windregimesedimenttransportation
Mary BourkeNASA Mars Data Analysis ProgramWind regime, sediment transport and the age of dunefields in the Northern Polar Sand Seas on MarsThe North Polar Sand Seas (NPSS) on Mars represent a major accumulation of windblown sediment that potentially preserves a rich geological record of arid and windy phases in the Martian paleo-climate. Their location at the North Pole makes them likely to be especially sensitive to past variations in obliquity. We propose to use satellite data released by recent NASA missions to determine the characteristics and evolution of the NPSS. Sand seas show a patterning of dune types, dune size and spacing. These attributes can be used to infer the wind and sediment regimes and the sequence of constructional events. Individual dune forms and their associated deposits can be used to infer local (recent) wind and sediment regimes.
Specifically, we will map dune form and dune pattern parameters at 18 study sites in the NPSS, an area of 73,000 km^2, in order to characterize the dunefield variability and identify discrete locations of sand sea formation. We will use crater retention age estimates and pattern dating techniques to determine the absolute and relative ages of sand sea formation. Dune crestline maps will be converted to wind direction maps through detailed mathematical modeling of dune form and crestline orientation. For more recent aeolian activity we will look for change in dune sand streak orientation and changes in dune form over the past ~10 years. We will also use geomorphic evidence and Thermal Inertia mapping to search for evidence of dune stabilization (sediment cementation). Evolutionary modeling will test hypotheses of ice entrainment in Martian dunes.
These combined analyses will advance our understanding of landform evolution on Mars, thereby fulfilling the guiding principle in NASA¿s Mars Exploration Program: to understand the planet¿s geology and to search for past and present life and life environments, specifically Goal III, Objective A: To determine the nature and sequences of the various geological processes that have created and modified the Martian surface.
Specifically, we will map dune form and dune pattern parameters at 18 study sites in the NPSS, an area of 73,000 km^2, in order to characterize the dunefield variability and identify discrete locations of sand sea formation. We will use crater retention age estimates and pattern dating techniques to determine the absolute and relative ages of sand sea formation. Dune crestline maps will be converted to wind direction maps through detailed mathematical modeling of dune form and crestline orientation. For more recent aeolian activity we will look for change in dune sand streak orientation and changes in dune form over the past ~10 years. We will also use geomorphic evidence and Thermal Inertia mapping to search for evidence of dune stabilization (sediment cementation). Evolutionary modeling will test hypotheses of ice entrainment in Martian dunes.
These combined analyses will advance our understanding of landform evolution on Mars, thereby fulfilling the guiding principle in NASA¿s Mars Exploration Program: to understand the planet¿s geology and to search for past and present life and life environments, specifically Goal III, Objective A: To determine the nature and sequences of the various geological processes that have created and modified the Martian surface.
