Tracy Arm Fjord, in southeastern Alaska ⁠within the Tongass National Forest, presents a majestic vista, with a narrow sea inlet surrounded by towering granite cliffs, waterfalls and glaciers. One morning last year it also was the site of a powerful landslide that triggered a huge localised tsunami. Researchers have now determined that the tsunami on August 10, 2025, was the second-highest ever recorded, with a wave reaching up to 481 metres (1,578 feet) tall – higher than New York City’s Empire.