Ali M. Bramson CV
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Planetary Geologic Mappers Annual Meeting
Program Lunar and Planetary Institute 3600 Bay Area Boulevard Houston TX 77058-1113 Planetary Geologic Mappers Annual Meeting June 12–14, 2018 • Knoxville, Tennessee Institutional Support Lunar and Planetary Institute Universities Space Research Association Convener Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Science Organizing Committee David Williams, Chair Arizona State University Devon Burr Earth and Planetary Sciences Department, University of Tennessee Knoxville Robert Jacobsen Earth and Planetary Sciences Department, University of Tennessee Knoxville Bradley Thomson Earth and Planetary Sciences Department, University of Tennessee Knoxville Abstracts for this meeting are available via the meeting website at https://www.hou.usra.edu/meetings/pgm2018/ Abstracts can be cited as Author A. B. and Author C. D. (2018) Title of abstract. In Planetary Geologic Mappers Annual Meeting, Abstract #XXXX. LPI Contribution No. 2066, Lunar and Planetary Institute, Houston. Guide to Sessions Tuesday, June 12, 2018 9:00 a.m. Strong Hall Meeting Room Introduction and Mercury and Venus Maps 1:00 p.m. Strong Hall Meeting Room Mars Maps 5:30 p.m. Strong Hall Poster Area Poster Session: 2018 Planetary Geologic Mappers Meeting Wednesday, June 13, 2018 8:30 a.m. Strong Hall Meeting Room GIS and Planetary Mapping Techniques and Lunar Maps 1:15 p.m. Strong Hall Meeting Room Asteroid, Dwarf Planet, and Outer Planet Satellite Maps Thursday, June 14, 2018 8:30 a.m. Strong Hall Optional Field Trip to Appalachian Mountains Program Tuesday, June 12, 2018 INTRODUCTION AND MERCURY AND VENUS MAPS 9:00 a.m. Strong Hall Meeting Room Chairs: David Williams Devon Burr 9:00 a.m. -
A Wunda-Full World? Carbon Dioxide Ice Deposits on Umbriel and Other Uranian Moons
Icarus 290 (2017) 1–13 Contents lists available at ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus A Wunda-full world? Carbon dioxide ice deposits on Umbriel and other Uranian moons ∗ Michael M. Sori , Jonathan Bapst, Ali M. Bramson, Shane Byrne, Margaret E. Landis Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA a r t i c l e i n f o a b s t r a c t Article history: Carbon dioxide has been detected on the trailing hemispheres of several Uranian satellites, but the exact Received 22 June 2016 nature and distribution of the molecules remain unknown. One such satellite, Umbriel, has a prominent Revised 28 January 2017 high albedo annulus-shaped feature within the 131-km-diameter impact crater Wunda. We hypothesize Accepted 28 February 2017 that this feature is a solid deposit of CO ice. We combine thermal and ballistic transport modeling to Available online 2 March 2017 2 study the evolution of CO 2 molecules on the surface of Umbriel, a high-obliquity ( ∼98 °) body. Consid- ering processes such as sublimation and Jeans escape, we find that CO 2 ice migrates to low latitudes on geologically short (100s–1000 s of years) timescales. Crater morphology and location create a local cold trap inside Wunda, and the slopes of crater walls and a central peak explain the deposit’s annular shape. The high albedo and thermal inertia of CO 2 ice relative to regolith allows deposits 15-m-thick or greater to be stable over the age of the solar system. -
Martian Crater Morphology
ANALYSIS OF THE DEPTH-DIAMETER RELATIONSHIP OF MARTIAN CRATERS A Capstone Experience Thesis Presented by Jared Howenstine Completion Date: May 2006 Approved By: Professor M. Darby Dyar, Astronomy Professor Christopher Condit, Geology Professor Judith Young, Astronomy Abstract Title: Analysis of the Depth-Diameter Relationship of Martian Craters Author: Jared Howenstine, Astronomy Approved By: Judith Young, Astronomy Approved By: M. Darby Dyar, Astronomy Approved By: Christopher Condit, Geology CE Type: Departmental Honors Project Using a gridded version of maritan topography with the computer program Gridview, this project studied the depth-diameter relationship of martian impact craters. The work encompasses 361 profiles of impacts with diameters larger than 15 kilometers and is a continuation of work that was started at the