On August 10, 2025, an enormous natural disaster occurred in Alaska. At 5:26 a.m. a big piece of rock broke off the mountain wall and crashed into Tracy Arm Fjord.
This wedge of rock had a volume of roughly 64 million cubic meters. When this enormous weight hit the water, it created one among the most important waves ever recorded in modern times.
According to Science In a journal written by Dan H. Shugar and his colleagues, the utmost run-up height of this megatsunami was 481 meters (1,578 ft). This is way taller than the enduring Petronas Twin Towers in Malaysia, which rise to a height of 451.9 meters.
How did the megatsunami occur?
Most people imagine that tsunamis “only” form from earthquakes under the ocean. However, when a landslide occurs in a narrow body of water corresponding to a fjord, the results are extremely destructive.
The steep partitions of the Tracy Arm acted like a funnel, trapping the water and forcing all of the kinetic energy into the tight space. Dan H. Shugar stated that the disaster began with a breaking wave 100 meters high. This initial wave moved through the fjord at a speed of over 70 meters per second.
The power of this moving water was enormous. As the wave broke through the fjord, it ripped off all of the trees, dirt and bushes from the rocky partitions. This destruction left a really distinct visual line within the landscape that scientists call the slash line.
This event also caused a really unusual geological phenomenon. When the landslide displaced the water, all the fjord began to behave like a large bowl. Water began to flow backwards and forwards repeatedly, which scientists call a landslide-induced seiche.
As the water moved backwards and forwards, it created constant, rhythmic vibrations that traveled on to the bottom. This seiche generated a monochromatic 66-second seismic signal that shook for 36 hours.
The impact of climate change
This landslide was not a random coincidence. The mountainside has actually remained untouched for hundreds of years. It only collapsed because global warming weakened the geological structures that held it together.
The retreat of the South Sawyer Glacier left the slope with none physical support. Local summer temperatures in the world have increased by 1.1 degrees Celsius since 1875. As the glacier melted and retreated, the mountain lost its natural rock support, making a significant collapse inevitable.
As global temperatures rise, Arctic glaciers will proceed to thin and melt. This implies that this sort of dangerous landslides will probably turn into rather more common in the long run. This is a major problem because these distant fjords in Alaska are popular routes for giant tourist cruise ships.
The rapid retreat of glaciers attributable to climate change has significantly increased the chance of those monstrous waves in coastal environments. As the positioning is one among Alaska’s famous tourist hotspots, scientists at the moment are attempting to use advanced seismic monitoring systems to detect microseismicity, or tiny ground tremors that occurred 24 hours before the landslide, to provide people an early warning next time.
