PSI SEMINAR SERIES: 10 January 2007, 3:30PM
Stratigraphy of water-equivalent hydrogen at high northern latitudes on Mars
William C. Feldman
Neutron leakage currents measured using the Mars Odyssey Neutron Spectrometer are used to develop a two-layer model of the spatial and stratigraphic distribution of water-equivalent hydrogen (WEH) at high northern latitudes. The WEH abundance in the upper layer, Wup, was found to range between 1% and 5%, but preferentially closer to 2% by mass. The maximum value of the thickness, D, of this upper layer peaks at about 60o latitude, giving the appearance of zonal bands of enhanced D in both hemispheres. This maximum is consistent with an expected transition from WEH contained solely in hydrous minerals at lower latitudes, to WEH contained both in the forms of water ice and water of hydration at high latitudes. A strong anti-correlation between the WEH concentration in the lower layer and depth, D, at high latitudes is observed and may provide a clue to the origin of these deposits.
