EESA06H3 Lecture 5: Lecture 5 In Class Notes
Document Summary
Rheology: the ability to flow, how easy it is for something to flow. Pyroclastic (broken by fire): these are rocks that are shattered by the power of the eruption and blown into the sky, either as volcanic bombs or as ash. The deepest earthquakes that occur are about 700km down, this shows that the descending slabs of oceanic crust are preserved until they reach that depth. Deep water trenches: is where the ocean floor is just starting to go down into the subduction zone. New zealand is the tip of a much larger landmass called zealandia . The small triangles on the continental boundary lines on the maps indicate the direction of subduction. Obduction : when continental crusts are pushing against each other like the himalayans. When two oceanic crusts collide, the older one subducts underneath as the new crust is warmer, thus lighter.