Explain the formation of a waterfall 12 marks

A waterfall is an erosional landform, which occurs where there is a layer of hard rock on top of a layer of softer rock. Erosional processes such as hydraulic action and abrasion occur as the river flows downstream, however differential erosion takes place as the softer rock erodes faster.

Explanation:

Waterfalls often form in the upper stages of a river where it flows over different bands of rock. It erodes soft rock more quickly than hard rock and this may lead to the creation of a waterfall.

Formation of a waterfall:

▪︎The soft rock erodes more quickly, undercutting the hard rock.

▪︎The hard rock is left overhanging and because it isn’t supported, it eventually collapses.

▪︎The fallen rocks crash into the plunge pool. They swirl around, causing more erosion.

▪︎Over time, this process is repeated and the waterfall moves upstream.

▪︎A steep-sided gorge is formed as the waterfall retreats.

d. new methods of assembly are introduced.

explanation:

this allows for the goods to be made on a larger scale. not faster because now it is shown to be made better, hence the greater productivity in the question. it is calling for something new to be introduced.

seismic wave -

an elastic wave in the earth produced by an earthquake or other means.

explanation: