coasts L6 weathering Flashcards
1
Q
What are SUBAERIAL PROCESSES?
A
a combination of weathering and mass movement that alter the shape of a coastline & are distinctively different from marine erosion processes
2
Q
BIOLOGICAL WEATHERING
A
- plant roots can get into small cracks in the rock
- as the roots grow, cracks become larger
- causes small pieces of rock to break away
- can also happen with animals who excavate material to build nests, further weakening the cliff face
- barnacles & limpets drill into the rock face and leave behind holes when they die
- birds, plants, moss, trees, barnacles, grass
3
Q
CHEMICAL WEATHERING
A
- involves DECOMPOSITION of ROCKS
- results of a weak CHEMICAL REACTION between water and limestone
- RAINWATER mixed with CO2 forms CARBONIC ACID. reacts with Calcium Carbonate in LIMESTONE to form Calcium BICARBONATE
- Rainwater has a PH of 5.0-5.6 in the UK
- Bicarbonate is SOLUBLE in water and the limestone gets weathered when CARBONATION occurs
- HONEYCOMBING
4
Q
MECHANICAL WEATHERING
A
- SUMMER -> salt CRYSTALLISATION
- WINTER -> FREEZE THAW
- FREEZE THAW when water gets into cracks and freezes - expands by 10% EACH TIME - pressure on rocks until they crack
- Cracks in rocks
5
Q
what is NEAP Tide?
A
normal/mid-range tide
6
Q
What is a GEO?
A
DIVIDE BETWEEN CLIFFS
7
Q
what is a BLOWHOLE?
A
INTERCONNECTED NETWORK OF JOINTS, FAULTS & FISSURES
