Telemark said:
the one who uses Mars bars to explain tectonics?
T
"New Zealand has many earthquakes because it straddles the boundary between two of the earth's great tectonic plates - the Pacific Plate in the east and the Australian Plate in the west. These two plates are conviging obliquely at about 40 mm/year in Fiordland and at about 50 mm/year at East Cape. While these rates are rather small, comparable to the rate your fingernails grow, the plates are about 100km thick, so a large volume of rock is deformed as the plates collide. This rock can deform in two ways: either through straining elastically and eventually fracturing, which produces earthquakes, or by flowing.
This situation is analogus to pushing the two ends of a Mars bar together. While the brittle chocolate layer deforms by fracturing in tiny earthquakes, the caramel interior deforms by flowing."
Next week he will explain the "Mohorovicic Discontinuity" using a Jaffa cake.