High-overtone bulk acoustic resonator as passive ground penetrating RADAR cooperative targets

2013

International audience; RAdio-frequency Detection And Ranging instruments—RADARs—are widely used for applications aimed at measuring passive target velocity or ranging for various metrology applications such as ground position and localization. Within the context of using piezoelectric acoustic passive sensors as cooperative targets to RADARs probed through a radiofrequency link, this paper reports on investigating the compatibility of narrowband resonator architectures with the classical operation mode of wideband RADAR instruments. Since single mode resonators are hardly compatible due to the limited bandwidth of their spectrum, the investigation has been extended to High-overtone Bulk Ac…

Change in geometry of a high Arctic glacier to 1948 to 2013 (Austre Lovénbreen, Svalbard)

2017

International audience; The change of Austre Lovénbreen, a 4.5 km2 land-based glacier along the west coast of Spitsbergen, is investigated using geodetic methods and mass balance measurements over 1948–2013. For 2008−2013, annual mass balances computed on 36-stake measurements were obtained, in addition to annual mass balances reconstructed from the neighbouring glaciers, Midtre Lovénbreen (1968−2007) and Austre Brøggerbreen (1963−1967). The mean rate of glacier retreat for 1948–2013 is −16.7 ± 0.3 m a−1. Fluctuations in area (1948–2013 mean, −0.027 ± 0.002 km2 a−1) showed a slowing as the glacier recedes within its valley from 1990 to 1995. For 1962–2013, the average volume loss calculated…

Where does a glacier end ? GPR measurements to identify the limits between the slopes and the real glacier area. Application to the Austre Lovénbreen…

2012

International audience

High density coverage investigation of The Austre LovénBreen (Svalbard) using Ground Penetrating Radar

2011

COM; International audience; A three week field survey over April 2010 allowed for the acquisition of 120 Ground Penetrating Radar (GPR) profiles, adding to a 40 km long walk across an Arctic glacier. The profiles were acquired using a Mal°a equipment with 100 MHz antennas, walking slowly enough to record a 2.224 s trace every 30 cm on the average. Some acquisitions were repeated with 50 MHz or 200 MHz antenna to improve data quality. The GPR was coupled to a GPS system to position traces. Each profile has been manually edited using standard GPR data processing, to pick the reflection arrival time from the ice-bedrock interface. Traveltimes were converted to ice thickness using a velocity o…

Hydrogeochemical approach to understanding the glacier-permafrost subglacial-system interactions in a glaciated catchment of Western Spitsbergen.

2012

COM; International audience

Evaluating the Austre Loven and its bedrock topography using Ground Penetrating Radar and differential GPS measurements.

2010

Hydro(geo)logical and geochemical approach to investigate the impact of active layer groundwater on runoff in the Austrelovenbreen watershed (Western…

2013

International audience

Relations entre eaux souterraines, cours d'eau et pergélisol au Spitsberg occidental : exemple du bassin versant du glacier Austre Lovén (79°N, Svalb…

2013

COM; National audience; Dans la zone arctique et sub - arctique, la dégradation du pergélisol est l'une des conséquences visibles du changement climatique. Elle s'associe à des flux croissants d'eau, de solutés et de sédiments qui peuvent significativement impacter les zones côtières et ainsi les océans. Le réchauffement climatique conduit logiquement à une augmentation de la fonte estivale, concentrée sur quelques mois d e l'année. Les flux générés pendant la période de fonte sont des eaux peu minéralisées, le suivi hydrologique aux exutoires couplé à des investigations hydrogéologiques, effectués dans un bassin versant englacé sur la côte occidentale du Spitsberg (Austre Lovénbre : 10 km …