DOCSLIB.ORG

Glaciers on Mars: Looking for The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Glaciers on Mars: Looking for The I m a g e c o ur t e s y o f E S A 2 0 0 7 M P S f r o O I S R I S T Glaciers on Mars: e a m M P S / U P D / L looking for the ice A M / I A A / R S S D / I N T A / One of the scientists’ main U P M / D A S interests in Mars research is P / I D water. Is there water on Mars? A True-colour image of Mars. The image was acquired in 2007 from a distance of about 240 000 km; its resolution is about 5 km/pixel. By Miguel A. de Pablo and Juan D. Centeno Do you know the composi- that Mars had liquid water millions tion of the Martian polar of years ago – flowing on its surface, caps? filling the basins of impact craters, t the expected time, the orbiter, forming lakes, flowing downslope of The northern polar cap of flying at about 300 km in alti- some volcanoes’ flanks, from the Mar- Mars is mainly H O ice. tudeA and around 3.5 km.s-1, focused 2 tian highlands to the lowlands, where However, the southern toward the surface of the arid, cold an extensive ocean could have existed polar cap comprises H O and reddish planet and opened the 2 (referred to as Oceanus Borealis). ice and CO2 ice. shutter of the complex and precise BACKGROUND Solid water is a different matter. Ice camera. A new image from the Mar- polar caps on Mars were identified tian surface, and gigabytes of data, from telescopes and clearly recognis- were then recorded at the same time. – never before have so many experts able on orbiters’ imagesw6, and frozen This process has been repeated many shared so much information and pro- soils have been confirmed in several times in recent decades by the differ- duced so many models and results. places on the planet, mostly thanks to ent orbiters, landers and roversw1 that we have sent to our nearest planet. Water and ice on Mars Every new image and data set increas- One of the scientists’ main interests w2,w3 es the incredibly huge database in Mars research is water. Is there Image courtesy of ESA of information on Mars. Scientists water on Mars? Where is it? Is it liquid from all around the world use these or frozen? In the past, were there resources to study the planet’s chemi- oceans, seas, lakes and rivers on Mars? cal, physical, climatic and geological How did they disappear? Is their environment, with the aim of under- disappearance related to the past and standing more about Mars and how present climate of the planet? But also: it – and even Earth – has evolved. This Is there, or was there, life on Mars? widespread availability of imagesw4 And could humans live there one day? and data is one of the most amazing Thanks to the data acquired by orbit- phenomena in the history of science ers, landers and roversw5, we know The ExoMars rover 12 I Science in School I Issue 28 : Spring 2014 www.scienceinschool.org Cutting edge science Image courtesy of NASA/JPL/HiRISE/University of Arizona HiRISE image of Mars from NASA’s Mars Reconnaissance Orbiter mission, showing the surface with very high resolution (0.35 m/pixel), enough to identify features as small as 1 m in size. ence of ice and glacial-related features using new high-resolution (as high as 35 cm/pixel) images acquired by the active missions of NASA and the European Space Agency (ESA). Our research group focused on the north- west flank of the Hecates Tholus vol- Physics cano in the Elysium region of Mars, Ages 10-11+ at tropical latitudes of the northern Earth science The article is interesting hemisphere. We analysed all the avail- because the teachers and able images from different orbiters stu dents can understand covering this region (at different spec- that currently research can mean temperature of Mars is about tral, temporal and spatial resolutions), be done if you spend many -80 ºC during daytime; at the Equa- and observed features that we inter- hours in search of free inter- tor, the sunny slopes in the summer at preted to be caused by glacial erosion national databases, if you or sedimentation: moraines, crevasses, noon hours can reach a surface temp- Physics compare many images and erature of 15 ºC. roches moutonnées, glacial cirques, of course if you have ex- hanging valleys, eskers, drumlins or arêtes, among othersw9. pertise in a scientific field. Studying martian glaciers Then you can emit a theory Our interpretations were based on w7 which has to be proved by Today, research on Martian ice fo- the comparison between the mars- another research and so on. cuses on finding evidence of the pres- forms (the reliefs observed on Mars) The supplementary links Image courtesy of NAS/JPL/HiRISE/University of Arizona and educational resources can be the starting point