Related words. 1  poke noun. 2  poke around phrasal verb. 3  poke fun (at) phrase.  a pig in a poke 1  phrase. poke a hole in something phrase.  poke/shove/stick your nose into something 1  phrase. poke about phrasal verb at poke around.  poke fun at phrase at make fun of.
Because the subduction zone (which is also the plate boundary) is generally an arc-shape, geologists named those volcanoes volcanic arcs. A volcanic arc built on continental crust is called a continental arc; when built on oceanic crust the volcanoes form an island arc. Volcanic arcs are made of an arc-shaped chain of volcanoes. 2  The position of which could be continental or mid-ocean. 3  While an island arc must be offshore and does not necessarily be volcanic (e.g. Hellenic arc).
Island arcs are volcanic islands that form parallel to ocean trenches in subduction zones. The Pacific Ring of Fire is home to many of these groups of islands. Volcanoes that form above hot spots like the Hawaiian islands are not volcanic arcs.Volcanic island eruption, USGS. Two oceanic plates converge. Islands form an arc when two oceanic plates converge creating a row of islands above the overriding plate.The older plate, which is heavier and denser, is forced beneath the lighter plate.he melting plate feeds magma chambers that supply volcanic islands that form an arc when the molten rock erupts onto the ocean floor of the overriding plate. Mariana Islands. Deep ocean trenches form between the converging plates.