Most volcanoes form at the boundaries of Earth's tectonic plates, which are huge slabs of crust and upper mantle that fit together like puzzle pieces. Think of these plates as massive rafts floating ...

(CNN) — Here's some background information about volcanoes, mountains that open downward to a reservoir of molten rock. Facts: More than 80% of the Earth's surface, both above and below sea level, is ...

When the Tonga volcano erupted beneath the South Pacific, it did what this type of volcanoes do: it blasted seawater, ash, and gas into the sky with terrifying force. But then it did something that ...

Scientists have discovered how two active volcanoes reacted following a massive earthquake - and what their unexpected silence revealed.