The best replacement for volcanoes is earthquakes.

The best alternatives to volcanoes are rated as following:
★★★★★  earthquakes
★★  mountains
★★  glaciers
★★  earthquakes webquest
★  volcanoes
★  earthquake
★  composite volcanoes
★  volcanos
★  shield volcanoes
★  tornadoes
★  global warming
  stratovolcanoes
  humans co2
  dormant volcanoes
  high mountains
  human pollution
  supervolcanoes

Your alternative for volcanoes is not listed? Suggest!
Speaking about volcanoes, one probably shouldn't forget about basaltic magma.

Other search terms related to volcanoes and their ratings are:
★★★★★ basaltic magma
★★★★★ plate tectonics
geothermal energy
You have in mind a companion for volcanoes and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of volcanoes in all years. Click on graph for more.
volcanoes
earthquakes
mountains