Question of the Day: Plate Boundary Characteristics

Question of the Day developed by William Prothero.

Question:

What kind of plate tectonic process or boundary would you expect if you find a seafloor region with:

1. A long, narrow linear or gently curving deep valley, earthquakes to depths of several hundred km, and volcanoes paralleling the topographic deep?

2. A long, linear, gentle rise in the seafloor, relatively few quakes, and no (or very few) volcanoes observed from the surface?

3. A land or seafloor region with many quakes with depths less than 50km, not particularly impressive topography, and no volcanoes?

4. Volcanic activity, but no deep (>50km) quake activity. Quake activity would be localized around the active volcanoes?

References and Notes:

Question of the Day is a method used by Dr. William Prothero in his Oceanography Course at the University of California, Santa Barbara.

The Question of the Day page with more examples and tips on using them is part of the Starting Point: Interactive Lectures Module.