Education

Illuminating sand deciphers the Ice Age

Dr. Jakob Wallinga shoots light at 100,000-year-old grains of sand. The result: more insight into the course of the river Rhine and a glimpse into the geographic future.

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Imagine if H.G. Well’s timemachine really existed. What period would be on top of the hit list of favourite destinations? The Renaissance, with a visit to Leonardo da Vinci’s workshop? Too recent history for Dr. Jakob Wallinga (30), Director of Delft%s Centre for Luminescence Dating.

%I%d travel back to the last interglacial, about 125,000 years ago. Back then, the climate and landscape resembled today’s. But of course there were no cities, no roads, just nature.”

Wallinga would certainly take a few interglacial days off to take a walk along the river Rhine. His topic of research is the influence that the last two Ice Ages have had on the course of the river. Research on 100,000-year-old samples of sand: what’s the purpose? Why not let bygones be bygones?

%I get that question all the times,” Wallinga says. %But only when we understand nature’s past, can we predict what she has waiting for us. When will the next Ice Age hit the planet? What is the exact influence of human kind on the greenhouse effect.” For his research, Wallinga uses luminescence dating, a relatively new technique to date sediments. Wallinga: %It%s just as reliable as other techniques, like C-14 dating, which can date sediments up to forty thousand years old. But luminescence dating can track the age of sediments up to 100,000 years old.” And that%s exactly the time span required for Ice Age research.

Darkroom

Wallinga kills the lights in his darkroom. A red glow covers the room. He grabs a disc, the size of a five-cent euro coin. It%s covered with a hundred tiny holes. Each hole traps a grain of sand from diggings near the Rhine, 50 metres deep. Wallinga places the disc in his illuminating machine. A laser gun illuminates the grains of sand one by one. Wallinga: %This causes radiation energy to release from the grains of sand. This so-called luminescence signal has a very specific wavelength and tells me when the grains of sand have last been exposed to sunlight. The bigger the intensity of the signal, the longer ago the grain of sand was covered by a new level of sediment.”

Wallinga will use this technique to uncover the influence of the last two Ice Ages on the course of the river Rhine. Last month his research proposal was rewarded with a 200,000 euro grant from the Dutch Organisation for Scientific Research.

Dr. Jakob Wallinga shoots light at 100,000-year-old grains of sand. The result: more insight into the course of the river Rhine and a glimpse into the geographic future.

Imagine if H.G. Well’s timemachine really existed. What period would be on top of the hit list of favourite destinations? The Renaissance, with a visit to Leonardo da Vinci’s workshop? Too recent history for Dr. Jakob Wallinga (30), Director of Delft%s Centre for Luminescence Dating.

%I%d travel back to the last interglacial, about 125,000 years ago. Back then, the climate and landscape resembled today’s. But of course there were no cities, no roads, just nature.”

Wallinga would certainly take a few interglacial days off to take a walk along the river Rhine. His topic of research is the influence that the last two Ice Ages have had on the course of the river. Research on 100,000-year-old samples of sand: what’s the purpose? Why not let bygones be bygones?

%I get that question all the times,” Wallinga says. %But only when we understand nature’s past, can we predict what she has waiting for us. When will the next Ice Age hit the planet? What is the exact influence of human kind on the greenhouse effect.” For his research, Wallinga uses luminescence dating, a relatively new technique to date sediments. Wallinga: %It%s just as reliable as other techniques, like C-14 dating, which can date sediments up to forty thousand years old. But luminescence dating can track the age of sediments up to 100,000 years old.” And that%s exactly the time span required for Ice Age research.

Darkroom

Wallinga kills the lights in his darkroom. A red glow covers the room. He grabs a disc, the size of a five-cent euro coin. It%s covered with a hundred tiny holes. Each hole traps a grain of sand from diggings near the Rhine, 50 metres deep. Wallinga places the disc in his illuminating machine. A laser gun illuminates the grains of sand one by one. Wallinga: %This causes radiation energy to release from the grains of sand. This so-called luminescence signal has a very specific wavelength and tells me when the grains of sand have last been exposed to sunlight. The bigger the intensity of the signal, the longer ago the grain of sand was covered by a new level of sediment.”

Wallinga will use this technique to uncover the influence of the last two Ice Ages on the course of the river Rhine. Last month his research proposal was rewarded with a 200,000 euro grant from the Dutch Organisation for Scientific Research.

Editor Redactie

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