When two tectonic plates collide at a convergent boundary, the cooler plate is subducted. Flux melting occurs as the subducting plate is heated. The molten material (magma) rises due to the increase in the heat creating the volcano's vent. Once the magma reaches a holding chamber beneath the earth's crust, it lies dormant until enough magma, water, and/or gas is introduced into the chamber. The magmatic and gaseous pressures exceeding the chamber's holding capacity can release through small fissures in the Earth's surface or erupt violently. Volcanic arcs are created hundreds of kilometers from the plate collision site, on the overlying plate.