Lunar and Planetary Institute in Houston, Texas under the guidance of Dr. Walter S. Keifer. Using the most ‘pristine,’ or deepest craters in the data a depth-diameter relationship was determined: d = 0.610D 0.327 , where d is the depth of the crater and D is the diameter of the crater, both in kilometers. This relationship can then be used to estimate the theoretical depth of any impact radius, and therefore can be used to estimate the pristine shape of the crater. With a depth-diameter ratio for a particular crater, the measured depth can then be compared to this theoretical value and an estimate of the amount of material within the crater, or fill, can then be calculated. The data includes 140 named impact craters, 3 basins, and 218 other impacts. The named data encompasses all named impact structures of greater than 100 kilometers in diameter. -
Eskers Associated with Extant Glaciers in Mid-Latitude Graben on Mars: Evidence for Geothermal Controls Upon Recent Basal Melting
Lunar and Planetary Science XLVIII (2017) 1234.pdf ESKERS ASSOCIATED WITH EXTANT GLACIERS IN MID-LATITUDE GRABEN ON MARS: EVIDENCE FOR GEOTHERMAL CONTROLS UPON RECENT BASAL MELTING. F.E.G. Butcher1, C. Gallagher2,3, N.S. Arnold4, M.R. Balme1, S.J. Conway5, S.R. Lewis1, A. Hagermann1. 1School of Physical Sciences, The Open University, UK ([email protected]), 2UCD School of Geography, University College Dublin, Ireland, 3UCD Earth Institute, University College Dublin, Ireland 4Scott Polar Research Institute, University of Cambridge, UK, 5CNRS, LPG Nantes, France. Introduction: Diagnostic evidence for past melting of putative debris-covered glaciers (DCGs) in Mars’ mid-latitudes [e.g. 1-2] is extremely rare. As such, it is widely believed that these DCGs have been perennially frozen to their beds in cold-based thermal regimes [e.g. 3] since their formation ~40 Ma to 1 Ga [4-8]. Here, we present a landsystem model that challenges this paradigm. We identify a sinuous ridge emerging from a DCG in the broad rift zone NE of the Tharsis volcanic province. We interpret this ridge as an esker formed by deposition of sediment within a subglacial meltwater conduit. This is only the second esker-like ridge to be identified in association with a mid-latitude DCG. Re- cent work [9] identified a complex of esker-like ridges on the foreland of an extant DCG in Phlegra Montes, for which high-resolution analysis is ongoing [10]. Significantly, both candidate eskers are located within graben. Graben are topographic troughs formed by crustal extension and are commonly associated with elevated geothermal heat (GH) flux [e.g. -
Eskers in a Complete, Wet-Based Glacial System in the Phlegra
Earth and Planetary Science Letters 431 (2015) 96–109 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Eskers in a complete, wet-based glacial system in the Phlegra Montes region, Mars ∗ Colman Gallagher a,b, , Matthew Balme c,d a UCD School of Geography, University College Dublin, Belfield, Dublin 4, Ireland b UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland c Dept. of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA, UK d Planetary Science Institute Tucson, 1700 E. Fort Lowell, Suite 106, Tucson, AZ 85719, United States a r t i c l e i n f o a b s t r a c t Article history: Although glacial landsystems produced under warm/wet based conditions are very common on Earth, Received 30 April 2015 even here, observations of subglacial landforms such as eskers emerging from extant glaciers are rare. Received in revised form 9 September 2015 This paper describes a system of sinuous ridges emerging from the in situ but now degraded piedmont Accepted 14 September 2015 terminus of a Late Amazonian-aged (∼150 Ma) glacier-like form in the southern Phlegra Montes region Available online 29 September 2015 of Mars. We believe this to be the first identification of martian eskers that can be directly linked to their Editor: C. Sotin parent glacier. Together with their contextual landform assemblage, the eskers are indicative of significant Keywords: glacial meltwater production and subglacial routing. However, although the eskers are evidence of a Mars wet-based regime, the confinement of the glacial system to a well-defined, regionally significant graben, glacier and the absence of eskers elsewhere in the region, is interpreted as evidence of sub-glacial melting eskers as a response to locally enhanced geothermal heat flux rather than climate-induced warming. -
