Volcanoes shape the world, both being a destructive force, but also building on new land and creating the conditions of fertile soils.
They come in different forms, and create different things during eruptions. This is pillow lava, found at the mid-oceanic ridges.
Basalt columns are the result of the rarely seen flood basalt eruption.
How rare? The last one was fourteen million years ago. Vast stretches of land or seabed get covered by basalt lava.
Shield volcanoes are large and relatively less destructive. The best known examples are the Hawaiian islands.
Cinder cones might be found on the flank of shield or composite volcanoes, and are characterized by a single vent.
Composite volcanoes are large volcanoes, and destructive, with a central vent. Mount Etna is a good example.
A lava dome is a volcano where a dome expands over time around a vent, trapping gases and resulting in a tremendous explosion. Mount St. Helens is a good example.
The results of some volcanoes across history are seen here.
Across the way, the other very destructive force of nature- earthquakes, a result of the plates grinding against each other.
There are quakes in Canada, mostly on the west coast. There was one several years ago here in Ottawa, strong enough that you could feel it rumble. I recall people calmly evacuating the building I was in by a staircase- except for one guy who was running as if his life depended on it, and who would have pushed an eighty year old grandma out of his way.