for inquiry based learning projects with the title like these: Earth and Mars Simi- larities, Studying the Mars Planet or Life on Mars. Corina Lavinia Toma, Com- puter Science High School “Tiberiu Popoviciu” REVIEW Cluj Napoca, Romania the images reported by NASA’s Phoe- nix mission at high latitudes. The low temperatures of the planet through- out the year, measured by different This unusual structure with traces of a glacier is located in Promethei Terra at the landers and rovers (such as Viking I eastern rim of the Hellas Basin. A so-called ‘block’ glacier flowed from a flank and II, Mars Pathfinder, Spirit, Oppor- of the massif, past mountains several thousand metres high, into a bowl-shaped tunity and Curiosity, which arrived on impact crater, nine kilometres wide, which has been filled nearly to the rim. The Mars in August 2012), confirm that block glacier then flowed into a 17 kilometre wide crater, 500 metres below, ice is stable at all latitudes. In fact, the taking advantage of downward slope. www.scienceinschool.org Science in School I Issue 28 : Spring 2014 I 13 Did you know that Mars had Images courtesy of NASA/JPL/University of Arizona ice ages? Polygonal terrain near the northern po- Crater counting has provided lar cap of Mars, where water ice was evidence of glacial activity, observed just a few centimeters below both ancient (more than 1000 the surface. million years ago) and recent (less than 2 million years ago). The cold periods in Mars history are related to orbital changes (mainly changes to spin axis angle) – just like Earth, where the orbital cycles control most of the Quaternary climate change, as discovered by Milutin BACKGROUND Milankovic in 1922! Images courtesy of NASA Polygonal terrain, typical of frozen soil areas on Earth, surrounding the Phoenix landing site. and the terrestrial landforms in the work in front of the computerw8 and Alps, Iceland or Antarctica, where on different field trips, and thanks to we conducted fieldwork looking for the satellite images and topographic, terrestrial analogues. We also used spectrometric and thermal data, we the ‘multiple working hypotheses’ carried out a detailed description, scientific method to discard other pro- mapping and age determination of the cesses that are able to produce similar features observed on the flank of the features as the origin of the marsforms Martian volcano. Our first conclusion, we observe. Then, after months of based on the long list of glacial-related features on the Hecates Tholus vol- cano, is that an important amount of ice existed there for a long time, form- ing glaciers that flowed downslope, Did you know that Martian sculpting the flanks of the edifice. volcanoes had glaciers? The problem is… we couldn’t find Many Martian volcanoes ice anywhere! However, we could see show reliefs on their flanks some glacial features that we know that are caused by glacial can’t survive for long after ice melts. ice flows – just as we see on This is the case for crevasses: fractures Earth. Those volcanoes are in the glacier disappear when ice located not at polar but at melts or sublimates. We didn’t see the tropical latitudes. Olympus ice on this part of Mars, but we could Mons, Ascraeus Mons and recognise the crevasses sculpted in the View of the Hecates Tholus volcano, Hecates Tholus are examples dust layer that covers the ice. For that in the Elyisum region of Mars, and of volcanoes with glaciers, reason, our second conclusion is that the area in which glacial marsforms similar to Mount Kiliman- the ice causing the extensive fields of have been observed. The area was jaro (Tanzania) and Cotopaxi glacial marsforms must still be below chosen because its high concentration of glacial forms found during general (Ecuador) on Earth. the surface – or it melted very, very BACKGROUND exploration of the volcano slopes. recently. 14 I Science in School I Issue 28 : Spring 2014 www.scienceinschool.org Cutting edge science Partial view of the geomorphological map showing multiple glacial-related features, highlighting the potential Earth science glacier tongues. Colours are part of a conventional map legend: blue hues Image courtesy of Miguel A. de Pablo and Juan D. Centeno represens glacial areas. A B Images courtesy of HiRISE/UA/NASA and DigitalGlobe Similarities between marsforms in Physics Hecates Tholus (A) and landforms in Deception Island, Antarctica (B) help scientists to deduce their origin – in this case, glacial ridges are observed in the images (black arrows). A B Crevasses (fractures on the ice due to its flow) on Hecates Tholus (A) and on glaciers on Deception Island, Antarctica (B), where they are cov- ered by volcanic deposits from the last eruption in 1970.
