The global coastline - Fundamentals of the Physical Environment - page 418

Plate 17.9 Computerized image of Westminster from Lionsgate Film, 'Flood'; showing the suggested impact of a 25 m storm
surge in the Thames estuary.
Source: Lionsgate Films

Fossil
cliff

Raised
platform

Arch

Wave cut
notch

Stack

Stack stump

Wave cut
rock platform

Sea cave Sea cave

Reef

High water mark High water mark

Low water mark Low water mark

Figure 17.21 Morphology of a rock coastline.

tides, predominant in the Pacific and Indian Oceans, show
elements of both patterns. Tidal range emphasizes the
effect of coastlines and enclosed seas on the global tide
wave ( Figure 17.23 ). The range is lowest on open coasts,
which reflect the wave, and increases with increasing
width of continental shelf and partial enclosure of marine

varying by 28·5 either side of the equator, but semi-

diurnal tides are still experienced over large sections of
Atlantic, south Pacific and Arctic coastlines. The tidal
bulge of one hemisphere dwindles with increasing latitude
in the opposite hemisphere, leaving one diurnal tide
around Antarctica and parts of the Arctic basin. Mixed