Enquiry Question One Flashcards
What is a glacier?
A large accumulation of snow, ice, rock, sediment and sometimes liquid which moves down slope under the influence of its own gravity
What is climate change?
The global warming, driven by the human emissions of greenhouse gases, which causes a change in the average weather patterns
What are the two climatic states?
Greenhouse and Icehouse
What is the ‘Icehouse’ state referring to?
This is where the temperature at the poles were colder and ice cover was was more common globally
What is the ‘greenhouse’ state referring to?
A time when the temperature was warmer and there was less ice cover globally
What is a glacial period?
A period where ice cover was dominate globally
What is an interglacial period?
A period of warmer temperatures and less ice cover globally
What is an epoch?
A period of time
What is the long term cause of climate change?
The Milankovitch Cycles
How does the eccentricity of the Milankovitch cycles cause climate change?
The change of the Earth’s orbit from circular to elliptical every 96,000 years changes the distance of Earth from the sun, varying how much solar radiation hits the Earth’s surface
How does the tilt of the Milankovitch cycles cause climate change?
When the Earth’s tilt changes from 21 degrees to 24 degrees every 41,000 years, the tropics receive more solar radiation, thus expanding
How does the Axial Procession of the Milankovitch cycles cause climate change?
Every 22,000, the Earth’s seasons change
What are two short term causes of climate change?
Variations in solar output and Volcanic eruptions
How does solar output cause climate change?
Energy output from the sun is not constant. Sunspots occur by magnetic storms, forming a dark area on the sun, increasing its solar output.
How do volcanic eruptions cause climate change?
The ash can block the sunlight, increasing global temperatures
What is the cryosphere process?
The parts of the Earth’s crust and atmosphere subject to below 0 degrees per year
What is periglaciation?
This describes how the thawing of snow in areas of permafrost (ice soil) runs off and refreezes into ice wedges and other structures.
What are 5 processes of periglaciation?
Nivation, Frost Heave, Freze Thaw, Weathering and Solifluction
What is Nivation?
Erosion of the ground around a slope of snow due to freeze and thaw
What is Frost Heave?
The uplift of soil due to the expansion of ground water when its frozen
What is Freeze Thaw?
Water falls through cracks in rocks, it freezes, expands and the rock breaks
What is weathering?
Wearing away of material due to the long exposure to the climate
What is Solifluction
The movement of wet soil/material down a slope
What is a zone of accumulation?
This is the area of a sheet of snow, or ice, where more snow is added
What is a glacial snout?
This is the lowest end of the glacier
What is the zone of ablation?
This is where ice melts at the snout, causing a net loss of ice of a glacier
How can we achieve equilibrium of a glacier?
The zone of accumulation and zone of ablation must be similar
What is the difference between ablation and accumulation known as?
Surface mass balance
What can affect surface mass balance?
Climate change. This can also alter rates of ablation and accumulation
When does a positive mass balance occur?
This is when glaciers gain more mass than they lose.
When does a negative mass balance occur?
This is when glaciers lose more than they gain
How can accumulation occur?
Direct snowfall, sublimation (solid to gas), avalanches and wind deposition
How can ablation occur?
Melting, evaporation, avalanches and calving (splitting of ice)
