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National Centre for Geophysical Research

National Centre for Geophysical Research

Brief presentation


The geophysical Research Center CRG was established in 1975 and is the oldest among the four CNRS centers. The CRG is both an observatory and a research laboratory continuing the studies initiated in 1920 in the Levantine region by the Observatory of Ksara. In addition, the CRG provides the public and the authorities, almost in real time, the objective data needed to evaluate the exposure of the country when an earth tremor is felt. Moreover, the Center deals around the clock with extreme events, and is involved in all actions aiming at raising the awareness and preparedness of fellow citizens by promoting risk culture either among the youth in schools, or in official fora. Furthermore, it conducts all geophysical studies that may help alleviate the impact of seismic hazards in the Lebanese tectonic environment, such as the monitoring of the geomagnetic and gravity fields and the state of the active faults using crustal deformation surveying techniques. The Center also pursues geophysical investigations that may help in a better understanding of available natural and mineral resources.


Research partnership


The main foreign longtime partner of CRG is the Institut de Physique du Globe de Paris IPGP. This institute helped starting the development of the GRAL network, launching the GPS crustal deformation application, supporting the geomagnetic Observatory of Qsaybeh, digging tectonic trenches on the Yammouneh lake site and elsewhere, introducing us to other French (IFREMER, CEREGE...) and non-French laboratories (JPL, UNAVCO). IFREMER made available its naval means to map Lebanese offshore. With the CEREGE, we extended our field of interest to paleoclimatology with an important already published study about the climate of Lebanon since 200000 years. With ISTERRE, CEREMA and the support of the IRD, we conducted the large project “Contribution to seismic hazard assessment in Lebanon” (LIBRIS). At the JPL, we were able to perform 14C dating to establish the past 12000 years history of large earthquakes. UNAVCO made available one of its prominent researcher to design the first GPS experiment.


Research Activities and Projects

 

Early warning systems
While seismic forecast is still a far reach aspiration, it is possible to monitor correctly tsunami generation and propagation resulting from a submarine earthquake or an underwater landslide. The Center hosts and runs the FTWP or Tsunami Warning Focal Point for Lebanon and is responsible of maintaining a continuous watch in order to receive and evaluate alert messages from regional tsunamis alert centers before routing them to Civil Defense and other authorities. For this purpose, the Center is an active partner in the NEAMTWS group of experts established by the IOC.
Another seismic network based activity is monitoring banned experimental nuclear blasts. Lebanon is a signatory of the Comprehensive Test Ban Treaty and our center now hosts the ad hoc National Data Center. Nuclear experiments being exceptional events, the high quality data from the CTBT Organization has been made available for a wide range of applications.

 

The national seismic network
A network of 10 permanent stations constituting the core of the so-called Geophysical Research Arrays of Lebanon or GRAL was established, which greatly improved real time monitoring and epicentral determinations. The GRAL network produced a new representation of the seismicity of Lebanon.

 

Monitoring crustal deformation
The first GPS campaign was established in 1999, then repeated in 2001 and 2010. The Northern profile extends from the Ramkine islet to East of Ras Baalbek whereas the Southern one runs from Damour to Deir el Aachayer. It was important to check the difference in deformation style North and South of the parallel of Beirut, which was clearly visible in the geomorphological coastal features and was reflected on the seismicity map.


Marine studies
Within the framework of a French-Lebanese partnership, the RN Le Suroît of the IFREMER fleet surveyed an area extending 100 km off the shores of Lebanon in order to complement the land studies about the exposure of the country to seismic risk. One of the main outcomes of this survey (code-named SHALIMAR for Seismic HAzard Liban MARin) was the new multi-beam bathymetric map of Lebanon.
Recognizing the necessity to connect offshore structures to the inland observed ones, it was possible to start to complete the bathymetric map within the Italian funded CANA-CNRS vessel, equipped with a costly multi-beam echo-sounder system with its sophisticated positioning system.


Seismological Bulletins
The Geophysical Research Centre publishes a monthly provisional Seismological Bulletin available online at the end of each month. (Download Page)


Personnel

 

BRAX Marleine

Director

JOMAA Rachid

Assistant Researcher

CHAMOUN Jean

Assistant Researcher

NOHRA Walid

Technician

ALLAM Cyrille

Technician



Contact us


Address: Bhaness Hospital Campus, Dahr El Sawan, P.O. Box: 16-5432, Metn, Beirut, Lebanon
Tel:         +961 4 981885
Fax:        +961 4 981886
E-mail:    geophys@cnrs.edu.lb