Observations of the Marker Bed at Gale Crater with Recommendations for Future Exploration by the Curiosity Rover
52nd Lunar and Planetary Science Conference 2021 (LPI Contrib. No. 2548) 1484.pdf OBSERVATIONS OF THE MARKER BED AT GALE CRATER WITH RECOMMENDATIONS FOR FUTURE EXPLORATION BY THE CURIOSITY ROVER. C. M. Weitz1, J. L. Bishop2, B. J. Thomson3, K. D. Seelos4, K. Lewis5, I. Ettenborough3, and R. E. Arvidson6. 1Planetary Science Institute, 1700 East Fort Lowell, Tuc- son, AZ ([email protected]); 2SETI Institute, Carl Sagan Center, Mountain View, CA; 3Dept. of Earth and Planetary Sciences, Univ. Tennessee, Knoxville, TN; 4Planetary Exploration Group, JHU Applied Physics Laboratory, Laurel, MD; 5Dept Earth and Planetary Sciences, John Hopkins University, Baltimore, MD; 6Dept Earth and Planetary Sci- ences, Washington University, St. Louis, Missouri. Introduction: A dark-toned marker bed is ob- pearance across the mound. Most of the sulfates served within the sulfates at Gale crater [1,2]. This above/below the marker bed are stratified, heavily marker bed is characterized by a dark-toned, smooth fractured, and erode into boulder-size blocks, but there surface that appears more indurated and retains more are examples where the sulfates appear massive with craters relative to the sulfate-bearing layers above and limited fracturing and no boulders eroding from the below it. The bed has a distinct physical appearance unit (Fig. 3a). from the sulfates in which it occurs, suggesting a change in the environment or geochemistry for a brief period of time within the depositional sequence that formed the sulfates or post-deposition alteration. In this study, we utilized HiRISE and CTX images to identify and map the occurrence of the marker bed throughout Aeolis Mons. -
16. Ice in the Martian Regolith
16. ICE IN THE MARTIAN REGOLITH S. W. SQUYRES Cornell University S. M. CLIFFORD Lunar and Planetary Institute R. O. KUZMIN V.I. Vernadsky Institute J. R. ZIMBELMAN Smithsonian Institution and F. M. COSTARD Laboratoire de Geographie Physique Geologic evidence indicates that the Martian surface has been substantially modified by the action of liquid water, and that much of that water still resides beneath the surface as ground ice. The pore volume of the Martian regolith is substantial, and a large amount of this volume can be expected to be at tem- peratures cold enough for ice to be present. Calculations of the thermodynamic stability of ground ice on Mars suggest that it can exist very close to the surface at high latitudes, but can persist only at substantial depths near the equator. Impact craters with distinctive lobale ejecta deposits are common on Mars. These rampart craters apparently owe their morphology to fluidhation of sub- surface materials, perhaps by the melting of ground ice, during impact events. If this interpretation is correct, then the size frequency distribution of rampart 523 524 S. W. SQUYRES ET AL. craters is broadly consistent with the depth distribution of ice inferred from stability calculations. A variety of observed Martian landforms can be attrib- uted to creep of the Martian regolith abetted by deformation of ground ice. Global mapping of creep features also supports the idea that ice is present in near-surface materials at latitudes higher than ± 30°, and suggests that ice is largely absent from such materials at lower latitudes. Other morphologic fea- tures on Mars that may result from the present or former existence of ground ice include chaotic terrain, thermokarst and patterned ground. -
Hubbard B, Souness C, Brough S. Glacier-Like Forms on Mars
