"300 feet tsunami at 170 kmph in 7 minutes: Explainer video about what exactly happened during Nepal Flash flood goes viral. Watch, goosebumps guaranteed

A terrifying sequence of events unfolded in Nepal after a glacier collapse sent an enormous surge of water, ice and debris racing down a Himalayan gorge. An explainer video breaking down what happened, almost minute by minute, has gone viral, highlighting the extraordinary speed and scale of the disaster.

The video describes a wall of water and debris reaching around 300 feet in height and travelling at an estimated 105 miles per hour, or nearly 170 kmph at one point. Most startlingly, the flood reached a building near the China-Nepal border just 7 minutes and 40 seconds after the glacier collapse was recorded.

But the video uses satellite imagery, geography and timestamps to explain how a collapse high in the Himalayas could turn into such a destructive flash flood within minutes.

Nepal Flash Flood Viral Video Expalins exactly what happened in the Himalayas

Nepal is home to the Himalayas, including Mount Everest, and has more than 3,000 glaciers. These frozen reservoirs are increasingly vulnerable to melting as temperatures rise. The video focuses on the Yala Glacier, where the collapse occurred at an elevation of roughly 16,700 feet.

The glacier had already been changing. According to the analysis presented in the video, the Yala Glacier lost about 33 feet of water equivalent over a decade, an indication of significant ice loss. Nepal was experiencing an exceptionally warm summer, according to the video. As temperatures rose, fresh snow on the glacier melted and exposed darker, rock-filled ice underneath.

That changed the way the surface absorbed heat. Fresh snow is highly reflective. Scientists refer to this property as albedo. A bright snow-covered surface reflects a large portion of incoming sunlight. Once that snow disappears, the darker surface absorbs more heat, potentially accelerating melting. And then the glacier gave way.

The collapse started high above the valley

The area involved in the collapse was around a mile wide, with the glacier sitting more than 16,000 feet above sea level. The video identifies the precise time at which the US Geological Survey registered the collapse: 10:52:10. What followed was a rapid descent.

The terrain below the glacier had another crucial feature. A channel carved by earlier glacial retreat created a natural pathway down the mountain. The video compares it to a half-pipe on a ski slope.

Instead of spreading evenly in every direction, the enormous mass of ice, water and debris was funnelled into a relatively narrow gorge. The elevation difference was huge. From the glacier to the river below, the route drops approximately 7,000 feet over just 3.4 miles. That steep descent helped turn the collapsing material into something far more destructive.

Ice turned into a massive surge of water

As the glacier came crashing down the mountainside, the force was so great that the ice was effectively pulverised. The result was not simply a giant block of ice sliding downhill. It became a rapidly moving mixture of water, ice, sediment and debris.

And because the surrounding Himalayan terrain is steep and confined, the water had nowhere to spread easily. It rose. According to helicopter surveys cited in the video, the peak debris line reached roughly 300 feet. That created what looked like an enormous moving wall of water and debris.

A 300-foot wall rushing through a narrow Himalayan valley is almost impossible to visualise. Survivors described the phenomenon as resembling a tsunami.

It took less than eight minutes to reach the border checkpoint

This is where the timeline becomes particularly shocking. The China-Nepal border checkpoint shown in the video is around 13.4 miles from the Yala Glacier collapse site.The route also loses roughly 10,500 feet in elevation over that distance.

For comparison, the video points out that the Mississippi River drops only around 750 feet over a roughly 1,700-mile journey from Minneapolis to New Orleans. The Himalayan route was dramatically steeper.

The surveillance camera footage provided another crucial timestamp. The first contact with the building was recorded at 10:59:50. The glacier collapse had been registered at 10:52:10. That is a difference of 7 minutes and 40 seconds.

Over the roughly 13.4-mile distance, the video calculates an average speed of around 105 mph, equivalent to nearly 170 kmph.

That does not mean the flood travelled at exactly 170 kmph throughout its entire journey. It is an average-speed estimate over that section, based on the timestamps and distance presented in the video. Still, the figure explains why people had so little time to react.

A 300-foot wall of water hits the valley

By the time the surge reached the border area, it was carrying far more than water. Ice and sediment had been swept along the route. Anything in its path could become part of the moving mass.

The force of the flood was also strong enough to send part of the surge backwards. After smashing into the riverbank, some of the water travelled roughly 1.5 miles upstream, while the main flow continued downstream. The disaster did not end at the border checkpoint. It kept moving.

What happened 32 miles downstream?

Around 32 miles farther downstream, the flood reached Trishuli Bazaar, according to the video. By then, the wall of water was no longer 300 feet high.

The terrain had become less steep, allowing some of the energy to dissipate and the flood to slow. But the destruction remained extensive.

The video shows areas crushed by the water and a bridge that had been swept away. The location was approximately 45 miles downstream from where the glacier collapse began. The flood had travelled a remarkable distance after starting at extreme elevation, gradually losing speed and height while continuing to carry destructive amounts of water and debris.

Why the seven minutes matter

The most frightening part of the video is perhaps not the 300-foot height or even the nearly 170 kmph speed. It is the timeline. A collapse high in the Himalayas was detected at 10:52:10. Less than eight minutes later, the resulting surge had reached a building more than 13 miles away.

That short window shows how quickly a glacier collapse can transform into a major downstream hazard when steep terrain, large quantities of ice and water, and narrow valleys combine. The video describes the event as an extraordinary disaster captured on camera.

For viewers watching the footage after the event, the scale is shocking. For people caught downstream, the speed would have made the approaching wall of water and debris even more terrifying.