About Plate Tectonics
Presenting the basics of plate tectonics.
Sizes of Lithospheric Plates
Thirty plates and microplates are listed in order of size.
How Many Plates Are There?
Teachers want one right answer to this question, but there isn't one.
Geo-Quiz 16: Plate Tectonics
See if you can answer these 12 questions on plate tectonics. Caution: this has been known to stump professors.
The Earth's Crust
This part of the planet is exceptionally important for plate tectonics.
About the Lithosphere
What you need to know about the lithosphere.
Five Myths of Plate Tectonics
Even geologists are prone to these misbeliefs: plate rigidity, ridge compression, ridge fixity, forcible subduction, and mantle convection.
Measuring Plate Motion
The five ways we track the motion of the lithospheric plates.
Convergent Zones in a Nutshell
What happens when lithospheric plates come together.
Divergent Zones in a Nutshell
Where the lithospheric plates move apart from each other.
Transforms in a Nutshell
What happens when lithospheric plates move past each other.
Subduction in a Nutshell
What happens when a lithospheric plate must go down.
A short explanation of triple junctions.
Microplates Defined and Explained
A short explanation of microplates.
Supercontinents of the Past and Future
Several times in Earth history, plate motion has pushed all the continents into one mass.
Arc Volcanism in a Nutshell
How subducting plates create most of the world's volcanoes.
Not a rock type, ophiolite is a whole assemblage of rocks representing oceanic crust.
Ophiolitic Rocks Photo Gallery
part of a typical ophiolite.
The Death of Plates
What happens to a lithospheric plate after it has been subducted.
Why Not Dispose of Waste in Ocean Trenches?
Waste disposal by subduction won't work.
A Hotspot Alternative
A new theory about hotspots is based directly on plate tectonics.
Lost City of Serpentinization
Lost City, on the Atlantic seafloor, is the product of a major geochemical process.
News From the Edge: The Calcite Stress Gauge
Microscopic grains show the strain on a whole continent.
True Polar Wander
A crazy idea resurfaces to knock Earth--and geology--upside the head.
Presenting the basics of paleomagnetism: how it arises, how it's measured, what it means.
Paleomagnetic records are ambiguous with respect to hemisphere, but there are a couple of ways to get past that difficulty.
The Expanding Earth Animation
The familiar expanding-Earth animation is an optical illusion based on a conceptual illusion.
The rise and fruition of a new kind of volcano.
"This Dynamic Earth"
The U.S. Geological Survey's 1996 pamphlet on plate tectonics is widely cited, but it is no longer accurate in several respects. For the history of the theory, though, it's the best source on the Web.
The MARGINS Initiative Home Page
A comprehensive introduction to current research on continental margins, a leading-edge problem in plate tectonics.
MORVEL Plate Motion Model
Charles De Mets and his team have the latest model to account for the motions of Earth's 25 largest plates.
Plate Animations from UC Santa Barbara
UCSB's Tanya Atwater, a pioneer in applying plate tectonics to the continents, is also a pioneer in visualizing how the process works. Get her animations at the Educational Multimedia Visualization Center.
Table of 52 Tectonic Plates and Their Sizes
The 52 tectonic plates from a 2003 paper, with their sizes.