3D View of a DTM of "Badger Crater"
Terraces in this crater are indicative of subsurface layering on Mars.

Current Projects:

Subsurface Water Ice Mapping (SWIM) in the Northern Hemisphere of Mars

The goal of the SWIM project is to provide a set of mapping products using existing spacecraft data that delineate subsurface ice in the mid-latitudes of Mars. We aim to identify and map indicators of possible subsurface ice in each data set and use a combination of all data sets to assess the likelihood of ice being present in shallow (less than 5 m depth) and deep (more than 5 m depth) zones. In this, we are developing the SWIM Equation, styled after the famous Drake Equation, which will provide maps of how consistent the data are with the presence or absence of water ice resources in the subsurface.
Click here to learn more about the SWIM Project!

Radar response of lunar cryptomaria and pyroclastic deposits in Mini-RF data

I am investigating the monostatic and bistatic radar response of cryptomaria and pyroclastic deposits in Mini-RF data, a side-looking hybrid-polarization radar system onboard the Lunar Reconnaissance Orbiter. I am comparing and modeling the radar response of these terrains to other datasets (e.g. Clementine color ratios, Titanium map, etc.) and to the radar response of other terrains (e.g. Mare and Highlands).

Modeling and laboratory experiments of ice sintering processes in non-terrestrial environments

Our team, led by Dr. Jamie Molaro, is combining laboratory experiments and theoretical modeling to explore the role of sintering on the evolution of water ice on icy satellites, Mars, and across the solar system. I will be applying our experimentally-validated model to Mars to explore the role that diurnal and seasonal thermal cycling plays in sintering rates, and the formation of subsurface density gradients to explore how these processes may produce layering in martian ice deposits, and relate the results to spacecraft images and radar subsurface detections that show layering within Martian ice deposits.

Dissertation Work:

My dissertation research 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 applied my ice stability model to the migrating troughs of Mars' North Polar Layered Deposits. This allowed me to investigate the role of sublimation on the migration of these troughs. I find that the troughs are less than 1.5 Myr old, consistent with the hypothesized age of the NPLD. The thickness of the sublimation lag is a key factor controlling sublimation rate and has varied over time, thinning from ~1 cm thick to ~mm over 100s of kyr.
Bramson et al. (2018; in review)

Additional topics and projects:

Radar and Remote Sensing

Theoretical Modeling of Icy Processes

Terrestrial Analog Studies


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.