Thousands of white crabs grazing on an extensive mussel bed: Up to now such high biomasses in the deep sea were only known from hot vents. Now scientists from the MARUM at the University of Bremen have found such scenes at a cold vent off the coast of Pakistan.
Another first was achieved by the videos they took of the cold-vent fluids seeping from the sea floor. Furthermore, the scientists were astonished at the wide variety of seep types. The scientists returned from an expedition with the RV Meteor heavily laden with new data. The expedition investigated the continental margin south of Pakistan from 31 October to 27 November.
Widely accepted doctrine has suggested that life at hot vents, such as black smokers, is much more bountiful than on cold vents. But the images sent up by the deep diving vehicle, Quest, of the Marum_Research Center Ocean Margins in Bremen told a different story: Mussel beds of more than 30 meters in diameter literally crawling with white crabs. "This puts to rest the credo that cold vents generally are less lively than hot vents", says Gerhard Bohrmann, leader of the expedition. "The organisms seem to have a similar amount of chemical energy - in the form of methane or hydrogen sulfide - available to them as hot-vent organisms. This results in an equally high biomass."
More surprises were in store for the scientists, like the variety of seep types: "We had a close look at nine separate seeps, and every one was different. The oxygen level in the water, which varies strongly with depth in the research area, is especially influential on the seep communities", explains Gerhard Bohrmann.
The great differences in seep types are also a product of the geological subsurface. "On satellite images the Pakistani coast north of the area we investigated looks wrinkled. The wrinkles continue under water off the coast. This is because the whole area is being compressed; at a speed of four centimetres a year the Arabian plate is being pushed beneath the Eurasian plate. While diving underneath Pakistan the muddy sea-floor sediments on the Arabian plate are literally being squeezed dry. The water, containing a heavy load of methane, hydrogen sulfide, and a host of other compounds, bubbles out of the sea floor at the so-called cold vents. "Normally such muddy sediments are about two to four kilometres thick, here they reach an astonishing seven kilometers". A good reason to look for vents in this area. "Where there is a lot of sediment to be squeezed, more fluids can seep out ", reasons Gerhard Bohrmann.
For the first time, the scientists from Bremen were able to observe fluids without associated bubbles seeping from a cold vent directly: "This is due to the extremely high-resolution video images of MARUM's diving vehicle, Quest. This has very likely never been seen before", enthuses Gerhard Bohrmann. Up to now such seepages have been postulated from measurements, but never directly observed because of technical limitations in the image quality. Cold seeps were either found through gas bubbles escaping with the fluids or because of the associated organisms growing at the seep sites.
"Seepages at the sea floor are of great importance to us, because they link the crust of the Earth and the ocean", reflects Gerhard Bohrmann about the relevance of the research. "Underwater vents transport enormous amounts of material like methane, sulfides and others as well as heat into the ocean, and therefore into the atmosphere. However, our understanding of these processes and how they shape the Earth are still sketchy." After all, methane is 30 times stronger as a greenhouse gas than carbon dioxide. "Every expedition teaches us more about how these systems work. On this one, we made a big step towards a better understanding of cold seeps at the ocean floor", resumes Professor Bohrmann.Furhter Information / Images / Interviews:
Kirsten Achenbach | idw
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences