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?