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| Titel |
Granular Electrification, Sand Transport and Mineralogy. |
| VerfasserIn |
Jonathan Merrison, Haraldur Gunnlaugsson, Christina Holstein-Rathlou, Svend Knak Jensen, Per Nørnberg, Keld Rasmussen |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250048003
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| Zusammenfassung |
| We present details of recent investigations of the electrification of fine granular materials
(dust) under various laboratory simulation conditions, including Terrestrial and Martian
environments. Specifically the dependence of dust electrification on grain size, mineralogy,
atmospheric composition and pressure will be described.
In nature such electrification often leads to the generation of intense electric
fields. The effect of such electric fields on the transport and structure of wind driven
granular materials will be discussed and recent laboratory work which expands the
current description of grain detachment and entrainment in the presence of electric
fields.
In related studies the effects of erosion as a result of wind driven particulate transport has
been investigated, specifically the effects on grain size, structure and mineralogy. These
studies suggest that a wide range of chemical/mineralogical alteration processes may be
possible as a result of mechanical surface activation generated during erosion (i.e.
as a result of wind driven sand transport). This could have implications for the
evolution of all planetary surfaces which posses an atmosphere. In the case of Mars,
erosion induced surface activation may explain a series of unexpected observations,
specifically; the apparent oxidizing nature of the Martian regolith as seen by the
NASA Viking landers, the lack of observed organics, the presence of chlorate (at
the NASA Phoenix landing site) and the (reddish) oxidized nature of the Martian
dust.
The combined effects of electrification and mechanical activation seems to make the
interface of planetary regolith with an atmosphere a potentially complex and active
environment even in the absence of liquid water.
1. K.R. Rasmussen, J.F. Kok, J.P. Merrison, Planetary and Space Science, 57, 804-808,
(2009)
2. J.P. Merrison*, H.P. Gunnlaugsson, S.J.K. Jensen, P. Nørnberg, Icarus, 205, 716
(2010)
3. J.P. Merrison, H.P. Gunnlaugsson, P. Nørnberg, A.E. Jensen, K.R. Rasmussen, Icarus,
191, 568-580, (2007) |
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