Former extent of glacier-like forms on Mars

Stephen Brough, Bryn Hubbard, Alun Hubbard

Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

264 Wedi eu Llwytho i Lawr (Pure)


Mars’ mid-latitude glacier-like forms (GLFs) have undergone substantial mass loss and recession since a hypothesised last martian glacial maximum (LMGM) stand. To date, there is a lack of knowledge of the nature and timing of the LMGM, the subsequent mass loss and whether this mass loss has been spatially variable. Here, we present the results of a population-scale inventory of recessional GLFs, derived from analysis of 1293 GLFs identified within Context Camera (CTX) imagery, to assess the distribution and controls on GLF recession. A total of 436 GLFs were identified showing strong evidence of recession: 197 in the northern hemisphere and 239 in the southern hemisphere. Relative to their parent populations, recessional GLFs are over-represented in the low latitude belts between 25 and 40o and in areas of high relief, suggesting that these zones exert some control over GLF sensitivity and response to forcing. This analysis is complemented by the reconstruction of the maximum extent and morphology of a specific GLF for which High Resolution Imaging Science Experiment (HiRISE) derived digital elevation data are available. Using Nye’s (Nye, J. F. [1951] Proc. Roy. Soc. Lond, Ser. A-Mat. Phys. Sci, 207, 554-572) perfect plastic approximation of ice flow applied to multiple flow-lines under an optimum yield strength of 22 kPa, we calculate that the reconstructed GLF has lost an area of 6.86 km2 with a corresponding volume loss of 0.31 km3 since the LMGM. Assuming the loss reconstructed at this GLF occurred at all mid-latitude GLFs yields a total planetary ice loss from Mars’ GLFs of 135 km3, similar to the current ice volume in the European Alps on Earth.
Iaith wreiddiolSaesneg
Tudalennau (o-i)37-49
Nifer y tudalennau13
Dyddiad ar-lein cynnar19 Maw 2016
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 01 Awst 2016

Ôl bys

Gweld gwybodaeth am bynciau ymchwil 'Former extent of glacier-like forms on Mars'. Gyda’i gilydd, maen nhw’n ffurfio ôl bys unigryw.

Dyfynnu hyn