Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2011-04-23
    Description: Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO(2)) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO(2) volatile release. If released into the atmosphere at times of high obliquity, the CO(2) reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Phillips, Roger J -- Davis, Brian J -- Tanaka, Kenneth L -- Byrne, Shane -- Mellon, Michael T -- Putzig, Nathaniel E -- Haberle, Robert M -- Kahre, Melinda A -- Campbell, Bruce A -- Carter, Lynn M -- Smith, Isaac B -- Holt, John W -- Smrekar, Suzanne E -- Nunes, Daniel C -- Plaut, Jeffrey J -- Egan, Anthony F -- Titus, Timothy N -- Seu, Roberto -- New York, N.Y. -- Science. 2011 May 13;332(6031):838-41. doi: 10.1126/science.1203091. Epub 2011 Apr 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Planetary Science Directorate, Southwest Research Institute, Boulder, CO 80302, USA. roger@boulder.swri.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21512003" target="_blank"〉PubMed〈/a〉
    Keywords: Atmosphere ; Carbon Dioxide ; Cold Temperature ; *Dry Ice ; Extraterrestrial Environment ; Ice ; *Mars ; Water
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2011-06-04
    Description: The first Cenozoic ice sheets initiated in Antarctica from the Gamburtsev Subglacial Mountains and other highlands as a result of rapid global cooling approximately 34 million years ago. In the subsequent 20 million years, at a time of declining atmospheric carbon dioxide concentrations and an evolving Antarctic circumpolar current, sedimentary sequence interpretation and numerical modelling suggest that cyclical periods of ice-sheet expansion to the continental margin, followed by retreat to the subglacial highlands, occurred up to thirty times. These fluctuations were paced by orbital changes and were a major influence on global sea levels. Ice-sheet models show that the nature of such oscillations is critically dependent on the pattern and extent of Antarctic topographic lowlands. Here we show that the basal topography of the Aurora Subglacial Basin of East Antarctica, at present overlain by 2-4.5 km of ice, is characterized by a series of well-defined topographic channels within a mountain block landscape. The identification of this fjord landscape, based on new data from ice-penetrating radar, provides an improved understanding of the topography of the Aurora Subglacial Basin and its surroundings, and reveals a complex surface sculpted by a succession of ice-sheet configurations substantially different from today's. At different stages during its fluctuations, the edge of the East Antarctic Ice Sheet lay pinned along the margins of the Aurora Subglacial Basin, the upland boundaries of which are currently above sea level and the deepest parts of which are more than 1 km below sea level. Although the timing of the channel incision remains uncertain, our results suggest that the fjord landscape was carved by at least two iceflow regimes of different scales and directions, each of which would have over-deepened existing topographic depressions, reversing valley floor slopes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Young, Duncan A -- Wright, Andrew P -- Roberts, Jason L -- Warner, Roland C -- Young, Neal W -- Greenbaum, Jamin S -- Schroeder, Dustin M -- Holt, John W -- Sugden, David E -- Blankenship, Donald D -- van Ommen, Tas D -- Siegert, Martin J -- England -- Nature. 2011 Jun 2;474(7349):72-5. doi: 10.1038/nature10114.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, USA. duncan@utig.ig.utexas.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21637255" target="_blank"〉PubMed〈/a〉
    Keywords: Antarctic Regions ; *Climate Change ; Geography ; *Ice Cover/chemistry ; Oceans and Seas ; Oxygen Isotopes/analysis
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2018-01-12
    Description: Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be 〉100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars’ high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate.
    Keywords: Geochemistry, Geophysics, Planetary Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...