In the visualization above, you can see earthquakes and volcanic eruptions not just as individual events, but as indicators of those regions of frenzied activity in Earth’s crust where plates push up against each other and are torn asunder. The key is timescale. By zooming out to the past 50 years, you can see that volcanoes aren’t merely catastrophic blips, but a steady pattern: the living heartbeat of a dynamic planet. “When we look on a long timescale, we see the constant pulse of the planet,” says Cottrell, who recommends watching the animation with the sound on to get the full effect. It is a “constant unrelenting beat punctuated by periods of high and low activity."
Calderas: A caldera is a bowl-shaped depression formed when a volcano collapses into the void left when its magma chamber is emptied; there are three types. The first type is a crater lake caldera. This is the result of a stratovolcano collapsing into its magma chamber during a violent eruption. Basaltic calderas have a concentric ring pattern resulting from a series of gradual collapses rather than a single event. They are often found at the summit of shield volcanoes such as the craters at the tops of Mauna Loa and Kilauea . Resurgent calderas are the largest volcanic structures on Earth. They are the result of catastrophic eruptions that dwarf any eruptions ever recorded by human beings. Yellowstone caldera, sometimes called the “super volcano,” is one example.