Thick, slow-moving block-lava flows are associated with extrusive activity in dacitic systems, where lava-core depressurization during flow-front collapse generates devastating block-and-ash flows. Dimensional and rare thermal data collected during January 2000 for an active dacitic block flow at Santiaguito (Guatemala) provide insight into cooling and emplacement mechanisms. Flow velocity was ...

Most basaltic lavas begin flowing as pāhoehoe but sometimes transition into ‘a‘ā. Field observations and previous models have demonstrated that the rheology of smooth, liquid-like is distinct from rough, pasty ‘a‘ā, cause this dramatic rapidly occurring change in has remained unclear. Here, we propose to ‘a‘ā could be initiated by Yih instability, an internal shear layered flow. We show conditi...

Introduction: New high-resolution datasets have prompted a mapping-based study of the Echus Chasma and Kasei Valles system. Some of the highlights of our new findings from the Amazonian (<1.8 Ga) period in this area include (1) a new widespread platy-flow surface material (unit Apf) that is interpreted to be 2,100-km-runout flood lavas sourced from Echus Chasma; and (2) a fracture in Echus Chas...

MAGFLOW is a physics-based numerical model for lava flow simulations based on the Cellular Automaton approach that has been successfully used to predict the lava flow paths during the recent eruptions on Mt Etna. We carried out an extensive sensitivity analysis of the physical and rheological parameters that control the evolution function of the automaton and which are measured during eruptive ...

[1] In 1999, a swarm of earthquakes and a lava flow signaled a volcanic eruption at the eastern end of Gakkel Ridge, the slowest spreading ridge worldwide. In summer 2001, the multidisciplinary Arctic Mid-Ocean Ridge Expedition studied these ridge processes which are unusual at ultraslow spreading rates. As part of these studies, we examined the microearthquake activity of the ridge with seismo...

Introduction. The Medusae Fossae Formation (MFF) is an enigmatic formation located between 130°-230°E and 12°S-12°N, in the southern parts of the Elysium and Amazonis quadrangles and the northern parts of the Aeolis and Memnonia quadrangles. It covers an area of approximately 2.1 x 10 km and has an estimated volume of 1.4 x 10 km [1]. The formation is composed of highly eroded, finegrained, fri...

Introduction: Our goal is to identify the optimal wavelengths for studying volcanic activity on Io. While better temporal, spatial, and spectral resolution is always desired, practical limitations lead one to limit both the wavelength range and spectral resolution of an observation. Our primary motivation is to assist the development of future spacecraft observations, but these results are also...

Introduction: A number of terrestrial analog studies have focused on characterizing individual lava flows [e.g., 3, 6-7]. Morphometric and compositional information from these features can be used to infer the rheological properties of similar lava flows, the timing and duration of the eruptions episodes, the depth of the magma chambers [2, 12-14], and even the eruptive and emplacement history ...