ASTR 1000 Lecture Notes - Lecture 16: Plate Tectonics, Coriolis Force, Diapir
19 Jun 2018
School
Department
Course
Professor
Class 16
Venus
-Shield Volcano
-Coronae - pancake look, pushing the land up somewhat
-Venus is completely covered in clouds so you can’t see the surface
-When it passes us, we only see the unlit side. How to get around this problem? Magellan
spacecraft - Fired pulses of radio waves at planet, Measure time of pluse – measures distance
from centre
-Venus does not have plate tectonics
-Venus does have impact craters. Reason it doesn't’t have many: Thick atmosphere. 100times
as much gas
-Pressure and heat in Venus is very high. Hot enough to melt led.
-Why venus has no plate tectonics – Earthquakes and volcanic activity on earth appear on plate
boarders
Earth’s Plate Tectonics - only planet that appears to have plate tectonics. Driven by the process
of convection, rifting and subduction. Total amount of surface area stays the same.
-Alfred Wegner - plate tectonics, Pangea
-Iceland is sitting on large magma flow. It is still being pulled apart but it is not as obvious
-Magma Plume - A mantle plume is posited to exist where hot rock nucleates at the core-
mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust.
Earth’s Atmosphere
Atmosphere is divided into different levels:
-Troposphere - the lowest region of the atmosphere, extending from the earth's surface to a
height of about 3.7–6.2 miles (6–10 km), which is the lower boundary of the stratosphere.
-Stratosphere - the layer of the earth's atmosphere above the troposphere, extending to about
32 miles (50 km) above the earth's surface (the lower boundary of the mesosphere).
-Mesosphere - the region of the earth's atmosphere above the stratosphere and below the
thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Coronae - pancake look, pushing the land up somewhat. Venus is completely covered in clouds so you can"t see the surface. When it passes us, we only see the unlit side. Magellan spacecraft - fired pulses of radio waves at planet, measure time of pluse measures distance from centre. Pressure and heat in venus is very high. Why venus has no plate tectonics earthquakes and volcanic activity on earth appear on plate boarders. Earth"s plate tectonics - only planet that appears to have plate tectonics. Driven by the process of convection, rifting and subduction. Total amount of surface area stays the same. Iceland is sitting on large magma flow. It is still being pulled apart but it is not as obvious. Magma plume - a mantle plume is posited to exist where hot rock nucleates at the core- mantle boundary and rises through the earth"s mantle becoming a diapir in the earth"s crust.
