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The World's Most Dangerous Faults and Volcanoes

Supervolcanoes, plate boundaries, and the faults that threaten millions.

The planet's surface is a set of moving plates, and most of its earthquakes and eruptions happen where those plates meet. These are the faults, subduction zones, and volcanoes that scientists watch most closely, and the cities that sit on top of them.

#PlaceWhereWhen
1 Campi Flegrei
The restless caldera on the western edge of Naples, where the ground has risen more than 1.5 meters since 2005 		Campi Flegrei, Pozzuoli, Naples, Italy Last erupted 1538
2 The Cascadia Subduction Zone
The quiet megathrust off the Pacific Northwest that last broke in a magnitude 9 earthquake in 1700 		Off the coast of Oregon (central Cascadia margin) Last great rupture 1700
3 The Alpine Fault
The plate boundary that runs up New Zealand's South Island and lifts the Southern Alps 		Franz Josef, West Coast, New Zealand (central Alpine Fault) Last great rupture c. 1717
4 The New Madrid Seismic Zone
The buried faults in the middle of North America that shook the Mississippi Valley in 1811 and 1812 		Near New Madrid, Missouri (central New Madrid Seismic Zone) Earthquake sequence 1811–1812
5 The Mid-Atlantic Ridge
The 16,000-kilometer undersea mountain range where the Atlantic Ocean is still being born 		St. Peter and St. Paul Archipelago, equatorial Atlantic (Mid-Atlantic Ridge) Confirmed by HMS Challenger 1872
6 The San Andreas Fault
California's 1,200-kilometer seam between the Pacific and North American plates 		Parkfield, California (central San Andreas Fault) Great rupture 1906
7 The Tectonic Plates
The seven great slabs and dozens of smaller ones that make up Earth's moving shell 		Þingvellir, Iceland (North American–Eurasian plate boundary on land) Continental drift proposed 1912
8 The North Anatolian Fault
Turkey's 1,500-kilometer strike-slip fault, unzipping westward toward Istanbul 		Tosya, Kastamonu Province, Turkey (central North Anatolian Fault) Westward rupture sequence 1939–1999
9 The Himalayan Collision Zone
Where India drives into Asia, raising the world's highest mountains and its deadliest continental quakes 		Gorkha District, Nepal (central Himalayan front) Largest recorded quake 1950
10 Mount Merapi
Indonesia's most persistently active volcano, looming over the city of Yogyakarta in central Java 		Central Java and Yogyakarta, Indonesia Current eruption since 2020
11 Hunga Tonga–Hunga Ha'apai
The submarine Tongan volcano whose January 2022 eruption sent the highest plume ever recorded into the mesosphere 		Hunga Tonga–Hunga Haʻapai, Tonga Erupted January 15, 2022
12 Mauna Loa
The largest active volcano on Earth, which ended 38 quiet years with a 12-day eruption in 2022 		Island of Hawaiʻi, Hawaii, United States Last erupted 2022
13 Cotopaxi
Ecuador's near-perfect glaciated cone, among the world's highest active volcanoes 		Cotopaxi Province, Ecuador
14 Krakatoa
The Indonesian volcano whose 1883 eruption was heard across the world 		Sunda Strait, Indonesia
15 Lake Toba
The largest volcanic lake on Earth, filling the caldera of the biggest eruption of the past two million years 		Lake Toba, North Sumatra, Indonesia
16 Mount Etna
Europe's tallest and most restless volcano, towering over eastern Sicily 		Etna, Sicily, Italy
17 Mount Fuji
Japan's sacred symmetrical volcano 		Honshu, Japan
18 Mount Pinatubo
The Philippine volcano whose 1991 eruption cooled the entire planet 		Luzon, Philippines
19 Mount St. Helens
The Cascade volcano whose 1980 blast tore off its own summit 		Skamania County, Washington, USA
20 Mount Tambora
The Indonesian volcano behind the 1816 Year Without a Summer 		Sumbawa, Indonesia
21 Mount Vesuvius
The volcano that buried Pompeii, looming over the Bay of Naples 		Vesuvius, near Naples, Italy
22 Nyiragongo
The Congolese volcano cradling one of the world's great lava lakes 		Virunga Mountains, DR Congo
23 Popocatepetl
Mexico's smoking mountain, a restless giant beside Mexico City 		Central Mexico
24 The Great Rift Valley
A continent tearing in two, and the trench it leaves behind 		The Great Rift Valley
25 The Ring of Fire
The Pacific rim of subduction, where the ground does not hold still 		The Ring of Fire
26 The Yellowstone Caldera
The vast volcanic system beneath Yellowstone National Park, source of three of the largest eruptions known 		Yellowstone National Park, Wyoming, United States

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