Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tsunami-Recording in the Deep Sea

20.11.2007
Data transfer for tsunami early warning system successfully tested

In order to extend alert times and avoid false alarms, a new seafloor pressure recording system has been designed to detect tsunamis shortly after their development in the open ocean. The project is directed by scientists of the working group 'Marine Observation Systems' at the Alfred Wegener Institute for Polar and Marine Research, part of the Helmholtz Association. Successful testing of the recording system off the Canary Islands in November 2007 means that a new mile stone for the development of the Indian Ocean Tsunami Early Warning System (GITEWS) has been reached.

The GITEWS project is supervised by the German National Research Centre for Geosciences (GFZ) in Postdam. Scientists of the Alfred Wegener Institute, in collaboration with companies Optimare and develogic, and with the Zentrum für Marine Umweltwissenschaften (MARUM) and the University of Rhode Island, are developing part of the simulation component and the so-called pressure-based acoustically coupled tsunami detector (PACT) for real-time detection of sea level rises in the deep ocean.

The German tsunami early warning system is unique in that it processes a multitude of information as the basis for a comprehensive and accurate evaluation of every particular situation. Within just few minutes, measurements of the vibrations and horizontal seafloor movements off the coast of Indonesia provide a clear picture of the location and intensity of a seaquake, which, at the warning centre, facilitate the appropriate selection of a previously calculated tsunami propagation model. However, not every seafloor quake causes a tsunami. "There is only one way to be clear about this and avoid nerve-wrecking and costly false alarms: we must measure sea level directly", says PACT-project leader Dr Olaf Boebel of the Alfred Wegener Institute.

For this purpose, sea level recordings must take place off the coast, in the deep ocean. At water depths of thousands of meters, a tsunami wave travels at several hundred km/hr, but is only some tens of centimetres high, and approximately one hundred kilometres long. Not before it reaches the coast or shallower waters, does a tsunami wave develop into a massive wall of water several meters high. Being able to detect the very slight sea level rise in the deep ocean reliably and precisely requires the use of bottom pressure sensors. These instruments are installed on the seafloor where they measure any sea level changes in the water column above. In this process, the weight of any additional water leads to minute pressure increases at the seafloor which are, nevertheless, reliably recorded by the PACT bottom units, precision instruments built by Optimare in Bremerhaven.

How is it possible then to send the potentially life-saving information about such pressure changes at the seafloor to the warning centre? Representing one of the greatest challenges of the PACT project, this problem was addressed by the Stuttgart-based company develogic through use of highly modern technology: Similar to a fax machine, an acoustic modem uses a sequence of sounds - the so-called telegram - to transmit information to a second modem which is connected to a buoy near the surface, sending the data via satellite to the warning centre.

Within the overarching GITEWS project, the primary PACT objective consists of the new development of a reliable, compact and highly energy efficient system which will record and analyse seafloor pressure every 15 seconds, and which will transmit the information to the surface modem if a tsunami event is detected. After approximately two years of development work on PACT, an important milestone was reached recently, when in-situ tests of the system were completed successfully north of the Canary Islands, using a trial fixture supplied by MARUM (Zentrum für Marine Umweltwissenschaften in Bremen). From depths below 3100 metres and over periods of several days, pressure data were transmitted repeatedly to the surface modem. The most important result: none of the data telegrams were lost, a crucial requirement for the reliable functioning of the warning system.

Having been tested successfully, the new system will now be integrated into the GFZ-developed surface buoy and the entire early warning system. Further tests, scheduled for early next year in the Mediterranean, will investigate the transmission reliability under various weather conditions. "Surely, the upcoming winter storms will give us the opportunity to discover the limits of the system", suggests Boebel.

The technology group 'Marine Observation Systems' at the Alfred Wegener Institute has been operating since January 2005. It consists of oceanographers, physicists, biologists and environmental scientists, and specialises in the development and use of innovative recording systems for marine scientific research and environmental protection. More information can be found on the internet at: http://www.awi.de/en/research/new_technologies/marine_observing_systems/

Information about the German-Indonesian tsunami early warning system can be found on the GITEWS project website at http://www.gitews.de. Apart from the Alfred Wegener Institute, other Helmholtz Institutes involved in the project include the National Research Centre for Geosciences in Postdam (project coordination), the German Aerospace Centre, and the GKSS Research Centre in Geesthacht.

Notes for Editors: Your contact person is Dr Olaf Boebel (Tel: ++49-471-4831-1879, email: Olaf.Boebel@awi-de), and in the public relations department Dr Susanne Diederich (Tel: ++49-471-4831-1376, email: medien@awi-de).

Please send us a copy of any published version of this document.

The Alfred Wegener Institute for Polar and Marine Research (AWI) conducts research in the Arctic, Antarctic and in oceans of mid and high latitudes. The AWI coordinates polar research in Germany, and provides important infrastructure, such as the research icebreaker Polarstern and stations in the Arctic and Antarctic, for international science organisations. The AWI is one of 15 research centres of the 'Helmholtz-Gemeinschaft' (Helmholtz Association), the largest scientific organisation in Germany.

Margarete Pauls | idw
Further information:
http://www.gitews.de
http://www.awi.de/en/research/new_technologies/marine_observing_systems/

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>