EARTH GEOLOGY EARTHQUAKES VOLCANOES SINKHOLES & LAND SUBSIDENCE LANDSLIDES & MASS MOVEMENTS WEATHER PHENOMENA OCEAN & COASTAL PHENOMENA NATURAL PHENOMENA HUMAN IMPACTS ON EARTH SYSTEMS SINKHOLES & LAND SUBSIDENCE LANDSLIDES & MASS MOVEMENTS WEATHER PHENOMENA OCEAN & COASTAL PHENOMENA NATURAL PHENOMENA HUMAN IMPACTS ON EARTH SYSTEMS STRANGE SOUNDS MYSTERY BOOMS THE HUM SKY TRUMPETS SPACE SOUNDS OCEAN SOUNDS ANIMAL SOUNDS SONIC WONDERS BROADCASTS SKY STRANGE CLOUDS STORM STRUCTURE ATMOSPHERIC OPTICS AURORAS & PLASMA PHENOMENA MYSTERIOUS OBJECTS & LIGHTS MAN-MADE SKY PHENOMENA STORM STRUCTURE ATMOSPHERIC OPTICS AURORAS & PLASMA PHENOMENA MYSTERIOUS OBJECTS & LIGHTS MAN-MADE SKY PHENOMENA SPACE ASTRONOMICAL EVENTS SOLAR & SPACE WEATHER PLANETARY GEOLOGY & IMPACTS ALIEN LIFE & HABITABILITY SOLAR SYSTEM MYSTERIES COSMIC MYSTERIES SPACE EXPLORATION & OBSERVATION ASTRONOMICAL EVENTS SOLAR & SPACE WEATHER PLANETARY GEOLOGY & IMPACTS ALIEN LIFE & HABITABILITY SOLAR SYSTEM MYSTERIES COSMIC MYSTERIES SPACE EXPLORATION & OBSERVATION ANIMALS & NATURE ANIMAL ANOMALIES & MASS DIE-OFFS PREHISTORIC EARTH LIVING EARTH ODDITIES MASS DIE-OFFS ANIMAL ANOMALIES & MASS DIE-OFFS PREHISTORIC EARTH LIVING EARTH ODDITIES CONTACT // REPORT EARTH GEOLOGY EARTHQUAKES VOLCANOES SINKHOLES & LAND SUBSIDENCE LANDSLIDES & MASS MOVEMENTS WEATHER PHENOMENA OCEAN & COASTAL PHENOMENA NATURAL PHENOMENA HUMAN IMPACTS ON EARTH SYSTEMS SINKHOLES & LAND SUBSIDENCE LANDSLIDES & MASS MOVEMENTS WEATHER PHENOMENA OCEAN & COASTAL PHENOMENA NATURAL PHENOMENA HUMAN IMPACTS ON EARTH SYSTEMS STRANGE SOUNDS MYSTERY BOOMS THE HUM SKY TRUMPETS SPACE SOUNDS OCEAN SOUNDS ANIMAL SOUNDS SONIC WONDERS BROADCASTS SKY STRANGE CLOUDS STORM STRUCTURE ATMOSPHERIC OPTICS AURORAS & PLASMA PHENOMENA MYSTERIOUS OBJECTS & LIGHTS MAN-MADE SKY PHENOMENA STORM STRUCTURE ATMOSPHERIC OPTICS AURORAS & PLASMA PHENOMENA MYSTERIOUS OBJECTS & LIGHTS MAN-MADE SKY PHENOMENA SPACE ASTRONOMICAL EVENTS SOLAR & SPACE WEATHER PLANETARY GEOLOGY & IMPACTS ALIEN LIFE & HABITABILITY SOLAR SYSTEM MYSTERIES COSMIC MYSTERIES SPACE EXPLORATION & OBSERVATION ASTRONOMICAL EVENTS SOLAR & SPACE WEATHER PLANETARY GEOLOGY & IMPACTS ALIEN LIFE & HABITABILITY SOLAR SYSTEM MYSTERIES COSMIC MYSTERIES SPACE EXPLORATION & OBSERVATION ANIMALS & NATURE ANIMAL ANOMALIES & MASS DIE-OFFS PREHISTORIC EARTH LIVING EARTH ODDITIES MASS DIE-OFFS ANIMAL ANOMALIES & MASS DIE-OFFS PREHISTORIC EARTH LIVING EARTH ODDITIES Understanding a Restless Planet Most earthquakes occur when accumulated stress overcomes friction along a fault, allowing blocks of rock to move suddenly. The released energy travels through Earth as seismic waves, shaking the ground near the rupture and sometimes across entire continents. Yet earthquakes are not all alike. Some rupture shallow crustal faults beneath cities. Others originate hundreds of kilometers deep inside subducting tectonic plates. Earthquake swarms, slow-slip events, volcanic earthquakes and human-induced seismicity reveal that the planet releases tectonic stress in many different ways. Use the main pillars below to move from basic earthquake mechanics to specific fault systems, seismic hazards, monitoring methods and landmark disasters. Earthquake Science Learn what causes earthquakes, how elastic rebound releases stored tectonic stress and why magnitude is different from observed shaking intensity. This pillar also examines foreshocks, aftershocks, earthquake swarms, deep-focus earthquakes, slow-slip events, supershear ruptures and common earthquake myths. What causes earthquakes Elastic rebound and fault rupture Magnitude versus intensity Foreshocks, aftershocks and earthquake swarms Deep, slow and supershear earthquakes Earthquake triggering and seismic myths Featured child pillar: Induced Seismicity and Man-Made Earthquakes Explore earthquake science Faults & Tectonic Settings Earthquake behavior depends heavily on tectonic setting. Explore subduction zones, transform faults, continental rifts, intraplate seismic zones and hotspot regions where magma, crustal stress and plate motion interact. Subduction-zone megathrust earthquakes Transform and strike-slip faults Rift earthquakes and crustal extension Intraplate earthquakes far from plate boundaries Hotspot and volcano-related seismicity Subduction-Zone Earthquakes San Andreas Fault Cascadia Megathrust Earthquake East African Rift New Madrid Seismic Zone Explore faults and tectonic settings

