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When the magma approaches the surface of the Earth, the rapid off-loading of overlying material causes the trapped gases to decompress rapidly, thus triggering explosive destruction of the magma and spreading volcanic ash over wide areas.
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When and magma
When a rock crystallizes from melt ( magma and / or lava ), it is an igneous rock.
When magma cools it begins to form solid mineral phases.
When the magma nears the top surface, it pools in a magma chamber under or within the volcano.
When fragmentation occurs, violently expanding bubbles tear the magma apart into fragments which are ejected into the atmosphere where they solidify into ash particles.
When magma rises above a certain depth the dissolved minerals start to crystallize at particular pressures and temperatures.
When this basaltic material mixes with the evolved rhyolitic magma, the composition is returned to andesite, its intermediate phase.
When high-silica ( dacitic ) magma rises to the Earth's surface, the trapped gases and vapors can erupt explosively to produce ash clouds and pyroclastic flows that consist of superheated gas, ash and volcanic fragments.
When a plume head encounters the base of the lithosphere, it is expected to flatten out against this barrier and to undergo widespread decompression melting to form large volumes of basalt magma.
When the magma cannot find a path upwards it pools into a magma chamber.
When this happens gravity pulls the weighty lithosphere away from the mid-ocean ridge, down the sloping asthenosphere, which, in turn, allows new molten magma to well up.
When the magma cooled to form rock, it aligned itself with the current position of the north magnetic pole of the Earth ( which has reversed many times in its past ) at the time of its cooling.
When the magma is extruded as lava and cools the lava solidifies around the gas bubbles, preserving them as vesicles.
When forming, a plug can cause an extreme build-up of pressure if volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption.
When upward flowing ( dyke-forming ) magma encounters horizontal boundaries or weakness's, such as between layers in a sedimentary deposit, the magma can flow horizontally creating a sill.
When the Enterprise crashes in the Underworld, Cid takes it back to the surface to outfit it with Mythril, which enables it to fly over magma.
When rocks are pushed deep under the Earth's surface, they may melt into magma.
Sonia Esperanca, program director in the National Science Foundation commented on the danger of subglacial volcanos: " When an ice-covered volcano erupts, the interplay among molten magma, ice and meltwater can have catastrophic results.
When and approaches
When debates polarise between techniques, the methods are often referred to by a colour code, based on the colours of the bindings of the two volumes from the first Oxford Conference, where the approaches were first distinguished.
When tested, it approaches standards for potable water.
* When some of the strings contain numerals ( or other non-letter characters ), various approaches are possible.
When she does not return, Ninshubur approaches Anu only to be told that he understands that his daughter is strong and can take care of herself.
When analyzing a stock, futures contract, or currency using fundamental analysis there are two basic approaches one can use ; bottom up analysis and top down analysis.
When a female approaches, the male guides or drives her into his burrow and prevents her from leaving until she oviposits.
When criminals see the abandoned vehicles, trash, and deplorable property, they assume that authorities do not care and do not take active approaches to correct problems in these areas.
When a train approaches the Gare d ' Ascq railyway station the railway line is blown apart.
When the Macedonian army approaches Thracian Chersonese ( the Gallipoli Peninsula ), an Athenian general named Diopeithes ravages this district of Thrace, thus inciting Philip's rage for operating too near one of his towns in the Chersonese.
When y is viewed as a function of x, the cycloid is differentiable everywhere except at the cusps where it hits the x-axis, with the derivative tending toward or as one approaches a cusp.
When we consider 100 billion monkeys, the probability falls to 0. 17 %, and as the number of monkeys n increases, the value of X < sub > n </ sub > – the probability of the monkeys failing to reproduce the given text – approaches zero arbitrarily closely.
When the angle approaches 0 ° or 180 °, then the disulfide is a significantly better oxidant.
When the concept of assured destruction is applied in the doctrine of law, it is often criticized by proponents of the restorative justice and transformative justice approaches, who point out that assured destruction doctrines are rarely implemented with rigor or integrity of due process.
When Caesar approaches Cicero ’ s camp, the Belgae abandon their siege of Cicero's camp and head toward Caesar ’ s troops.
When a warm front approaches, cirrostratus clouds deepen and lower into altostratus, and rain usually begins 12 to 24 hours later.
When Altaira declares her love for Adams in defiance of her father's wishes, the monster approaches the house.
When a stepped leader approaches the ground, the presence of opposite charges on the ground enhances the strength of the electric field.
When the above concepts are considered simultaneously, fifteen evaluation approaches can be identified in terms of epistemology, major perspective ( from House ), and orientation.
When winter approaches, in drought conditions, or at times of other harsh environmental conditions, production of new female generations ceases and parthenogenic males are produced.
When beginning to create E-Learning content, the pedagogical approaches need to be evaluated.
When Telegonus arrives on Ithaca, he approaches Odysseus ' house, but the guards do not admit him to see his father ; a commotion arises, and Odysseus, thinking it is Telemachus, rushes out and attacks.
When Patrick approaches it he raises his crozier, the central figure falls face-down, with the imprint of the crozier left in it, and the surrounding figures sink into the earth.
When these two elements are combined then there is the best of both worlds ; relevant approaches and tools for the way the world works today AND a system of routine that promotes better and quicker decisions and actions at the planning and execution level.
When his name is called, each new guard approaches the Swiss Guard's flag, grasping the banner in his left hand.
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