[1] Lava dome eruptions are commonly characterized by large fluctuations in discharge rate with cyclic behaviour on time-scales ranging from hours to decades. Examples include Bezymianny volcano (Russia), Merapi (Java), Santiaguito (Guatemala), Mt St Helens (USA), Mt Unzen (Japan), and Soufrière Hills volcano (Montserrat). Previous models have assumed simple cylindrical conduits for magma trans...

Initially homogeneous uspensions of bubbles in basaltic magmas and lava flows may become unstable and form rising waves or layers of bubbles. We derive a set of model equations for the two-phase (bubble-liquid) system and present the results of a linear stability analysis and numerical simulations. Periodic vesicle layers are preserved in Columbia l•iver flows with a spacing of •1 m; the predic...

Lava caves are an understudied ecosystem in the subterranean world, particularly in regard to nitrogen cycling. The diversity of ammonia oxidation (amoA) and nitrogen fixation (nifH) genes in bacterial mats collected from lava cave walls on the island of Terceira (Azores, Portugal) was investigated using denaturing gradient gel electrophoresis (DGGE). A total of 55 samples were collected from 1...

We present a shallow, isothermal, Newtonian model for the transient interaction of lava flows with topography. Numerical integrations and simple mathematical approximations are deployed to quantify how topography controls thicknesses flow speeds. Considering idealised topographic features, we show that modest depressions thicken accelerate - even far downstream whilst mounds have opposite effec...

The formation of islands following a rise in sea level at the end of Pleistocene is expected to disrupt the equilibrium between genetic drift and gene flow in species with limited ability to disperse. Here, we test the hypothesis that genetic drift in isolation has caused the differentiation of Galápagos lava lizards (Microlophus albemarlensis complex) found on 12 islets that are likely to have...

Abstract Modeling lava flow propagation is important to determine potential hazards local populations. Thermo-rheological models such as PyFLOWGO track downflow cooling and rheological responses for open-channel, cooling-limited flows. The dominant radiative component governed partly by the emissivity, which a material property that governs efficiency. Emissivity commonly treated constant in mo...

[1] In contrast to other terrestrial planets, Mercury does not possess a great variety of volcanic features, its history of volcanism instead largely manifest by expansive smooth plains. However, a set of landforms at high northern latitudes on Mercury resembles surface flow features documented on Earth, the Moon, Mars, and Venus. The most striking of such landforms are broad channels that host...