Search Publications
Formation timescales of large Martian valley networks
Hynek, Brian M.; Hoke, Monica R. T.; Tucker, Gregory E.
Assessing timescales for formation of the ancient Martian valley networks is key to interpreting the early climate on Mars. We determined the likely formation times for seven of the largest ancient valley networks on Mars using the Darcy-Weisbach equation for average flow velocity, three different sediment transport models, and a range of input pa…
Equatorial glaciations on Mars revealed by gravitational collapse of Valles Marineris wallslopes
Mège, Daniel; Bourgeois, Olivier
Martian global climate models that account for evidence of past glaciations reported in tropical to mid-latitude regions of Mars predict accumulation of water ice in Valles Marineris during past periods of high obliquity. Observational evidence for such glaciations is given here. Topographic basement ridges of tectonic origin are common in Valles …
Mud volcanoes in the geologic record of Mars: The case of Firsoff crater
van Gasselt, S.; Rossi, A. P.; Pondrelli, M. +3 more
We report the detection of mound-like landforms interpreted as mud volcanoes within Firsoff crater, in the Arabia Terra region of Mars. The mounds stratigraphically overlie layered deposits within the crater, which consist of high albedo well-bedded deposits disrupted in meter-sized polygons. Hundreds of mounds are observed on the crater floor, as…
Eruption history of the Elysium Volcanic Province, Mars
Platz, Thomas; Michael, Gregory
Volcanism has played a significant role in shaping the surface of Mars. Volatiles released during eruptions profoundly altered the composition and density of the Martian atmosphere in the past. Quantifying the amounts of volcanic outgassing has been attempted regionally and globally, however, volume estimates of erupted volcanic material in time a…
On the run-out distance of geophysical gravitational flows: Insight from fluidized granular collapse experiments
Mangeney, A.; Lucas, A.; Roche, O. +1 more
We present the results of laboratory experiments on the emplacement of gravitational granular flows generated from axisymmetrical release of columns of fine (~ 75 µm) or coarse (~ 330 µm) particles initially fluidized with air. Internal friction is first negligible in the granular columns and then increases as pore pressure diffuses wi…
Volatiles in the atmosphere of Mars: The effects of volcanism and escape constrained by isotopic data
Gillmann, Cédric; Lognonné, Philippe; Moreira, Manuel
We study the long term evolution of the conditions on the surface of Mars through the modeling of the effects of volcanic degassing and atmospheric non-thermal escape during the last four billion yr. We propose to use the recent advances due to observation and modeling to constrain possible evolutions of the atmosphere of Mars with the help of iso…
Vertical and lateral collapse of Tharsis Tholus, Mars
Neukum, G.; Platz, T.; Dumke, A. +4 more
Tharsis Tholus, a more than 3.9 Ga old composite shield volcano to the east of the major Tharsis Montes, has experienced a complex history of growth and destruction. On the basis of new high resolution images we analysed the morphology as well as the tectonic structures of the Tharsis Tholus volcano in detail. From morphological data, cross-cuttin…
Recent tectonics and subsidence on Mars: Hints from Aureum Chaos
van Gasselt, Stephan; Hauber, Ernst; Rossi, Angelo Pio +1 more
High spatial and spectral resolution imagery and topography collected during the last decade are changing our vision of Mars into that of a geologically active planet, even in recent times. However, the connection between internal activity such as faulting and other recent geomorphic processes and deposits, such as eolian or mass wasting units, is…