lesson 3- tides Flashcards
explain the process of wave refraction
-waves approach a straight shoreline at an angle
-the part of a wave crest closer to the shore is in shallower water, so slower than the part further away
-which catches up, so the wave crest becomes parallel to the shore
longshore/ littoral drift
process responsible for moving significant amounts of sediment along the coast. usually in one direction, which is dictated by the prevailing wind
what are tides
rising and falling of the sea due to the gravitational pull of the moon and sun
-moon has a greater pull as it is closer
-the moon pulls water towards it to create a bulge, and high tide
-inbetween bulges it is low tide
as the moon moves around earth, tides follow
-tides are strongest when the earth, sun and moon are moon are in a straight lime- twice a lunar month-spring tide
-tides are weakest when sun and moon are 90 degrees to each other- neap tides
what is a coastal sediment budget
the balance between sediment added to and removed from the coastal system
what is a high energy coast
waves are powerful
rate of erosion>deposition
-forms headlands, cliffs, WCPs
-e.g. south west england
what is a low energy coast
waves are weak
deposition>erosion
-e.g. baltic sea
what is the spring tide
after a new or full moon (sun, moon and earth are in a straight line),greatest difference between high and low water
what is a neap tide
moon and sun are perpendicular
least difference between high and low water
what is the Coriolis force
global winds and ocean currents curve as they move. The curve is due to the rotation of the Earth on its axis and leads to winds blowing diagonally. In the northern hemisphere, it curves winds to the right. On the southern hemisphere it curves winds to the left.
what is macrotidal
more than 4m high
what is mesotidal
2-4m high
what is microtidal
less than 2m high
