Story: Charting the sea floor
Where the land meets the sea, it doesn’t end there. In the deep, dark world beneath the oceans, there are mountains, valleys, plateaus and volcanoes. The early explorers first charted this dramatic and inaccessible terrain by lowering ropes, weighted with lead, to measure water depth. Today’s map makers use more complex technology – multiple sound beams sweep across the seabed to give a precise record of its depth, shape, sediment character and much more.