Tides

What are tides?

The periodic rise and fall of sea levels

What are tides caused by?

The gravitational pull of the moon and sun

What has the greatest gravitational pull?

The moon (double the strength of sun)

How does the gravitational pull cause tides?

It creates water to bulge on earth

What do tides influence?

Coastlines

Are all coastlines tide-dominated?

No, few coastlines are tide-dominated

What is an example of a tide-dominated coastline?

Lowland sandy estuarine coasts

What is the Coriolis force?

An apparent caused by the earths rotation that deflects moving objects like the wind and ocean currents

Why does water move in different directions in different hemispheres?

Due to the earths rotation

What direction does water and storms move in the Northern hemisphere?

Anticlockwise

What direction does water and storms move in the Southern hemisphere?

Clockwise

What does the Coriolis force do to tides?

Modifies tidal paths and influences tidal patterns along coastlines

What are the 2 main types of tides?

Spring and Neap

What is a tidal bore?

Where water is funnelled from a large coastal area into a narrow river and salty sea water heads back up the river

When do tidal bores mostly occur?

During high tides

What is an example of a tidal bore?

The Severn bore

What is a storm surge?

Coastal flooding caused by a low pressure system (eg hurricanes and storms)

What does a storm surge cause?

Sea levels to rise

What is an example of a storm surge?

Superstorm Sandy

What is meant by differentiation between land and sea?

When the land is warm the sea is cold and vice-versa

How many high tides are there per day?

2

How many low tides are there per day?

2

Roughly how often do high tides change?

Every 12 hours and 25 minutes

How many spring tides are there per month?

2

How many neap tides are there per month?

2

How do tides change throughout the year?

Due to the gravitational pull of the sun and moon - depending on the position and distance of the moon and sun

When is the Severn Bore at its highest?

During a spring tide in March and September

When are storm surges most frequent?

Between August and October as it is hurricane seaason

Why are storm surges most frequent during this time?

As the land is cooling and the ocean is at its warmest

When do the most severe storms and tides occur?

March and September

Why are storms and tides most severe during this time?

As the earth is closer to the sun during these equinoxes so its gravitational force is stronger