EQ1: How has climate change influenced the formation of glaciated landscapes over time? Flashcards
What is the term for long-term changes to climate and ice cover known as?
Glacial and interglacial periods
These periods are part of the Pleistocene epoch.
What is the geological period that follows the Pleistocene?
Holocene
The Holocene spans from 12,000 years ago to the present day.
Define ‘Icehouse’ in the context of glacial change.
‘Icehouse’ describes a time when ice cover was present across large areas of the globe
Icehouse conditions are characterized by cooler global temperatures.
What does ‘Greenhouse’ refer to in glacial terminology?
‘Greenhouse’ describes when the climate was much warmer and the land was largely ice-free
Greenhouse conditions indicate a lack of significant ice cover.
What is the estimated temperature difference between glacials and interglacials?
5-6°C colder
Glacials are characterized by colder temperatures and more extensive ice cover.
How many major climate fluctuations occurred during the Pleistocene?
Over 20
These fluctuations involved transitions between glacials and interglacials.
What significant climatic event occurred during the Loch Lomond stadial?
Glaciers re-grew in the Scottish Highlands
This event took place between 12,700 and 11,500 years ago.
What was the temperature difference during the Little Ice Age compared to present day?
1°C cooler
The Little Ice Age occurred from the 15th to 18th centuries AD.
Fill in the blank: The Pleistocene was a geological time period that spans from ______.
2.6 million to 12,000 years ago
It is known for significant glacial and interglacial periods.
What crops were reportedly grown in the British Isles during the Medieval warming?
Warm-temperature crops (e.g., grapes)
This warming occurred in the 12th/13th centuries AD.
What are Milankovitch cycles?
Milankovitch cycles refer to the ‘wobble, roll and stretch’ changes in the Earth’s orbit around the sun.
What does the ‘Eccentricity’ part of the Milankovitch cycles describe?
The ‘stretch’ part describes the Earth’s orbit changes from circular to elliptical.
How does the ‘Eccentricity’ affect solar radiation?
It affects how much solar radiation is received on the Earth’s surface.
What does the ‘Obliquity’ part of the Milankovitch cycles describe?
The ‘roll’ part describes the axis tilting from 21 to 24 degrees and back again, over a period of 41,000 years.
What is the impact of the ‘Obliquity’ on solar radiation?
It leads to changes in the amount of solar radiation received at the Earth’s surface.
What does the ‘Precession’ part of the Milankovitch cycles refer to?
The Earth’s axis is said to ‘wobble’, altering the distance between the sun and the Earth.
What are other natural causes of climate change?
Other natural causes include sunspot activity and volcanic activity.
What are sunspots?
Sunspots are temporary spots on the Sun’s photosphere that send more solar radiation towards the Earth.
What is the cycle period for the smallest sunspot activity?
The smallest cycle is every 11 years.
What is the net increase in radiation associated with sunspots?
The net increase in radiation with sunspots is 0.1%.
What do volcanoes emit that affects climate?
Volcanoes emit ash, sulphur dioxide, carbon dioxide, and water into the atmosphere.
How do volcanic emissions affect solar radiation?
These gases and ash reduce the amount of solar radiation received at the surface by forming a buffer between the sun’s rays and the Earth’s surface.
What is a recent example of significant volcanic activity?
A recent example was Mt Pinatubo, which erupted in 1991.
What is the term for the collective ice cover on Earth?
Cryosphere
What are large dome-shaped ice masses that cover underlying topography?
Ice sheets
What is the thickness range of ice sheets?
Several kilometres
What are smaller ice sheets called?
Ice caps
What is the term for ice sheets covering a mountain plateau with peaks showing through?
Ice fields
What are large tongues of ice constrained within a valley called?
Valley glaciers
What type of glaciers occupy a hollow on a mountainside?
Cirque/Corrie glaciers
What are the surface temperatures of cold-based (polar) glaciers?
−20 to –30°C
What is the state of the base of cold-based glaciers?
Frozen to the bedrock
What allows the base of warm-based (temperate) glaciers to slide and move?
Layer of meltwater that forms due to high pressures
Where is ice predominantly found in high latitude regions?
Arctic and Antarctic Circles
What is the latitude threshold for polar regions where ice is likely to form?
More than 65 degrees
What types of ice formations are found mainly in high latitude regions?
-Ice sheets
- Ice caps
- Ice fields
- Glaciers
What are the two states of ice in high altitude regions?
- Constrained (e.g. glaciers)
- Unconstrained (e.g. ice sheets, ice caps)
What evidence indicates formerly glaciated upland areas?
Relict landscapes from the Pleistocene period
What are some areas in the UK with relict glaciated features?
- Lake District
- Snowdonia
- Grampians
- Scottish Highlands
