How Many Volcanoes are in the World?By Amy Curtis; Updated June 08, 2017
Volcanic activity ahead: Learn more about the world's volcanoes and more
Towering over the landscape or rising from the ocean, volcanoes are found on every continent, and many are popular tourist destinations. There are even volcanoes in a continuous belt across the ocean floor. Determining the exact number of volcanoes on Earth is almost impossible, but experts agree on the number of active volcanoes.
Some fun facts
About 1500 potentially active volcanoes exist in the world, but only 500 have erupted in recorded history. This total doesn’t include the volcanoes on the ocean floor. How much do you really know about volcanoes? Here are a few fun volcano facts:
Over 80 percent of the earth’s surface is volcanic. This doesn’t mean it’s all in danger of erupting
just that the origin is volcanic. This estimation includes the ocean floor as part of the earth’s surface. Volcanoes are essentially vents on the surface of the earth, to allow the heat from the inside to escape. After building up, molten rock, gases, and debris burst from the volcano with great force. When there’s less pressure underneath, the eruption is slower and less dramatic, as lava oozes from the volcano.
Even though volcanoes look like mountains, they’re really just the hardened remains of prior eruptions. The lava hardens into rock, and the next eruption adds a new layer. Some scientists believe that studying these layers, or “zones,” is the key to predicting a volcano’s future activity.
* Volcanoes can have an impact on the weather. After Mount Pinatubo erupted in the Philippines in 1991, spectacular sunsets and sunrises resulted from the ash and gases in the stratosphere and across the world, and cooler than normal temperatures were reported. Back in 1815, when Tambora Volcano in Indonesia erupted, much of the Northern Hemisphere was cooler for an entire year. In fact,
1816 was often described as “the year without a summer” in some parts of Europe and North America.
Ten famous volcanoes
Here's a list of 10 of the most famous active volcanoes in the world and where to find them:
- Mauna Loa, Hawaii
- Taal, Philippines
- Ulawun, Papua New Guinea
- Mt. Nyiragongo, Democratic Republic of Congo
- Mt. Merapi, Indonesia
- Galeras, Columbia
- Sakurajima, Japan
- Popocatepetl, Mexico
- Mt Vesuvius, Italy
- Yellowstone National Park, United States
That last one may seem surprising, because people often forget that Yellowstone is an active volcano, thinking of it as a collection of hot springs and geysers. In fact, Yellowstone is a supervolcano, meaning that at some point in its history, it erupted at a level 8 on the Volcanic Explosivity Index.
Developed in 1982, the VEI measures the strength of volcanoes: the amount of volcanic material the volcano has ejected, the height that the material has reached in the atmosphere, and the length of time the eruption has lasted. VEI 8 is the highest possible level, so supervolcanoes have the potential for eruptions on a globally catastrophic scale. The good news? It's been tens of thousands of years since the last VEI 8 eruption occurred.
Safety tips for visiting a volcano
If a volcano is on the bucket list, go for it! It’s perfectly safe to visit a volcano, but pay attention to some safety rules:
- Dress protectively. Long pants, a shirt with sleeves and sturdy close-toed shoes are a must when visiting a volcano.
- Stay on the path. Trails around a volcano are marked for a reason, and straying from the designated path can result in injury or even death, especially because of steam vents and lava cracks.
Heed the fume warnings. The steam rising from a volcano may look like pretty white smoke but it’s not
it’s poisonous gas. Volcanic fumes are made up of things like sulfuric acid, hydrochloric acid and glass particles, and it’s important to stay at least a quarter mile away to avoid inhaling them.
Never approach lava. Lava flows through vegetation, and methane gas is created by the burning plants. Ignition of this gas can result in explosions 100 yards ahead of the lava flow.
Listen to the experts. Rangers and guides know more about the volcano than visitors do, so it’s important to pay special attention and follow all instructions to the letter, in order to stay safe.