Alaska’s 2025 Tracy Arm Landslide and Tsunami: New Study Reveals Unprecedented Risks for Fjords

The 10 August 2025 landslide and tsunami at Alaska’s Tracy Arm fjord has been meticulously analyzed in a landmark study published by Science (Shugar et al., 2026). This open-access paper provides the most comprehensive assessment of such an event to date, offering critical insights into the growing threat posed by large landslides in fjord settings.

Key Findings from the Study

The research reveals that the landslide generated a 481-meter run-up tsunami, narrowly avoiding a human catastrophe. Had a cruise ship or tourists been in the area at the time, the consequences could have been devastating. The study underscores the increasing frequency of landslides in Alaska’s fjords, a trend exacerbated by rapid climate change.

The landslide’s sheer scale is staggering: the crown of the collapse reached over 1,000 meters above the fjord, with a subaerial volume exceeding 63 million cubic meters. An aerial image from the U.S. Geological Survey (USGS) captures the aftermath, showing the exposed rock surface where the mountainside gave way. The retreat of South Sawyer Glacier—once thick enough to stabilize the slopes—has further heightened instability in the region. Credit: Cyrus Read/U.S. Geological Survey

Why This Event is a Turning Point

While large landslides in fjords are not uncommon, this study represents the first systematic analysis of such a catastrophic event. The authors emphasize that these environments are increasingly vulnerable due to:

• Climate change: Melting glaciers and thawing permafrost destabilize slopes.
• Human activity: Fjords attract tourism, fishing, and local communities, increasing exposure to risk.
• Seasonal patterns: Landslides are more likely in spring and summer, when human presence peaks.

The study warns that current resilience to tsunamis generated by such events remains critically low. For context, a potential landslide-triggered tsunami in New Zealand’s Milford Sound—linked to an Alpine Fault earthquake—could mirror the Tracy Arm disaster.

Industry and Policy Responses

In response to the findings, cruise companies have already begun revising itineraries to avoid high-risk fjord areas. The paper calls for urgent policy changes to address the growing hazard, including:

• Enhanced monitoring of unstable slopes in fjord regions.
• Stricter regulations for tourism and infrastructure in vulnerable zones.
• Public education on tsunami preparedness in coastal communities.

Expert Recommendations

"The Tracy Arm event is a wake-up call. Fjords are dynamic environments, and our understanding of their hazards must evolve with the climate. This study provides a roadmap for mitigating risks before the next disaster strikes."

For those seeking deeper insights, the full paper (Shugar et al., 2026) is available as an open-access resource. Additional coverage and explanations can be found in AGU Eos’ comprehensive write-up, which breaks down the science for broader audiences.