A powerful earthquake struck southwestern Japan Tuesday afternoon local time, collapsing part of a shopping mall, toppling a stone wall at the centuries-old Kumamoto Castle, and sending more than 150,000 people to evacuation shelters, the BBC reported.

The quake, which the U.S. Geological Survey (USGS) measured as a magnitude 6.8, hit at 4:27 p.m. local time near Kumamoto, a city of more than 700,000 people located on the island of Kyushu in southern Japan.

Thousands of homes lost power, and roads buckled across the region. The second floor of a shopping center collapsed, trapping shoppers inside, according to the BBC report; some of these people were evacuated and later hospitalized. A brief tsunami warning was issued and lifted within an hour.

The USGS measurement is different from the magnitude 7.1 reported by the Japan Meteorological Agency, "primarily because the agencies are reporting different magnitude types," the USGS reported. While Japan is looking at local magnitude, the USGS measured the moment magnitude, which is derived from the physical size of the fault rupture and gives the "most reliable estimate of earthquake size" for large earthquakes, since local-magnitude scales can lose accuracy once a rupture grows big enough, the USGS reported.

These measurements are helpful, as "different magnitude types capture different characteristics of earthquake source processes," the USGS noted. Local magnitude, for example, reflects how strongly the ground shook nearby, while moment magnitude reflects the total energy released across the fault.

Why this quake is scientifically interesting

Japan sits atop one of the most active plate boundaries on Earth, where the Philippine Sea Plate dives beneath the Eurasia Plate. That process, known as subduction, is responsible for the massive, tsunami-generating earthquakes that periodically strike offshore Japan, and it's been studied intensively for decades.

But Tuesday's earthquake didn't occur at the boundary itself. Instead, the rupture happened within the Eurasia Plate, more than 60 miles (100 kilometers) inland from where the plates meet, Jeffrey Park, a theoretical seismologist at Yale University, told Live Science. Roughly 90% of earthquakes happen at plate boundaries, where the constant grinding of two plates builds up stress until a fault gives way. Quakes that strike farther inside a plate — sometimes called intraplate earthquakes — are rarer and less understood, though scientists suspect that stress transmitted through the plate can reactivate old, dormant faults far from the boundary that produced it.

According to Park, the fault in Tuesday's earthquake moved in a way that suggests the plate tore horizontally as it was twisted by subduction occurring at an angle.

The USGS describes this event as shallow strike-slip faulting: the two sides of the fracture slid past each other horizontally, rather than one side thrusting up and over the other. This faulting style, combined with the shallow depth of just 6 miles (10 kilometers) down, points to the same type of rupture behind Kyushu’s deadly 2016 Kumamoto earthquake sequence.

That inland location is also why the quake didn't generate a damaging tsunami, despite the brief precautionary warning. Tsunamis are produced when a big event ‪—‬ such as an earthquake, volcanic eruption or landslide ‪—‬ displaces water; the force from that displacement then propagates as a wave.

Tuesday's rupture stayed entirely on land, so it never pushed the seafloor up the way offshore quakes do. That's why the tsunami risk stayed low, even with the brief precautionary warning. Still, an inland quake isn't automatically off the hook: if the shaking triggers a landslide that spills into the sea, that alone can generate a tsunami.

The depth mattered just as much as the location. The quake was shallow enough to concentrate its energy near the surface, which Park said explains the structural damage.

"Because it is shallow it will cause more structural damage than a similar-sized event that might occur deeper and offshore," he told Live Science in an email.

Earthquake country

Several earthquakes have already clustered in the area, and numerous aftershocks are expected over the coming days. Japan experiences roughly 1,500 earthquakes annually, making it one of the most seismically active countries on the planet — a byproduct of sitting at the junction of several tectonic plates.

To protect itself, Japan has spent decades — and learned from painful lessons from disasters like the 2011 Tohoku earthquake and tsunami — engineering a response system built for exactly this scenario.

Bullet trains are programmed to halt automatically the instant seismic sensors detect a major earthquake, a safeguard Park pointed to as a defining feature of the country's earthquake readiness. That automatic shutdown extends to other transit and utility systems, part of a broader early-warning network that alerts the public within seconds of a quake's detection, giving people crucial time to take cover before shaking arrives.

