نتایج جستجو برای: volcanic eruptions
تعداد نتایج: 18049 فیلتر نتایج به سال:
Many volcanoes exhibit temporal changes in their degassing process, from rapid gas puffing to lava fountaining and long-lasting quiescent passive degassing periods. This range of behaviors has been explained in terms of changes in gas flux and/or magma input rate. We report here a simple laboratory experiment which shows that the nonNewtonian rheology of magma can be responsible, alone, for suc...
Studies have shown that the variability of precipitation depends primarily of climatic factors, wind, temperature, and atmospheric pressure, however in the past twenty years the continuous eruptive process of volcano Tungurahua has been a natural factor that contributed to the variability of precipitations in short term and to the extension of the watershed of Ambato River. To incorporate the e...
Among the paintings and engravings found in the Chauvet-Pont d'Arc cave (Ardèche, France), several peculiar spray-shape signs have been previously described in the Megaloceros Gallery. Here we document the occurrence of strombolian volcanic activity located 35 km northwest of the cave, and visible from the hills above the cave entrance. The volcanic eruptions were dated, using 40Ar/39Ar, betwee...
Viscosity of hydrous silicate melts is essential in modeling the dynamics of magma transport and volcanic eruptions. Numerous experimental measurements of viscosity, as well as viscosity models, have been published. For general melt compositions, the classic models of either Bottinga and Weill (1972) or Shaw (1972) are still used, not because they are reliable, but because of the extreme diffic...
Introduction: Highland paterae [1-2] represent one of the most distinctive landforms on the Martian surface. The term patera (paterae if plural) was originally applied to any large, flat-floored depression with irregular margins identified in Mariner 9 and Viking imagery and included volcanoes as well as impact craters [3]. However, highland paterae represent an individual class of patera that ...
Glossary andesite magma or volcanic rock is characterised by intermediate SiO2 concentration. Andesite magmas have rheological properties that are intermediate between basalt and rhyolite magmas. Silica content in andesites ranges from approximately 52 to 66 weight percent. Common minerals in andesite include plagioclase, amphibole and pyroxene. Andesite is typically erupted at temperatures bet...
Paper presents a simplistic approach towards the detection and dynamics analysis of volcanic eruptions represented as unevenly spaced spatio-temporal time series of satellite retrieved hot spots. The paper discusses isolation and interpolation of hot spots data produced by Nightfire algorithm for the purposes of short-term volcanic activity ARIMA based forecasting. The case study for Chirpoi Sn...
In 1984, the volcano Mauna Loa erupted in Hawaii, sending ribbons of lava winding down its slopes. Geologist and former pilot David Pieri of the California Institute of Technology’s Jet Propulsion Laboratory wanted to get measurements and observation of every part of the lava flow to predict its ultimate route and length. However, he only had one way to see the lava: with a helicopter. “I remem...
The mechanical conditions for a volcanic eruption to occur are conceptually simple: a magma-driven fracture (normally a dyke) must be able to propagate from the source to the surface. The mechanics of small to moderate (eruptive volumes less than 10 km 3 ) is reasonably well understood, whereas that of large eruptions (eruptive volumes of 10-1000 km 3 ) is poorly understood. Here I propose that...
[1] Accelerations in seismicity are important precursors to eruptions at volcanoes reawakening after extended repose intervals. These have previously been quantified for subduction-zone settings in terms of the linkage of crustal faults by shearing. Introducing a damage-mechanics criterion for the weakening of rock between major fractures, the model is here modified for failure in tension, cons...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید