Timeline of Glacial Change
Geography: Edexcel A Level, topic 2.1.1
Terminology of Glacial Change
There is specific terminology associated with glacial change that is important to remember.
Glacial change
- There have been long-term changes to climate and ice cover known as glacial and interglacial periods (the Pleistocene).
- Shorter-term changes have taken place more recently during the Holocene geological period.
Icehouse and greenhouse
- 'Icehouse' describes a time when ice cover was present across large areas of the globe.
- 'Greenhouse' describes when the climate was much warmer and the land was largely ice-free.
The Pleistocene and Holocene
- The Pleistocene was a geological time period that spans from 2.6 million to 12,000 years ago.
- The Holocene was a geological time period that goes from 12,000 years ago to the present day.
- Some scientists now believe that we are in a new geological age called the Anthropocene, a time where humans are the leading cause of environmental change.
Chronolgy
There have been long-term changes to climate and ice cover known as glacial and interglacial periods (the Pleistocene). Shorter-term changes have taken place more recently during the Holocene geological period.
Chronology (time-line)
- The Pleistocene has seen many (over 20) major climate fluctuations where the climate has changed between:
- Glacials with colder temperatures and extensive ice cover.
- Interglacials with warmer temperatures and less ice cover.
- Glacials are thought to have been about 5-6oC colder than interglacials.
Ice advance and retreat periods
- The Loch Lomond stadial happened between 12,700 and 11,500 years ago. In this time, glaciers re-grew in the Scottish Highlands.
- During the Little Ice Age from the 15th to 18th centuries AD, temperatures were 1oC cooler than at present and some British rivers froze (e.g. the Thames).
- Some suggest that there was a Medieval warming before this in the 12th/13th centuries AD, when some warm-temperature crops (e.g. grapes) were grown in the British Isles.
Test yourself on Timeline of Glacial Change
When was the Pleistocene?
How much colder are glacial than interglacial time periods?