Calderas are collapse structures related to the emptying of magmatic reservoirs, often associated with large eruptions from long-lived magmatic systems. Understanding how magma is transferred from a magma reservoir to the surface before eruptions is a major challenge. Here we exploit the historical, archaeological and geological record of Campi Flegrei caldera to estimate the surface deformatio...

Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness r...

Introduction: Crystallization of the lunar magma ocean occurred ~4.4 Ga [e.g., 1-4] and produced three principal magma source regions [5-6]. These sources are characterized chemically by low titanium (Ti), high Ti, and high potassium, rare earth element, and phosphorous (KREEP) abundances. The KREEP component was produced after nearly complete solidification of the magma ocean and is highly enr...

Dome growth at the Soufriere Hills volcano (1996 to 1998) was frequently accompanied by repetitive cycles of earthquakes, ground deformation, degassing, and explosive eruptions. The cycles reflected unsteady conduit flow of volatile-charged magma resulting from gas exsolution, rheological stiffening, and pressurization. The cycles, over hours to days, initiated when degassed stiff magma retarde...

The Gandy gold-base metal deposit is located in Tertiary Torud-Chahshirin volcano-plutonic range, north of Central Iran. Various styles of gold mineralization occur throughout the range. Mineralization at Gandy occurs in close spatial relation with rhyolitic domes in a caldera setting in a series of narrow brecciated veins. Two mineralogically and spatially different argillic alterations have a...

Very large volume (>1000 km of magma) crystal-rich dacitic ignimbrites that lack pronounced evidence of fractional crystallization or vertical zonation erupt in some continental magmatic arcs (e.g. the Lund Tuff of the Great Basin and the Fish Canyon Tuff of Colorado in western USA). Apparently, their magma chambers were only modestly heterogeneous and not systematically zoned from top to botto...

exact solution for steady two-dimensional flow of an incompressible magma is obtained. themagmatic flow is studied by considering the magma as a second grade fluid. the governing partialdifferential equations are transformed to ordinary differential equations by symmetry transformations. resultsare discussed through graphs to understand the rheology of the flowing magma

[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...

[1] Thirty interferometric synthetic aperture radar (InSAR) images, spanning various intervals during 1992–2000, document coeruptive and posteruptive deformation of the 1992–1993 eruption on Seguam Island, Alaska. A procedure that combines standard damped least squares inverse methods and collective surfaces, identifies three dominant amorphous clusters of deformation point sources. Predictions...

Understanding the mechanisms that control the start-up of volcanic unrest is crucial to improve the forecasting of eruptions at active volcanoes. Among the most active volcanoes in the world are the so-called persistently degassing ones (e.g., Etna, Italy; Merapi, Indonesia), which emit massive amounts of gas during quiescence (several kilotonnes per day) and erupt every few months or years. Th...