Research & Projects

Project 1

Morphology and Stratigraphy of Sediment-Rich Flows Under Mars Conditions

Decades of Mars exploration have provided evidence of past transport of sediments by liquid water that persisted during the Noachian and Hesperian epochs when surface pressures were at least 100 mbar or higher. However, punctuated water events also occurred into the cold and arid Amazonian when surface pressures were much lower, likely near the 7 mbar average of today. Previous experimental studies at 5 mbar, showed that in modern Mars pressures, low viscosity, sediment-poor water flows (composed of bentonite clay and salt water) could boil over warm surfaces and levitate. The same mixture could also freeze and flow like pahoehoe lava over cold surfaces. However, more experimental studies are needed to constrain if these processes are significant for basaltic sediment-rich water flows at early Mars pressures. This information is important as deposit properties are commonly used to interpret past surface processes and the hydrological history on Mars.

Objectives

Experiments were conducted in “George” The Large Dirty Mars Chamber in the HVI & SPE Laboratories at the Open University to assess the morphology and stratigraphy of sediment-rich flows under varying Mars-like conditions in the Noachian through Amazonian. Results from this study provide a framework for interpreting martian sedimentary deposits and landforms that formed under varying pressure and temperature conditions on early Mars.

Water mixed with sand flow

Weighing out the mixture

In situ results on the screen

Capturing images of the flow

Project 2

Morphology and Stratigraphy of different sediment-water ratios at low pressures

Past transport of sediments by liquid water persisted during the Noachian and Hesperian epochs when surface pressures were at least 100 mbar or higher. As the pressure decreased through the cold and arid Amazonian epoch to the present 7 mbar average, water events became interspersed. Recent experiment studies investigated how present low-pressure conditions on Mars impacts flow deposits.

Objectives

The primary objectives are to 1) discover how the flow experiments are impacted by different types of basalt (i.e. change in simulant grain size). 2) Parse out at what specific sediment-water ratio threshold does the morphology and stratigraphy change significantly between the basalt simulants. 3) observe and record how the deposit geometries vary with systematic changes in sediment-water ratios.

Project 3

Evaluating the sensitivity of combined thermal inertia and roughness data for characterizing sedimentary properties at multiple scales

Grain size is a crucial parameter needed to interpret the hydrologic and climatic history of martian alluvial fans. Constraining fan grain sizes on Mars is difficult as these are often at or below the spatial resolution of orbital visible images. Previous studies have suggested that thermal inertia may provide a useful proxy for estimating fan grain sizes on Earth and Mars, as coarser sediments (>10 cm)generally have high thermal inertia, whereas finer-grained sediments have low thermal inertia. However, fan deposits consist of a range of grain sizes that vary spatially, and we lack constraints on what size fraction within that distribution is reflected in thermal inertia data at different spatial scales. This analog study focuses on the Milner Creek fan in California and uses orbital- and drone-based thermal images to systematically constrain how spatial resolution impacts the interpretation of grain size from apparent thermal inertia (ATI).

Objectives

Orbital-based ATI images were calculated for the Milner Creek fan using Landsat8 images (~90 m/pxl), whereas the drone-based ATI were from a DJI Mavic 3T (~3-10 cm/pxl). The fans’ grain size properties were determined in the field by conducting pebble counts at three drone flight locations in an incised channel onthe fan. Preliminary results indicate that overall orbital ATI values and grain sizegenerally decrease down fan with increasing distance away from the apex. ATI values show a relative decrease, reflecting small changes in the grain size distribution from ~1,000 m (closer to the apex) to 4,271 m, with sand-sized particles further down fan. Generally, ATI values reflect no notable correlations of size fractions per location. The Landsat 8 results will be compared with the drone-based ATI to test if changing spatial resolutions affects the grain size that dominates the ATI values. Understanding the relationship between grain size and thermal inertia at varying scales is important for interpreting past aqueous processes on Earth and Mars.

Page updated

Google Sites

Report abuse