# Variations in seafloor create freak ocean waves

February 01, 2019TALLAHASSEE, Fla. -- Florida State University researchers have found that abrupt variations in the seafloor can cause dangerous ocean waves known as rogue or freak waves -- waves so catastrophic that they were once thought to be the figments of seafarers' imaginations.

"These are huge waves that can cause massive destruction to ships or infrastructure, but they are not precisely understood," said Nick Moore, assistant professor of mathematics at Florida State and author of a new study on rogue waves.

The study is published in the journal

*Physical Review Fluids*, Rapid Communication.

Once regarded as a myth, these waves have stumped the scientific community for several decades.

Over the years, researchers across the globe have examined a number of different factors they thought might contribute to these waves, including the seafloor, wind excitation and a phenomenon called Benjamin-Feir where deviations from a periodic waveform are reinforced by nonlinearity.

Most of the studies that focused on the seafloor considered only gentle slopes, and the few studies that pushed the slopes to greater extremes relied primarily on computer simulations.

"There was a relative underrepresentation of real-world data that you can get from laboratory experiments, where you can carefully control the various factors," Moore said. "Often you need this real-world data to see whether the computer simulations are giving you sensible predictions at all."

Moore's laboratory experiments were the first to examine the effect of abrupt seafloor variations on wave statistics.

Along with FSU's Geophysical Fluid Dynamics Institute Director Kevin Speer and now-former FSU student Tyler Bolles, Moore created a long chamber with a variable bottom. Using a motor to generate randomized waves, the research team tracked thousands of waves to see if any patterns emerged.

After the waves passed through several feet of a constant depth, they encountered a step in the bottom of the tank that represented an abrupt change in the seafloor. Moore and his colleagues found that initially the waves appeared normal, following a traditional bell curve. But when they passed over the step, the structures of the waves significantly changed.

The altered waves followed what's called a gamma distribution, a mathematics function describing certain patterns that defy the bell curve in a particular way.

"It is surprising how well the gamma distribution describes the waves measured in our experiments," Moore said. "As a mathematician, that is screaming to me that there is something fundamental to understand."

The experiments and the emergence of this gamma distribution have spurred new investigations into the origin of rogue waves.

"We have to understand them on a fundamental level first by developing new mathematics," Moore said. "The next step is to use that new mathematics to try to predict where and when these extreme events will occur."

-end-

This research was funded by the National Science Foundation and the Simons Foundation.Florida State University

## Related Mathematics Articles from Brightsurf:

A new method for boosting the learning of mathematics

How can mathematics learning in primary school be facilitated? UNIGE has developed an intervention to promote the learning of math in school.

Could mathematics help to better treat cancer?

Impaired information processing may prevent cells from perceiving their environment correctly; they then start acting in an uncontrolled way and this can lead to the development of cancer.

People can see beauty in complex mathematics, study shows

Ordinary people see beauty in complex mathematical arguments in the same way they can appreciate a beautiful landscape painting or a piano sonata.

Improving geothermal HVAC systems with mathematics

Sustainable heating, ventilation, and air conditioning systems, such as those that harness low-enthalpy geothermal energy, are needed to reduce collective energy use and mitigate the continued effects of a warming climate.

How the power of mathematics can help assess lung function

Researchers at the University of Southampton have developed a new computational way of analyzing X-ray images of lungs, which could herald a breakthrough in the diagnosis and assessment of chronic obstructive pulmonary disease (COPD) and other lung diseases.

Mathematics pushes innovation in 4-D printing

New mathematical results will provide a potential breakthrough in the design and the fabrication of the next generation of morphable materials.

More democracy through mathematics

For democratic elections to be fair, voting districts must have similar sizes.

How to color a lizard: From biology to mathematics

Skin color patterns in animals arise from microscopic interactions among colored cells that obey equations discovered by Alan Turing.

US educators awarded for exemplary teaching in mathematics

Janet Heine Barnett, Caren Diefenderfer, and Tevian Dray were named the 2017 Deborah and Franklin Tepper Haimo Award winners by the Mathematical Association of America (MAA) for their teaching effectiveness and influence beyond their institutions.

Authors of year's best books in mathematics honored

Prizes for the year's best books in mathematics were awarded to Ian Stewart and Tim Chartier by the Mathematical Association of America (MAA) on Jan.

Read More: Mathematics News and Mathematics Current Events

How can mathematics learning in primary school be facilitated? UNIGE has developed an intervention to promote the learning of math in school.

Could mathematics help to better treat cancer?

Impaired information processing may prevent cells from perceiving their environment correctly; they then start acting in an uncontrolled way and this can lead to the development of cancer.

People can see beauty in complex mathematics, study shows

Ordinary people see beauty in complex mathematical arguments in the same way they can appreciate a beautiful landscape painting or a piano sonata.

Improving geothermal HVAC systems with mathematics

Sustainable heating, ventilation, and air conditioning systems, such as those that harness low-enthalpy geothermal energy, are needed to reduce collective energy use and mitigate the continued effects of a warming climate.

How the power of mathematics can help assess lung function

Researchers at the University of Southampton have developed a new computational way of analyzing X-ray images of lungs, which could herald a breakthrough in the diagnosis and assessment of chronic obstructive pulmonary disease (COPD) and other lung diseases.

Mathematics pushes innovation in 4-D printing

New mathematical results will provide a potential breakthrough in the design and the fabrication of the next generation of morphable materials.

More democracy through mathematics

For democratic elections to be fair, voting districts must have similar sizes.

How to color a lizard: From biology to mathematics

Skin color patterns in animals arise from microscopic interactions among colored cells that obey equations discovered by Alan Turing.

US educators awarded for exemplary teaching in mathematics

Janet Heine Barnett, Caren Diefenderfer, and Tevian Dray were named the 2017 Deborah and Franklin Tepper Haimo Award winners by the Mathematical Association of America (MAA) for their teaching effectiveness and influence beyond their institutions.

Authors of year's best books in mathematics honored

Prizes for the year's best books in mathematics were awarded to Ian Stewart and Tim Chartier by the Mathematical Association of America (MAA) on Jan.

Read More: Mathematics News and Mathematics Current Events

Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.