Load more

Recommended publications
  • Atypical Landslides in the Nilosyrtis Region of Mars Anthony Guimpier, Susan Conway, Nicolas Mangold
    Atypical landslides in the Nilosyrtis region of Mars Anthony Guimpier, Susan Conway, Nicolas Mangold To cite this version: Anthony Guimpier, Susan Conway, Nicolas Mangold. Atypical landslides in the Nilosyrtis region of Mars. 14th Europlanet Science Congress, Oct 2020, held online, Unknown Region. 10.5194/epsc2020- 746. hal-03091587 HAL Id: hal-03091587 https://hal.archives-ouvertes.fr/hal-03091587 Submitted on 7 Jan 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. EPSC Abstracts Vol. 14, EPSC2020-746, 2020, updated on 07 Jan 2021 https://doi.org/10.5194/epsc2020-746 Europlanet Science Congress 2020 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Atypical landslides in the Nilosyrtis region of Mars Anthony Guimpier, Susan Conway, and Nicolas Mangold Laboratoire de Planétologie et Géodynamique CNRS UMR6112, University of Nantes, France ([email protected]) Introduction:This study focuses on four unusual landslides located inside a 25 km diameter impact crater located in Nilosyrtis Mensae (Fig.1). Our initial study revealed that one of these landslides bears close similarity to a mudslide on Earth [1]. We performed a detailed morphological analysis and a comparison with terrestrial analogues to better understand their formation mechanism.
    [Show full text]
  • Review of the MEPAG Report on Mars Special Regions
    THE NATIONAL ACADEMIES PRESS This PDF is available at http://nap.edu/21816 SHARE Review of the MEPAG Report on Mars Special Regions DETAILS 80 pages | 8.5 x 11 | PAPERBACK ISBN 978-0-309-37904-5 | DOI 10.17226/21816 CONTRIBUTORS GET THIS BOOK Committee to Review the MEPAG Report on Mars Special Regions; Space Studies Board; Division on Engineering and Physical Sciences; National Academies of Sciences, Engineering, and Medicine; European Space Sciences Committee; FIND RELATED TITLES European Science Foundation Visit the National Academies Press at NAP.edu and login or register to get: – Access to free PDF downloads of thousands of scientific reports – 10% off the price of print titles – Email or social media notifications of new titles related to your interests – Special offers and discounts Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the National Academies Press. (Request Permission) Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved. Review of the MEPAG Report on Mars Special Regions Committee to Review the MEPAG Report on Mars Special Regions Space Studies Board Division on Engineering and Physical Sciences European Space Sciences Committee European Science Foundation Strasbourg, France Copyright National Academy of Sciences. All rights reserved. Review of the MEPAG Report on Mars Special Regions THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001 This study is based on work supported by the Contract NNH11CD57B between the National Academy of Sciences and the National Aeronautics and Space Administration and work supported by the Contract RFP/IPL-PTM/PA/fg/306.2014 between the European Science Foundation and the European Space Agency.
