Cold-Climate (Periglacial) Landforms on the Earth and Mars: Geomorphic Evidence for Ice-Related Flow and Conditions for the Generation of Meltwater.

Morgan, Gareth A.

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Year:: 2009
Contributor:: Morgan, Gareth A. (creator); Head, James (director); Pieters, Carle (reader); Herbert, Timothy (reader); Wyatt, Michael (reader); Chicarro, Augustin (reader); Brown University. Geological Sciences (sponsor)
Genre:: theses
Subject:: Mars; Gullies; Climate; Geomorphology; Glaciers; Climatology; Mars (Planet); Antarctica
Extent:: xxii, 326 p.
DOI: https://doi.org/10.7301/Z0833Q9F

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Abstract:: Under the current paradigm of Mars history, the planet is thought to have undergone a global climatic change, from relatively warm and wet conditions during the Noachian, to conditions during the Amazonian characterized by temperatures and pressures largely below the triple point of water. Analysis of high-resolution datasets have revealed an array of young landforms associated with both ice and liquid water at latitudes where it is currently unstable, suggesting that significant climatic change has also occurred during the post-Noachian. This thesis reports on the detailed morphological investigation, mapping and dating of Amazonian and Hesperian landforms indicative of the action of ice/water. This includes: gullies, previously unreported lobate debris tongues, large-scale lineated valley fill/lobate debris apron (LVF/LDA) deposits, and valley networks. Comparisons of these features of different ages permit an examination of the magnitude and extent of climatic change. To aid the interpretation of the landform assemblages, two field campaigns were undertaken in the Antarctic Dry Valleys. These have long been described as the most Mars-like terrestrial environment and are also an important focus of climate research on Earth due to their sensitivity. This has led to the development of a martian gully formation model based on the melting of windblown snowpacks under specific insolation conditions. This research indicates that multiple episodes of climate change have occurred on Mars resulting in the surficial deposition and evolution of ice, at both the regional scale in the form of debris-covered glaciers (LVF/LDA deposits), and within localized microclimate zones. The melting of surface ice has provided a source of water for the generation of fluvial activity. This appears to have occurred over the last several million years during periods of preferential insolation to form gullies, and during the Hesperian, in response to a large impact into glacial deposits, resulting in valley formation.
Notes:: Thesis (Ph.D.) -- Brown University (2009)

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Morgan, Gareth A., "Cold-Climate (Periglacial) Landforms on the Earth and Mars: Geomorphic Evidence for Ice-Related Flow and Conditions for the Generation of Meltwater." (2009). Earth, Environmental and Planetary Sciences Theses and Dissertations. Brown Digital Repository. Brown University Library. https://doi.org/10.7301/Z0833Q9F

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Earth, Environmental and Planetary Sciences Theses and Dissertations

Theses and Dissertations for the Earth, Environmental and Planetary Sciences department.
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