costal systems and processes Flashcards
(23 cards)
what is the tidal range
difference in height between low tide and high tide
what are tides
periodic rise and fall in the level of sea and are caused by the gravitational pull of the sun and the moon
the moon has the greatest influence because it is nearer
what is a Luna month
29 and a half days - corresponds with the time it takes the moon to orbit the earth.
what are tides like on a temporal scale
not all high tides and low tides and range at the same location are the same they will all differ over the luna month
what are tides like on a spatial scale
Different point around the coastline and heigh will vary for tides . the shape of the coastline and ocean base will mean the heights of the tides can vary
where has the largest tidal range
atlantic ocean
where has the smallest tidal range
Mediterranean sea
what is the time difference between 2 high tides or 2 low tides
12h and 25 mins= tide cycle
what is a spring tide
highest high tide and lowest low tide - tidal range will be at its greatest
what is a neap tide
lowest high tide and highest low tide - tidal range will be at its lowest
how many times a month are the different types of tides
2
when does a spring tide occur
when the sun and moon align with the earth
when does a neap tide occur
sun and moon are at a right angle to each other
what does it mean if their is a larger tidal range
wide zone , longer area for potential erosion and deposistion
what does it mean if their is a smaller tidal range
smaller zone so less erosion
where is the largest tidal range in the world
bay of fundy - north east USA - spring tide 15m range
what landforms can be created from a large tidal range
wave cut platform as cliff has retreated (erosional feature)
sand dunes (depositional feature)
what is marine erosion
primary cause of erosion and is from wave action
do all waves cause erosion
no
why do some waves cause erosion
because they have excess energy
how do waves loose energy
- movement e.g- breaking
- transporting sediment
what is cavitation
air is in a crack/ joint and water fills the crack and pushes air into rocks the increase of air pressure then causes the rocks to finally crack
air is compressed and compact and eventually explodes