    [Show full text]
  • Amazonian Northern Mid-Latitude Glaciation on Mars: a Proposed Climate Scenario Jean-Baptiste Madeleine, François Forget, James W
    Amazonian Northern Mid-Latitude Glaciation on Mars: A Proposed Climate Scenario Jean-Baptiste Madeleine, François Forget, James W. Head, Benjamin Levrard, Franck Montmessin, Ehouarn Millour To cite this version: Jean-Baptiste Madeleine, François Forget, James W. Head, Benjamin Levrard, Franck Montmessin, et al.. Amazonian Northern Mid-Latitude Glaciation on Mars: A Proposed Climate Scenario. Icarus, Elsevier, 2009, 203 (2), pp.390-405. 10.1016/j.icarus.2009.04.037. hal-00399202 HAL Id: hal-00399202 https://hal.archives-ouvertes.fr/hal-00399202 Submitted on 11 Apr 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 Amazonian Northern Mid-Latitude 2 Glaciation on Mars: 3 A Proposed Climate Scenario a a b c 4 J.-B. Madeleine , F. Forget , James W. Head , B. Levrard , d a 5 F. Montmessin , and E. Millour a 6 Laboratoire de M´et´eorologie Dynamique, CNRS/UPMC/IPSL, 4 place Jussieu, 7 BP99, 75252, Paris Cedex 05, France b 8 Department of Geological Sciences, Brown University, Providence, RI 02912, 9 USA c 10 Astronomie et Syst`emes Dynamiques, IMCCE-CNRS UMR 8028, 77 Avenue 11 Denfert-Rochereau, 75014 Paris, France d 12 Service d’A´eronomie, CNRS/UVSQ/IPSL, R´eduit de Verri`eres, Route des 13 Gatines, 91371 Verri`eres-le-Buisson Cedex, France 14 Pages: 43 15 Tables: 1 16 Figures: 13 Email address: [email protected] (J.-B.
    [Show full text]
  • PUTTING LIFE on MARS: Using Computer Graphics to Render a Living Mars
    InSight: RIVIER ACADEMIC JOURNAL, VOLUME 9, NUMBER 1, SPRING 2013 PUTTING LIFE ON MARS: Using Computer Graphics to Render a Living Mars Kevin M. Gill ‘11G* Senior Software Engineer, Thunderhead.com, Manchester, NH Keywords: Computer Graphics, Mars, Life, Planetary Science, OpenGL Abstract This article describes the software, algorithms & decisions that went into the development of the Living Mars image project. This includes topics related to computer graphics, software development, astronomy, & planetary science. The purpose of the project was to create a visualization of the planet Mars as could look with a living biosphere. This makes no distinction as to whether this biosphere would represent an ancient or future, possibly terraformed planet. 1 Background Mars, named for the Roman god of war. Ancient civilizations have forever associated the planet with fear, war, and destruction. It is the color of blood, and “one of a handful of planets visible to the naked eye, and the only one of marked color, so the planet demanded attention (Pyle, 2012).” Ever since man has noticed it, there have been dreams and visions of life on Mars, from Giovanni Schiaparelli and Percival Lowell describing channels and canals to Robert A. Heinlein’s science fiction. Lowell, in particular famous for fantastic writings of Mars, asked “are physical forces alone at work there, or has evolution begotten something more complex, something not unakin to what we know on Earth as life?” (Lowell, 1895) Even more recent discoveries by NASA’s Curiosity rover have found proof that liquid water once flowed billions of years ago positing an environment that could have served host to life (Brown, 2013).
    [Show full text]
  • Companion Q&A Fact Sheet: What Mars Reveals About Life in Our
    What Mars Reveals about Life in Our Universe Companion Q&A Fact Sheet Educators from the Smithsonian’s Air and Space and Natural History Museums assembled this collection of commonly asked questions about Mars to complement the Smithsonian Science How webinar broadcast on March 3, 2021, “What Mars Reveals about Life in our Universe.” Continue to explore Mars and your own curiosities with these facts and additional resources: • NASA: Mars Overview • NASA: Mars Robotic Missions • National Air and Space Museum on the Smithsonian Learning Lab: “Wondering About Astronomy Together” Guide • National Museum of Natural History: A collection of resources for teaching about Antarctic Meteorites and Mars 1 • Smithsonian Science How: “What Mars Reveals about Life in our Universe” with experts Cari Corrigan, L. Miché Aaron, and Mariah Baker (aired March 3, 2021) Mars Overview How long is Mars’ day? Mars takes 24 hours and 38 minutes to spin around once, so its day is very similar to Earth’s. How long is Mars’ year? Mars takes 687 days, almost two Earth years, to complete one orbit around the Sun. How far is Mars from Earth? The distance between Earth and Mars changes as both planets move around the Sun in their orbits. At its closest, Mars is just 34 million miles from the Earth; that’s about one third of Earth’s distance from the Sun. On the day of this program, March 3, 2021, Mars was about 135 million miles away, or four times its closest distance. How far is Mars from the Sun? Mars orbits an average of 141 million miles from the Sun, which is about one-and-a-half times as far as the Earth is from the Sun.
