Observed Seasonal Variations Of Hydrogen Abundance
In The Shallow Subsurface Of Martian Tropics And
Implications For Water Cycle.
M. A. Kreslavsky , Earth And Planetary Sciences, University Of California – Santa Cruz, Santa Cruz, Ca, Usa
(Mkreslav@Ucsc.Edu).

Introduction:
Ground Ice Is Known To Be Abundant In The Very
Shallow Subsurface At High Latitude Of Mars And
Slightly Deeper At Midlatitudes. At Low Latitudes Some
Modest Spatially Varying Amount Of Hydrogen Is Present As A Component Of Hydrated Salts Or As An Unstable, Currently Sublimating Deposits.
Significant Amount Of Information About H Distribution In The Shallow Subsurface Came From Two
Neutron Detectors Onboard Mars Odyssey Orbiter,
Mars Odyssey Neutron Spectrometer (Mons)
[Feldman Et Al., 2002], And High-Energy Neutron
Detector (Hend) [Mitrofanov Et Al., 2002]. They Are
Based On Different Measurement Approaches, However, They Measure The Same Physical Quantity, Local
Neutron Flux As A Function Of Neutron Energy.
With Hend Data, Significant Seasonal Variations
Of Neutron Spectra In Martian Tropics Have Been Reported And Interpreted As Seasonal Changes In Ice