The next map I've put up shows the geologic features and activities that plate tectonics explains: volcanoes, earthquakes and faults, mainly. These things line up in very specific ways around the world, and those lines are what led scientists to come up with plate tectonics. When geologists get together to talk about plate tectonics, these are the things they refer to. The map is a snapshot of the world that shows only the parts that are active today—if you count the last 1 million years as "today." Find the Tectonic Activity of the World map in the Plate Tectonic Maps category.

Maybe maps of plates like the one I posted about yesterday, all outlines and schematics, aren't what you want. What about a map of the geologic features themselves that stand for plate boundaries? After all, this is how geologists began to work out plate tectonics: from actual things on the ground and in outcrops. That's the next new map I've put up, Plate-Tectonic Features and Global Topography. It may seem like a fine distinction, but I think this map is especially helpful in showing how plate concepts play out in the landscape around us.

The venerable USGS plate-tectonic map I mentioned on Saturday is OK as far as it goes, but it doesn't go far at all. In 2006 the USGS produced a beautiful poster and website called This Dynamic Planet, and it includes a small world map that deserves wider exposure. It shows the plate boundaries, of course, but it also shows whether they're divergent, convergent, transform or diffuse—key to understanding how everything fits and interoperates. See it on this site now.

For many years, the U.S. Geological Survey's cartoon map of the tectonic plates has crept farther behind the times. But I continue to feature it here on About.com Geology because it's still beautiful and still gets the most basic point across: Earth's outer shell is made of plates. Since its first appearance on the web in 1996, the map has been a good reminder of the names of the major plates, with one exception—the "Philippine plate" is correctly called the Philippine Sea plate. After all, the Philippine Islands sit on the adjacent Eurasian plate (well, the Sunda plate, but that's another topic). The other day I checked and the Survey has made the change. Here's the corrected map. Maybe more geologists will get that right now.