Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Amadeus and Esmeraldas: two marine geophysics campaigns to investigate strong earthquakes off Ecuador and Colombia

17.02.2005


Several large earthquakes with magnitude higher than 8 on the Richter scale have already occurred along the margins between the Nazca and South American tectonic plates, under the ocean off Ecuador and Colombia. This region is vulnerable, all the more so because since the 1980s, Ecuador’s oil export terminal is sited within it. More information is needed on this zone of extremely high seismic risk. For this reason, two scientific campaigns, “Amadeus” and “Esmeraldas” were launched on 3 February and will run until 6 April 2005.



These campaigns, conducted by the mixed research unit (UMR) Geosciences-Azur (involving the IRD, CNRS, Universities Pierre et Marie Curie and Nice Sophia-Antipolis) working jointly with the University of Bordeaux, the Marine Technology Unit of the CSIC (Higher Council for Scientific Research) at Barcelona, and its international partners: Canadian (University of Victoria, PGC), Colombian (DIMAR, EAFIT and Caldas Universities, and INGEOMINAS) and Ecuadorian (INOCAR, EPN, Petroproduction) have the objective of studying the natural hazards associated with the large subduction earthquakes, submarine avalanches and tsunamis they trigger. The ocean-going campaigns are being conducted on the IFREMER research ship Atalante.

In 1906, a strong earthquake of 8.8 magnitude shook this part of the world. It was induced by the slipping of the Nazca plate under the North Andean margin. The two plates converge at an average rate of 5.5 cm/year. The slipping is expressed as a fracture zone about 500 km long. Reactivation occurred by earthquakes in 1942, 1958 and 1979, of magnitude 7.7 to 8.2, which provoked large tsunamis and submarine sediment slides.


Data from recent campaigns (between 1998 and 2001) showed the spatial variations of the geological structures and the tectonic regime of the margin, demonstrating the complexity of the fracture system that operates when an earthquake occurs and of the conditions that generate tsunamis. This variability prompted researchers to devise more precisely focused investigations, targeting in particular morphological detail and involving “three-dimensional scanning".

The AMADEUS campaign (3 February-9 March) should provide a picture of the morphology and geology of active faults and submarine “landslides”. The research team are performing the three-dimensional mapping of seismic fractures of the past, to date and quantify the volumes of sediment caused to slide in response to earthquake activity and to find the recurrence time of the large subduction earthquakes over the past 5000 years.

The research team is using high-resolution multi-beam probes (EM12D, EM1000), a sediment penetrator (3.5 kHz), rapid seismic probes, and will take drill-core samples of sediments which probably hold a record of the large-scale earthquakes of the past (strong earthquakes can generate large mudslides like the one that occurred for example when the recent earthquake shook Algeria.

The ESMERALDAS campaign (15 March-6 April) will give the opportunity to examine, down to 30 to 50 km depth, the structure and geometry of the contact zone between the two plates, at the points where the most massive earthquakes are initiated.

A network of about 60 submarine and terrestrial seismic stations (OBS) will record the sound waves produced by a device towed by the Atalante. The interpretation of the signals thus recorded will enable the researchers to derive a three-dimensional “echogram” of the sector. The network will then be maintained until June 2005 in order to record the zone’s natural seismic activity.

Analysis of these new data will allow a better understanding of past earthquakes, assessment of the probability of new earthquake occurrence along the coast of Ecuador and Colombia, and to make more reliable digital simulation models of the initiation and propagation of tsunami in the area.

"Amadeus will bring a clearer picture of the activity of the faults identified and also, we hope, record in the sediments to the great earthquakes of the past, which could allow us to trace back to well before the 20th Century," Philippe Charvis, IRD researcher and Director of Geosciences Azur, explained. “Esmeraldas”, he continued, “will provide us with a three-dimensional image of the zone and a means of locating microseisms which signal the accumulation of the various pressures at work."

Helene Deval | alfa
Further information:
http://www-geoazur.unice.fr/
http://www.ird.fr

More articles from Earth Sciences:

nachricht Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University

nachricht NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | 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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>