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).
On the subducting side of the island arc is a deep and narrow oceanic trench, which is the trace at the Earthâs surface of the boundary between the downgoing and overriding plates.here is some debate about the usefulness of the distinction between island arcs and volcanic arcs. The term volcanic island arc is merely a sub-classification of island arc.. Island arcs are tectonically created arc-shaped mountain belts that are partly below sea level.