The 10 Biggest Earthquakes

1. The 1960 Valdivia Earthquake, Chile

The Valdivia earthquake of 1960 is widely regarded as the largest earthquake ever recorded by modern instruments. It reached an estimated magnitude of 9.5, a number so large that it still defines the upper boundary of the moment magnitude scale. The quake ruptured along a massive stretch of the Chilean subduction zone, where the Nazca Plate dives beneath the South American Plate. Shaking lasted for many minutes, long enough for people to struggle to remain standing and for entire landscapes to change shape. Cities in southern Chile suffered catastrophic damage, with buildings collapsing and ground surfaces warping. Landslides dammed rivers, creating temporary lakes that later burst and caused additional flooding. The earthquake also triggered volcanic activity, with several volcanoes erupting in the months that followed. Its most far-reaching effect was a Pacific-wide tsunami that crossed entire oceans. Waves struck Hawaii, Japan, and the Philippines, causing deaths thousands of kilometers from the epicenter. The Valdivia earthquake fundamentally changed how scientists understand megathrust earthquakes. Even decades later, it remains a benchmark event in seismology.

2. The 1964 Great Alaska Earthquake, United States

The Great Alaska Earthquake struck on March 27, 1964, with a magnitude of about 9.2. It occurred along the boundary where the Pacific Plate subducts beneath the North American Plate. The shaking lasted approximately four and a half minutes, which is extraordinarily long for an earthquake. Entire neighborhoods in Anchorage were destroyed due to soil liquefaction and ground failure. Coastal areas experienced dramatic vertical land movement, with some regions rising several meters while others sank. The earthquake generated powerful tsunamis that devastated coastal towns in Alaska. Tsunami waves also traveled south and caused damage in California and Oregon. Despite its immense power, the death toll was relatively low due to Alaska’s sparse population at the time. The event provided scientists with unprecedented data on plate tectonics. It helped confirm the theory of subduction-driven megathrust earthquakes. The 1964 Alaska earthquake reshaped building codes and tsunami preparedness across the Pacific.

3. The 2004 Indian Ocean Earthquake, Sumatra-Andaman

The 2004 Indian Ocean earthquake was one of the deadliest natural disasters in human history. With a magnitude estimated between 9.1 and 9.3, it ruptured a fault over more than 1,300 kilometers. The earthquake occurred off the west coast of northern Sumatra along a major subduction zone. Shaking itself caused destruction in nearby regions, but its greatest impact came from the tsunami it generated. Massive waves raced across the Indian Ocean at jetliner speeds. Coastal communities in Indonesia, Sri Lanka, India, and Thailand were overwhelmed with little warning. The tsunami ultimately affected more than a dozen countries. Over 200,000 people lost their lives, making it one of the deadliest earthquakes ever recorded. Entire towns were erased from the map within minutes. The disaster exposed the lack of a tsunami warning system in the Indian Ocean. In response, international monitoring and warning networks were rapidly developed.

4. The 2011 Tōhoku Earthquake, Japan

The Tōhoku earthquake struck northeastern Japan on March 11, 2011, with a magnitude of about 9.0 to 9.1. It occurred along the Japan Trench, where the Pacific Plate subducts beneath the Okhotsk Plate. The ground shaking was severe, but Japan’s strict building codes prevented even greater structural collapse. The most destructive force was the tsunami that followed the earthquake. Waves in some areas exceeded ten meters in height. Entire coastal towns were inundated within minutes. The tsunami caused the Fukushima Daiichi nuclear disaster, adding a technological crisis to a natural one. Large areas of land were permanently flooded or contaminated. Economic losses reached hundreds of billions of dollars, making it one of the costliest disasters in history. The earthquake shifted parts of Japan several meters eastward. It also slightly altered Earth’s rotation and shape. The Tōhoku earthquake remains a defining moment in modern disaster preparedness.

