Sea Technology

JUN 2017

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

Issue link:

Contents of this Issue


Page 55 of 72 June 2017 / st 55 P: (408) 954-0522 • E: • • 2190 Fortune Drive • San Jose, CA 95131 650 650 900 900 850 850 800 750 700 700 750 950 950 800 Hoop Fault Complex, Data Courtesy WGP Survey/TGS-NOPEC parrotfish without eliciting any reac- tion. The research indicates that com- petition among grazers is the real force in structuring both the space use pat- terns and the feeding patterns of these parrotfish. Demo Shows How Wind Can Cause Rogue Waves A team of scientists from Australia, Belgium, Italy and the U.K. have dem- onstrated how ocean winds can gener- ate spontaneous rogue waves, the first step to predicting the potentially dan- gerous phenomena. These waves might cause severe damage to ships and structures such as oil and gas platforms. The ability to forecast them would be hugely benefi- cial, but little is currently understood about what generates them. Researchers from The University of Melbourne (Australia), The Swinburne University of Technology (Australia), The University of Leuven (Belgium) and The University of East Anglia (U.K.) used a special circular wave tank at The University of Turin (Italy) to study the statistical properties of wind-gener- ated waves and the likelihood of rogue wave development. Unlike previous experiments on rogue waves generated in conven- tional longitudinal tanks, the wave field they created by blowing wind in the annular wave flume can be thought of as infinitely long. Research- ers started with still water in the tank, before turning on fans that replicated a steady wind, similar to conditions that might be seen on the ocean. Wind was blown over the surface for 2 hours, and the surface elevation of the water mea- sured throughout. As wind starts blowing, an erratic wave field is generated. Rogue waves appear to develop naturally during the growth of the waves, and were detect- ed just before the wave height reaches a stationary condition. The measure- ments let the research team estimate the probability of finding high, steep waves, showing that this is higher than expected, thus providing crucial infor- mation about the mathematical likeli- hood of these waves occurring. Phytoplankton Research at Sea Using New Instruments A swath of new instruments were debuted during a 25-day expedition across the Pacific exploring a wide va- riety of oceanic ecosystems. The focus of chief scientist Dr. Ivo- na Cetinic, USRA/NASA, and her team was to explore ocean particles, specifi- cally the phytoplankton at the base of the food web. The research will allow the team to learn how plankton and other living things in the ocean con- tribute to global climate. The team will use the data to ground-truth satellite observation of ocean color (influenced by phytoplankton) and better under- stand the processes each planktonic community carries out with regard to the carbon and nitrogen cycles. Phyto- plankton produce much of the world's oxygen and remove carbon dioxide from the atmosphere, thereby helping to control climate. The research was conducted on a cruise on Schmidt Ocean Institute's RV Falkor. It allowed, for the first time, the following of parti- cles all the way from space with NASA satellites through the surface of the ocean to ocean depths. The oceans are changing, and having accurate ocean color satellites will allow scientists to monitor change over a long period of time. ST

Articles in this issue

Links on this page

Archives of this issue

view archives of Sea Technology - JUN 2017