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 Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory

nachricht Artificial Glaciers in Response to Climate Change?
10.08.2018 | Universität Heidelberg

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

'Building up' stretchable electronics to be as multipurpose as your smartphone

14.08.2018 | Information Technology

During HIV infection, antibody can block B cells from fighting pathogens

14.08.2018 | Life Sciences

First study on physical properties of giant cancer cells may inform new treatments

14.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>