Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - The effect of atmospheric pressure on the dispersal of pyroclasts from martian volcanoes
AU - Kerber, Laura
AU - Forget, François
AU - Madeleine, Jean-Baptiste
AU - Wordsworth, R.
AU - Head, James
AU - Wilson, Lionel
PY - 2013/3
Y1 - 2013/3
N2 - A planetary global circulation model developed by the Laboratoire de Météorologie Dynamique (LMD) was used to simulate explosive eruptions of ancient martian volcanoes into paleo-atmospheres with higher atmospheric pressures than that of present-day Mars. Atmospheric pressures in the model were varied between 50 mbar and 2 bars. In this way it was possible to investigate the sensitivity of the volcanic plume dispersal model to atmospheric pressure. It was determined that the model has a sensitivity to pressure that is similar to its sensitivity to other atmospheric parameters such as planetary obliquity and season of eruption. Higher pressure atmospheres allow volcanic plumes to convect to higher levels, meaning that volcanic pyroclasts have further to fall through the atmosphere. Changes in atmospheric circulation due to pressure cause pyroclasts to be dispersed in narrower latitudinal bands compared with pyroclasts in a modern atmosphere. Atmospheric winds are generally slower under higher pressure regimes; however, the final distance traveled by the pyroclasts depends greatly on the location of the volcano and can either increase or decrease with pressure. The directionality of the pyroclast transport, however, remains dominantly east or west along lines of latitude. Augmentation of the atmospheric pressure improves the fit between possible ash sources Arsia and Pavonis Mons and the Medusae Fossae Formation, a hypothesized ash deposit.
AB - A planetary global circulation model developed by the Laboratoire de Météorologie Dynamique (LMD) was used to simulate explosive eruptions of ancient martian volcanoes into paleo-atmospheres with higher atmospheric pressures than that of present-day Mars. Atmospheric pressures in the model were varied between 50 mbar and 2 bars. In this way it was possible to investigate the sensitivity of the volcanic plume dispersal model to atmospheric pressure. It was determined that the model has a sensitivity to pressure that is similar to its sensitivity to other atmospheric parameters such as planetary obliquity and season of eruption. Higher pressure atmospheres allow volcanic plumes to convect to higher levels, meaning that volcanic pyroclasts have further to fall through the atmosphere. Changes in atmospheric circulation due to pressure cause pyroclasts to be dispersed in narrower latitudinal bands compared with pyroclasts in a modern atmosphere. Atmospheric winds are generally slower under higher pressure regimes; however, the final distance traveled by the pyroclasts depends greatly on the location of the volcano and can either increase or decrease with pressure. The directionality of the pyroclast transport, however, remains dominantly east or west along lines of latitude. Augmentation of the atmospheric pressure improves the fit between possible ash sources Arsia and Pavonis Mons and the Medusae Fossae Formation, a hypothesized ash deposit.
KW - Mars, Atmosphere
KW - Mars, Surface
KW - Volcanism
KW - Geological processes
KW - Atmospheres, Dynamics
U2 - 10.1016/j.icarus.2012.11.037
DO - 10.1016/j.icarus.2012.11.037
M3 - Journal article
VL - 223
SP - 149
EP - 156
JO - Icarus
JF - Icarus
SN - 0019-1035
IS - 1
ER -