North-south asymmetry of eolian features in Martian polar regions - Analysis based on crater-related wind markers

• Main Author: Thomas, P.
• Format: Other/Unknown Material
• Language: unknown
• Published: 1981
• Subjects: 91; South Pole; South pole
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19820035948

Crater-related wind markers in the north and south polar regions of Mars are analyzed in a study of possible north-south asymmetries in wind activity. Features including crater splotches and associated streaks, and depositional, erosional, frost and frost-sediment streaks were identified and analyzed as wind direction indicators on Viking Orbiter and Mariner 9 images of areas poleward of + or - 40 deg latitude. The wind streaks reveal eolian activity at present to be strongest in the north in winter and in the south in spring, due to the hemispherical asymmetry in climate. The alignment of the more massive intercrater dune fields with the presently strongest wind may reflect a longer-term asymmetry in spring flows, as the reorientation times of the dunes exceeded the period of climate asymmetry cycles. Finally, a wider distribution of dune latitudes in the southern polar region is noted to be suggestive of the greater effectiveness of windflow from the south pole.