Hubbard B, Souness C, Brough S. Glacier-like forms on Mars. The Cryosphere 2014, 8, 2047-2061. Copyright: © Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License. DOI link to article: https://doi.org/10.5194/tc-8-2047-2014 Date deposited: 24/11/2017 This work is licensed under a Creative Commons Attribution 3.0 Unported License Newcastle University ePrints - eprint.ncl.ac.uk The Cryosphere, 8, 2047–2061, 2014 www.the-cryosphere.net/8/2047/2014/ doi:10.5194/tc-8-2047-2014 © Author(s) 2014. CC Attribution 3.0 License. Glacier-like forms on Mars B. Hubbard, C. Souness, and S. Brough Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK Correspondence to: B. Hubbard ([email protected]) Received: 7 May 2014 – Published in The Cryosphere Discuss.: 5 June 2014 Revised: 15 September 2014 – Accepted: 26 September 2014 – Published: 5 November 2014 Abstract. More than 1300 glacier-like forms (GLFs) are lo- concerned and of broader planetary issues such as (i) how cated in Mars’ mid-latitudes. These GLFs are predominantly Mars’ present-day landscape was formed, (ii) the presence composed of ice–dust mixtures and are visually similar to and phase state of H2O on Mars’ surface, and (iii) how Mars’ terrestrial valley glaciers, showing signs of downhill viscous climate has changed in geologically recent times. The aim of deformation and an expanded former extent. However, sev- this paper is to summarize and develop our understanding of eral fundamental aspects of their behavior are virtually un- the fundamental physical glaciology of Mars’ GLFs. -
Explosive Lava‐Water Interactions in Elysium Planitia, Mars: Geologic and Thermodynamic Constraints on the Formation of the Tartarus Colles Cone Groups Christopher W
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115, E09006, doi:10.1029/2009JE003546, 2010 Explosive lava‐water interactions in Elysium Planitia, Mars: Geologic and thermodynamic constraints on the formation of the Tartarus Colles cone groups Christopher W. Hamilton,1 Sarah A. Fagents,1 and Lionel Wilson2 Received 16 November 2009; revised 11 May 2010; accepted 3 June 2010; published 16 September 2010. [1] Volcanic rootless constructs (VRCs) are the products of explosive lava‐water interactions. VRCs are significant because they imply the presence of active lava and an underlying aqueous phase (e.g., groundwater or ice) at the time of their formation. Combined mapping of VRC locations, age‐dating of their host lava surfaces, and thermodynamic modeling of lava‐substrate interactions can therefore constrain where and when water has been present in volcanic regions. This information is valuable for identifying fossil hydrothermal systems and determining relationships between climate, near‐surface water abundance, and the potential development of habitable niches on Mars. We examined the western Tartarus Colles region (25–27°N, 170–171°E) in northeastern Elysium Planitia, Mars, and identified 167 VRC groups with a total area of ∼2000 km2. These VRCs preferentially occur where lava is ∼60 m thick. Crater size‐frequency relationships suggest the VRCs formed during the late to middle Amazonian. Modeling results suggest that at the time of VRC formation, near‐surface substrate was partially desiccated, but that the depth to the midlatitude ice table was ]42 m. This ground ice stability zone is consistent with climate models that predict intermediate obliquity (∼35°) between 75 and 250 Ma, with obliquity excursions descending to ∼25–32°. -
Solar-System-Wide Significance of Mars Polar Science
Solar-System-Wide Significance of Mars Polar Science A White Paper submitted to the Planetary Sciences Decadal Survey 2023-2032 Point of Contact: Isaac B. Smith ([email protected]) Phone: 647-233-3374 York University and Planetary Science Institute 4700 Keele St, Toronto, Ontario, Canada Acknowledgements: A portion of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). © 2020. All rights reserved. 1 This list includes many of the hundreds of current students and scientists who have made significant contributions to Mars Polar Science in the past decade. Every name listed represents a person who asked to join the white paper or agreed to be listed and provided some comments. Author List: I. B. Smith York University, PSI W. M. Calvin University of Nevada Reno D. E. Smith Massachusetts Institute of Technology C. Hansen Planetary Science Institute S. Diniega Jet Propulsion Laboratory, Caltech A. McEwen Lunar and Planetary Laboratory N. Thomas Universität Bern D. Banfield Cornell University T. N. Titus U.S. Geological Survey P. Becerra Universität Bern M. Kahre NASA Ames Research Center F. Forget Sorbonne Université M. Hecht MIT Haystack Observatory S. Byrne University of Arizona C. S. Hvidberg University of Copenhagen P. O. Hayne University of Colorado LASP J. W. Head III Brown University M. Mellon Cornell University B. Horgan Purdue University J. Mustard Brown University J. W. Holt Lunar and Planetary Laboratory A. Howard Planetary Science Institute D. McCleese Caltech C. Stoker NASA Ames Research Center P. James Space Science Institute N. -
