Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NRL measures record wave during Hurricane Ivan

08.08.2005


Scientists at the Naval Research Laboratory - Stennis Space Center (NRL-SSC) measured a record-size ocean wave when the eye of Hurricane Ivan passed over NRL moorings deployed last May in the Gulf of Mexico. The possibility of a super wave is often suggested by anecdotal evidence such as damage caused by Hurricane Ivan in September of 2004 to an offshore rig in the Gulf of Mexico that was nearly 80 feet above the ocean surface. Hence, some of the destruction done by Ivan has been attributed to a rogue wave. According to industry and national weather sources, the damage done by waves during Ivan has been on the extreme high end for a category 4 hurricane. Ivan has been the most expensive hurricane ever for the oil and gas industry in the Gulf. The Minerals Management Service (MMS) reported that Ivan amazingly forced evacuation of 75% of the manned platforms in the Gulf (574 platforms) and 59% of the drilling rigs (69 rigs), set adrift 5 rigs and sunk 7 rigs entirely. However, the damage by Hurricane Ivan in the oil fields in the Gulf cannot be measured by how many platforms or rigs were destroyed. The most costly damage is believed to have been made to the underwater pipelines. Aside from obvious leaks, some pipelines were reported to have moved 3000 ft while others were buried under 30 feet of mud and cannot be found. The most extensive damage to the pipelines is attributed to undersea mudslides (equivalent to a snow avalanche) and to extreme waves. The complete findings of this study are published in the August 5, 2005 issue of Science.



During NRL’s Slope to Shelf Energetics and Exchange Dynamics (SEED) field experiment, six current profiler moorings that also contained wave/tide gauges (Sea-Bird Electronics SBE 26) were deployed on the continental shelf at water depths ranging between 60 and 90 meters just west of the DeSoto Canyon, about 100 miles south of Mobile Bay, Alabama. An additional eight deep moorings were deployed down the shelf slope but did not contain wave/tide gauges. Fortuitously, between 8:00 pm CDST and midnight on September 15, the eye of Ivan passed through the center of the array, and almost directly over moorings 2, 5, 8, and 11. Historically, instruments in the ocean do not even survive near misses of such powerful storms, much less direct hits. Fortunately, all of the SEED moorings survived this powerful storm, and provided the best ocean measurements of currents and waves ever obtained directly under a major hurricane.

During the approach of Ivan, a moored buoy (ID 42040), deployed by the National Data Buoy Center (NDBC) near the west side of the SEED array, registered a significant wave height of 16.0 meters (53 ft). Unfortunately, the NDBC buoy broke loose and was set adrift on September 15 at 5:00 pm CDST, just before the arrival of the main force of the hurricane. According to a spokesman at NDBC, this wave height appears to be the largest ever reported by NDBC from a hurricane and comes within a few tenths of a meter of NDBC’s all-time record reported in the North Pacific. Note that the wave heights reported by the NDBC buoys are derived from wave spectra. Buoy measurements do not report time series of surface wave elevations, and hence, maximum individual wave heights can only be statistically postulated from spectrum-derived significant wave heights. The SEED wave/tide gauges, however, provided direct time series measurements of surface wave elevations. The maximum individual crest-to-trough wave heights can be reliably obtained. At mooring 3, located under the most intense winds, the maximum measured wave height was 27.7 meters (91 feet) which was part of a group of large waves with periods of approximately 10 seconds where several waves reached heights of about 20 meters (66 feet). These waves recorded by the NRL SEED gauges are by far the largest waves ever directly measured. Even larger waves could have been missed entirely on the shelf since the surface wave data from the SEED gauges were not closely sampled in time, but were instead sampled at 1 hertz over a 512 second data burst only every 8 hours. Analysis of the wave data with the winds suggests that the wave heights likely exceeded 130 feet near the eye wall of the hurricane. Orbital wave velocities generated by such large waves during Hurricane Ivan (not rogue waves) exceeded 2 meters/second at the ocean bottom (in addition to lower-frequency measured currents that exceeded 1 meter/second) and could certainly have caused much damage to underwater structures and pipelines. The measurement of "super waves" cannot be planned and are indeed very rare. These in-situ measurements made by NRL directly under a category 4 hurricane are very valuable since they can be used to provide an assessment of potential impacts to offshore structures and operations by energetic storm waves.

Donna McKinney | EurekAlert!
Further information:
http://www.nrl.navy.mil

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>