Presentation Title

Characterizing the morphology and evolution of martian linear dune gullies

Start Date

November 2016

End Date

November 2016

Location

HUB 302-#73

Type of Presentation

Poster

Abstract

Grooves on martian dunes have been cited as evidence of liquid water, but may be formed through a unique martian process instead. These grooves, known as linear gullies, are a class of martian gullies defined by long, narrow channels that are either straight or sinuous. Unlike other gullies on Earth and Mars that end in depositional aprons, linear gullies end in circular depressions known as pits. Determining the process that forms these linear gullies remains a challenge, partly because these features are only found on Mars. It was initially proposed that they are formed by water-driven debris flow. However, several shortcomings have been found with this theory. Instead, recent studies suggest that these features could be formed by the downslope movement of CO2 blocks driven by sublimation. In our study, we aimed to further constrain the linear gully formation process by collecting morphological data and tracking the activity of linear gullies in the southern hemisphere using HiRISE images. Our results showed that morphologies and types of activity may differ between dune sites, potentially due to differences in frost activity levels and dune shape. We also found that activity occurs between late winter and early spring, supporting the CO2 hypothesis. Determining the formation mechanism that forms these martian features can improve our understanding of both the climatic and geological processes that shape the Martian surface.

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Nov 12th, 4:00 PM Nov 12th, 5:00 PM

Characterizing the morphology and evolution of martian linear dune gullies

HUB 302-#73

Grooves on martian dunes have been cited as evidence of liquid water, but may be formed through a unique martian process instead. These grooves, known as linear gullies, are a class of martian gullies defined by long, narrow channels that are either straight or sinuous. Unlike other gullies on Earth and Mars that end in depositional aprons, linear gullies end in circular depressions known as pits. Determining the process that forms these linear gullies remains a challenge, partly because these features are only found on Mars. It was initially proposed that they are formed by water-driven debris flow. However, several shortcomings have been found with this theory. Instead, recent studies suggest that these features could be formed by the downslope movement of CO2 blocks driven by sublimation. In our study, we aimed to further constrain the linear gully formation process by collecting morphological data and tracking the activity of linear gullies in the southern hemisphere using HiRISE images. Our results showed that morphologies and types of activity may differ between dune sites, potentially due to differences in frost activity levels and dune shape. We also found that activity occurs between late winter and early spring, supporting the CO2 hypothesis. Determining the formation mechanism that forms these martian features can improve our understanding of both the climatic and geological processes that shape the Martian surface.