A lateral eruptions or lateral blast is a volcanic eruption which is directed laterally from a volcano rather than upwards from the summit. Lateral eruptions are caused by the outward expansion of flanks due to rising magma. Breaking occurs at the flanks of volcanoes making it easier for magma to flow outward. As magma is pushed upward towards the volcano it diverges towards the flanks before it has a chance to erupt from the crater. When the expanding flank finally gives it releases a flow of magma. More explosive lateral eruptions are referred to as lateral blasts. Some of the most notable examples of a lateral eruption include Mount St. Helens, Mount Pelée, and Mount Etna.