broad-based consortium is not least the cost factor. The budget for the project is more than two million dollars. Among the major expenses is the work of the drilling company that will operate heavy equipment from a floating platform.

Hendrik Vogel has a major role in the Towuti project, which is being conducted in the framework of the International Continental Scientific Drilling Program. He is one of three coordinators, and will be present as scientist in charge during the drilling, which is expected to last about three months. "This is the first project where I have had so much responsibility. I suddenly have to think about things that don't actually have a lot to do with science."

These new duties certainly involve a lot of drudgery, but they are an unmistakable indication of the reputation which the Bernese geologist has already gained in the research community at the age of only 34.