نتایج جستجو برای: multiple magma source
تعداد نتایج: 1150256 فیلتر نتایج به سال:
Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean ...
Introduction: We have obtained multiple contemporaneous ground and space-based visible and hyperspectral infrared observations of a persistent active lava lake, one of the rarest volcanonological phenomenon. This unique dataset advances our understanding of remote sensing of lava lake activity on Earth and Io. The Mt. Erebus lava lake: Active lava lakes are the top of an open magma system and p...
Introduction: Lunar high-titanium (HiTi) ultra-mafic glasses provide us with evidence of the mantle processes that led to the melting of the lunar magma ocean cumulates nearly one billion years after the magma ocean solidified. Constraints on the depth, temperature and melting processes that formed the HiTi glasses are crucial for understanding the melting history of LMO products. The Apollo 17...
We utilize a theoretical analysis of the generation, ascent, intrusion and eruption of basaltic magma on the Moon to develop new insights into magma source depths, supply processes, transport and emplacement mechanisms via dike intrusions, and effusive and explosive eruptions. We make predictions about the intrusion and eruption processes and compare these with the range of observed styles of m...
The relatively low rates of magma production in island arcs and continental extensional settings require that the volume of silicic magma involved in large catastrophic caldera-forming (CCF) eruptions must accumulate over periods of 105 to 106 years. We address the question of why buoyant and otherwise eruptible highsilica magma should accumulate for long times in shallow chambers rather than e...
We report the oxygen isotope composition of olivine and orthopyroxene phenocrysts in lavas from the main magma types at Mt Shasta and Medicine Lake Volcanoes: primitive high-alumina olivine tholeiite (HAOT), basaltic andesites (BA), primitive magnesian andesites (PMA), and dacites. The most primitive HAOT (MgO [ 9 wt%) from Mt. Shasta has olivine dO (dOOl) values of 5.9–6.1%, which are about 1%...
[1] Multiple mechanisms have been suggested to explain seaward motion of the south flank of Kīlauea Volcano, Hawai‘i. The consistency of flank motion during both waxing and waning magmatic activity at Kīlauea suggests that a continuously acting force, like gravity body force, plays a substantial role. Using finite element models, we test whether gravity is the principal driver of long-term moti...
A variety of methods have been employed to decipher magmatic systems, including geophysical, petrological, textural and geochemical approaches, and these elucidate a large variety of characteristics of different plumbing systems and magmatic differentiation processes. A common theme to the papers presented in this book is the observation of transport of small volume magma batches with a relativ...
Geological and physical observations and constraints are applied to the development of a model of the ascent and emplacement of basaltic magma on the earth and moon. Mathematical models of the nature and motion of gas/liquid mixtures are developed and show that gas exsolution from terrestrial and lunar magmas commonly only occurs at shallow depths (less than 2 km); thus the ascent of bubble-fre...
Kinetic and fluid dynamic constraints on deepseated magma migration rates suggest ascent velocities in the range 10 to 30 m/s, 10 -1 to 10m/s and 10 -2 to 5m/s for kimberlitic, garnet peridotite-bearing and spinel peridotite-bearing alkalic magmas. These rates virtually demand translithospheric magma transport by a fracture as opposed to diapiric mechanism. The hypothesis that volatile exsoluti...
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