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
Turbulence creates ice in clouds
08.11.2019 | Leibniz-Institut für Troposphärenforschung e. V.
Manganese nodules: project on environmental impact during deep sea mining
08.11.2019 | Jacobs University Bremen gGmbH
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
An international research group has observed new quantum properties on an artificial giant atom and has now published its results in the high-ranking journal Nature Physics. The quantum system under investigation apparently has a memory - a new finding that could be used to build a quantum computer.
The research group, consisting of German, Swedish and Indian scientists, has investigated an artificial quantum system and found new properties.
Researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory have reported a new mechanism to speed up the charging of lithium-ion...
05.11.2019 | Event News
30.10.2019 | Event News
02.10.2019 | Event News
12.11.2019 | Machine Engineering
12.11.2019 | Power and Electrical Engineering
12.11.2019 | Physics and Astronomy