Maynooth Geography Seminar! 4:15-5:30pm, 16 October 2014
Rocque Lab, Rhetoric House., South campus
Active Surface Processes on Mars
Dr. Mary Bourke, Earth and Planetary Surface Process Group
Geography Department, School of Natural Sciences, TCD
The high-resolution satellite data returned from Mars has revealed an active
surface and aeolian dunes are shown to be one of the more dynamic
systems. Mission data that extends over three Mars years has confirmed that
winds are of sufficient strength and duration to cause the dunes to actively
migrate and mobile sand on dunes triggers lee slope avalanches that erode
substantial alcoves. In addition to wind, the seasonal CO2 and H2O ice
deposit that blankets the polar dunes contributes to significant dune change.
Images taken one Mars year apart indicate extensive mass movement on
dunes. The slump morphology suggests collapse of ice-cemented dune brink
sediments. The mobile deposits bury remnant lenses of seasonal H2O ice.
This rapid burial has the potential to sequester significant volumes of pure
lenticular ice in dune avalanche-face strata. Slumped deposits at the slip-face
toe will be preserved as ice-cemented blocks and grains. This seminar will
discuss the operation of active and dynamic geomorphic processes at polar
locations on Mars and illustrate some ʻuniqueʼ processes that have no Earth
analogue.
Event flyer (PDF)