Japan's investment in its infrastructure may help to explain why, even after a magnitude 7 event near a city of 700,000, Japan's death toll and damage have historically been far lower than those from comparable quakes elsewhere in the world.

Search-and-rescue efforts are continuing in Kumamoto, with CNN reporting that between 20 and 30 employees remained unaccounted for at the Aeon Mall in Kashima Town, where the building’s second floor had collapsed. Firefighters were also working to reach the site and contain nearby fires.

This striking satellite photo shows a multicolor "fan" of folded rocks sculpted by a longtime collision between two of Earth's tectonic plates.

The geological feature, known as an imbricate fan, is located around 3 miles (5 kilometers) east of the town of Murgha Kibzai in Pakistan's Balochistan province. The photographed section of folded rocks measures around 9 miles (15 km) across, but the fan stretches up to 55 miles (89 km) from end to end, well beyond the area in this image.

The dramatic structure sits at an altitude of around 5,000 feet (1,500 meters) in the Sulaiman Range, a series of mountains that covers around 2,500 square miles (6,500 square kilometers) of Pakistan and Afghanistan. ("Sulaiman" means "of Solomon," in reference to the biblical figure King Solomon, and the range's largest peak is Takht-e-Sulaiman, which translates to "Throne of Solomon.")

This is one of several unique features that emerged along the boundary between the Eurasian and Indian tectonic plates, which have been colliding for more than 60 million years. At one point during this tectonic tug-of-war, the two plates became somewhat intertwined, allowing the fan to take shape, according to NASA's Earth Observatory.

"As India moved northward, it began to rotate in a counter-clockwise direction, wrenching the northwestern part of the Indian plate backwards into part of the Eurasian plate," Earth Observatory representatives wrote. "The countervailing forces put the rocks of the Sulaiman Range in a unique compressional vice, causing many of its faults to curve and stretch in convoluted ways."

The fan is made up of alternating layers of sandstone, which appear dark in the image, and limestone, which has a much lighter hue. These sedimentary rocks were formed by "thrust faults" that shot upward from the boundary between the Eurasian and Indian plates and became entangled as the boundary moved back and forth.

The satellite image is false-color, meaning it includes wavelengths of the electromagnetic spectrum that are not normally visible to humans. This helps to accentuate the differences between the two rock types, although they can also be easily distinguished with the naked eye. Pockets of vegetation appear in red throughout the image.

The photo is a small part of a larger, wide-field image (see above), which showcases several other intriguing geological features across the Sulaiman Range in false color.

Continental collision

The collision between the Eurasian and Indian plates became inevitable around 80 million years ago, when dinosaurs still ruled Earth, according to the Earth Observatory. At this point, the pair became locked on a collision course, with each plate moving more than 8 inches (20 centimeters) per year — around twice the speed of the fastest tectonic plates today.

Around 60 million years ago, the plates slowly slammed together. Normally, this would cause the smallest tectonic plate to sink below the other. However, the two plates' massive size meant neither receded. Instead, the continental crust along the boundary grew thicker, and the ground buckled, folded and pushed upward.

This process created not only the Sulaiman Range but also the Karakoram (a huge mountain range that spans the borders of China, India, Pakistan, Tajikistan and Afghanistan) and the Himalayas — the two tallest mountain ranges on Earth, according to the Earth Observatory.

This collision continued at full speed for around 30 million years, before eventually slowing down. However, the two plates are still technically colliding today, making the region a major earthquake hotspot.

See more Earth from space

Science word of the day: Seamount

Pronunciation: SEE'-mount

What it means: A seamount is an undersea mountain that rises at least 3,300 feet (1,000 meters) above the seafloor but does not come close to breaking the surface. According to the National Oceanic and Atmospheric Administration, there are at least 100,000 seamounts in the oceans, and less than 0.1% of them have been explored. Seamounts typically form from volcanic activity, and many host dramatic communities of sea life ‪—‬ from coral, to sharks, to an assortment of weird jellyfish-looking things.

How to use it in a sentence: Every time marine biologists explore a seamount with their remotely operated vehicles, they seem to discover a new universe of strange and blobby deep-sea creatures.

Can you crack our science word of the day puzzle, Chain Word?

