Research project SR/00/150 (Research action SR)
This project is in line with continuous efforts of MRAC and ECGS-NMNH to monitor and understand the geodynamical processes of the Virunga Volcanic Province (VVP) in the frame of a global risk management/evaluation of the area.
The Nyiragongo volcano and its semi-permanent lava lake threaten the city of Goma (~1 Mo inhabitants) distant of ~12km. The last eruption in Januray 2002 devastated approximately 10 % of the city including major infrastructues (roads, airport, public and private buildings). The Nyamulagira volcano is located 15 km NNW of Nyiragongo erupts in average every 2-4 years. Its lava flows repeatedly destroy large forested areas of the Virunga National Park.
In this context, high resolution SAR products are highly desirable and necessary to 1/ pursue the InSAR monitoring initiated with ENVISAT in 2006, and 2/ exploit the unvaluable DEM that will be produced in the TANDEM-X mission. Recently, DLR launched the TD-X SAR sensor that, with the already operational TerraSAR-X sensor, makes the Tandem-X mission. This Tandem mission offers unprecedented possibilities in terms of SAR Remote Sensing. Therefore, it will be now possible to generate a full DEM of the whole studied area. Moreover, since being wide band sensors, they offered the possibility to perform split-band interferometric measurements on the lava lake, which are axpected to allow lava lake levelling.
Methodology
The RMCA will act as PI and will be in charge of the geomorphological studies using the Tandem-X DEM and the lava flow simulations. RMCA will also work on detailed analysis of specific ENVISAT dataset from the existing database.
ECGS-NMNH, acting as Co-PI, and RMCA will exploit the Tandem-X data for ground deformation studies and monitoring if some volcanic or tectonic activity takes place during the duration of the project.
The ULg, acting as Co-PI, will further develop the advanced Split Band Interferometric technique to monitor topographic changes associated to the rapid and unmonitored 50-80m/year rising of the lava-lake located inside the Nyiragongo main crater.
All team members but ULg have a long standing field experience in Africa including 5 in this specific area.
Results expected
The Expected results are:
- Improved lava flow simulations for Nyiragongo and Nyamulagira
- First detailed geomorphological interpretation of the Virunga Volcanic Province and the western/southern border of Lake Kivu
- A full validation of split band interferometric processing based on bistatic InSAR acquisitions
- A monitoring methodology to issue lava lake level time series.
The proposed project will be successful if these results are achieved. With respect to processing, another success criterion will be the generation of a global DEM of the area validated with respect to classically generated InSAR DEM. Also, using X-band interferometry, we are aiming to achieve better accuracy in measuring ground deformation due to a shorter wave length in comparison to C- and L-band interferometry.
