Post-glacial climate change and its effect on geomorphic processes Flashcards
What are glacio-fluvial landforms?
Glacio-fluvial landforms are those produced by meltwater from glaciers.
What types of landforms are considered in this context?
Only the depositional landforms are considered here.
When are most glacio-fluvial landforms formed in the contemporary landscape?
Most glacio-fluvial landforms visible in the contemporary landscape were formed during periods of short, often seasonal melting and retreat of glaciers, especially during deglaciation.
What happens to the glacio-fluvial landforms produced during seasonal melting and retreat?
Glacio-fluvial landforms produced during seasonal melting and retreat are often severely modified or degraded during periods of subsequent re-advance.
What causes the end of glacial periods?
Glacial periods end when global temperatures rise, leading to a general warming trend.
What are the periods following glacial periods called?
The periods following glacial periods are called inter-glacials, and they typically last from 10,000 to 15,000 years.
What type of sediment is deposited by glacio-fluvial streams and rivers?
Glacio-fluvial streams and rivers deposit a distinctive sediment type known as outwash.
How does outwash sediment differ from till sediment?
In contrast to till, which is directly deposited by glacial ice, outwash tends to be smaller in size, smooth and rounded due to contact with water and attrition.
How is outwash sediment sorted horizontally and vertically?
Outwash sediment is sorted horizontally, with the largest material found furthest up the valley and progressively finer material found with distance down the valley. It is also stratified vertically, with distinct seasonal and annual layers of sediment accumulation in many of the landforms.
What can cause extremely high discharge in meltwater rivers during summer months?
Meltwater rivers may have extremely high discharge in summer months due to increased melting from glaciers.
What is an example of an extreme glacial outburst caused by geothermal or volcanic activity?
An example of an extreme glacial outburst caused by geothermal or volcanic activity is the jökulhlaup in Iceland.
What was the estimated discharge during the glacial outburst caused by the 2010 eruption of Eyjafjallajokull volcano in Iceland?
During the glacial outburst caused by the 2010 eruption of Eyjafjallajokull volcano in Iceland, the estimated discharge through the Markarfljót valley was over 2500 cumecs, and more than 200,000 tonnes of sediment were deposited in the valley
