1.5 - Sea Level Change And Raised Beaches

Question 1

What does tectonics do to the seabed?

Answer 1

Plates subduction causing movement of ocean floor

Seabed is pushed up

Question 2

What processes uplift the beach?

Answer 2

Isostasy:
NZ mountains in one side have a build up of snow causing glaciers so that side sinks due to malleable crust being pushed down on and SLR occurs
CC causes these glaciers to melt, so this part of NZ rises up, making it seem raised
Other side sinks

Question 3

How does eustasy occur?

Answer 3

As the glaciers melt and the other side sinks, water is pushed out into the oceans causing global SLR

Question 4

Emergent coasts become

Answer 4

Prone to erosion as they’re more exposed now

Question 5

Why is this due to tectonic processes?

Answer 5

Soft and viscous fluid allows malleability allowing sinking
Friction and pressure build up as continental plate slides past oceanic, then slips releasing pressure which triggers EQ that shifts seabed up

Question 6

Why is it due to smaller scale processes?

Answer 6

CC - causes evaporation, reducing sea level making beaches seem raised; melts glaciers changing water levels on both sides
More CC as Kaikoura is annually warm, so more susceptible to eustasy

Question 7

About Kaikoura:

Answer 7

7.8 magnitude EQ
Seabed went up 2m
4 faults broke