One of the more controversial environmental issues, which emerged in the final years of the Soviet era, was the plan to dam and reverse the flow of north-flowing rivers in order to irrigate the dry southern steppes. This scheme was roundly criticised by scientists and environmentalists at the time because of fears for the impact on the Arctic Ocean and global climate. It now appears that nature performed this experiment some 90,000 years ago.
This months issue of the Journal of Quaternary Science reports evidence based on years of fieldwork in Siberia by Professor Jan Mangerud, of the University of Bergen, Norway, which indicates that early in the last Ice Age, natural ice dams formed and drastically altered the drainage patterns of the region.
At the start of the ice age an ice sheet formed over the shallow Barents and Kara seas forming a natural dam. As the ice advanced onto the Siberian mainland, it blocked the flow of the northerly flowing rivers, including the Yenissei, Ob, Pechora and Dvina, which supply most of the Arctic Ocean with its freshwater. Huge ice-dammed lakes were formed which covered massive areas of Siberia. One of these on the western Siberian Plain was more than twice as large as any lake on Earth today. The overflows from these lakes were towards the south, into the Aral, Caspian and Black seas which were also connected by large rivers. The drainage of the Eurasian continent was thus reversed.
Joanna Gibson | alphagalileo
Mineral discoveries in the Galapagos Islands pose a puzzle as to their formation and origin
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Massive organism is crashing on our watch
18.10.2018 | S.J. & Jessie E. Quinney College of Natural Resources, Utah State University
Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.
Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
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