Science word of the day: Pando

Pronunciation: PAN'-doh

What it means: In Latin, "Pando" means "I spread." And boy, does it. Pando is a clonal stand of aspen trees in Utah that weighs about 13 million pounds (6 million kilograms), making it the world's heaviest living organism ever found. Its 40,000 trees cover 106 acres (43 hectares) in Fishlake National Forest, and they're all connected by a single, sprawling root system. Some DNA analysis suggests that this many-fingered megatree is tens of thousands of years old.

How to use it in a sentence: When you walk through Pando, what seems like a normal stroll through an aspen grove is actually a trip through a single, ancient living being.

Can you crack our science word of the day puzzle, Chain Word?

Science word of the day: Cenozoic

Pronunciation: See-noh-ZOH'-ihk

What it means: The ascendency of mammals, the birth of the Himalayas, the diversification of birds ‪—‬ Earth's in its Cenozoic era, baby!

The Cenozoic is the geological era happening right now. It started 66 million years ago with the abrupt mass extinction known as the Cretaceous-Paleogene extinction event, when a massive asteroid hit Earth and wiped out the nonavian dinosaurs. It's been a busy few tens of millions of years, ushering in such hits as Earth's first cacti, whales and most (if not all) of the Grand Canyon.

How to use it in a sentence: The Cenozoic is called the Age of Mammals, but the University of California Museum of Paleontology in Berkeley would like you to know it could have been called the Age of Teleost Fish, if mammals weren't so dang self-centered.

Can you crack our science word of the day puzzle, Chain Word?

In satellite data captured over Antarctica, what appears to be a beautiful, colorful hummingbird emerges from the crest of a mountaintop.

What is it?

While there are no hummingbirds flying around Antarctica, we can see what looks like a small, purple bird in a new satellite image of an Antarctic mountain. The dark belly of this "bird" at the center of this image is actually the top of the mountain Nunatak Zaterjavshijsja in East Antarctica.

What looks like a bird's tail is a stream of ice flowing northeast all the way out to the ocean, and what appear to be feathers splaying outward from the mountaintop are actually crevasses down the mountain. These crevasses are formed by a glacier fracturing the mountain's surface as it flows in the icy current toward the ocean.

This view was captured by radar instruments onboard the satellite NISAR (NASA-ISRO Synthetic Aperture Radar) that launched as a collaboration between NASA and ISRO (Indian Space Research Organisation). The director of NASA's Earth Science Division called NISAR "the most sophisticated radar we've ever built" in a pre-launch briefing last year.

Why is it incredible?

At first glance, this image is puzzling. What could it possibly be? Its bold colors and sharp lines evoke almost alien qualities. But the strange beauty of the shapes and colors in this satellite image reveal important information about glacier movements on the mountain.

"First, it's a beautiful image, with rich details of features that provide insights to how the glacier is moving. Then, because radar can often see through snow and deep into the ice, NISAR can observe fundamentally different properties of Antarctic ice than can be seen in optical imagery," Seongsu Jeong, the signal analysis engineer who produced the image at NASA's Jet Propulsion Laboratory, said in a statement. "With NISAR we're seeing what's hidden beneath the surface."

And now anyone can explore NISAR's data. Earlier this week, on July 20, NISAR started making the data from its radar instruments public. Moving forward, mission teams will be rolling out this data so researchers everywhere can use it to study and protect our ever-changing planet.

Science word of the day: Abiotic

Pronunciation: Ay-bye-AH'-tik

What it means: Abiotic means "without living organisms." Scientists typically use the term when referring to nonliving aspects of an ecosystem that affect organisms' growth or reproduction. Some abiotic factors might be light, water, fertilizer, nutrients or chemical elements, such as oxygen or sulfur. Others include the tides or rain. Sometimes, "abiotic" is used to describe the origin of a particular chemical. Abiotic methane, for example, comes from chemical reactions between rocks and water in Earth's crust, unlike biotic methane, which comes from decaying organic matter as well as microbes living in your gut.

How to use it in a sentence: A new "gold rush" of exploration is on for abiotic hydrogen, which forms when rocks react with water deep underground and could be a renewable, carbon-free fuel of the future.

Can you crack our science word of the day puzzle, Chain Word?

