All posts by aguerin

Yosemite Fieldwork Campaign, October 2015

From 1 to 23 October, Antoine Guerin, Olivier Dubas and Michel Jaboyedoff spent three weeks at the North Pines Campground in the Yosemite Valley (California, USA). Since 2010, the Risk group works with GregStock of the Yosemite National Park service and with Brian Collins of the US Geological Survey to study rockfalls in this popular area. That was the fourth time the Risk group went there!


All the famous cliffs of the valley (El Capitan, Half Dome, Cathedral, Glacier Point, Three Brothers, Rhombus wall…) have been periodically scanned with our Optech IlRIS LiDAR. The new 2015 data will be compared with the 2013 point clouds in order to identify rockfalls and complete the inventory of events maintained daily by Greg Stock. The purpose of this study is to improve the understanding of processes that control the erosion of steep rockwalls.


A series of thermal panoramas were also taken in the evening to see the effect of cooling on a cliff, in particular air propagation in fractured areas. Finally, a 24-hour monitoring was done on a 19 m high and 10 cm thick rocky flake. Thermal images were collected every 20 minutes and LiDAR acquisitions every hour. At night and within a dense forest, amid deers, bobcats and squirrels, this experience will be unforgettable!


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.


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.