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True or False?
The Pleistocene epoch had 11 periods of glaciation.
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True or False?
The Pleistocene epoch had 11 periods of glaciation.
True.
The Pleistocene epoch had 11 periods of glaciation.
Define the term interglacial period.
An interglacial period is a warmer phase between glacial periods characterised by glacial retreat and sea level rise.
State the meaning of glacial maximum.
The glacial maximum is the point of maximum ice extent during a glacial period.
What is the Pleistocene epoch?
The Pleistocene epoch is a geological time period roughly covering 2.6 million to 11 700 years ago, characterised by alternating glacial and interglacial periods.
What is the definition of periglacial?
Periglacial is an environment adjacent to glaciers or ice sheets, typically characterised by freezing and thawing cycles.
True or False?
During the last glacial maximum, the Earth's average temperature was 14–15 °C.
False.
During the last glacial maximum, the Earth's average temperature was 6 °C.
Define the term isotherm.
An isotherm is a line on a map connecting points having the same temperature at a given time or on average over a given period.
State the approximate time of the last glacial maximum.
The last glacial maximum was about 21 000 years ago.
What are the four main types of present-day cold environments?
The four main types of present-day cold environments are polar, glacial, alpine, and periglacial areas.
Define the term isotherm.
An isotherm is a line on a map connecting points with the same temperature.
What is the July isotherm used to define the Arctic polar environment?
The Arctic polar environment is defined by the July isotherm of 10 °C.
True or False?
The Antarctic is warmer than the Arctic.
False.
The Antarctic is much colder than the Arctic.
What is the minimum altitude typically associated with alpine environments?
Alpine environments are typically found at altitudes of over 3 000 m.
Define permafrost.
Permafrost is large sections of permanently frozen ground found in periglacial areas.
What does the active layer refer to in periglacial environments?
The active layer refers to the surface layer of soil in periglacial environments that undergoes seasonal thawing and re-freezing, up to 5 metres in depth.
True or False?
Periglacial environments account for about half of the Earth's surface.
False.
Periglacial environments account for about a third of the Earth's surface.
Define tundra.
Tundra is a type of periglacial environment located at the fringes of permanent glaciated areas, either in high-altitude alpine regions or high-latitude polar regions.
What is the defining characteristic of glacial environments?
The defining characteristic of glacial environments is that ice remains throughout the year.
What is the mean temperature range in the Arctic?
The Arctic's mean temperature range is -28 °C to 4 °C.
Define talik.
Talik is unfrozen soil found within the permafrost, thought to form when latent heat is released as the active layer re-freezes.
True or False?
Periglacial soils are a good source of carbon and methane sequestering.
True.
Periglacial soils are a good source of carbon and methane sequestering.
What is the average annual precipitation in the Arctic?
The average annual precipitation in the Arctic is approximately 100 mm.
What is the mean average temperature of periglacial environments?
The mean average temperature of periglacial environments is between -1 °C and -3 °C.
True or False?
The decay pathway is the fastest nutrient transfer in periglacial environments.
False.
The decay pathway is the slowest due to the cold climate restricting detritivores and decomposition.
What adaptations do low-growing plants in periglacial environments have?
Low-growing plants in periglacial environments have small, waxy leaves designed to retain warmth and reduce transpiration through wind exposure.
What is the largest and fastest nutrient transfer in periglacial environments?
The largest and fastest nutrient transfer in periglacial environments is between biomass and litter (the fallout pathway).
What is the main limiting factor for growth and diversity in cold environments?
Climate is the main limiting factor for growth and diversity in cold environments.
True or False?
Inputs from precipitation and weathering are less than runoff and leaching in periglacial nutrient cycling.
False.
Inputs from precipitation and weathering are greater than runoff and leaching in periglacial nutrient cycling.