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Small scale polygonal patterns along the southern water ice margin on Mars.

Författare och institution:
Andreas Johnsson (Institutionen för geovetenskaper); Eveliina Kakkinen (Institutionen för geovetenskaper); John F. Mustard (-); Ralph E. Milliken (-); Dennis Reiss (-); Harald Hiesinger (-); Mats Olvmo (Institutionen för geovetenskaper)
Publicerad i:
Lunar and Planetary Science Conference 39, XXXIX ( 1753 )
Konferensbidrag, poster
Sammanfattning (abstract):
From the high resolution images acquired by Mars Orbiter Camera an array of small scale polygon patterns have been detected which range in size and shape. They occur in a continuous meters-thick deposit interpreted to be ice rich which is observed at latitudes above 60º at both hemispheres, but which has undergone degradation at lower latitudes and is absent in the equatorial regions (within ±30º). Also, the Mars Odyssey’s Neutron spectrometer measurements of hydrogen emissions shows the presence of high water-ice abundance (>60% by volume) in the surface soils in the northern and southern latitudes above 60º [3]. The polygons interpreted to be forming in ice-rich terrain are thus strongly supported by indirect measurements of water-ice for those observed at latitudes higher than 60º S and for those at lower latitudes the morphology indicate a past when ice was stable to lower latitudes. We have performed a comprehensive investigation of polygons along the latitudes of 30º S – 80º S on the southern hemisphere of Mars to highlight the change in morphology with latitude due to the presence or absence to subsurface water ice. The hypothesis is that the surface morphology would reflect the proposed subsurface ice content, similar to periglacial landscapes on Earth, which is both theorised and measured indirectly by Mars Odysseys Neutron spectrometer. The idea is also to differentiate the genesis of polygons and link them to different processes and time of formation. As an addition we includ cryocarst data which reflect the absence of near surface ice (m to tens of m). These previously unpublished results are the outcome of a master thesis project. This work focus on the latitudinal distribution of polygons in relation to the cryocarst terrain.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
Fysik ->
Astronomi, astrofysik och kosmologi ->
Geovetenskap och miljövetenskap
Mars, polygons, ice, permafrost
Postens nummer:
Posten skapad:
2010-04-08 13:40

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