EESA06H3 Lecture Notes - Lecture 3: Continental Crust, Asthenosphere, Fault Scarp
Document Summary
Lec 03: january 18, 2016 - probing the earth"s deep interior. Drilling only goes 13 km deep because rocks gets hot. Generate seismic energy that we can use to learn about the earth"s interior. Can be as deep as 700 km underground. In ontario, they are about 15 to 20 km underground. To break something, it has to be brittle, but the rocks down 700 km are too soft so they don"t break. 1891 nobi earthquake in japan, they learnt earthquakes were produced by force: earthquake caused a fault scarp moved 6 metres. Surface waves love and rayleigh these ones do the damage. Primary: fastest about 7 km per second, motion of these waves is extension and contraction, a little slower about 5 km per second. Wave pass can be direct (origin on focus to seismic station) or can be refracted. If you have a station close to the focus, the time lag is shorter.
