Mapped: The countries with the most volcanoes – where does Indonesia rank?
Mount Agung, on the Indonesian island of Bali, has erupted for the second time in a week, forcing the cancellation of hunders of flights. Agung, on the eastern edge of the popular long-haul holiday destination, has been rumbling for months, but there are growing fears that a major eruption could be imminent.
But how many volcanoes does Indonesia, and the rest of the world, possess?
According to the National Museum of Natural History’s Global Volcanism Program, there are more than 1,500 volcanoes on the planet that have erupted at some point in the last 11,500 years, the current geological epoch otherwise known as the Holocene period.
The majority of these are found in clusters, or strips, mostly following the faultlines of the world’s tectonic plates. For this reason, mapping the world’s volcanoes according to country is slightly misleading, as most are linked to the same geological highway.
The "Ring of Fire" that encircles the Pacific Ocean – which stretches up the west coast of the Americas, around and across to Asia, looping down to the east of Japan, before overwhelming much of Indonesia and the Philippines and whipping around Australasia – boasts the most, with 452.
This is why Indonesia has the third most volcanoes in the world, at 139. The island of Bali has three: Agung, Batur and Buyan-Bratan. Japan comes fourth with 112. Chile (also on the Ring of Fire, on the cusp of the South American plate) is fifth, with 104.
But it is the United States that takes the title with the most, 173, followed by Russia, with 166 – both large countries, and also both on the Ring of Fire.
Another hotspot for volcanoes is on the African continent, where the African Plate meets the Arabian Plate, which is why Kenya (23), Tanzania (10) and Ethiopia (57) boast a wealth of volcanoes.
It is no surprise that many of the countries high on our list also feature near the top in our guide to the countries most likely to hit by a natural disaster (according to the 2015 World Risk Report).
One of the anomalies in volcanic activity over the last 11,000 or so years is Iceland, which appears on the map above to sit alone on a cluster of volcanoes. This is because Iceland is part of the Mid-Atlantic Ridge, where the Eurasian and North American Plates meet (you can scuba dive in a gap between the two). It was created by the volcanic rifting between two tectonic plates, which explains its fondness for eruptions and geysers.
For more information on the technical side of volcano monitoring, including information on the definitions in the legend, visit the Smithsonian Institution National Museum of Natural History Global Volcanism Program.