MegaTsunami was Triggered by Glacial Retreat

Photo of Tracy Arm after megatsunami on 10 August 2025 (from Wikimedia) 9 August 2026 A year ago, on 10 August 2025, a mega tsunami flooded the Tracy Arm fjord south of Juneau, Alaska. It began at the foot of the South Sawyer Glacier. embedded Google map of showing South Sawyer Glacier at the head of Tracy Arm. Note Juneau near top of the map at Sitka near bottom left. The tsunami was truly “mega” with a wall of water 1,578 ft tall (481m). To put this in perspective, the wave would have over-topped Acadia National Park’s highest peak, Cadillac Mountain (1,530 feet) and was almost twice the height of the U.S. Steel Tower in Downtown Pittsburgh. The tsunami was triggered not by an earthquake but by a landslide at the point where the South Sawyer Glacier has retreated. Fortunately it happened so early in the morning that no one was there. At midday as many as 100 sightseeing boats would have been in the fjord. This simulation by Patrick Lynett shows what it would have looked like from a…