    [Show full text]
  • Volcanism on Mars
    Author's personal copy Chapter 41 Volcanism on Mars James R. Zimbelman Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC, USA William Brent Garry and Jacob Elvin Bleacher Sciences and Exploration Directorate, Code 600, NASA Goddard Space Flight Center, Greenbelt, MD, USA David A. Crown Planetary Science Institute, Tucson, AZ, USA Chapter Outline 1. Introduction 717 7. Volcanic Plains 724 2. Background 718 8. Medusae Fossae Formation 725 3. Large Central Volcanoes 720 9. Compositional Constraints 726 4. Paterae and Tholi 721 10. Volcanic History of Mars 727 5. Hellas Highland Volcanoes 722 11. Future Studies 728 6. Small Constructs 723 Further Reading 728 GLOSSARY shield volcano A broad volcanic construct consisting of a multitude of individual lava flows. Flank slopes are typically w5, or less AMAZONIAN The youngest geologic time period on Mars identi- than half as steep as the flanks on a typical composite volcano. fied through geologic mapping of superposition relations and the SNC meteorites A group of igneous meteorites that originated on areal density of impact craters. Mars, as indicated by a relatively young age for most of these caldera An irregular collapse feature formed over the evacuated meteorites, but most importantly because gases trapped within magma chamber within a volcano, which includes the potential glassy parts of the meteorite are identical to the atmosphere of for a significant role for explosive volcanism. Mars. The abbreviation is derived from the names of the three central volcano Edifice created by the emplacement of volcanic meteorites that define major subdivisions identified within the materials from a centralized source vent rather than from along a group: S, Shergotty; N, Nakhla; C, Chassigny.
    [Show full text]
  • Prospects for Life on Mars Without Doubt, Mars Is the Planet That Has Inspired the Most Speculation About Life Outside Earth. It
    Prospects for Life on Mars Without doubt, Mars is the planet that has inspired the most speculation about life outside Earth. It has also starred in more science fiction stories than all other non-Earth planets put together. In this lecture we will have some fun exploring the history of these notions, as well as the entirely serious pursuit of life on Mars that is an ongoing focus of NASA. Lowell and the canals Fascination with Mars has probably occurred since the dawn of humans. Its bright red aspect draws attention, and it is probably no accident that multiple civilizations identified it with the god of war. We take our tradition in this respect from the Romans. Mars, the fourth planet from the Sun, is the second smallest of the terrestrial planets. It has about 1/10 of the mass of the Earth and 1/3 of Earth’s surface gravity, with the consequence that it has difficulty holding onto gases and thus has an atmosphere with only about 1% of the density of Earth’s. The atmosphere itself is mostly carbon dioxide; the oxygen that was in the atmosphere has combined with the iron in the crust to make rust, which is why the planet is red. Mars has no detectable magnetic field, which suggests to some people that it is solid throughout: for comparison, the Earth’s molten interior combined with its rotation (which is similar to that of Mars) generates our magnetic field. Nonetheless, Mars has some spectacular surface features including the largest volcano in the Solar System, Olympus Mons, which rises an amazing 25 km above the surface and is 600 km wide at its base.
