نتایج جستجو برای: lava rock

تعداد نتایج: 41494  

Journal: :Journal of geophysical research. Planets 2015
Vincenzo Cataldo David A Williams Colin M Dundas Laszlo P Keszthelyi

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 ...

2004
Yohannes Demissie

A central loop Transient Electromagnetic TEM Resistivity Survey was conducted at the Geysir high temperature geothermal area as part the project of the author. The area is situated 110 km away from Reykjavik and lies in a shallow valley elongated north-south. Geologically it is surrounded by three volcanic domes made-up of rhyolites, hyloclastites and inter-glacial basaltic lava that obtain hea...

2006
M. R. Balme V. Rocchi C. Jones P. R. Sammonds P. G. Meredith S. Boon

A sound knowledge of mechanical properties of rocks at high temperatures and pressures is essential for modelling volcanological problems such as fracture of lava flows and dike emplacement. In particular, fracture toughness is a scale invariant material property of a rock that describes its resistance to tensile failure. A new fracture mechanics apparatus has been constructed enabling fracture...

2007
Seongyup Kim Marc A. Deshusses

Gas film mass transfer coefficients (kGat , kGaw) and liquid film mass transfer coefficients (kLaw) for packing materials used in biofilters and biotrickling filters for air pollution control were determined experimentally. Lava rock, polyurethane foam cube (PUF), Pall ring, porous ceramic beads, porous ceramic Raschig rings and compost–woodchips mixtures were investigated. The experiments were...

2008
Paul D. Spudis Jeffrey Taylor

The lunar regolith records both the geological history and processes of the Moon and also that of particles from the Sun and galaxy. Such a record extends back to the age of the rock unit upon which the regolith is developed, but complex impact gardening and processing makes this record difficult to recover and interpret. Ancient rock units, such as lava flows, begin to have regolith developed ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2016
Amber Dance

From October 26 to November 12, 2010, Indonesia’s Mount Merapi blew its top in the volcano’s largest series of eruptions in decades. It spewed ash and lava rock thousands of meters into the air. Hundreds of thousands of villagers fled, abandoning their homes along with more than 1,000 ha of farm fields to the scalding ash, rock, and mud spilling down the slope (1, 2). The following July, space ...

2004
Jeffrey Taylor

Jupiter's moon Io is the most volcanically active body in the Solar System. Observations by instruments on the Galileo spacecraft and on telescopes atop Maunakea in Hawai'i indicate that lava flows on Io are surprisingly hot, over 1200 oC and possibly as much as 1300 oC; a few areas might have lava flows as hot as 1500 oC. Such high temperatures imply that the lava flows are composed of rock th...

Journal: :Plant biology 2004
M E Puente Y Bashan C Y Li V K Lebsky

Dense layers of bacteria and fungi in the rhizoplane of three species of cactus (Pachycereus pringlei, Stenocereus thurberi, Opuntia cholla) and a wild fig tree (Ficus palmeri) growing in rocks devoid of soil were revealed by bright-field and fluorescence microscopy and field emission scanning electron microscopy. These desert plants are responsible for rock weathering in an ancient lava flow a...

2002
T. Vanorio M. Prasad D. Patella A. Nur

This paper summarizes results of a study of porosity, permeability, microstructure and acoustic properties of volcanic and pyroclastic rocks fromCampi Flegrei (CF) andMt. Etna (ET), Italy. We have measured the hydraulic, transport and acoustics properties of 28 room-dry samples at ambient conditions, 25 room-dry samples under confining pressure (up to 60 MPa) and 5 brine saturated samples under...

Journal: :Science 2004
J A Grant R Arvidson J F Bell N A Cabrol M H Carr P Christensen L Crumpler D J Des Marais B L Ehlmann J Farmer M Golombek F D Grant R Greeley K Herkenhoff R Li H Y McSween D W Ming J Moersch J W Rice S Ruff L Richter S Squyres R Sullivan C Weitz

The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes. Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth. Some rocks have been textured and/or partially buried by windblown sediments l...

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