Physical geography

Question 1

describe a construcitve wave

Answer 1

-move up beach with powerful swash
-at peak of swash, loses energy so sediment is deposited
-weak backwash means no erosion happens

Question 2

Describe a destructive wave

Answer 2

-they have a weak swash
-when the wave reaches the coats it violently breaks with a strong backwash
-this causes erosion, transporting material/sediment off the beach out to sea

Question 3

how does the wavelength affect themovement of sediment

Answer 3

smaller= more erosion due to more crests hitting the shore

larger= may cause more deposition

Question 4

What are the 3 types of plate movement

Answer 4

ridge push
slab pull
convection currents

Question 5

What is ridge push, and draw a labelled diagram

Answer 5

-magma rises when plates move apart to fill in gap created
-magma cools, filling in gap to form a new plate
-causes other plates to move as a result

Question 6

What is slab pull, and draw a diagram

Answer 6

-denser plate sinks into mantle due to gravity as it subducts

Question 7

Definition of convection current

Answer 7

-Convection currents happen in the upper mantle
-The core is hot and heats molten (melted) rock
-This heated rock rises and hits the underside of the plate

Question 8

What are the two different types of crust, and describe them

Answer 8

Oceanic:
-newer
-denser
-can subduct
-thinner

Continental
-less dense
-thicker
-can’t subduct

Question 9

Desribe the structure of the crust

Answer 9

-made of continental snd oceanic plates
-solid
->made of granite and basalt
-10 degrees
-0-17km thick

Question 10

Describe the structure of the mantle

Answer 10

-2900km thick
-rheological (solid that can move)
-375 degrees

Question 11

Describe the inner and outer core and how they differ

Answer 11

Inner:
-1250km thick
-solid
->iron and nickel
3000 DEGREES

Outer:
-2200 km thick
-liquid
3000 DEGREES

Question 12

Describe the distribution of earthwuakes an volcanoes

Answer 12

-uneven
-correlate with plate bounderies
-earthquakes are in linear chains
—>along all types of plate bounderies
(e.g west coast south america)

-Volcanoes are also in linear distribution
—>around 3/4 of these are in the ring of fire (related to the destructive plate boundary)

Question 13

Why might erathquakes and volcanoes form away from a plate boundary

Answer 13

earthquake:
-plate movement
-human activity
—>building dams or resovoirs, or fracking
-this causes lots of pressure on the crust

volcanoes:
-these are hotspot volcanoes
—>where isolated plumes of lava push through the crust and form active volcanoes