Earth geological and climatic history : Khan Academy on a Stick

Khan Academy on a Stick

Cosmology and astronomy

Plate tectonics: Difference between crust and lithosphere
Plate Tectonics Introduction and Difference between crust and lithosphere
Structure of the earth
Structure of the Earth - crust, mantle, core
Plate tectonics: Evidence of plate movement
Plate Tectonics -- Evidence of plate movement
Plate tectonics: Geological features of divergent plate boundaries
Plate Tectonics -- Geological Features of Divergent Plate Boundaries
Plate tectonics: Geological features of convergent plate boundaries
Geological features of Convergent Plate Boundaries
Plates moving due to convection in mantle
Plates Moving Due to Convection in Mantle
Hawaiian islands formation
Hawaiian Islands formed by stationary hot spot under Pacific plate
Pangaea
Pangaea - the idea of Pangaea and some of the evidence behind it
Compositional and mechanical layers of the earth
Crust, mantle, core, lithosphere, asthenosphere, mesosphere, outer core, inner core
How we know about the earth's core
S-wave shadow and P-wave detection patterns give us information about the core

Plate tectonics

Is it a coincidence that Africa and South America could fit like puzzle pieces? Why do earthquakes happen where they do? What about volcanoes and mountains? Are all of these ideas linked? Yes, they are. This tutorial on plate-tectonics explains how and why the continents have shifted over time. In the process, we also explore the structure of the Earth, all the way down to the core.

Seismic waves
S-waves and P-waves
Why S-waves only travel in solids
Why S-Waves Only Travel in Solids
Refraction of seismic waves
Refraction of Seismic Waves
The mohorovicic seismic discontinuity
The Mohorovicic Seismic Discontinuity- boundary between crust and mantle (or Moho)

Seismic waves and how we know earth's structure

How do we know what the Earth is made up of? Has someone dug to the core? No, but we humans have been able to see how earthquake (seismic) waves have been bent and reflected through our planet to get a reasonable idea of what is down there.

Seasons aren't dictated by closeness to sun
Why our closeness to the sun does not dictate the seasons
How earth's tilt causes seasons
How being Earth's tilt causes seasons
Are southern hemisphere seasons more severe?
Are Southern Hemisphere seasons more severe because of the eccentricity in Earth's orbit?
Milankovitch cycles precession and obliquity
How changes in Earth's rotation can effect Earth's seasons and climate
Precession causing perihelion to happen later
Clarifying the effect of axial precession on the calendar and the date of perihelion and aphelion
What causes precession and other orbital changes
What causes precession and other orbital changes
Apsidal precession (perihelion precession) and Milankovitch cycles
Apsidal Precession (Perihelion Precession)

Earth's rotation and tilt

What causes the seasons? Even more, can Earth's climate change over long period just to "wobbles" in its orbit? This tutorial explains it all. You'll know more about orbits (and precession and Milankovitch cycles) than you ever thought possible. Have fun!