نتایج جستجو برای: source of magma

تعداد نتایج: 21186166  

2016
Leif Karlstrom Eric M. Dunham

Oscillations of magma in volcanic conduits are thought to be the source of certain seismic and infrasonic signals observed near active volcanoes. However, the multiphase and stratified nature of magma within the conduit complicates the calculation of resonant modes that is required to interpret observations. Here we present a linearized mathematical framework to describe small-amplitude oscilla...

احمدی خلجی, احمد, طهماسبی, زهرا ,

The studied area located in south and south western Arak town and are the part of Sanadaj-Sirjan Zone. The plutonic rocks in Astaneh and Boroujerd areas are quartz diorite, granodiorite and monzogranite. In addition to plutonic rocks, subvolcanic rocks of rhyodacite composition are present in Astaneh area. In general, in these areass mineral assemblage is the same in different units. The common...

Journal: :فیزیک زمین و فضا 0
مینا علی صوفی دانشجوی کارشناسی ارشد، دانشکده مهندسی نقشه برداری، دانشگاه خواجه نصیرالدین طوسی، تهران، ایران بهزاد وثوقی دانشیار، گروه مهندسی ژئودزی، دانشکده مهندسی نقشه برداری، دانشگاه صنعتی خواجه نصیرالدین طوسی، تهران، ایران

volcanoes and their eruption indicate dynamic process of the inside of ground, which are often located along the boundaries of tectonic plates. study of movements and surface deformation of the volcano is essential because surface deformation reflects changes in the subsurface. in the studies of crustal deformation, volcanic models provide valuable insights of the features of volcanoes and thei...

Journal: :Science 1999
Wylie Voight Whitehead

Volatiles dissolved in silicic magma at depth exsolve as the magma nears the surface and cause an increase in viscosity of the magma. A model of a volcanic conduit within an elastic medium and a viscosity dependent on the volatile content of the magma produces oscillatory magma flow for a critical range of steady input flow rates. Oscillatory flow is recognized as a fundamental mode of behavior...

2016
Harri Geiger Abigail K. Barker Valentin R. Troll

Mt. Cameroon is one of the most active volcanoes in Africa and poses a possible threat to about half a million people in the area, yet knowledge of the volcano's underlying magma supply system is sparse. To characterize Mt. Cameroon's magma plumbing system, we employed mineral-melt equilibrium thermobarometry on the products of the volcano's two most recent eruptions of 1999 and 2000. Our resul...

By left magma-$e$-magma, I mean a set containingthe fixed element $e$, and equipped by two binary operations "$cdot$", $odot$ with the property $eodot (xcdot y)=eodot(xodot y)$, namelyleft $e$-join law. So, $(X,cdot,e,odot)$ is a left magma-$e$-magmaif and only if $(X,cdot)$, $(X,odot)$ are magmas (groupoids), $ein X$ and the left $e$-join law holds.Right (and two-sided) magma-$e$-magmas are de...

2008
A. P. Santo

Oxygen isotope data are reported for clinopyroxene phenocrysts from volcanic rock samples from Filicudi island, Italy, with the aim of investigating mechanisms of magma evolution and mantle source characteristics in a continental arc volcano. Filicudi rocks range from calc-alkaline basalt to high-K andesite and dacite. Mafic rocks have MgO 6-7 wt%, Mg# 60, Ni < 50 ppm and Cr < 200 ppm, suggesti...

2007
Patrick J. Shamberger Michael O. Garcia

Geochemical modeling of magma mixing allows for evaluation of volumes of magma storage reservoirs and magma plumbing configurations. A new analytical expression is derived for a simple two-component box-mixing model describing the proportions of mixing components in erupted lavas as a function of time. Four versions of this model are applied to a mixing trend spanning episodes 3–31 of Kilauea V...

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