Mass movement

Question 1

Mass movement

Answer 1

Downhill movement of material under influence of gravity, common at coast as weak geology and rain weight, important flows as energy and sediment input

Question 2

Soil creep

Answer 2

Slow movement of individual soil particles downhill as they freeze and expand then thaw and fall. Can’t see but implied by shallow terracettes, bent tree trunks, soil buildup upslope of walls

Question 3

Mudflow

Answer 3

Earth and mud flows downhill after water trapped in weak bedrock and pore water pressure forces rock particles apart and shape fails, often fast-flowing

Question 4

Landslide

Answer 4

Largely intact rock moving rapidly downhill down a straight slide plane, especially if rain lubricates slip planes

Question 5

Landslide example

Answer 5

1993: 60m cliff fall onto beach near Scarborough, taking part of a hotel

Question 6

Rockfall

Answer 6

Sudden collapse of rock fragments, often in heavily jointed rocks and due to earthquakes/mechanical, to form scree - a temporary store then input

Question 7

Landslip (slump)

Answer 7

Pore water pressure builds in a curved slide surface with unconsolidated material above to form a scar and sharp slope break

Question 7

Landslip example

Answer 7

2014: on Jurassic Coast damaged holiday chalets

Question 8

Runoff

Answer 8

Overland flow moves small particle downslope to littoral zone, input as carries sediment, water can assist flows, toxic chemicals carried threaten coastal ecosystems

Question 8

Solifluction

Answer 8

Soil creep in cold periglacial environments form solifluction lobes as permafrost below