Nothing highlight’s Mother Nature’s awesome power quite like a volcano. Contained deep within the Earth, these formations are vents where molten rock, debris, and gases from the planet's interior are emitted.
When thick magma and gas build up under the surface, volcanoes expel lava, rocks and ash into the air. The mountain-like mounds that we associate with volcanoes are what remains after material spewed during eruptions has hardened around the vent.
A large eruption can be extremely dangerous for people living near a volcano. Flows of searing lava can reach 1,250 degrees or more, burning everything in its path, including humans and entire towns. Ash and toxic gases can cause lung damage and other problems.
It’s estimated that more than 260,000 people have died in the past 300 years from volcanic eruptions and their aftermath.
About 1,900 volcanoes on Earth are considered active, meaning they show some level of activity and are likely to explode again. Many other volcanoes are dormant, showing no current signs of exploding but likely to become active at some point in the future. Others are considered extinct.
Earlier this year, scientists discovered the world's longest known chain of continental volcanoes running across Eastern Australia.
A giant crack that appeared suddenly near Yellowstone National Park has raised concerns that the park’s supervolcano could be about to erupt.
In 2010, ash from an Iceland volcano went 11 kilometres into the sky and caused worldwide air travel disruption.
Could the Icelandic volcano erupt again? Find out in Into Iceland’s Volcano – tonight at 9.30pm on National Geographic Channel