Eighth International Conference on (2014) sess453.pdf

Wednesday, July 16, 2014 POSTER SESSION: CLIMATE AND ICE CAPS 4:00 p.m. Dabney Hall and Garden

Hartmann W. K. Martian Climate Variations Driven By Obliquity Excursions: Evidence From Small-Crater Populations [#1051] Obliquity-driven climate variations drive ice-rich mantling in some mid-latitude regions of Mars. Craters of depth ~10 m (and human scale topography east of Hallas) last only only from the last few high-obliquity episodes (>45deg).

Zuschneid W. van Gasselt S. Episodoc Fluvial Processes in Eastern , Mars [#1120] Small fluvial features in Hellas Planitia, Mars, were dated using crater counts. The results indicate a major episode of fluvial activity 0.25 to 0.75 Ga ago.

Weitz C. M. Bishop J. L. Diversity of Hydrated Minerals and Deposits at : Implications for Late to Amazonian Aqueous Activity on Mars [#1222] We have identified numerous hydrated minerals and sedimentary deposits at Noctis Labyrinthus. Our results indicate aqueous activity in localized geologic settings and environmental conditions occurred during the Late Hesperian to Amazonian.

Zaki A. S. Inverted Wadis in Western Desert and its Comparison with Inverted Wadis on Mars [#1084] Inverted wadis in Western Desert are similar to Inverted wadis on . This study has been invoked to explain a number of geomorphic features of martian surface.

Audouard J. Poulet F. Vincendon M. Milliken R. E. Jouglet D. Bibring J.-P. Gondet B. Langevin Y. Martian Surface Water Reservoir [#1179] We present a comprehensive study of the water-related 3µm absorption using OMEGA data. We quantify the surface water reservoir using laboratory studies and reveal the distribution of the amorphous hydrated component measured by Curiosity.

Litvak M. L. Mitrofanov I. G. Sanin A. Lisov D. Behar A. Boynton W. Deflores L. Fedosov F. Golovin D. Hardgrove C. Harshman K. Jun I. Kozyrev A. Kuzmin R. Malakhov A. Mischna M. Moersch J. Mokrousov M. Nikiforov S. Shvetsov V. Starr R. Tate C. Tretyakov V. Vostrukhin A. Measurements of Subsurface Water Distribution in Current and Future Orbital and Landing Missions: Comparison Between Mars Odyssey, MSL Curiosity and ExoMars Missions [#1130] Joint analysis of subsurface water observations performed at different orbital and landing missions.

Liu L. Sletten R. S. Hallet B. Mischna M. A. Vasavada A. R. Martin-Torres F. J. Ground Ice Dynamics at Beacon Valley, Antarctica and its Application to the Potential Persistence of Ground Ice at on MARS [#1049] This study examines the long-term stability of ancient ground ice in Beacon Valley, Antarctica with a vapor diffusion model, then similar approach will be applied to study possibility of preservation of old equatorial ground ice at Gale on Mars.

Dundas C. M. Byrne S. McEwen A. S. Clean Ground Ice on Mars: Evidence from Spacecraft, Fresh Craters, and Thermokarst [#1375] New impact craters expose ice in the martian mid-latitudes, while thermokarst landforms reveal ice loss. Both likely indicate clean subsurface ice.

Eighth International Conference on Mars (2014) sess453.pdf

Sizemore H. G. Zent A. P. Rempel A. W. Initiation and Growth of Martian Ice Lenses [#1089] We employ numerical simulations of climate and soil-ice interactions to place quantitative constraints on the growth of segregated ice lenses throughout the high latitudes. We discuss how ice lenses may contribute to observations of excess ice.

Soare R. J. Horgan B. Conway S. J. El-Maarry M. R. Volcanic Terrain and the Origin of Ground Ice in , Mars [#1055] We discuss the formation of ground ice and of periglacial landforms in volcanic terrain at the mid- to low-lats of Utopia Planitia and show that there is no spatial coincidence between these landforms and the so-called “latitude-dependent mantle”.

Jawin E. R. Head J. W. Marchant D. R. Paraglacial Geomorphology on Mars: A Conceptual Framework for Post-Glacial Geomorphic Processes [#1033] The paraglacial period is a terrestrial post-glacial phase that describes the environmental response to deglaciation. We use this period as a framework for analyzing martian impact craters that bear evidence of ice accumulation, flow, and loss.

Diot X. El-Maarry M. R. Schlunegger F. Norton K. P. Thomas N. Grindrod P. N. Chojnacki M. Banded Terrain in Hellas Basin, Mars: Results from Geomorphological Investigations and Morphometry [#1056] The NW of the Hellas basin (centered at 40.8°S; 67.8°E) displays a possibly unique terrain type called “banded terrain”. This unit is characterized by morphological features with convolute forms consistent with the presence of a flowing material.

Levy J. S. Fassett C. I. Schwartz C. Watters J. L. Head J. W. Estimating the Volume of Midlatitude Debris Covered on Mars: New Totals for Lobate Debris Aprons, , and [#1121] Buried ice on Mars / Not uniformly spread out / Surprisingly thick.

Rutledge A. M. Christensen P. R. Hypsometric Analysis of Glacial Features: A Survey of Populations in Eastern Hellas Basin and Deuteronilus Mensae, Mars [#1435] Hypsometric curves of lobate debris apron populations in Hellas Basin and Deuteronilus Mensae were evaluated and compared with respect to inferred ice accumulation and flow. Curve types are elevation-dependent, indicating a past shift in climate.

