Martin Melles
Martin Melles (born August 27, 1960 in Bremen ) is a German geologist and professor at the University of Cologne . He researches the climate history of the Arctic and Antarctic in the Pliocene and Quaternary periods .
Life
Melles attended the Wesermünde grammar school in Bremerhaven (Abitur 1980) and studied geology and paleontology at the University of Göttingen (graduated in 1987). He then worked as a research assistant at the Alfred Wegener Institute in Bremerhaven and received his doctorate in 1990 from the University of Bremen on research in the Antarctic (paleoglaciology and paleo-oceanography in the late Quaternary on the continental margin of the southern Weddell Sea, Antarctica) . In 1992 he moved to Potsdam at the Alfred Wegener Institute . He completed his habilitation in 2000 at the University of Potsdam to reconstruct the late Quaternary development history of polar coastal regions with the help of lake sediments.
After a substitute professorship in Leipzig, he became Professor of Geology at the University of Leipzig in 2001 and has been Professor at the University of Cologne since 2006.
plant
Melles deals with the climate history and climate fluctuations in the Quaternary, especially in the polar regions . In particular, he researched the climate archive in the sediment deposits of the Elgygytgyn crater lake in Chukotka in northeast Siberia, which is around 12 km in diameter and 170 m deep. It was formed 3.6 million years ago in the Pliocene, probably as a result of a meteorite impact , was not glaciated in the Ice Age (as Olga Gluschkowa discovered in 1994) and is therefore particularly well suited to the climatic fluctuations of the recent past (end of the Neogene and the entire Quaternary) in the Investigate the polar region ( e.g. via the pollen content and the paleomagnetism of the sediments). As part of an international project ( ICDP ; Russia, USA, Germany, Austria and other European countries), in which Melles was project manager on the German side, the ice sheet there in 2009 a. a. recovered a 315 m long sediment core. It enabled conclusions to be drawn about precipitation, vegetation and temperature and their fluctuations with good temporal resolution over 3.6 million years. Previously, there were essentially climate records from ice cores in the Greenland ice sheet , but these only went back 120,000 years.
The most important result was that the climate in the Arctic was warmer than previously assumed in two warm periods within the Ice Age (400,000 and 1.1 million years ago). At that time there were dense coniferous forests around the lake , and the studies in the Arctic showed a clearer difference for these so-called super warm periods with a mean temperature that was four to five degrees above that of normal warm periods in the Quaternary (mean temperature 13 degrees) than was previously known from studies in Europe, for example. They can not be explained solely from changes in the orbit parameters of the earth and although they correlate with high levels of carbon dioxide , they cannot be explained by these alone. During these times, however, a large part of the ice sheet in western Antarctica had melted. Feedback effects from the degree of glaciation, especially in the Antarctic and Greenland, are therefore assumed , which suggest that the polar regions react more sensitively to climate changes and that the climate there may change more quickly than previously assumed.
At the end of the records in the Pliocene around 3.6 million years ago, it was around eight degrees warmer in the Arctic in summer than today, with a comparable carbon dioxide content of around 400 ppm.
Melles was on a research trip on the Polarstern , among other things, which examined the climate and environmental history of South Georgia .
Recently, Melles expanded his research in Siberia, Greenland and Antarctica to study the history of climate in more moderate latitudes. Its participation in the Collaborative Research Center 806 of the German Research Foundation (DFG) plays a special role. The aim of the SFB 806 is to reconstruct the migration of modern man from Africa to Europe since its creation around 190,000 years ago. The lake sediment investigations by Melles provide information on whether and, if so, to what extent climatic fluctuations have influenced human history.
Fonts
- with Julie Brigham-Grette, Pavel Minyuk, NR Nowaczyk, V. Wennrich, RM DeConto, PM Anderson, AA Andreev, A. Coletti, TM Cook, E. Haltia-Hovi, M. Kukkonen, AV Lozhkin, P. Rosen, P Tarasov, H. Vogel, B. Wagner 2.8 Million Years of Arctic Climate Change from Lake El'gygytgyn, NE Russia , Science , Volume 337, 2012, pp. 315-320, abstract
- with Julie Brigham-Grette, Pavel Minyuk, A. Andreev, P. Tarasov, R. DeConto, S. Koenig, N. Nowaczyk, V. Wennrich, P. Rosen, E. Haltia-Hovi, T. Cook, T. Gebhardt , C. Meyer-Jacob, J. Snyder, U. Herzschuh: Pliocene Warmth, Polar Amplification, and Stepped Pleistocene Cooling Recorded in NE Arctic Russia , Science, May 9, 2013, abstract
- with Julie Brigham-Grette, Pavel Minyuk, Christian Koeberl, Andrei Andreev, Timothy Cook, Grigory Fedorov, Catalina Gebhardt, Eeva Haltia-Hovi, Maaret Kukkonen, Norbert Nowaczyk The Lake El'gygytgyn Scientific Drilling Project - conquering arctic challenges through continental drilling , Scientific Drilling, March 2011, pdf
- Editors with J. Brigham-Grette, P. Minyuk, B. Wagner, T. Cook, D.-D. Rousseau: Initial results from lake El'gygytgyn, western Beringia: first time-continuous Pliocene-Pleistocene terrestrial record from the Arctic , in: Climate of the Past , Special Issue 48, 2012, Online
Web links
Remarks
- ↑ Chukchi for "White Lake"
- ^ In addition to the Alfred Wegener Institute, the GeoForschungsZentrum Potsdam (GFZ)
- ↑ Head of the US side Julie Brigham-Grette (University of Massachusetts), on the Russian side Pawel Minjuk (NEISRI Magadan), on the Austrian side Christian Koeberl (University of Vienna)
- ↑ The lake is covered with ice for nine months of the year
- ^ The oxygen isotope stage (Marine Isotope Stage) MIS 11c, from 420,000 to 400,000 years ago; In Central Europe, many Quaternary geologists attribute it to the Holstein warm period, although its dating is controversial
- ↑ Today there is tundra
- ↑ Like the current warm period, which began 12,000 years ago, or the Eem warm period 120,000 years ago
- ↑ And with an average of 600 liters of rain per square meter, twice as much as in normal warm periods
- ↑ The deep current from the Antarctic transports cold water into the North Pacific and is thus coupled to the climate of the Arctic - when the Antarctic ice sheet melts, this current will be greatly weakened or could be eliminated; In addition, the sea level rose back then (about 5 m higher than today) and warm water increasingly reached the Arctic via the Bering Strait
- ↑ The scientists suspect that a large part of Greenland was ice-free during the super-warm periods
- ↑ Today the mean temperature at the lake is -10.3 ° C and fluctuates between -40 ° C in winter and +26 ° C in summer (data from 2002). Brigham-Grette et al. a. The Lake El'gygytgyn ... ; for the information in the Pliocene: Brigham-Grette u. a. Pliocene Warmth ... (both see section Scriptures )
Individual evidence
- ↑ Report at Planet Erde ( Memento of the original from September 24, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . Retrieved May 11, 2013.
| personal data | |
|---|---|
| SURNAME | Melles, Martin |
| BRIEF DESCRIPTION | German geologist and university professor |
| DATE OF BIRTH | August 27, 1960 |
| PLACE OF BIRTH | Bremen |