SEA LEVELS

When temperatures rise, the ice at the poles melts and sea levels rise. One third of this rise is linked to the thermal expansion of water, which occupies more space at higher temperatures.

Over the last million years the sea levels have risen and fallen by up to 100 metres in response to natural climatic variations.

(Chart 1)

• Top X-axis: Climate
• Bottom X-axis: Thousands of years
• Left Y-axis: Temperature
• Right Y-axis: Sea level
• Dashed line 1: Current temperature
• Dashed line 2: Current sea level

Flandrian transgression

Sea levels have risen by over 100 m in the last 10,000 years.

The distant coastline of prehistoric times

Just 20,000 years ago the Arctic ice reached as far as Northern Europe and sea levels were 120 metres lower than they are today, with coastlines a further 10 km out.

(Chart 2)

If we follow this platform under the sea we will see that it has small steps that reveal ancient cliffs / lower sea levels in the recent past.  

• Top X-axis: Current platform / Ancient underwater platforms
• Bottom X-axis: Profile
• Y-axis: Depth
• Current cliff
• Ancient cliffs
• Platforms 0-6 

(Right panel)

Current sea level

Abrasion platforms form when sea levels remain stable for a prolonged period of time.