Science word of the day: Abiogenesis

Pronunciation: Ay-bye-oh-JEN'-ih-sis

What it means: Abiogenesis is the emergence of life from nonliving matter through chemical processes. Scientists still don't know exactly how abiogenesis happened on Earth. Theories range from lightning strikes that could have scrambled water, methane, ammonia and hydrogen into amino acids and sugars ‪—‬ the building blocks of life ‪—‬ to chemical reactions at deep-sea vents. Abiogenesis is not the same as spontaneous generation, which held that living organisms such as maggots formed directly from decaying matter. It was a compelling idea for anyone who had watched meat rot, but Louis Pasteur, inventor of pasteurization, disproved it in the 1860s by showing that microbes could only grow from preexisting microbes.

How to use it in a sentence: All life on Earth may owe itself to an incident of abiogenesis more than 3.7 billion years ago.

Can you crack our science word of the day puzzle, Chain Word?

Runoff from Greenland's rapidly melting ice sheet could severely disrupt currents in the Atlantic Ocean that regulate the global climate, researchers say. But the fresh water won't trigger the complete and irreversible collapse of the circulation that some research predicts, a new study suggests.

By 2100, Greenland meltwater could cause a reduction in the strength of the Atlantic Meridional Overturning Circulation (AMOC) equivalent to an additional 10% to 20% on top of the weakening that many scientists already expect for this huge system of currents, researchers found.

Previous research suggests the AMOC, which moves heat from the tropics to the Northern Hemisphere and cold water back south toward Antarctica, is at its weakest in more than 1,000 years due to Arctic ice melt and soaring ocean temperatures. Models indicate that the circulation will continue to weaken for decades to come, potentially unleashing freezing weather in Northwest Europe, additional sea-level rise along the U.S. East Coast and droughts around the equator.

The new study revealed that by 2300, Greenland's ice sheet could cause a whopping 40% of AMOC weakening on top of the declines projected by some climate models if we continue to cook the planet. The results highlight the effects on the AMOC of a growing freshwater pulse from Greenland that most climate models currently don't take into account, the authors said.

"By the year 2100, yes, we have something, but the greatest fraction is what we add later," study co-author Jost von Hardenberg, a professor in the Department of Environment, Land and Infrastructure Engineering at the Polytechnic University of Turin in Italy, told Live Science.

Meltwater from the Arctic and Greenland slows the AMOC by preventing the formation of deep currents in the North Atlantic that drive the circulation south toward Antarctica. Deep currents form when masses of cold, salty water sink to the seabed, but inputs of fresh water and rising water temperatures are blocking this step by diluting and warming surface waters.

While Arctic meltwater is commonly integrated into climate simulations, researchers have been slower to include runoff from the Greenland ice sheet in models, partly because this runoff may not be as disruptive as Arctic meltwater on shorter timescales, von Hardenberg said.

"In order to represent correctly the Greenland melt, you need a specific, dynamic model for the Greenland ice sheet. It's nice to have, but it requires a lot of resources to develop," von Hardenberg said

The Community Ice Sheet Model version 2 (CESM2) is one of the few available simulations of the Greenland ice sheet. For the study, von Hardenberg and his colleagues used a global climate model called EC-Earth3, which does not include the Greenland ice sheet. The team added the ice sheet from CESM2 to explore how it might affect the AMOC over the next few centuries. Adding the ice sheet separately enabled them to compare AMOC weakening with and without Greenland, clearly revealing the impact of the ice sheet on the AMOC's strength.

The results, published June 19 in the journal Science Advances, suggest the Greenland ice sheet will have a big influence on Atlantic ocean currents, especially after 2100.

"Greenland starts really melting strongly only after that date," von Hardenberg said. "If you go farther in our simulation — we go up to the year 2300 — that is also when this meltwater really becomes extremely strong."

Yet unlike other studies that show the AMOC collapsing irreversibly under climate change, in this model, the circulation recovered once the team switched off the meltwater or dialed down greenhouse gas emissions. Both the simulations that didn't include the Greenland ice sheet and those that did had similar results, recovering partially when the meltwater was turned off and fully when greenhouse gas emissions were stopped.

The recovery in the model suggests that the AMOC is more stable than previously thought and doesn't suddenly flip from an active state into a collapsed one, von Hardenberg said. "It's consistent with a strong weakening, but not a shutdown," he said.

Overall, the findings show that it is important to include the Greenland ice sheet in climate models — something von Hardenberg and his colleagues are planning to do in the next version of the EC-Earth3 model.

"It's really something which is worthwhile doing to better constrain the uncertainty of these future simulations," von Hardenberg said. "If we have a larger set of models which include this component, we will be in a better position to try to answer the question, 'How much do we expect AMOC to decrease in different scenarios?'"

Other experts agreed that integrating the Greenland ice sheet in climate models will increase the accuracy of AMOC predictions.

"What makes the study particularly interesting is that it directly tests a process that has often been highlighted as an important source of uncertainty in future AMOC projections," said Jonathan Baker, a senior climate scientist at the Met Office in the U.K. who was not involved in the study.

The results are consistent with previous research showing that Greenland meltwater causes additional AMOC weakening, but whether the system could collapse is still uncertain, given that the team used only one model, Baker told Live Science in an email. "Repeating these experiments across a wider range of models will be important to assess how robust the findings are," he said.

Nicholas Foukal, an assistant professor at the University of Georgia's Skidaway Institute of Oceanography who was not involved in the study, said he doesn't think the use of a single model limits the analysis.

"I think this result is robust and I am glad to see the authors come to this conclusion in such a high-resolution and realistic coupled climate model," Foukal told Live Science in an email. "This finding also agrees with other modeling results that require immense amounts of fresh water, much more fresh water than is available on Greenland, to cause irreversible change in the AMOC."

However, a third expert said the model used in the study is unrealistic, because its parameters make the AMOC more resilient than those of other models. Therefore, the study should be replicated in other models to draw unbiased conclusions.

"While the experiment reported is interesting, its outcomes are neither surprising nor should be interpreted as exemplary for the whole model ensemble," Sybren Drijfhout, a professor of physical oceanography at the University of Southampton in the U.K., told Live Science in an email.

Researchers should investigate the impact of the Greenland ice sheet on the AMOC further, von Hardenberg said. "It would be interesting in the future to check it [the AMOC's recovery with Greenland meltwater] with other models, but of course it's encouraging to see it in one case," he added.

An amateur astronomer's plans for a camping vacation two years ago transformed into a possible crater find in Canada's north.

Amateur astronomer Joël Lapointe, using Google Maps to figure out his route for the 2024 vacation, saw some odd terrain in Quebec's Côte-Nord region centered on Lake Marsal. Lapointe suspected it was an impact crater from a meteorite, and made a report on Impact Earth — a crowdsourcing website for craters with Canada's Western University in London, Ontario near Toronto. Western planetary geologist Gordon Osinski made a visit to the region in 2025, provisionally not only confirming the crater, but saying it's probably one of the biggest discovered in recent years. The 390-million-year old feature is roughly 15 miles (25 kilometers) wide.

In an email interview with Space.com while on travel in Scotland, Osinski — known as "Oz" by the space community — said to his knowledge the last discovery of that scale was the approximately 31-km (19-mile) Hiawatha structure, also possibly a crater, spotted in Greenland in 2018. "However, that structure is completely buried by ice, so its diameter is uncertain and there is still some controversy about its origin," Oz said.

But in the case of the new crater, called Uhackatik with approval from the Innu Council of Ekuanitshit in whose traditional lands the crater lies, there is no doubt at all where the crater came from. Oz's expedition to the area revealed "shock metamorphic effects", which are deformations to the rocks induced by the shock waves and heating produced by a meteorite impact.

"Impact melt rocks are like they sound: large volumes of rock that are melted by the impact event, but then cool and crystallize to look a lot like volcanic rocks," he said. "Finding these preserved — as they are usually some of the first parts of a crater to be eroded — was a big surprise."

While most of the features are microscopic, Oz said in the field he and his collaborators could easily see "shatter cones", which are branching features in rock layers produced by the shockwave of impact. The research is not yet peer-reviewed, but it will be presented at the 88th Annual Meeting of the Meteoritical Society in Frankfurt, Germany in August.

While 400-million-year-old impact craters on Earth are hard to find, as geologic activity as well as erosion change their features over time, the precious evidence is helpful for scientists to better understand meteorite impacts on the moon, Mars and other rocky extraterrestrial bodies.

In terms of age, Oz noted, the moon's prominent Tycho crater best represents what Uhackatik probably looked like 390 million years ago. But On Earth, one of the best comparisons to Uhackatik is a moon-like crater used to help the Artemis II astronauts get ready for their moon mission this year.

That Earth crater is called Kamestastin (also known as Mistastin) in northern Labrador, Canada. Oz regularly runs expeditions there in consultation with the Mushuau Innu First Nation, as the crater lies within their traditional hunting grounds. Kamestastin includes anorthosite, a common mineral found in craters at the moon's south pole, where NASA hopes to land astronauts under the US-led Artemis program.

Artemis II astronauts Jeremy Hansen (from the Canadian Space Agency or CSA) and Christina Koch (NASA), as well as CSA backup astronaut and lunar-flyby capcom Jenni Gibbons, did an expedition to Kamestastin crater in 2023 alongside Oz and collaborators.

"For comparative craters [to Uhackatik], Kamestastin is actually a great one as the size is very similar," Oz said. "Kamestastin is well-preserved and I've worked there a lot … so in my mind, I was using Kamestastin as a template for exploring this new potential crater."

To fully confirm Uhackatik's extraterrestrial origin, Oz and collaborators are examining samples microscopically for more evidence of shock effects, such as chemistry indicating a high-temperature melt, or deformation effects in the quartz. In the meantime, Oz's lunar work with NASA continues: he will be part of the geology teams supporting the moon-landing astronauts during the Artemis 4 and 5 missions, which will touch down as soon as 2028.

This eye-catching astronaut photo shows a cloud of sediment swirling into a giant, milky-green vortex in one of Europe's largest lakes.

Lake Skadar (also known as Shkodër, Shkodra or Scutari) is the largest lake in Southern Europe, with a surface area between 140 and 200 square miles (360 to 520 square kilometers), depending on the time of year. It is situated on the border between Montenegro, which surrounds the western half of the lake (left in the photo), and Albania, which encircles the lake's eastern shore. The body of water is split 65% to 35% in Montenegro's favor.

The lake's main water source is the Morača River, to the northwest, and its biggest outlets are the Bojana and Drin rivers, which start at the lake's easternmost point and eventually drain into the Adriatic Sea, which is partially visible in the bottom left of the photo. Skadar's southern shore is also hugged by a lofty mountain range, known as the Dinaric Alps.

During late winter and early spring, the lake's water level rises, and it usually fills with a milky-green substance that often gets whipped into a vortex by a combination of wind-driven surface currents and the natural flow of water between the lake's major inlets and outlets.

The swirling material looks very similar to blooming algae, but it is actually made of sediments — predominantly limestone and dolomite — that wash into the lake from the Dinaric Alps and other nearby mountains as the snow melts.

Skadar is a karst lake, meaning it was once a cave system that flooded and eventually collapsed, likely because the caves were made from the same easily erodible rocks that now swirl on the lake's surface, according to NASA's Earth Observatory. The lake is a "cryptodepression" because most of the lake's floor is below sea level.

The lake originally formed during the Cenozoic Era (66 million years ago to the present), according to the International Lake Environment Committee Foundation's World Lake Database. It is home to several small islands, some of which can be seen in the photo along the lake's southern shore. These include Beška, which is home to a pair of 600-year-old churches, and Grmožur, where the remains of a 19th-century fortification loom above the lake's surface.

The shipwreck of a paddle steamboat, named Skanderbeg, lies along the lake's western shore. Local partisans sank the vessel in 1942 after Italian soldiers commandeered it during the Axis occupation of Yugoslavia in World War II. When the lake's water levels are at their lowest, part of the shipwreck rises above the surface.

Skadar Lake is a biodiversity hotspot and has protected wildlife status on both sides of the Montenegro-Albania border. It is a particularly important site for birds; more than 280 avian species call it home, including the Dalmatian pelican (Pelecanus crispus) and several endemic species, according to BirdLife International.

The lake also hosts around 50 freshwater snail species ‪—‬ more than any other lake on Earth, according to a 2013 study.