Chloe Troulan + Alex Ince
Headlands, Bays and Blow Holes
Headlands and Bays:
 A headland is an area of land that is surrounded by water on three sides and
is made of hard rock which takes a long time to erode.
 A bay is an area of water that is surrounded by land on three sides and it is
made of soft rock.
 A bay is an area in the shore of a sea or lake between two headlands.
 The waves that reach the bay are usually constructive waves which mean
that many bays have beaches. The beaches can range in size from being very
small (a couple of meters) or even a couple kilometres long.
 Bays form where weak rocks (sands and clays) have eroded, leaving lines of
stronger rocks such as limestone, granite, chalk etc forming a headland.
 The coastline has parallel bands of hard and soft rock which were
perpendicular to the sea.
 As a result of differential erosion, the bands of soft rock eroded much more
quickly than the bands of hard rock. This causes headlands and bays to be
formed.
 Large headlands may also be called peninsulas.
 When headlands dramatically effect the the ocean currents they are often
called capes.
 Headlands and bays are usually found together on the same stretch of
coastline
 When the refraction of waves occurs on headlands then often many other
landforms such as, arches, caves and stacks form on headlands.
 The headlands protect bays from storms
 Bays can sometimes be formed when movements of the earths crust bring
land together or move them apart. These bays are usually referred to as seas
or gulfs but not bays
 Long narrow and high headlands can also be called promontories
 Any bay may include another bay
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.
Blowholes:
 Blowholes are created when the pounding ocean undercuts a shoreline lava
shelf. A hole in the lava shelf causes a geyser like effect. When the surf is just
right, it forces water up through the hole as high as a hundred feet into the
air.
 In geology, a blowhole is formed as caves grow landwards and upwards into
vertical shafts and expose themselves towards the surface , which can result
in quite spectacular blasts of water from the top of the blowhole if
the geometry of the cave and blowhole and state of the weather are
appropriate.
 Caves, blowholes, arches and stacks: Where cliffs are composed of resistant
rock, wave action attacks the lines of weakness sometimes creating a steep
sides, narrow inlet, called a geo, or where the cliff is undercut, a cave might
form. These caves may also be enlarged by a combination of marine erosion
processes, vertical erosion may also occur, hence blowholes are formed.
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