The Devastating 2025 Afghanistan Earthquake: A Geological Analysis

When the Mountains Shook: The Story Behind Afghanistan’s Deadly 2025 Earthquake

On the night of Sunday, August 31st, 2025, people in the mountains of eastern Afghanistan were settling in for what they thought would be an ordinary evening. In remote villages along steep valleys, families gathered in mud-brick homes, while the nearby cities of Asadabad and Jalālābād were winding down after a hot summer day. Just before midnight, at 11:47 p.m. local time, the ground began to move — at first a rumble, then a violent shudder that sent walls crashing down and triggered avalanches of rock.

In just a few seconds, a magnitude 6.0 earthquake had ripped through Kunar Province, close to the border with Pakistan. The shaking radiated out across the region, toppling homes, collapsing shops, and shaking people awake hundreds of kilometres away. In Kabul and Peshawar, more than 200 kilometres from the epicentre, residents reported swaying furniture and rattling windows. For those who lived closer, especially in the narrow valleys of Kunar and Nangarhar, the quake was catastrophic.

*Image is of the quake details taken from Geoscience Australia.

The Human Cost

By the time the sun rose, the scale of devastation was becoming clear. More than 1,400 people had been killed, and over 3,000 others injured. Whole villages, such as Mazar Dara and Andarlachak, were flattened. In some communities like Wadir, nearly 90% of the residents were dead or wounded. Survivors described digging graves with pickaxes, burying neighbours and family members side by side.

Around 5,400 homes were completely destroyed, many of them traditional adobe and stone houses. These structures are cheap to build and stay cool in the heat, but they crumble like sand under strong shaking. And in these remote valleys, where access to reinforced concrete and rebar is scarce, adobe is often the only option.

As if the earthquake itself wasn’t enough, landslides piled onto the disaster. The Hindu Kush mountains are rugged, with slopes cut by rain and gravity into unstable piles of rock and soil. Add the monsoon rains of late summer, and they become primed to fail. When the quake struck, huge swathes of hillside slumped down, burying roads and cutting off survivors from help. Entire valleys were left isolated, reachable only by helicopter — and Afghanistan has few of those to spare.

The United Nations estimated at least 12,000 people were directly affected — either injured, displaced, or suddenly without a home. Hospitals were quickly overwhelmed. Supplies of medicine and food were stretched thin. For families who survived the initial quake, the days afterward were a struggle to find shelter and clean water in a landscape of wreckage.

What Happened Geologically?

So, what exactly happened under the ground to unleash this destruction? The short version is this: a shallow thrust fault in the upper crust gave way, releasing centuries of accumulated strain in less than half a minute.

If you picture the tectonic setting of Afghanistan, it’s like the seams of a crumpled rug. The country sits on a collision zone between the Indian and Eurasian Plates. The Indian Plate is plowing northward at about 40 millimetres per year — about the speed your fingernails grow. Over millions of years, that relentless shove has built the Himalayas, the Pamirs, and the Hindu Kush. But the crust doesn’t just smoothly fold; it breaks along faults, and each slip is an earthquake.

There are several big fault systems in Afghanistan. The most famous is the Chaman Fault, a huge left-lateral strike-slip system (imagine two blocks of crust grinding past each other horizontally) that runs for hundreds of kilometres along the country’s south. To the north, the Hari Rud Fault cuts across western Afghanistan. But in the east — right where this quake struck — the main players are thrust faults along the Spin Ghar (Safēd Kōh) mountain front.

*Image depicts the strike-slip fault nature of the Chaman Fault.

*Image depicts thrust faulting

A thrust fault is like a giant ramp in the crust. One side of the fault gets shoved up over the other, crumpling the rocks and shortening the landscape. That’s exactly what the August quake did. Seismologists looking at the moment tensor solutions (the seismographic fingerprint of the quake) found the slip was reverse (thrust) motion, dipping at around 40–60 degrees. In plain language: one block of crust lurched upward and over its neighbour, squeezing the land from north to south.

The depth was only about 10–15 kilometres. That’s shallow for an earthquake, which is why the shaking was so strong at the surface. Compare that to the infamous deep earthquakes of the Hindu Kush — which happen at 200 kilometres or more — and you can see why this one, though smaller in magnitude, was so deadly.

*Image depicts some of the major faults in Afghanistan. Note: Not all faults are pictured. Only the major ones close to the Earthquake epicentre.

*Image depicts some of the fault lines near the quake epicentre.

Which Fault Was It?

Now, here’s where things get tricky: scientists don’t yet know the exact fault that ruptured. Many faults in Afghanistan are poorly mapped, especially in the east where decades of conflict have limited fieldwork. And not every earthquake ruptures all the way to the surface — many are “blind thrusts” that break at depth but leave no obvious scar for geologists to see.

What we do know is that the orientation of the rupture fits the geometry of the Spin Ghar thrust system near Jalālābād. This system runs east–west and accommodates some of the north–south squeezing as India slams into Eurasia. The fault likely dips northward, pushing the mountains upward a little more with each event.

To figure out exactly which fault segment failed, scientists are now waiting on satellite radar data (InSAR). These images can detect tiny changes in the ground surface — even a few centimetres of uplift or subsidence. When those patterns are mapped, they reveal the shape of the fault at depth. So in the coming weeks, expect clearer answers. But for now, we can say: it was almost certainly a local thrust fault along the Spin Ghar front, not one of the giant strike-slip faults farther away.

*Image depicts the major fault lines beneath Afghanistan. The Chaman fault isn't listed on this map, but it is shown as the fault that runs north-south in the bottom right side of the image, where it briefly cuts through Pakistan before heading north. 

The Herat Fault (also known as the Hari Rud fault) is listed on the map.

The Aftershocks

As with most major quakes, the story didn’t end with the mainshock. On September 2nd, a magnitude 5.2 aftershock rattled the region, this time about 50 kilometres north-northeast of Jalālābād. That quake, though smaller, was still powerful enough to trigger fresh landslides and shake down buildings that had been left cracked and unstable.

Aftershocks are the crust’s way of adjusting after the main rupture. They can continue for weeks or months, usually tapering off in both size and frequency. For survivors living in tents or under tarps, each tremor brings fresh fear — will another big one come? For engineers and aid workers, aftershocks mean extra caution: even slightly damaged buildings can collapse if shaken again.

*Image depicts the three aftershocks that occurred (in white) and the main quake epicentre (red).

Why the Damage Was So Severe

A fair question is: why did a magnitude 6.0 quake, which in other parts of the world might cause limited fatalities, kill more than a thousand people here? The answer lies at the intersection of geology, geography, and construction.

Shallow Depth: At around 10 kilometres, the quake was close to the surface. Shallow quakes deliver much stronger shaking to communities right above them.

Steep Terrain: The Hindu Kush is a land of narrow valleys hemmed in by steep slopes. That topography both amplifies shaking and triggers landslides, which can bury villages or block lifelines like roads and rivers.

Building Materials: The majority of homes in rural Afghanistan are built of unreinforced adobe or stone, with heavy earthen roofs. These materials have almost no resistance to lateral shaking. When the ground moves sideways, walls simply crumble.

Isolation: Many villages are hours — even days — from the nearest paved road. When the quake struck and landslides blocked the few existing routes, rescue crews simply couldn’t reach people quickly. Survivors dug with their hands or farm tools to rescue loved ones.

Put together, these factors turned a moderate-sized earthquake into a disaster of national scale.

How It Fits into the Bigger Picture

Afghanistan has been hit hard by earthquakes before. In 2022, a quake in Paktika and Khost provinces killed more than 1,000 people. In 2023, a series of tremors around Herat in the west caused hundreds of deaths. Each time, the pattern is the same: shallow quakes striking vulnerable communities with fragile infrastructure.

Geologically, this isn’t surprising. The country is caught in one of the most active tectonic zones on Earth. To the south, the Chaman Fault grinds like a miniature San Andreas, sliding blocks of crust sideways. To the north, the Hari Rud Fault slices east–west. And deep beneath the Hindu Kush, the subducting Indian slab is literally tearing apart, generating some of the world’s deepest earthquakes.

But the eastern Kunar quake of 2025 highlights the shallow thrusts — the mountain-front faults that quietly accumulate stress until, every few decades or centuries, they let go with devastating force. These are the faults that build the mountains, lifting peaks like Spin Ghar higher with each slip, but also threatening the people who live in their shadow.

Looking Ahead

What happens now? From a geological perspective, the rupture released some local strain, but the India–Eurasia collision is ongoing. The plates haven’t stopped moving, and stress will continue to build. That means more earthquakes in the years and decades ahead — some shallow and deadly, others deep and less destructive but still powerful.

For the people of Afghanistan, the challenge is rebuilding in ways that reduce vulnerability. Strengthening housing, improving roads, and developing early warning and disaster response systems can save lives. But in a country facing economic hardship and political isolation, those solutions are easier said than done.

For scientists, this quake is an opportunity to learn. Satellite data, seismic aftershock networks, and field studies will reveal more about the fault that ruptured. Each new piece of knowledge sharpens the map of Afghanistan’s hidden faults — information that can, someday, inform better planning and resilience.

Final Thoughts

The August 2025 earthquake in eastern Afghanistan was more than just a number on the seismograph. It was the violent release of geologic forces that have been shaping Central Asia for tens of millions of years. A shallow thrust fault slipped, lifting part of the Spin Ghar front by a few centimetres and shaking human settlements with devastating effect.

But beyond the tectonics, it was also a human tragedy: families buried under collapsed mud homes, villages cut off by landslides, survivors digging graves in the moonlight. It’s a reminder that geology doesn’t just build mountains — it also decides, in moments, the fate of the people who live among them.

And as long as the Indian Plate keeps pushing north, Afghanistan will remain on the seismic front line, where the earth’s slowest collisions sometimes make themselves felt in the most sudden and tragic ways.

Here's the video we made for this on the OzGeology YouTube channel: