Just as rivers move sediment across the land, turbidity currents are the dominant process carrying sediments and organic carbon from coastal areas into the deep sea. Turbidity currents can also destroy underwater cables, pipelines, and other human structures. Unlike rivers, however, turbidity currents are extremely difficult to study and measure.
At the Fall 2017 meeting of the American Geophysical Union, scientists from around the world will present 19 talks and posters about the Coordinated Canyon Experiment--the most extensive, long-term effort to monitor turbidity currents ever attempted. The results of this two-year project challenge existing paradigms about what causes turbidity currents, what they look like, and how they work.
This illustration shows some of the 16 sediment-flow events documented during the Coordinated Canyon Experiment. The arrows indicate minimum estimates of how far each event traveled down the floor of Monterey Canyon.
Credit: Image © 2017 MBARI
Usage Restrictions: May only be used in conjunction with an article about this research
The Coordinated Canyon Experiment (CCE) was conducted in Monterey Canyon, off the coast of Central California, over an 18-month period between October 2015 and April 2017. During this time, scientists observed and measured at least 16 turbidity currents using dozens of instruments at seven different locations in the canyon. These instruments allowed researchers to track sediment flows over a 50-kilometer stretch of canyon, from depths of about 250 to 1,850 meters.
Using a variety of new instruments and technologies, researchers collected data not just on the movement of water and sediment, but also on the evolution and shape of the seafloor. Physical processes within the flows were monitored at spatial scales ranging from centimeters to kilometers, and over time scales from seconds to months. The resulting data yielded a new and unexpectedly complicated view of a globally important phenomenon that has been studied and modeled for nearly 100 years.
During the experiment, an international team of researchers from the Monterey Bay Aquarium Research Institute, the U.S. Geological Survey, the University of Hull, the University of Southampton, the University of Durham, and the Ocean University of China combined their expertise and equipment. This allowed the team to monitor each turbidity current in unprecedented detail.
The experiment showed that sediment-transport events in Monterey Canyon are more common and much more complex than previously recognized. Rather than simply being flows of sediment-laden water, some turbidity currents also involved large-scale movements of the entire seafloor. Furthermore, many turbidity currents changed character as they moved down-canyon, suggesting that no single flow model can explain all the processes involved.
The researchers were particularly surprised to find that the timing of the 16 monitored turbidity currents did not coincide with commonly-proposed triggers, such as earthquakes or floods, and only a few coincided with extreme surf events. One possible explanation is that sediments build up gradually within and around the edges of Monterey Canyon until they reach some certain threshold, after which turbidity currents can be triggered by relatively small canyon-wall failures.
Of particular interest to geologists searching for oil and gas deposits, the quantitative sediment measurements and detailed seafloor and sub-bottom surveys used in this experiment gave geologists their first opportunity ever to correlate turbidity currents of known magnitude, extent, and duration with large- and small-scale sedimentary structures observed firsthand on the seafloor. After millions of years, these same sedimentary structures sometimes form conduits or traps for oil and gas in sedimentary rocks.
The Coordinated Canyon Experiment yielded many other firsts in the field of marine geology:
Kim Fulton-Bennett | EurekAlert!
World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen
A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy