Reported earthquake magnitudes change as more data refines initial estimates

Earthquakes of identical magnitudes are unlikely to cause equal damage

The severity of earthquakes depends on factors beyond the energy released in a region, including local architecture and geological conditions, such as water-saturated soil behaving like quicksand. Secondary effects, such as landslides, floods, and fires, may also contribute.

The Richter scale was only intended to quantify Southern California earthquakes

The scale, designed to rate the energy of the largest seismic waves released by an earthquake, was calibrated to the region’s crust and mantle properties. Since the 1970s, seismologists have instead used the moment magnitude scale, which considers all waves of released energy.

Visualize the power and frequency of earthquake magnitudes

About 150 medium earthquakes—magnitude 6.0—occur every year, resulting in moderate shaking and some property damage. While millions of earthquakes below category 2.0 occur yearly, fewer than one of category 9.0 or higher occurs on average.

A magnitude 25 earthquake would release enough energy to destroy the sun

Since Richter and moment magnitude scales rank earthquake energies logarithmically, theoretical magnitude values can cover an enormous range with no upper or lower mathematical limit. A particle of dust drifting onto a table would have a magnitude of about -15.

Differences in seismic wave speeds let scientists determine an earthquake’s location

Because primary waves are faster than secondary waves, seismic stations will detect longer gaps between these waves’ arrivals the farther an earthquake is. Calculating the distance to the earthquake from three stations allows its origin to be triangulated.

Variations in rock types contribute to uncertainty in earthquake predictions

Different rock types can withstand different amounts of stress before breaking and melt at different temperatures within Earth’s interior, preventing uniform modeling. The planet’s uneven mass distribution also creates variations in gravitational force, complicating mantle movement.

View the 10 largest earthquakes ever recorded as of 2024

In 1960, a magnitude 9.5 earthquake in Chile became the largest in recorded history, leaving about 2 million people homeless. Two of the largest occurred in back-to-back years in Alaska, with 9.2 and 8.7 quakes each generating tsunamis.

Earthquake early warning systems do not predict earthquakes

Systems like ShakeAlert® use a network of hundreds of ground sensors to detect earthquakes moments after they begin. Since seismic waves travel about 5 km/s, individuals may be notified of earthquakes before they feel the seismic activity has reached them.

What makes the Earth shake?

Researchers are demystifying the science of earthquakes—from their origins deep within the Earth to the scales that measure their strength. This article, which was part of a series of weekly reports from Cornell University, serves as a guide to...

An 800-ton shake table is the world's largest earthquake simulator

After the 1995 Kobe earthquake killed over 6,000 people, Japan created E-Defense to reproduce the force of earthquakes and test them against structures as tall as 10 stories, leading to changes in Japanese building codes to reduce collapse rates.

Boomerang earthquakes reverse direction and ripple back the way they came

Computer simulations show that rapid changes in friction along a fault where an earthquake has traveled for long distances can produce a smaller quake in the opposite direction. Data consistent with the phenomena has only been recorded a handful of times from 2011 to 2023.

Unlike hurricanes, tornadoes are not ranked based on measured wind speed

Technological limitations prevent direct measurements of wind speeds where tornadoes make contact with the ground. Instead, the Enhanced Fujita scale assigns a rating with a range of speeds based on how much damage a tornado caused to various types of structures. These types are more extensive than the original Fujita scale.

Geological tremors on the moon provide evidence that it is shrinking

Apollo seismometers have collected moonquake data, which scientists have analyzed to map the moon's interior and reveal that fault slips producing tremors are the result of sublunar cooling and contraction. It also revealed that the moon's inner core is about 500 kilometers (311 miles) across.

Records of Earth's magnetic field on the seafloor validated plate tectonics

Matching glacial, fossil, and rock records, mountain ranges, and continental shapes across oceans was insufficient evidence for continental drift. Precise measurements of magnetic minerals on the ocean floor revealed seafloor spreading, which could only be explained by moving landmasses.

How search and rescue teams remove survivors from rubble

At any time, large-scale seismic activity can devastate entire regions, often with little warning. Emergency responders, then, are perpetually on call. This is particularly critical in areas with poor infrastructure.

Scientists quantify how far from the poles auroras will be visible using the G-scale

The Geomagnetic Storm scale indicates the expected severity of the deformation of Earth's magnetic field based on the amount of energy injected by the solar wind. Solar activity is monitored using various satellites to forecast these storms, which can also be used to anticipate damage and disruption to power systems, radio communications, and satellite navigation.

The composition of magma affects the explosivity of volcanic eruptions

Silicate-rich magma contains extensive molecular chains that trap dissolved gases like water and carbon dioxide. These gases build pressure until they violently escape, creating explosive eruptions. Low-silica magmas produce gentler eruptions categorized as effusive.

Hurricanes may kill 300 times more people than officially reported

A recent study suggests that, since 1930, more than 3.5 million people have died due to hurricanes. This incorporates the long-term effects of storms on people's health and economic well-being, contributing to thousands of premature deaths each year.

Only 40% of city-destroying asteroids have been detected

Statistical modeling shows that while we have identified the majority of extinction-level asteroids, smaller asteroids that can cause significant damage remain elusive. Some asteroids, like the one that exploded over Chelyabinsk in 2013, can't be detected ahead of time since they come from the sun's direction.

Disposal wells for fracking wastewater have been linked to spikes in seismic activity

A study of all such underground wells in the central and eastern US found that they were 1.5 times more likely to be associated with earthquakes than oil recovery wells. The link between fluid injection and earthquakes was strongest at disposal wells where fluid was injected quickly.

Measurements of an electron’s magnetic moment help test the Standard Model

A particle’s magnetic moment quantifies how it responds to the presence of an external magnetic field. An electron’s value can be measured down to 14 decimal places, with certainties in the first 12 allowing it to be used to assess the accuracy of predictive models.

World records are often broken later in the day—and scientists wonder if muscle clocks explain the difference

For reasons that are still not entirely clear, on average, people tend to lift more weight and achieve other exercise feats later in the day. Theories to explain this discrepancy include muscle clocks are at peak performance in the afternoon and that there's morning-to-afternoon variation in core body temperature, hormones, and neural activity.

When they merge, black holes release multiple solar masses of energy

The energy emanates outward in the form of gravitational waves, which can be detected at observatories like LIGO. After merging, it is impossible to determine the characteristics of the two black holes that merged to create it.

Compare the true size of any country

This interactive lets you drag any country across the conventional Mercator projection to compare its true size to others. Africa, which appears similar in size to Greenland on standard maps, is actually close to 15 times larger. It's a great way to recalibrate your assumptions about world geography.

How accurate are climate models?

RealClimate: A new paper from Hausfather and colleagues with the most comprehensive assessment of climate model projections since the 1970s. Bottom line? Once you correct for small errors in the projected forcings, they did remarkably well.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

Fireworks make a loud booming sound after exploding due to air expanding faster than the speed of sound.

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

View the ten deadliest tornadoes in US history.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.