Regional Seismic Systems Some earthquake zones are larger than any single fault. This pillar examines broad tectonic belts where multiple plates, faults and subduction systems combine to produce recurring seismic crises. The Pacific Ring of Fire The Mediterranean–Alpine seismic belt The Caribbean plate boundary Middle Eastern fault systems The Himalayan collision zone South Pacific subduction systems Ring of Fire Volcanoes and Earthquakes Himalayan Earthquakes Explore global seismic systems Earthquake Hazards Ground shaking is only the beginning. Earthquakes can rupture the surface, destabilize slopes, liquefy waterlogged sediment, damage infrastructure and ignite urban fires long after the shaking stops. Surface fault rupture Liquefaction and lateral spreading Soil amplification and basin effects Building collapse Infrastructure and utility failure Fire following earthquakes Tsunamis, landslides and rockfalls are covered in their dedicated Strange Sounds hubs and are cross-linked from this pillar to avoid duplicate content. Explore earthquake hazards Earthquake Monitoring & Forecasting Scientists cannot reliably predict the exact time, place and magnitude of a future earthquake. They can, however, identify active faults, measure deformation, estimate long-term probabilities and issue warnings after rupture begins. Seismographs and seismic networks GPS and ground deformation Satellite radar monitoring Earthquake early-warning systems Probability-based forecasting Earthquake lights and unusual precursors Animal behavior and gas emissions Featured child pillar: Earthquake Early Warning Explore monitoring and forecasting Earthquake Preparedness Earthquakes strike without conventional warning, making preparation essential. Learn how to secure a home, assemble emergency supplies, protect yourself during strong shaking and respond safely to aftershocks and tsunami alerts. Earthquake emergency kits Drop, Cover and Hold On Home earthquake safety Family and community drills Seismic building codes Aftershock safety Tsunami evacuation Explore earthquake preparedness Historic Earthquakes The world’s most destructive earthquakes reveal how geology, population density, construction quality and secondary hazards combine to create disaster. Explore landmark earthquakes that transformed science, cities and emergency planning. Major case studies 1755 Lisbon earthquake and tsunami 1811–1812 New Madrid earthquakes 1906 San Francisco earthquake 1960 Valdivia earthquake 1964 Alaska earthquake 1976 Tangshan earthquake 2004 Sumatra–Andaman earthquake and tsunami 2011 Tōhoku earthquake and tsunami 2023 Turkey–Syria earthquakes Explore historic earthquakes Earthquake Records & Statistics Which was the largest earthquake ever measured? Which earthquakes were the deadliest, deepest or most expensive? This reference pillar compares major seismic events and explains what earthquake records really mean. Largest earthquakes ever recorded Deadliest earthquakes in history Deepest known earthquakes Costliest earthquake disasters Earthquake records by country Major earthquakes by year Explore earthquake records Earthquakes and Connected Natural Phenomena Earthquakes rarely exist in isolation. Large ruptures can disturb oceans, destabilize mountains, alter groundwater systems and interact with volcanic regions. Explore the related Strange Sounds topics below for a wider view of Earth’s interconnected hazards. Volcanoes: Earthquake swarms can accompany magma movement and volcanic unrest. Explore the Volcanoes hub . Tsunamis: Undersea megathrust earthquakes can displace enormous volumes of water and send destructive waves across entire ocean basins. Landslides: Strong shaking can trigger rockfalls, debris avalanches, submarine slope failures and widespread ground collapse. Earth degassing: Fault movement may alter pathways used by groundwater and naturally occurring gases. Explore Earth degassing and toxic gas emissions . Earthquake FAQs Most earthquakes occur when tectonic stress causes rocks to break or slip suddenly along a fault. The released energy travels outward as seismic waves and produces ground shaking. Scientists cannot reliably predict the exact time, location and magnitude of an individual earthquake. They can identify active faults, calculate long-term probabilities, monitor seismic activity and provide early warning after a rupture has begun. Magnitude measures the size of an earthquake at its source. Intensity describes the level of shaking and damage observed at a particular location, so one earthquake can produce many different intensity values. Yes. Large earthquakes redistribute stress within the crust and can trigger aftershocks or alter seismic activity on nearby and sometimes distant faults. Triggering does not mean that every affected fault will produce a major earthquake. Large earthquakes can disturb volcanic and hydrothermal systems, but a direct eruption usually requires a volcano that is already close to instability. Most earthquakes do not trigger eruptions. In most indoor situations, drop to the ground, take cover beneath sturdy furniture and hold on until the shaking stops. Stay away from windows and do not run outside while debris may be falling. Terms of Service affiliate disclaimer CONTACT//REPORT Privacy Overview