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
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy