Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

TU Delft Produces Unique Quake Images Using GPS

15.07.2005


Thanks to extensive GPS measurements and analyses by TU Delft and its scientific partners, unique images showing the development of the earthquake on 26 December 2004 in South East Asia have been created. This is the first time that a quake of such magnitude has been recorded and made visible using GPS. Today, Thursday 14 July 2005, an article on this subject will be published in the scientific journal Nature.



In the past few years, working together with French, Indonesian, Malaysian and Thai researchers and scientists, the Delft Institute of Earth Observation and Space Systems (DEOS) of the Faculty of Aerospace Engineering at TU Delft, has established an extensive network of about 45 scientific GPS stations in South East Asia. These stations play an important role in the research done in the SEAMERGES (South East Asia: Mastering Environmental Research with GEodetic Space techniques) project. SEAMERGES is a cooperative research project between universities in the European Union and the ASEAN (Association of South East Asian Nations).

GPS, currently well known for its use in navigation systems, can also be used to accurately measure movement and deformation of the tectonic plates. To achieve this, the Delft researchers use a special, highly accurate geodetic version of the standard GPS method. The unique GPS measurements in South East Asia collected by the SEAMERGES project enabled the scientists to compute the size and direction of the deformations resulting from the earthquake on 26 December 2004 with an accuracy of a few millimetres.


In January of this year, Delft researchers made the news with images showing the development of the tsunami wave, but not the quake itself. Those images were largely based on measurements of water levels in the area, taken by satellites equipped with radar technology to measure ocean surface levels.

The latest research shows that the well known Thai island of Phuket moved 27 cm directly after the quake, which is more than twice the distance initially predicted. Even thousands of kilometres away, in countries like India and China, displacements were registered. Another important development is that, for the first time, the deformations of the tectonic plates during the ten minutes the quake lasted have been made visible. The DEOS scientists have visualised this in an impressive animation, which can be found at their website (www.deos.tudelft.nl).

Moreover, based on the GPS measurements, a number of new conclusions about the quake have been drawn. The most important conclusion is that the rupture plane was much longer (at least 1000 km) than initially expected, based on seismological measurements (~450 km). This means that the force of the quake was not 9.0, but 9.2 to 9.3 on the Richter scale, approximately twice as strong. Also, a significant increase in the likelihood of earthquakes in the surrounding regions was determined. This was dramatically confirmed by the severe earthquake on 28 March 2005 (near the Indonesian Island of Nias). Thankfully, the consequences of this quake were less severe. The results of this research are a marked example of the importance of good international cooperation.

Tsunami-warning

Belgian scientist Ir. Wim Simons, a researcher in Prof. Boudewijn Ambrosius’ group of Astrodynamics and Satellite Systems, played an important part in this Delft success. He initiated the SEAMERGES project, was co-developer of the GPS-measurement systems and he worked on the collection and analysis of the data. According to Simons, the GPS-measurements in South East Asia are still taking place. “There is lag effect in the deformations. For example, Phuket, directly after the quake, had moved 27 cm, that value has now already increased to about 40 cm.” These follow-up measurements provide important information about the way in which forces within the earth’s crust can decrease in some places and build up again (elsewhere).

Simons and other researchers will investigate the data even further to see if they can find any signs in the measurements taken in the months before the quake that could be used to possibly predict such events in the future. As another challenge for the future, Simons sees the use of GPS for the issuing of fast tsunami-warnings. “If all the stations were to relay their measurements in real-time, which is technically possible, the data could be used to generate a model (of a possible tsunami) within about half an hour. If necessary, a warning could then be issued,” says Simons.

Currently, Dr. Julie Pietrzak and her colleagues at professor Guus Stelling’s section for Environmental Fluid Mechanics of the Faculty of Civil Engineering and Geosciences, are using the GPS measurements to create more accurate computer simulations of the tsunami. This kind of modelling was previously done almost exclusively using seismological data. Simons: “Their first results match the real tsunami well, and this research could lead to better and faster tsunami predictions in the future.”

Maarten van der Sanden | alfa
Further information:
http://www.tudelft.nl

More articles from Earth Sciences:

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

nachricht Earth's magnetic field measured using artificial stars at 90 kilometers altitude
14.11.2018 | 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: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>