The rugged coast of Labrador, northeast Canada, owes much of its topography to glaciation during the last ice age, which peaked some 20,000 years ago. The numerous fjords and inlets visible here were hollowed out by the ice. The excavated, ground-up rock was deposited as a loose gravely sediment called ‘till’. Modern streams and rivers erode the soft till, washing into the sea great plumes of sediment. The right half of this shuttle photograph shows the sediment stirred by strong coastal currents. The image covers an area 420 kilometers wide.