Formulations for Simulating the Multiscale Physics of Magma Ascent

Monogenetic Basaltic Volcanoes: Genetic Classification, Growth, Geomorphology and Degradation

“…The initiation of magma (crystals + melt) ascent starts as porous flow in deformable media and later transforms into channel flow (or a dyke) if the physical properties such as porosity/permeability of the host rock are high enough in elastic or brittle rocks in the crust [50,75,[106][107]. The critical vol-ume of melt essential for dyke injections is in the range of a few tens of m 3 [76], a volume which is several orders of magnitude less than magma batches feeding eruptions on the surface, usually ≥0.0001 km 3 [39,108]. An increase in melt propagation distance is possible if small, pocket-fed initial dykes interact with each other [50,76], which is strongly dependent on the direction of maximum (σ 1 ) and least principal stresses (σ 3 ), both in local and regional scales [109] and the vertical and horizontal separation of dykes [50,76,110].…”

“…The critical vol-ume of melt essential for dyke injections is in the range of a few tens of m 3 [76], a volume which is several orders of magnitude less than magma batches feeding eruptions on the surface, usually ≥0.0001 km 3 [39,108]. An increase in melt propagation distance is possible if small, pocket-fed initial dykes interact with each other [50,76], which is strongly dependent on the direction of maximum (σ 1 ) and least principal stresses (σ 3 ), both in local and regional scales [109] and the vertical and horizontal separation of dykes [50,76,110]. These dykes move in the crust as self-propagating fractures controlled by the density contrast between the melt and the host rock from the over-pressured source zone [50].…”

“…A volcanic eruption on the surface is considered to be a result of a successful coupling mechanism between internal processes, such as melt extraction rate and dyke interaction en-route to the surface [50,76,110], and external processes, such as local and regional stress fields in the crust [42,109]. Therefore, the spatial and temporal location of a volcanic event represents the configuration of the magmatic system at the time of the eruption.…”

“…Other studies have elucidated plumbing and feeder systems of monogenetic volcanoes [8][9][55][56][57], eruption mechanisms [58][59][60][61] and associated volcanic hazards [34,[62][63][64][65][66][67] as well as surface processes [68][69][70][71] and long-term landscape evolution [72][73][74]. Eruption of magma on the surface can be interpreted as the result of the dominance of magma pressure over lithostatic pressure [50,[75][76]. On the other hand, freezing of magma en route to the surface are commonly due to insufficient magma buoyancy, where the lithostatic pressure is larger than the magma pressure, or insufficient channelling/focusing of the magma [50,[76][77][78].…”

“…Eruption of magma on the surface can be interpreted as the result of the dominance of magma pressure over lithostatic pressure [50,[75][76]. On the other hand, freezing of magma en route to the surface are commonly due to insufficient magma buoyancy, where the lithostatic pressure is larger than the magma pressure, or insufficient channelling/focusing of the magma [50,[76][77][78]. Once these small-volume magmas (0.001 to 0.1 km 3 ) intrude into the shallow-crust, they are vulnerable to external influences such as interactions with groundwater at shallow depth [79][80][81][82].…”