Petersen E. I. Holt J. W. Levy J. S. Parsons R. A. A Synthesis of Radar Sounding, Geomorphic Characterization, and Ice Flow Modeling to Understand Regional Differences Between Lobate Debris Aprons in Western and Eastern Deuteronilus Mensae [#1451] Unraveling the processes behind regional variability in radar observations of LDA in Deuteronilus Mensae to shed light upon emplacement conditions and data interpretation.

Bramson A. M. Byrne S. Putzig N. E. Mattson S. Plaut J. J. Holt J. W. Thick, Excess Water Ice in [#1042] We constrain the extent and composition of a layer of subsurface ice in Arcadia Planitia, Mars using depths to crater terraces and SHARAD delay times. Results suggest this ice layer is thick (10s of meters) and relatively pure (dirtiness < 8%).

Viola D. McEwen A. S. Dundas C. M. Byrne S. Expanded Craters in Arcadia Planitia: Evidence for >20 M.y. Old Subsurface Ice [#1022] The formation and preservation of thermokarstically-expanded secondary craters suggests the existence and persistence of long-lived (tens of millions of years old) excess water ice in Arcadia Planitia, Mars.

Eighth International Conference on Mars (2014) sess453.pdf

Calvin W. M. James P. B. Cantor B. A. Seasonal Cap Retreat MY 28–31 Using MARCI: Development and Evolution of the Cryptic Region and Other Interesting Features [#1299] We compare features of the south seasonal cap retreat as observed by MARCI, including development and evolution of the cryptic region, persistence of high albedo deposits and state of the brighter outlier adjacent to the residual dome.

Thomas P. C. Calvin W. Haberle R. James P. B. Lee S. W. Mass Balance of Mars’ South Polar Residual Cap from Spacecraft Imaging [#1085] Imaging data covering over 20 Mars year span are used to estimate the mass balance of the south polar residual cap.

Ogohara K. The Poleward Ekman Transport Induced by CO2 Condensation in the Martian Polar Regions [#1102] The atmospheric mass change due to CO2 condensation in polar regions enhances the Ekman transport in mid-latitudes. The atmosperic mass, dust and vapor may be transported to the polar region through the very thin layer (about 1 km) near the surface.

Wong M. L. Ingersoll A. P. Ehlmann B. L. Pilorget C. Buhler P. The Case for Stable Entombed CO2 in Mars’ South Polar Layered Deposits [#1472] Motivated by the discovery of a massive deposit of buried CO2 ice in the south polar cap, we use a 1-D thermal model of the martian polar caps to show that it is possible for solid carbon dioxide to be stably buried under a layer of water ice.

Bapst J. Bandfield J. L. Wood S. E. Mars’ Dynamic Albedo: Evidence for Widespread Seasonal Water Frost in the Northern Hemisphere from TES, HiRISE and THEMIS [#1469] Using multi-year TES bolometric albedo and temperature data, we identify the presence of seasonal water frost on Mars. Our findings show a stark hemispherical asymmetry, consistent with our understanding of atmospheric water transport.

Mount C. P. Titus T. N. Distinct CO2 Ice Endmembers on the Northern Polar Seasonal Cap [#1027] We study surface features, albedos, and densities of seasonal CO2 ice over time on the north pole of Mars. Our results suggest two distinct endmembers. We develop a conceptual model to explain the changes in the states of these ices during spring.

Di Primio M. Marinangeli L. Marinelli V. Pettinelli E. Mattei E. Lauro S. Radar Stratigraphy of the Greenland Ice Cap and Implications for the Mars PLDs Investigation [#1244] Our work aim is to reproduce a direct inversion model obtained using dielectric properties data measured at Greenland ice cores to give an interpretation of radar profiles acquired on Martian Polar Layered Deposits.

Campbell B. A. Morgan G. A. Putzig N. E. Holt J. W. Phillips R. J. Properties of the Mars Polar Layered Deposits from Radar Sounding [#1350] We use SHARAD to study the nature of reflecting interfaces within the NPLD, and to analyze the possible geologic implications of diffuse radar echoes from the SPLD.

Becerra P. Byrne S. Mattson S. Pelletier J. D. Herkenhoff K. E. HiRISE Team Polar Stratigraphy from HiRISE Stereo Topography [#1183] High-resolution topographic data (HiRISE Digital Terrain Models) provide a new means of analyzing the stratigraphic record of Mars’ Polar Layered Deposits.

Milkovich S. M. Surface Expression of Radar Reflections Within Promethei Lingula, South Polar Layered Deposits [#1358] Examination of SHARAD radar reflections that intersect the surface of the SPLD in imaging datasets can provide clues to the source of individual reflections within the deposits.

Eighth International Conference on Mars (2014) sess453.pdf

Lalich D. E. Holt J. W. Determining the Composition of the North Polar Layered Deposits Using SHARAD Observations and Modeling: Climate Implications [#1018] In this work we use a simple plane wave model to estimate the effective dielectric constants of multiple SHARAD radar reflectors in the North Polar Layered Deposits.

Landis M. E. Byrne S. Daubar I. J. Herkenhoff K. E. Dundas C. M. Reinterpreting the Impact Craters of the North Polar Layered Deposits, Mars [#1019] We use the Daubar et al. (2013) production function and updated HiRISE images to reinterpret the impact crater population of the North Polar Layered Deposits, Mars.