Determining Emplacement Conditions and Vent Locations for Channelized Lava Flows Southwest of Arsia Mons

The lava flow field southwest of Arsia Mons, Mars has complex volcanic geomorphology. Overlapping flows make observations of their total lengths and identification of their source vents impossible. Application of flow emplacement models, which rely upon physical parameters such as flow length, using only the exposed flow may produce inaccurate estimates of effusion rate, viscosity, and yield strength. We use an established terrestrial thermorheological model (PyFLOWGO), modified to Mars conditions, to estimate effusion rates, viscosities, yield strengths, and possible vent locations for five Mars flows. Our investigation found a range of effusion rates from 2,500 to 6,750 m3 s-1 (average of ∼4,960 m3 s-1). These results are an order of magnitude higher than terrestrial channelized basaltic flows. Corresponding modeled viscosities and yield strengths ranged from 9.4 × 103 to 6.6 × 105 Pa s (average of 5.5 × 104 Pa s) and 66 to 381 Pa (average of 209 Pa), respectively. A novel secondary application of PyFLOWGO that assumes upslope channel narrowing provided estimates of the entire channel length, which is on average four times longer than the exposed portions. Projecting these lengths upslope shows that four of the five flows may have a common vent location, which shares morphologic similarities to other Tharsis region vents. This modeling approach for partially-exposed lava flows makes it possible to not only determine eruptive parameters, but also to estimate total channel lengths and thereby identify possible source vents.

Volcanism and tectonism across the inner solar system: an overview

Volcanism and tectonism are the dominant endogenic means by which planetary surfaces change. This book, in general, and this overview, in particular, aim to encompass the broad range in character of volcanism, tectonism, faulting and associated interactions observed on planetary bodies across the inner solar system – a region that includes Mercury, Venus, Earth, the Moon, Mars and asteroids. The diversity and breadth of landforms produced by volcanic and tectonic processes are enormous, and vary across the inventory of inner solar system bodies. As a result, the selection of prevailing landforms and their underlying formational processes that are described and highlighted in this review are but a primer to the expansive field of planetary volcanism and tectonism. In addition to this extended introductory contribution, this Special Publication features 21 dedicated research articles about volcanic and tectonic processes manifest across the inner solar system. Those articles are summarized at the end of this review.