Headward

The highest, flattest, and smoothest part of Tibet (3 ) is the central, Oligo-Miocene plateau, mature but still sheltered, especially in the west, from headward erosion.

[View Larger Version of this Image (130K GIF file)] Discussion The martian landforms resemble terrestrial gullies, which form by a combination of processes, including overland flow, headward sapping (32 ), debris flow, and other mass movements (33 )--all processes that, on Earth, involve the action of water.

Even without the structures, there was a morphological feedback: As headward stream channels widened from lateral erosion, new floodplains developed that were lower, fine textured, and vegetated (Fig. 3 ), a condition noted in 1975 (2 ).

When lift is applied, forces are experienced which appear to the pilot as being applied from a headward direction, i.e., from head to toe.

As the isthmus disappeared at the close of the 17th century, the river continued to erode the island headward and build it up at its downstream end, so that the western and southern shores where the first settlement had been built, were partly destroyed.