The bay contains seven tidewater glaciers, which flow from the mountains to the sea. As the ocean undermines the frozen massifs, giant chunks—up to 60 meters high—crash into the water. Known as “calving,” these icefalls tend to be spectacular. Glacier Bay National Park shelters the world’s largest concentration of actively calving tidewater glaciers, which remain the park’s biggest draw. Stop and listen to the roar of icebergs being born, which the Tlingit people call “white thunder.”