    [Show full text]
  • Linking Glaciers on Earth to the Climate on Mars
    Q&A Linking Glaciers on Earth to the Climate on Mars Geophysicist Jack Holt explains how Earth’s debris-covered glaciers can teach us about the climate history of Mars. By Rachel Berkowitz s a student, Jack Holt had three loves: geology, technology on the 2006 Mars Reconnaissance Orbiter, he exploring remote mountain regions, and aviation. applied to be part of the science team. (That spacecraft ANow, as a geophysicist at the University of Arizona, he’s searched for signs of ice below the Martian surface.) Now he merged those loves into his academic pursuits. Holt has tracked spends summers mapping debris-covered glaciers in Wyoming the history of Earth’s magnetic field, which required visits to and Alaska to piece together the history of ice and climate on Death Valley in California, Baja California in Mexico, and the Big Mars. Physics spoke to Holt about the allure of glaciers and Island, Hawaii, and he ran an airborne field program to study about what he hopes to learn about these icy bodies, both on the internal properties of glaciers, which took him to Antarctica. Earth and on Mars. There, he used his postdoctoral experience in airborne radar sounding—a geophysical technique based on long-wave echo All interviews are edited for brevity and clarity. reflections—to map features buried beneath ice sheets. What fascinates you about glaciers? When Holt learned that NASA planned to put similar radar Glaciers grow and shrink on timescales of a few months to a few years, which is short enough that we can witness how they change the features of a landscape almost in real time.
    [Show full text]
  • Possible Recessional Moraines in the Nilosyrtis Mensae Region, Mars
    50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132) 3085.pdf POSSIBLE RECESSIONAL MORAINES IN THE NILOSYRTIS MENSAE REGION, MARS. A. Johnsson1, 2 3 1 J. Raack , E. Hauber . Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden ([email protected]), 2Institut für Planetologie, Westfälische Wilhelms-Universität, Münster, Germany. 3Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Berlin, Germany. Introduction: Previously, numerous studies re- age is available of the studied landforms. For Earth ported on glacier landforms on Mars such as viscous comparison we used publicly available Google Earth flow features (VVF) [1], glacier-like flows (GLF) [2] images. and lobate debris aprons (LDA) [3] where water-ice is Observations and results: The area is dominated by believed to be present under insulating debris cover fretted terrain, mesas, cliffs and flat floored valleys. [1]. This notion was confirmed by SHARAD meas- The studied north-facing cliff range is ~250 km long urements [4]. In terms of possible glacial erosional and and are a few hundred to a more than a thousand me- depositional landforms most studies have focused on ters in height. The cliff is characterized by deeply in- small-scale moraine-like ridges that are associated to cised valley systems. Here we report observations from gully systems in interior crater environments [e.g., 5], two valleys. large-scale glacier landforms at the equatorial volcanic province [e.g., 6], landforms suggesting basal glacial meltwater processes [7,8] and possible drop-moraines from past CO2 glaciers [9]. In this study we surveyed an area that border areas of known VVF's and GLF's along the dichotomy.
    [Show full text]
  • Cold-Based Glaciation of Pavonis Mons, Mars: Evidence for Moraine Deposition During Glacial Advance Reid A
    Parsons et al. Progress in Earth and Planetary Science (2020) 7:13 Progress in Earth and https://doi.org/10.1186/s40645-020-0323-9 Planetary Science RESEARCH ARTICLE Open Access Cold-based glaciation of Pavonis Mons, Mars: evidence for moraine deposition during glacial advance Reid A. Parsons1,2* , Tomohiro Kanzaki3, Ryodo Hemmi1 and Hideaki Miyamoto3 Abstract The three large volcanoes in the Tharsis region of Mars: Arsia, Pavonis, and Ascraeus Montes all have fan-shaped deposits (FSDs) on their northern or western flanks consisting of a combination of parallel ridges, knobby/ hummocky terrain, and a smooth, viscous flow-like unit. The FSDs are hypothesized to have formed in the Amazonian during a period of high spin-axis obliquity which redistributed polar ice to the equatorial Tharsis region resulting in thick (> 2 km), flowing ice deposits. Based on previous ice flow simulations and crater surveys, the ridges are interpreted to be recessional drop moraines formed as debris on the ice sheet surface was transported to the ice margin—forming a long ridge sequence over an extended (∼100 Myr) period of ice sheet retreat. We test this hypothesis using a high-resolution, thermomechanical ice sheet model assuming a lower ice loss rate (~ 0.5 mm/year) than prior work based on new experimental results of ice sublimation below a protective debris layer. Our ice flow simulation results, when combined with topographic observations from a long sequence of ridges located interior of the Pavonis FSD, show that the ridged units were more likely deposited during one or more periods of glacial advance (instead of retreat) when repetitive pulses (approx.
