Columbia Glacier Terminus

View of Columbia Glacier's terminus as it enters the waters of Prince William Sound. Columbia Glacier is one of Alaska's many tidewater glaciers, and it has been the focus of numerous studies due to its unusually high rate of retreat. The glacier has retreated nearly 20 km (12.43 mi) since 1980. In fact, it has receded so quickly that parts of it began floating in 2007, contrary to how most tidewater glaciers behave. In this picture, taken after the glacier developed its floating sections, the terminus is 5 km (3.12 mi) wide and between 20 and 70 m (65.6-229.7 ft) tall.