@article{fdi:010066975,
  title = {{G}round-penetrating radar and surface nuclear magnetic resonance monitoring of an englacial water-filled cavity in the polythermal glacier of {T}ete {R}ousse},
  author = {{G}arambois, {S}. and {L}egchenko, {A}natoli and {V}incent, {C}. and {T}hibert, {E}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n polythermal glaciers, specific climatic, topographic, and exposure conditions may lead to the formation of englacial lakes that can produce catastrophic effects downstream in the event of abrupt natural drainage. {W}e have determined how a combination of ground-penetrating radar ({GPR}) and surface nuclear magnetic resonance ({SNMR}) surveys helped to locate and visualize the evolution of a water-filled cavity within the {T}ete {R}ousse glacier ({F}rench {A}lps). {W}e have used {GPR} results to delineate the roof of the cavity and monitor the cavity deformation caused by artificial drainage. {B}ecause the glacier bed and cavity have complex 3{D} geometries, we needed dense acquisition lines and 3{D} {GPR} views to qualitatively identify out-of-plane reflections. {T}his 3{D} approach made it possible to establish a precise map of the glacier bed topography, the accuracy of which was verified against borehole observations. {T}hen, repetitive {GPR} measurements were used to obtain a quantitative estimate of the vertical deflection of the cavity's roof and changes in crevasse geometry observed in response to the decrease in the water pressure when 47; 800 m(3) of water was drained by pumping. {W}e have used 3{D} {SNMR} imaging to locate water accumulation zones within the glacier and to estimate the volume of accumulated water. {T}he {SNMR} monitoring revealed that in two years, the cavity lost approximately 73% of its initial volume, with 65% lost after the first drainage. {K}nowledge of the water contained in the ice provided a better understanding of {GPR} images and thus a more reliable interpretation of {GPR} data. {H}owever, {SNMR} imaging had a much lower resolution in comparison with {GPR}, and consequently {GPR} allowed a more accurate study of the evolution of cavity geometry caused by consecutive drainage and refilling. {T}his study demonstrated the value of combining {GPR} data with {SNMR} data for the study of polythermal glaciers.},
  keywords = {{FRANCE} ; {ALPES}},
  booktitle = {},
  journal = {{G}eophysics},
  volume = {81},
  numero = {1},
  pages = {{WA}131--{WA}146},
  ISSN = {0016-8033},
  year = {2016},
  DOI = {10.1190/geo2015-0125.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066975},
}