5. The 1952 Kamchatka Earthquake, Russia

The Kamchatka earthquake of 1952 reached an estimated magnitude of 9.0. It occurred off the eastern coast of Russia’s Kamchatka Peninsula. At the time, the region was sparsely populated, limiting direct human losses. Despite this, the earthquake released enormous energy beneath the Pacific Ocean. The resulting tsunami traveled across the ocean basin. Waves struck Hawaii with significant force, causing damage to coastal infrastructure. This event demonstrated that tsunamis could travel vast distances with little loss of power. Scientific documentation was limited due to Cold War secrecy. However, later analysis confirmed its place among the largest earthquakes ever recorded. The quake highlighted the seismic danger of the Pacific “Ring of Fire.” It also influenced the development of tsunami monitoring in the Pacific. Even today, it is remembered as one of the great but lesser-known megathrust earthquakes.

6. The 2010 Maule Earthquake, Chile

The Maule earthquake struck central Chile on February 27, 2010, with a magnitude of about 8.8. It occurred along the same subduction zone responsible for Chile’s historic seismicity. Shaking lasted for roughly three minutes, affecting a large portion of the country. Major cities such as Concepción suffered widespread structural damage. Roads, bridges, and ports were heavily impacted. The earthquake also generated a tsunami that struck coastal communities. Warning systems existed but were not fully effective, leading to additional casualties. Power and communication networks failed across large regions. Despite the damage, modern building standards saved countless lives. The event provided valuable data on earthquake rupture processes. It also showed how stress transfers along plate boundaries. The Maule earthquake reinforced Chile’s reputation as one of the world’s most earthquake-prone nations.

7. The 1906 Ecuador–Colombia Earthquake

The 1906 earthquake off the coasts of Ecuador and Colombia is estimated to have had a magnitude of about 8.8. It occurred along the boundary between the Nazca and South American plates. Because it happened before modern instruments, its exact size is still debated. The earthquake caused severe shaking along coastal regions. Many buildings constructed from masonry and wood were destroyed. A powerful tsunami followed the main shock. Waves traveled across the Pacific and were recorded as far away as California and Japan. Coastal villages near the epicenter were heavily damaged. The event produced thousands of fatalities, though precise numbers are uncertain. It is considered one of the earliest well-documented megathrust earthquakes. Scientists later used historical records to reconstruct its rupture area. The 1906 event helped establish the seismic history of northwestern South America.

8. The 1965 Rat Islands Earthquake, Alaska

The Rat Islands earthquake occurred in the Aleutian Islands of Alaska in 1965. It reached a magnitude of approximately 8.7. The quake ruptured a long section of the Aleutian subduction zone. Because the region is remote, there were no direct human casualties. Despite this, the earthquake generated a noticeable tsunami. Waves were recorded across the Pacific Ocean. The event caused significant uplift and subsidence of the seafloor. It provided scientists with important insights into how stress accumulates in island arcs. The earthquake also helped refine models of plate boundary segmentation. Data from this event improved tsunami forecasting methods. Although less famous, it remains one of the largest earthquakes ever measured. Its isolation does not diminish its geophysical importance.

9. The 1950 Assam–Tibet Earthquake

The Assam–Tibet earthquake struck in 1950 with an estimated magnitude between 8.6 and 8.7. It occurred in a complex collision zone between the Indian and Eurasian plates. Unlike many great earthquakes, it happened far from an oceanic subduction zone. Shaking triggered massive landslides throughout the Himalayas. Rivers were blocked, forming temporary lakes that later caused devastating floods. Entire villages were destroyed in remote mountainous regions. The rugged terrain made rescue efforts extremely difficult. Casualty estimates vary widely due to limited records. The earthquake altered river courses and reshaped valleys. It remains one of the largest continental earthquakes ever recorded. Scientists still study it to understand intraplate and collision-zone seismicity. Its effects were felt across a vast portion of South Asia.

10. The 1957 Andreanof Islands Earthquake, Alaska

The Andreanof Islands earthquake occurred in 1957 along the Aleutian chain. It had an estimated magnitude of about 8.6. The quake ruptured a long segment of the plate boundary beneath the Pacific Ocean. Like other Aleutian earthquakes, it produced a large tsunami. Waves affected Hawaii, causing damage along the coastline. The remote location meant there were few direct casualties. However, the geophysical impact was immense. The earthquake helped scientists map the structure of the Aleutian subduction zone. It also contributed to early tsunami warning research. This event showed how energy can be released over enormous fault areas. It remains a key case study in megathrust earthquake behavior. Together with other Alaskan quakes, it underscores the region’s seismic power.