A European team of researchers has demonstrated that sediment is transported to the deep sea via canyons in the seabed. The sediment accumulates in the head of the submarine canyons. At the end of the canyons, mud avalanches disperse into the deep sea. Scientists from the Netherlands Institute for Sea Research (NIOZ) presented their findings at an international congress held from 7 to 10 April 2002.
With bottom landers, onboard the ship R.V. Pelagia, the researchers explored the Nazaré Canyon off the Portuguese coast. This is one of the largest submarine canyons in the world. The Canyon starts at the beach. At a distance of 150 kilometres from the coast it opens out into a deep-sea area, 5 km deep. Locally the canyon cuts more than one kilometre deep into the continental slope. In the floor of the canyon the researchers measured unusually high biochemical activity. The sediment is enriched in organic material, which can serve as food for the rich floor life in the canyon and the deep-sea area. However, the sediment is possibly mixed with chemical pollutants originating from human activity. In addition to this the water in the canyon was noticeably turbid. This indicates an elevated transport of sediment particles. The sediment accumulates rapidly in the canyon. As a result of this the floor becomes unstable. The researchers demonstrated that the accumulated sediment runs off the slope as submarine mud avalanches into the deep-sea area. This happens at intervals of several decades to several centuries. With the rapid growth of the world population, the use of the continental margin (the transition area between the mainland and the open ocean) is quickly increasing. As a result of this marine ecosystems are being subjected to greater pressure. Ecosystems close to the mainland are comparatively well studied. However, the edges of the continental shelf and the continental slope have for a long time received comparatively little attention.
Michel Philippens | alphagalileo
NASA examines Peru's deadly rainfall
24.03.2017 | NASA/Goddard Space Flight Center
Steep rise of the Bernese Alps
24.03.2017 | Universität Bern
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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