4: Plate Tectonics

• 4.0: Introduction to Plate Tectonics
The surface of the Earth is divided into rigid blocks, called tectonic plates that are bounded by narrow regions of high deformation called plate boundaries. Tectonic plates are comprised of both crust (oceanic or continental) and mantle rock and owe their rigidity to the stiffness of mantle rock at low temperatures. Tectonic plates come in various shapes and sizes and are continuously changing shape.
• 4.1: The Forces Driving Plate Motions
The motion of tectonic plates is driven by one simple principle, convection. Convection is the idea that dense, cold things sink, and buoyant, warm things rise.
• 4.2: Magnetic Anomalies on the Seafloor
While there are multiple ways to determine the age of rocks, such as radiometric dating and fossil dating, for large-scale plate tectonic studies the most useful way of determining the age of plates is using magnetic stratigraphy.
• 4.3 Magnetic Anomaly Jupyter Notebook
An interactive example about the distribution and patterns of seafloor magnetic anomalies, using real data. See how the spreading rate and dead ridges affect the pattern of seafloor stripes.
• 4.4: Plates Moving on a Plane
• 4.5: Relative Velocity and Reference Frames
• 4.6: Relative Plate Velocity Jupyter Notebook
An interactive example about relative plate velocities. Create a basic plate tectonic model and use it to identify plate boundary types and calculate relative plate velocities.
• 4.7: Plate Motions on a Sphere
Now that we understand plate motion on a plane, let's move to a sphere. In order to move to a sphere, we need to master five ideas/concepts: (1) Spherical Coordinates, (2) Euler Pole, (3) Angular Distance, (4) Relative motion from Euler Poles, and (5) Velocity and direction of motion at a point.
• 4.8: Summary