query: subclass_of phreatomagmatic eruption
supports: Ancient Greek includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD. It is often roughly divided into the Archaic period (9th to 6th centuries BC), Classical period (5th and 4th centuries BC), and Hellenistic period (3rd century BC to the 6th century AD). It is antedated in the second millennium BC by Mycenaean Greek. A magma chamber is a large underground pool of liquid rock found beneath the surface of the Earth. The molten rock in such a chamber is under great pressure, and given enough time, that pressure can gradually fracture the rock around it creating outlets for the magma. If it finds a way to the surface, then the result will be a volcanic eruption; consequently many volcanoes are situated over magma chambers. 
  Magma chambers are hard to detect, and most of the known ones are therefore close to the surface of the Earth, commonly between 1 km and 10 km under the surface. In geological terms, this is extremely close to the surface, although in human terms, it is considerably deep underground. Pyroclastic rocks or pyroclastics (derived from the , meaning fire; and , meaning broken) are clastic rocks composed solely or primarily of volcanic materials. Where the volcanic material has been transported and reworked through mechanical action, such as by wind or water, these rocks are termed volcaniclastic. Commonly associated with unsieved volcanic activitysuch as Plinian or krakatoan eruption styles, or phreatomagmatic eruptionspyroclastic deposits are commonly formed from airborne ash, lapilli and bombs or blocks ejected from the volcano itself, mixed in with shattered country rock. Lava is the molten rock expelled by a volcano during an eruption. The resulting rock after solidification and cooling is also called "lava". The molten rock is formed in the interior of some planets, including Earth, and some of their satellites. The source of the heat that melts the rock within the earth is geothermal energy. When first erupted from a volcanic vent, lava is a liquid usually at temperatures from .  Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism. A natural satellite or moon is, in the most common usage, an astronomical body that orbits a planet or minor planet (or sometimes another Small Solar System Body). A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Phreatomagmatic eruptions are defined as juvenile forming eruptions as a result of interaction between water and magma . They are different from magmatic and phreatic eruptions . The products of phreatomagmatic eruptions contain juvenile clasts , unlike phreatic eruptions , and are the result of interaction between magma and water , unlike magmatic eruptions . It is very common for a large explosive eruption to have magmatic and phreatomagmatic components . Magma (from Ancient Greek  ("mágma") meaning "thick unguent") is a mixture of molten or semi-molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals, dissolved gas and sometimes gas bubbles. Magma often collects in magma chambers that may feed a volcano or solidify underground to form an intrusion. Magma is capable of intruding into adjacent rocks (forming igneous dikes and sills), extrusion onto the surface as lava, and explosive ejection as tephra to form pyroclastic rock. Earth, otherwise known as the world, is the third planet from the Sun and the only object in the Universe known to harbor life. It is the densest planet in the Solar System and the largest of the four terrestrial planets.
candidates: action ancient greek composition fire forming gas greek heat lava life magma mass material minor planet mixture natural object planet pressure rock satellite surface tephra third volcanic eruption volcano water wind world
answer: volcanic eruption