Tor Hagfors

Publications (3)62.4 Total impact

• Source

  Available from: Iwan P Williams

  Article: Subsurface radar sounding of the south polar layered deposits of Mars.

  Jeffrey J Plaut, Giovanni Picardi, Ali Safaeinili, Anton B Ivanov, Sarah M Milkovich, Andrea Cicchetti, Wlodek Kofman, Jérémie Mouginot, William M Farrell, Roger J Phillips, [......], Iwan P Williams, Donald A Gurnett, Erling Nielsen, Tor Hagfors, Essam Heggy, Ellen R Stofan, Dirk Plettemeier, Thomas R Watters, Carlton J Leuschen, Peter Edenhofer
  [show abstract] [hide abstract]
  ABSTRACT: The ice-rich south polar layered deposits of Mars were probed with the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express orbiter. The radar signals penetrate deep into the deposits (more than 3.7 kilometers). For most of the area, a reflection is detected at a time delay that is consistent with an interface between the deposits and the substrate. The reflected power from this interface indicates minimal attenuation of the signal, suggesting a composition of nearly pure water ice. Maps were generated of the topography of the basal interface and the thickness of the layered deposits. A set of buried depressions is seen within 300 kilometers of the pole. The thickness map shows an asymmetric distribution of the deposits and regions of anomalous thickness. The total volume is estimated to be 1.6 x 10(6) cubic kilometers, which is equivalent to a global water layer approximately 11 meters thick.
  Science 05/2007; 316(5821):92-5. · 31.20 Impact Factor
• Source

  Available from: Roberto Orosei

  Article: Radar soundings of the subsurface of Mars.

  Giovanni Picardi, Jeffrey J Plaut, Daniela Biccari, Ornella Bombaci, Diego Calabrese, Marco Cartacci, Andrea Cicchetti, Stephen M Clifford, Peter Edenhofer, William M Farrell, [......], Roberto Orosei, Elena Pettinelli, Roger J Phillips, Dirk Plettemeier, Ali Safaeinili, Roberto Seu, Ellen R Stofan, Giuliano Vannaroni, Thomas R Watters, Enrico Zampolini
  [show abstract] [hide abstract]
  ABSTRACT: The martian subsurface has been probed to kilometer depths by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express orbiter. Signals penetrate the polar layered deposits, probably imaging the base of the deposits. Data from the northern lowlands of Chryse Planitia have revealed a shallowly buried quasi-circular structure about 250 kilometers in diameter that is interpreted to be an impact basin. In addition, a planar reflector associated with the basin structure may indicate the presence of a low-loss deposit that is more than 1 kilometer thick.
  Science 01/2006; 310(5756):1925-8. · 31.20 Impact Factor
• Article: Dielectric properties of the Martian south polar layered deposits: MARSIS data inversion using Bayesian inference and genetic algorithm

  Zhenfei Zhang, Tor Hagfors, Erling Nielsen, Giovanni Picardi, Arturo Mesdea, Jeffrey J. Plaut
  Journal of Geophysical Research, v.113 (2008).