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 ARC AND TRENCH. MAP VIEW. Island arcs and trenches are major structural features, together with oceanic ridges, of ocean basins. As the name implies, island arcs are typically a curving chain of volcanic islands occurring around the margin of ocean basins.The curvature and the volcanic nature are important characteristic features.The arc is convex toward the ocean and concave toward the continent with a deep trench running parallel to the arc along the convex (ocean) side. Arcs and trenches are hundreds of miles long.ROSS-SECTION. Not all volcanic chains are island arcs, however, and not all island arcs are âislandsâ. For example, the Hawaiian Islands are an example of a linear chain of volcanoes in the middle of the Pacific Ocean that is not an island arc.