Exploring Radar Observations of Dusty Ice Layers on Mars through Observations, Modeling, and Lab Experiments

Martian ice, especially its large polar ice caps, holds an important key to interpreting Mars’ past climate. Mars’ polar ice deposits are comprised of layers of ice and dust, and are thought to preserve a record of climate throughout their evolution. Smaller deposits also exist nearby, located in craters that may help prolong their preservation. Ground penetrating radar is an effective tool for understanding Martian ice, as it can probe the subsurface and place constraints on the properties of buried materials. Through a combination of radar remote sensing observations, modeling, and lab experiments, we analyze the dusty ice stratigraphies in Mars polar regions as well as the layer properties that make up the signals in the radar observations of these stratigraphies. We find that the northern ice deposits seem to have more consistency across the north polar region, and have identified at least 2 sub-populations of ice deposits in the south polar regions. This shows that the northern deposits hold one more consistent depositional history, and that there may be multiple depositional histories recorded in the southern deposits. The properties of the layers that make up these deposits are a product of their depositional environment, so studying the physical properties can help us better decode these depositional histories. Through experiments and modeling we find that brighter reflectors are caused by thin, dusty layers. The results in this dissertation have direct implications for interpretation of radar sounding data on Mars for climate studies, especially observations of the Polar Layered Deposits.