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Headlands and bays

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Headland on which lies the community of Argentia, on the island of Newfoundland, Canada
Headland on which lies the community of Argentia, on the island of Newfoundland, Canada
The bay at San Sebastián, Spain
The bay at San Sebastián, Spain

A headland is an area of land adjacent to water on three sides. A bay is the reverse, rather an area of water bordered by land on three sides. A large headland may also be called a peninsula. Long, narrow and high headlands may be called promontories. When headlands dramatically affect the ocean currents they are often called capes. A large bay may also be called a gulf, sound or bight. A narrow bay may also be called a fjord if its sides are relatively steep. Any bay may include other bays (for example, James Bay is a bay within Hudson Bay).

Contents

Formation

A headland is a piece of land that juts into the sea from the main land coast line. Headlands are shaped by erosion. They are formed when the sea attacks a section of coast consisting of alternating bands of hard and soft rock. The bands of soft rock such as sand and clay, erode more quickly than those of more resistant hard rock such as chalk. This would form a headland.

A bay is an area of water bordered by land on three sides. Bays are found between headlands where there are alternating outcrops of resistant rock and less resistant rock. Waves erode the areas of softer rock more rapidly than the hard rock to form bays.

Geology and geography

Headlands and bays are often found together on the same stretch of coastline. Headlands and bays form on discordant coastlines, where bands of rock of alternating resistance run perpendicular to the coast. Bays form where weak (less resistant) rocks (such as sands and clays) are eroded, leaving bands of stronger (more resistant) rocks (such as chalk, limestone, granite) forming a headland, or peninsula. Refraction of waves occurs on headlands concentrating wave energy on them, so many other landforms, such as caves, natural archs and stacks, form on headlands. Wave refraction disperses wave energy through the bay, and along with the sheltering effect of the headlands this protects bays from storms. This effect means that the waves reaching the shore in a bay are usually constructive waves, and because of this, many bays feature a beach. A bay may be only metres across, or it could be hundreds of kilometres across.

Sometimes bays form where movements of the earth's crust (tectonics) bring areas of land together, or move them apart. Usually these bays are referred to as seas or gulfs and not bays.

List of some well-known headlands

List of some well-known bays

Image:Port Phillip Bay.png
Landsat 7 composite imagery of Port Phillip Bay.

A couple of non-gulfs (actually straits) are:

See also

External links

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