Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


NRL measures record wave during Hurricane Ivan


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:

More articles from Earth Sciences:

nachricht UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

3-D-printed structures shrink when heated

26.10.2016 | Materials Sciences

Indian roadside refuse fires produce toxic rainbow

26.10.2016 | Health and Medicine

First results of NSTX-U research operations

26.10.2016 | Physics and Astronomy

More VideoLinks >>>