The Athabasca Valles flood lava is among the most recent (<50 Ma) and best preserved effusive lava flows on Mars and was probably emplaced turbulently. The Williams et al. [2005] model of thermal erosion by lava has been applied to what we term "proximal Athabasca," the 75 km long upstream portion of Athabasca Valles. For emplacement volumes of 5000 and 7500 km3 and average flow thicknesses of ...

Introduction: Lava flow surface morphology results from processes that occur during emplacement. Features such as tumuli and lava rises are indicators of flow inflation [1]. Tumuli in particular have been identified as possible indicators of lava tube location [2-5], indicating that their distribution on the surface of a lava flow is a function of the internal pathways of lava present during fl...

The Figuera Lava, the oldest stratigraphic unit now recognized in northeastern Puerto Rico, and the overlying Fajardo Formation are redescribed and the name Figuera redefined and reinstated for formal use. Previously, lower Tertiary strata some distance from the type areas of the Figuera and Fajardo were correlated with the units by reconnaissance. Recent detailed mapping and paleontology now p...

River channels and valleys have been observed on several planetary bodies in addition to the Earth. Long sinuous valleys on Venus, our Moon and Jupiter's moon Io are clearly formed by lava, and branching valleys on Saturn's moon Titan may be forming today by rivers of methane. But by far the most dissected body in our Solar System apart from the Earth is Mars. Branching valleys that in plan res...

We report on spectral reflectance measurements of basaltic lava flows on Tenerife Island, Spain. Lava flow surfaces of different ages, surface roughness and elevations were systematically measured using a field spectroradiometer operating in the range of 350–2500 nm. Surface roughness, oxidation and lichen coverage were documented at each measured site. Spectral properties vary with age and mor...

Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical stu...

Accurate forecasts of lava flow length rely on estimates of eruption andmagma properties and, potentially more challengingly, on an understanding of the relative influence of characteristics such as the apparent viscosity, the yield strength of the flow core, or the strength of the lava’s surface crust. For basaltic lavas, the relatively high frequency of eruptions has resulted in numerous oppo...

The primary objective of this study was to map the distribution and abundance of firetree (Myrica faya) in the state of Hawai`i. Reconnaissance data were used to map 85,912 a (34,365 ha) of infestation throughout the State. Infestations of 72,265 a (28,906 ha) occur on the island of Hawai`i, 4,770 a (1,908 ha) on Maui, 2,518 a (1,007 ha) on Lana`i, 435 a (174 ha) on O`ahu, and 5,925 a (2,370 ha...

Nucleotide sequences of mitochondrial genes (ND1, ND2, COI, and tRNAs) were determined for 38 samples representing 15 taxa of tropidurid lizards from the Galapagos Islands and mainland South America. Phylogenetically informative characters (759 of 1,956) were analyzed under Bayesian, maximum likelihood, and parsimony frameworks. This study supports the hypothesis that tropidurid lizards dispers...