A recent analysis has unveiled that a colossal megatsunami triggered by a landslide in Alaska ranks as the second highest ever documented. This event, which occurred in August 2025, serves as a stark reminder of the escalating dangers presented by climate change, particularly the melting of glaciers. The findings have sparked urgent discussions among scientists about the implications for both the environment and human safety.
A Catastrophic Event Unveiled
Last summer, a massive wave surged through a remote fjord in southeast Alaska, wreaking havoc on the landscape. Initially overlooked, the incident has gained attention following a thorough scientific investigation revealing that a staggering 64 million cubic metres of rock—equivalent to 24 Great Pyramids—plummeted into the fjord. This enormous mass of rock generated a wave that reached nearly 500 metres in height.
The timing of the event, occurring in the early morning hours, may have spared cruise ships and tourists from disaster. Dr. Bretwood Higman, an Alaskan geologist who assessed the aftermath at Tracy Arm Fjord, stated, “It was a close call. We know that there were people that were very nearly in the wrong place. I’m quite terrified that we’re not going to be so lucky in the future.”
Understanding Megatsunamis
Megatsunamis are distinct from their more commonly known counterparts. While traditional tsunamis are often triggered by underwater earthquakes or volcanic eruptions and can travel vast distances across oceans, megatsunamis typically result from large landslides into bodies of water. These waves are usually localised, dissipating quickly but can be devastating in their immediate vicinity.
The largest recorded megatsunami occurred in the 1950s and surpassed 500 metres in height. The latest event in Alaska now holds the title of the second largest, raising concerns about the potential for future occurrences.
Climate Change and Glacier Melting
Dr. Stephen Hicks from University College London led a research team that integrated fieldwork, seismic data, and satellite imagery to understand the events leading to the megatsunami. Their findings indicate that the retreat of glaciers—accelerated by climate change—has weakened the stability of the surrounding rock formations. “The glacier was previously helping to hold up this piece of rock,” Dr. Hicks explained. “When the ice retreated, it exposed the bottom of the cliff face, allowing that rock material to suddenly collapse into the fjord.”
This alarming trend suggests that as glaciers continue to melt, the risk of similar catastrophic events will only escalate. Dr. Higman expressed his concerns, asserting that the frequency of megatsunamis has likely increased significantly, estimating them to be “maybe in the order of 10 times as frequent as they were just a few decades ago.”
The Call for Action
In light of these findings, scientists are urging for enhanced monitoring of regions in Alaska that are susceptible to megatsunami events. Some cruise companies have already begun to reconsider their itineraries, ceasing operations in Tracy Arm due to safety concerns. The juxtaposition of tourism’s allure and the inherent dangers of visiting these breathtaking yet precarious landscapes presents a complex challenge.
Why it Matters
The Alaskan megatsunami serves as a critical wake-up call about the urgent need to address climate change and its far-reaching impacts. As glaciers melt and geological instability increases, both environmental and human safety are at risk. The recent events highlight the necessity for proactive measures to safeguard vulnerable areas and educate the public about the potential dangers lurking within nature’s beauty. Understanding these risks is essential as we strive to protect both our planet and the lives of those who seek to explore its wonders.