Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Huge waves from one storm slam coasts some 6000 km apart

31.05.2007
Huge waves that struck Reunion Island and coastlines across Indonesia earlier this month all originated from the same storm that occurred south of Cape Town, South Africa, and were tracked across the entire Indian Ocean for some 10 000 kilometres over a nine-day period by ESA’s Envisat satellite.

Waves reaching up to 11 metres devastated France’s Reunion Island in the Indian Ocean when it slammed into the southern port of Saint Pierre on 12 May. Six days later waves created from the same storm measuring as high as seven metres began crashing into Indonesia coastlines from Sumatra to Bali, killing at least one person and causing some 1200 people to flee their homes.

Dr Bertrand Chapron of IFREMER, the French Research Institute for Exploitation of the Sea, and Dr Fabrice Collard of France's BOOST Technologies in Brest located and tracked the swells using standard processed Synthetic Aperture Radar (SAR) ESA Wave Mode products, as shown in the animation above.

"The extreme swell systems originated from the same storm, which moved rapidly and had two main strong wind periods," Chapron said. "As illustrated in the animation, the resulting waves were organised into two main swell systems that followed each other across the entire Indian Ocean, hitting Reunion Island, Mauritius, Australia and Indonesia."

According to the Reuters news agency, no official warning about the huge waves that hit Indonesia were issued. Although the waves that hit Reunion Island were forecasted, their intensity was predicted to be 20 to 30% below measurements, Collard explained.

"Although swells are still surprise factors, these particular swells were created by natural events so they could be tracked," Chapron said. "By using the SAR Wave Mode product, we can locate and systematically track swells globally, making it possible to put a network of early warning systems in place in the near future."

"Because of its unique capacity to restitute wavelength and directional information of the propagation of swells, the SAR instrument is about to bring a remarkable contribution to the monitoring of energetic wave systems," Collard said.

Chapron and Collard are working on a global swell-tracking project, which was presented for the first time at the Envisat Symposium held in Montreux, Switzerland, from 23 to 27 April 2007, using the Advanced Synthetic Aperture Radar (ASAR) aboard Envisat to follow these waves in order to refine their propagation paths and determine their arrival times and intensities.

Once in place, this system will be the equivalent of deploying a global network of virtual buoys that are able to detect and track large swell systems carrying large energy from all available remote sensing measurements of waves, such as SAR and radar altimetry.

Each virtual buoy will have the capacity to detect and measure the wavelength and the direction of propagation as well as the height of the swell systems crossing the oceans, complementing the sea forecast models used by weather centres and allowing alarms to be raised a few hours before these devastating swells hit coasts.

Storms are capable of generating waves of different wavelengths that travel in several directions upon leaving the storm system, with the longest wavelengths travelling the fastest. As these waves cross open seas, they can accumulate energy at precise locations and become very dangerous for marine safety.

In addition, wave systems slow down as they approach the coastline, and individual waves increase to reach at least two times the mean average of their initial wave height. For instance, a 5-metre significant wave height system can hit the coast with the height of 10 metres.

Today, the ASAR Wave Mode acquires 10 by 5 km small images, or 'imagettes', of the sea surface every 100 km along the satellite orbit. These small ‘imagettes’ are then mathematically transformed into averaged-out breakdowns of wave energy and direction, called ocean-wave spectra, which ESA makes available to scientists and weather centres.

As part of the Global Monitoring for Environment and Security (GMES), a joint initiative of the European Commission and ESA, the space agency has undertaken the development of Sentinel-1, a European polar-orbiting satellite system for the continuation of SAR operational applications.

The Sentinel-1 SAR instrument will also have a dedicated enhanced Wave Mode capability to double the present ASAR Envisat Wave Mode samplings, to improve the actual demonstrations for a Near Real Time tracking and forecasting of swell for European users.

ESA and IFREMER will sponsor an ocean wave data user workshop at IFREMER in Brest, France, on 20 and 21 September 2007 that will address and capture user requirements for a possible future wave data service.

In January 2008, ESA will host its second SAR oceanography workshop, SEASAR 2008, entitled "Advances in SAR Oceanography from Envisat and ERS missions," at ESRIN, ESA’s Earth Observation centre, in Frascati, Italy.

Mariangela D'Acunto | alfa
Further information:
http://www.esa.int/esaEO/SEMMJJ9RR1F_economy_0.html

More articles from Earth Sciences:

nachricht Predicting eruptions using satellites and math
28.06.2017 | Frontiers

nachricht NASA sees quick development of Hurricane Dora
27.06.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>