My dissertation is focused on Mars mid-latitude ice and what it can tell us about the Martian climate system, particularly the stability of water (at least in ice and vapor form) in the Amazonian period.
In 2015, I published my study on an ice sheet the size of California and Texas combined just underneath the surface of Mars that goes as deep as a 13-story building. To find this
ice, I used a high-resolution camera called HiRISE, which we operate here at the Lunar and Planetary Lab on campus, as well as a radar instrument called SHARAD. Both of these instruments are onboard NASA's Mars Reconnaissance Orbiter. Creating 3D Digital Terrain Models of terraced craters (above) allowed me to constrain the thicknesses of the ice layering, and by
combining these measurements with the time delays of the subsurface radar returns, I was able to estimate the dielectric constant of this deposit.
Bramson et al. (2015) Widespread excess ice in Arcadia Planitia, Mars. GRL, 42, doi:10.1002/2015GL064844
More recently, I have written a 1D thermal conduction model to look into how this ice could have been preserved. We find that decameters-thick ice sheets at the mid-latitudes of
Mars can be orders of magnitude older than the obliquity cycles that are typically thought to drive mid-latitude ice deposition and sublimation. Retreat of this ice in the last 4
Myr could have contributed ~6% of the volume of the North Polar Layered Deposits (NPLD) and more than 10% if the NPLD are older than 4 Myr.
Bramson et al. (2017) Preservation of Mid-Latitude Ice Sheets on Mars. JGR-Planets, 112, doi:10.1002/2017JE005357
Ice in the mid-latitudes exchanges with polar ice over geologic time so to understand the other half of the system, I am applying my ice stability model to the migrating troughs of Mars' Polar Layered Deposits. This will allow me to investigate the role of sublimation on the migration of these troughs, and the accumulation that would have occured over the same period of time.
This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1143953. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation.