|Regel 30:||Regel 30:| |Sediment supply from soft cliffs <br> ©
A. J. Chadwick |Sediment supply from soft cliffs <br> © A. J.
Chadwick The current world’s coastlines were formed as a result
of the last ice age, which ended about 10,000 years ago (see the
beach management manual <ref name="CIRIA">CIRIA (2010). Beach
management manual, Second Edition. Publication no. RP787,
London.</ref>). At that time large ice sheets covered more of
the world’s land masses than they do at present. As they melted
there was a rapid rise of sea level (about 120m between 20,000
and 6000 years ago). Vast quantities of sediment were carried by
rivers to the sea during this period, eventually forming the
pre-cursor to our present coastlines as the rate of sea level
rise rapidly reduced about 6000 years ago. Much of our beaches
today are composed of the remnants of these sediments, composed
predominantly of sand and gravel. These sources of beach
material have subsequently been supplemented by [[Coast
erosion|coastal erosion]] of sof