Massive Alaska megatsunami was second largest ever recorded

Massive Alaska megatsunami was second largest – Scientists have identified a recent colossal ‘megatsunami’ in Alaska, which ranks as the second tallest ever documented, underscoring the growing dangers linked to glacial retreat. Last summer, a monumental wave surged through a secluded fjord in southeast Alaska, leaving widespread destruction in its path. Initially, the event went unnoticed by the public, but a new study has unveiled its origin: a massive landslide triggered by glacial melting. The incident, though brief, highlights the unpredictable power of nature and the potential threats to coastal regions.

Unveiling the Scale of the Disaster

The landslide involved an astonishing 64 million cubic metres of rock, equivalent to the combined volume of 24 Great Pyramids of Giza, which plunged into the fjord’s depths within a minute. This sudden collapse generated a wave nearly 500 metres high, a phenomenon that left the area in shock. Dr. Bretwood Higman, an Alaskan geologist, noted that the wave’s intensity was so great it could have engulfed cruise ships had it occurred during daylight hours. “It was a close call,” he remarked, emphasizing the near-miss for tourists.

Dr. Bretwood Higman, an Alaskan geologist, described the event as “a close call,” noting that “there were people very nearly in the wrong place.” He added, “I’m quite terrified that we won’t be so fortunate in the future.”

The wave, which occurred in the early hours of the morning, was a stark reminder of how quickly natural disasters can strike without warning. While the timing spared large cruise vessels, it still left behind a trail of devastation. Dr. Higman visited the site weeks after the incident at Tracy Arm Fjord, a popular tourist destination. His observations revealed a landscape transformed by the event: broken trees littered the mountainside, and vast sections of rock had been stripped of soil and vegetation.

Understanding Megatsunamis

Megatsunamis, as the researchers call them, occur when a landslide—whether caused by an earthquake or the loosening of rock—impacts water. These waves are typically localized, losing energy quickly as they move through the fjord. In contrast, traditional tsunamis are generated by seismic activity in the open ocean and can travel thousands of miles before striking coastal areas. Such events, like the 2011 Japan tsunami, often result in widespread destruction and loss of life.

Dr. Stephen Hicks of University College London explained that the glacier was “previously helping to hold up this piece of rock,” and its retreat exposed the cliff face, “allowing that rock material to suddenly collapse into the fjord.”

The study, published in *Science*, combines field data, seismic recordings, and satellite imagery to trace the sequence of events. The team discovered a domino effect: as the glacier melted, the stability of the mountainous terrain was compromised, leading to the landslide. This collapse into the fjord produced the towering wave, which was confirmed to be the second-largest recorded in history. The largest megatsunami, from the 1950s, reached over 500 metres in height, making this new event a significant benchmark.

The Role of Climate Change

Alaska’s vulnerability to megatsunamis stems from its rugged topography, narrow fjords, and frequent seismic activity. However, researchers warn that climate change is intensifying these risks. The accelerated melting of glaciers is not only reducing the landmass that supports cliffs but also increasing the likelihood of sudden rock collapses. “The glacier was acting as a stabilizing force,” Dr. Hicks said. “Now, with its retreat, we’re witnessing a chain reaction that could become more frequent.”

Dr. Higman, who has dedicated decades to studying such phenomena, is concerned about the growing frequency of these events. “I’m pretty confident these are increasing not just a little, but substantially,” he stated. “It might be ten times more frequent than a few decades ago.” This projection is based on data showing a rise in both the number and magnitude of landslides in the region. The implications are clear: areas once considered safe are now at higher risk.

Impact on Tourism and Safety Measures

The incident has prompted a reevaluation of safety protocols in Alaska’s fjords. Tracy Arm Fjord, a prime location for cruise ship excursions, is now under scrutiny. Some operators have announced plans to suspend visits to the area, citing the threat posed by the recent event. Dr. Higman highlighted the paradox of modern travel: “More people are venturing into remote regions, often to experience natural beauty and learn about climate change. But these areas are also becoming more dangerous.”

Scientists are urging broader monitoring of potential hazards, particularly in regions where glaciers are retreating rapidly. They argue that the combination of melting ice and unstable terrain could lead to more frequent and severe megatsunamis. The researchers emphasize the need for real-time tracking of landslides and early warning systems to mitigate risks. “This isn’t just a one-off occurrence,” Dr. Higman said. “It’s a growing trend we need to address.”

Glacier melt, driven by rising