Hawaii is a state of rugged slopes and abrupt changes in elevation. This is the result of the erosion of the volcanic surfaces by moving water. Sea cliffs cut by waves form a spectacular edge to parts of the islands. Some small streams on the northeast side of the Big Island drop over such cliffs directly into the sea. Stream erosion has heavily dissected many of the lava surfaces.
Canyons lace many of the domes.
The floor of Waimea Canyon, on Kauai, is more than 800 meters below the surface of the surrounding land. Waterfalls several hundred meters high are common on the islands. The Pali, on Oahu, is a line of cliffs where the headwaters of streams eroding from opposite sides of the island meet. One important result of this intense erosive action is a limited amount of level land on the islands. Kauai is particularly rugged, with the only lowlands formed as a thin coastal fringe.