    [Show full text]
  • Glacial and Gully Erosion on Mars: a Terrestrial Perspective Susan Conway, Frances Butcher, Tjalling De Haas, Axel A.J
    Glacial and gully erosion on Mars: A terrestrial perspective Susan Conway, Frances Butcher, Tjalling de Haas, Axel A.J. Deijns, Peter Grindrod, Joel Davis To cite this version: Susan Conway, Frances Butcher, Tjalling de Haas, Axel A.J. Deijns, Peter Grindrod, et al.. Glacial and gully erosion on Mars: A terrestrial perspective. Geomorphology, Elsevier, 2018, 318, pp.26-57. 10.1016/j.geomorph.2018.05.019. hal-02269410 HAL Id: hal-02269410 https://hal.archives-ouvertes.fr/hal-02269410 Submitted on 22 Aug 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. *Revised manuscript with no changes marked Click here to view linked References 1 Glacial and gully erosion on Mars: A terrestrial perspective 2 Susan J. Conway1* 3 Frances E. G. Butcher2 4 Tjalling de Haas3,4 5 Axel J. Deijns4 6 Peter M. Grindrod5 7 Joel M. Davis5 8 1. CNRS, UMR 6112 Laboratoire de Planétologie et Géodynamique, Université de Nantes, France 9 2. School of Physical Sciences, Open University, Milton Keynes, MK7 6AA, UK 10 3. Department of Geography, Durham University, South Road, Durham DH1 3LE, UK 11 4. Faculty of Geoscience, Universiteit Utrecht, Heidelberglaan 2, 3584 CS Utrecht, The Netherlands 12 5.
    [Show full text]
  • Extensive Aqueous Deposits at the Base of the Dichotomy Boundary in Nilosyrtis Mensae, Mars
    Extensive aqueous deposits at the base of the dichotomy boundary in Nilosyrtis Mensae, Mars Joshua L. Bandfield1 and Elena S. Amador2 1Space Science Institute 2Earth and Space Sciences, University of Washington, Seattle Manuscript Correspondence: 5 Joshua Bandfield Space Science Institute 4750 Walnut Street, Suite 205 Boulder, CO 80301, USA [email protected] 10 Manuscript Pages: 32 Figures: 13 Keywords: Mars, surface; Infrared observations; Spectroscopy; Mineralogy; Geological processes 1 Abstract Thermal Emission Imaging System (THEMIS) and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral datasets were used to identify high bulk SiO2 and hydrated 15 compositions throughout the Nilosyrtis Mensae region. Four isolated locations were identified across the region showing short wavelength silicate absorptions within the 8–12 μm spectral region, indicating surfaces dominated by high Si phases. Much more extensive exposures of hydrated compositions are present throughout the region, indicated by a spectral absorption near 1.9 μm in CRISM data. Although limited in spatial coverage, detailed spectral observations indicate that the hydrated materials contain 20 Fe/Mg-smectites and hydrated silica along with minor exposures of Mg-carbonates and an unidentified hydrated phase. The high SiO2 and hydrated materials are present in layered sediments near the base of topographic scarps at the hemispheric dichotomy boundary, typically near or within low albedo sand deposits. The source of the high SiO2 and hydrated materials appears to be from groundwater discharge from Nili Fossae and Syrtis Major to the south, where there is evidence for extensive aqueous alteration 25 of the subsurface. Although discontinuous, the exposures of high SiO2 and hydrated materials span a wide area and are present in a similar geomorphological context to previously identified deposits in western Hellas Basin.
    [Show full text]