Monthly Archives: June 2014

Field camp in Barcelonnette (French Alps)

Barcelonnette2014groupStudents from Geosciences (UNIL) and Geology (UNIL-UNIGE) master programs attended the Slope Instability Field Camp from June 1st to June 7th 2014.
On the menu, a close examination of the La Vallette landslide, a big slope instability in the heights of the Ubaye Valley, above the municipality of Barcelonnette, and a visit to the famous Riou Bourdoux, a torrent on which the torrential mitigation techniques were pioneered in the XIXth century.
Field mapping of cracks, bulges, water presence, as well as LiDAR acquisitions were carried out on the La Vallette site. The goal was to assess the general behaviour and volume of the moving mass, its geological and structural context, and to elaborate its hazard potential for the human settlements. Field data was combined with existing data (aerial photographs, existing DEMs, published litterature) and with numerical methods (Coltop 3D, SLBL, GIS tools) each evening.

A big thank you to our hosts at the Séolane center for the wonderful stay and to our guides on the field, Georges Guiter (ONF-RTM) and Alexandre Mathieu (Univ. Strasbourg).

Badakhshan landslides, Afghanistan

The village of Abi Barik (Badakhshan Province, North East Afghanistan) was destroyed by two consecutives landslides on May 2 2014 (DailyMail). About 1000 houses were affected and 300 of them were buried under 60 meters of debris (AlJazeera). Fatalities number is unknown but some sources reported 350 killed people and 2500 missing persons (LeMonde).

While the villagers attempted to save some goods and cattle after the first little landslide, a second massive landslide occurred, covering many people (LeFigaro). Landslides trigger is probably the very heavy rain that occurred a week before the events (TheWallStreetJournal).

Wakil Kohsar/AFP/Getty Images
Wakil Kohsar/AFP/Getty Images

Massive landslide in the United States – Oso (Washington State)

The area named “Steelhead Haven” was engulfed by a major landslide on March 22, 2014, in Oso, Washington, United States (SeattleTimes). 41 fatalities (Snohomish County Sheriff’s Office) and 2 missed persons were identified (Snohomish County Sheriff’s Office). Mud masses collapsed from an unstable hill and covered an area of about 2.5 km2 , destroying 49 houses and other structures (SeattleTimes). Suspected cause is soil saturation because of heavy rainfall (WashingtonPost).

For more information about the geology of the landslide, please see the article in the ScienceMag and from the USGS site. To have a look at the landslide area, see the ArcGis 3D model and the “before versus after” graphic.

TED S. WARREN/ASSOCIATED PRESS

Source: Ted. S WARREN / Associated Press

Fieldwork in Tunisia

Fieldwork Campaign in Tunisia – Structural characterization of oil reservoirs with Terrestrial Laser Scanning and GigaPan technics.

As part of her PhD thesis, Raja Mastouri of the Risk Group is working on coupling terrestrial LiDAR and 3D seismic to characterize brittle structures in a sedimentary basins on Eastern Tunisia. The goal of this research is to interpret the fractures and faults systems to understand the local tectonic history and how they affect reservoir rocks. This project is done in partnership with ETAP (Entreprise Tunisienne d’Activités Pétrolières) and Prof. Samir Bouaziz at Ecole Nationale d’Ingénieurs de Sfax.

Tunisie_fieldwork

During the last week of May 2014, Raja went for fieldwork in different sites of Eastern Tunisia with Robin Marchant (curator at the Museum of Geology of Lausanne), Antoine Guerin (PhD student in the Risk Group) and engineering geologists and geophysicists from ETAP: Marzouk Lazzez, Wiem Harrathi, Achraf Boulaares and Majdi Akremi. They collected extensive information (in-situ measurements, terrestrial laser scanner and GigaPan) on fracture systems at outcrop level, with a particular focus on reservoir analogues.

 

 

Landslides and Floods Training – Les Diablerets

The field work training in Les Diablerets related to the Landslide and Flooding modules from the Specialisation certificate for the Assessment and Management of Geological and Climate Related Risk (CERG), have taken place between the 26-30 May 2014. This international training aims to increase the capacities of local scientists on disaster risk reduction related to natural hazards (http://www.unige.ch/sciences/terre/mineral/CERG/index.html).

During the field work, the teaching team was composed by: Dr. Corine Frischknecht and Dr. Irene Manzella from the University of Geneva, Dr. Olivier Lateltin from SwissTopo and David Consuegra from HEIG-VD Yverdon Les Bains, and Prof. Michel Jaboyedoff and Dr. Ivanna Penna from our Group Risk (University of Lausanne).

The field work in Les Diablerets was attended by 19 students from Africa, Asia, Europe, and South America, who conducted a risk assessment considering the contribution of landslides and debris flows to flooding, and evaluated the vulnerability of the exposed values and infrastructure, with a final goal of a risk map construction.

Drone capture - CERG-C 2014 Group