Subduction: getting rid of oceanic crust, rheology: the ability to flow, how easy is it for something to flow. Eesa06 lecture 5: when oceans close: volcanic eruptions- how easy does magma flow, magma more vicious, they throw up , very dangerous, pyroclastic: broken by fire. rocks shattered by eruption and blown up either as volcanic bombs or as ash. Cooke- highest point in southern alps www. notesolution. com: white island, volcano poking up from sea floor- very young volcano, still growing, lateral blast- rim of volcano blasts off to the side. result of sector collapse: green lake of sulphuric acid. Indonesia: volcanic arch, merapi volcano- most dangerous, very steep slopes- can collapse, creating continental crust, by collision of 2 plates of oceanic crust, you generate islands, volcanoes which generates continental crust, protocontients. Eruptions: pyroclastic flows (#1) the white stuff most dangerous, blown out from sides of volcanoes.