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Ship-sinking monster waves revealed by ESA satellites   This rare photo of a rogue wave was taken by first mate Philippe Lijour aboard the supertanker Esso Languedoc, during a storm off Durban in South Africa in 1980. The mast seen starboard in the photo stands 25 metres above mean sea level. The wave approached the ship from behind before breaking over the deck, but in this case caused only minor damage. The mean wave height at the time was between 5-10 metres.  Rogue waves are most common in the Agulhas current off the east coast of South Africa, with numerous well documented cases of extreme individual waves, including some striking photographs of damaged ships.
Here is shown bow damage received by Norwegian tanker Wilstar in 1974: the combination of pitch motion and a steep incoming wave can cause excessive local structural damage. One of the aims of rogue wave research is to recommend changes in ship design to make them less vulnerable in future.  Merchant ship labouring in heavy seas as huge wave looms astern. Huge waves are common near the 100-fathom curve on the Bay of Biscay. Published in Fall 1993 issue of Mariner's Weather Log.  Like its predecessor ERS-1 (launched in July 1991 by Ariane 4 and successfully put into orbit at an altitude of some 780 km), the ERS-2 satellite launched on 21.04.95 by Ariane 4, monitors the Earth day and night under all weather conditions thanks to its powerful sharp-eyed, cloud-piercing radars. ERS-2 also carries an instrument to help monitor the ozone layer around the Earth.  Example of an imagette from ERS-2. Imagettes are 10 by 5 km samples of the sea surface acquired by the satellite's SAR instrument as it works in Wave Mode every 200 km. Normally they are then converted into ocean-wave spectra, but raw imagettes are useful in themselves, and have been used to carry out a global census of so-called rogue waves.  Giant wave detected during a global census using three weeks of raw ERS-2 SAR imagette data, carried out by the German Aerospace Centre (DLR). This SAR data set was inverted to individual wave heights and investigated for individual wave height and steepness. The wave shown here has a height of 29.8 m.  Giant wave produced with a hydaulically-powered wave generator in the Giant Wave Tank in Hannover in 2002. As part of the MaxWave project, a team at the Technical University of Berlin worked on simulating their production. Their work guided by computer modelling, the team found rogue waves appear to be formed when slow-moving waves are caught up by a succession of faster waves moving at more than twice their speed, then merge together. Release date: 17 September 2004 |