Lesson 7 - Estuaries

Question 1

What happens when fresh and sea water meet?

Answer 1

‘Lock-exchange’ = two layer density driven flow

Question 2

What modifies the density driven flow in and out of estuaries? (2)

Answer 2

Mixing and tidal movement of salt water

Question 3

What is entrainment?

Answer 3

In a salt wedge estuary the main outflow to the sea is freshwater as it passes over the salty inflow. (one way mixing)

Question 4

What happens as an estuary flow becomes more mixed?

Answer 4

The salinity contour lines become more vertical

Question 5

Describe water flow inside a fjord

Answer 5

Surface flow remains unchanged due to little mixing. Salt water enters over sill and can become stagnant at depth

Question 6

Fjord depth and tidal features

Answer 6

Deep basin and little tide

Question 7

Dominant beach feature in summer/swell weather?

Answer 7

Berm

Question 8

Dominant beach feature in Winter/storm weather?

Answer 8

off shore sand bar

Question 9

Delta zones (3)

Answer 9

Prodelta, deltafront, deltaplain