Large Impact Crater Histories of Mars: the Effect of Different Model Crater Age Techniques ⇑ Stuart J
Icarus 225 (2013) 173–184 Contents lists available at SciVerse ScienceDirect Icarus journal homepage: www.elsevier.com/locate/icarus Large impact crater histories of Mars: The effect of different model crater age techniques ⇑ Stuart J. Robbins a, , Brian M. Hynek a,b, Robert J. Lillis c, William F. Bottke d a Laboratory for Atmospheric and Space Physics, 3665 Discovery Drive, University of Colorado, Boulder, CO 80309, United States b Department of Geological Sciences, 3665 Discovery Drive, University of Colorado, Boulder, CO 80309, United States c UC Berkeley Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720, United States d Southwest Research Institute and NASA Lunar Science Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302, United States article info abstract Article history: Impact events that produce large craters primarily occurred early in the Solar System’s history because Received 25 June 2012 the largest bolides were remnants from planet ary formation .Determi ning when large impacts occurred Revised 6 February 2013 on a planetary surface such as Mars can yield clues to the flux of material in the early inner Solar System Accepted 25 March 2013 which, in turn, can constrain other planet ary processes such as the timing and magnitude of resur facing Available online 3 April 2013 and the history of the martian core dynamo. We have used a large, global planetary databas ein conjunc- tion with geomorpholog icmapping to identify craters superposed on the rims of 78 larger craters with Keywords: diameters D P 150 km on Mars, 78% of which have not been previously dated in this manner. -
MARTIAN GEOLOGIC "REVOLUTIONS": a TALE of TWO PROCESSES; Kenneth L
LPSC XXI 1237 MARTIAN GEOLOGIC "REVOLUTIONS": A TALE OF TWO PROCESSES; Kenneth L. Tanaka, U.S. Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001 The antiquated geologic term "revolution" is defined as "A term formerly popular among geologists for a time of profound orogeny and other crustal movements, on a continentwide or even worldwide scale, the assumption being that such revolutions produced abrupt changes in geography, climate, and environment" [I]. The term is little used today because of changes in our definition of "orogeny" and in our understanding of Earth's geologic history. Herein, I informally resurrect the term for Mars, in modified form, because of its suitability to this planet. My definition is "a time of profound geologic activity resulting in global changes in physiography, climate, or environment." On Earth, most surface rocks (except the youngest) record a cumulatively complex geologic history, and their landscapes are largely molded by surficial processes. On Mars, however, structure and topography are more directly the results of volcanism and tectonism. Singular, major volcanic and tectonic events dominated in shaping the surface, and they strongly influenced the planet's environment. Impact cratering has also had a major role in the geology of Mars, and geologic revolutions related to cratering events may be proposed. However, here I examine only those revolutions apparently or possibly related to volcanism and tectonism, because I am reviewing the thrust of work from NASA's research project "Mars: Evolution of Volcanism, Tectonism, and Volatiles." Below I outline three possible revolutions on Mars that are based on geologic evidence. Each includes uncertainties in such fundamental aspects as origin, nature and sequence of events, and environmental significance.