Cold environments 1

Select only Sub-Arctic types of cold environments

Cold environments 2

Which type of cold environment is described below:

In winter, temperatures often drop to –50°C! They include Antarctica, Greenland and some of the islands inside the Arctic and Antarctic Circles, such as Spitzbergen. Despite the snowy image of these polar environments, they are very dry – with relatively low amounts of precipitation (snow). There are also extensive areas of sea ice, particularly in the Arctic.

Polar Environments

In winter, temperatures often drop to –50°C! They include Antarctica, Greenland and some of the islands inside the Arctic and Antarctic Circles, such as Spitzbergen. Despite the snowy image of these polar environments, they are very dry – with relatively low amounts of precipitation (snow). There are also extensive areas of sea ice, particularly in the Arctic.

 

Alpine Environments

Moutain area such as the Alps, experience very cold winters with heavy snow. Because of the high altitude, the temperature can drop to –10°C or less. The extreme winter cold is replaced in the summer with warmer weather, where the temperature can even exceed 20°C.

 

Periglacial Environments

Periglacial literally means ‘edge’ of glacial. Periglacial environments are found on the fringes of polar or glacial environments, e.g. in parts of Siberia, Canada and Greenland. Periglacial areas experience permanently frozen ground (permafrost). During their brief warmer summers, the ground surface layer thaws – enabling hardy plants to grow. Periglacial environments are not permanently covered by ice.

 

Glacial Environments

These environments are specifically associated with glaciers. While some enormous glaciers are found in polar environments, most of the world’s actively moving glaciers are found high up in alpine mountain regions. The heavy winter snowfall in those areas provides the ice to feed the glaciers. Then, in the summer, meltwater lubricates the glaciers – helping them to move like giant conveyor belts down the alpine valleys.

 

Distribution of Polar Landscapes

About 20 million km2 of treeless tundra is found on Earth in the two polar zones and in alpine regions. 

  • Polar climates occur poleward of the 10° C isotherm for the warmest month, and the summer position of the arctic/antarctic Front separating Arctic/Antarctic air masses from polar air masses. 
  • Some ecologists prefer to use the Nordenskjöld line, an isopleth of the mean temperature of the warmest month equalling (9 – 0.1K), K being the mean temperature of the coldest month in degrees celsius. 
  • Although the 10° C January temperature works quite well in the Antarctic, many prefer the marine Antarctic Convergence which separates cold antarctic water from cool subantarctic water. 
  • The details of climates in polar regions are much affected by the incursion of ocean currents from warmer latitudes.
Cold environments 3

Read the describtion below and complete by missed term

______________occurs when rocks and stones become frozen to the base or sides of the glacier and are removed from the ground or rock face as the glacier moves. It leaves behind a jagged landscape.

There are 4 main processes that could be observed in cold environments.

Plucking

The ripping of material from the bedrock of a glacier

It occurs when there is a large downwards pressure from the weight of glacier. As the glacier moves downwards, friction between the basal ice of the glacier and the rock below causes melting. This water freezes to obstacles, which are then 'plucked' from the bedrock.

Abrasion

The sandpaper effect

It occurs when there is material present at the base or sides of the glacier. This material is dragged along the rock, erasing it. This process may cause grooves called striations to be formed. The larger and more angular material causes the most erosion.

Freeze-thaw

The weathering of rock with water

It occurs when water, which has penetrated cracks or fractures in rock, freezes. Water expands approximately 9% when it freezes so this expansion puts pressure on the rock. Repeated freezing and thawing (over many years) can lead to fracturing. As this process relies on fluctuating temperatures, it is mainly seen in periglacial areas.

Chemical weathering

The weathering of carbonate rocks by carbonic acid

It occurs when CO2 in the air dissolves into rainwater, forming a weak carbonic acid. CO2 is more soluble at lower temperature, so therefore the water becomes more acidic. This acid then reacts with carbonate rocks, such as limestone, dissolving them.

 

Cold environments 4

Read the describtion below and complete by missed term

____________    occurs when rocks and stones become embedded in the base and sides of the glacier. These are then rubbed against the bedrock (at the bottom of the glacier) and rock faces (at the sides of the glacier) as the glacier moves. This causes the wearing away of the landscape as the glacier behaves like sandpaper. It leaves behind smooth polished surfaces which may have scratches in them called striations. Striations are carved out by angular debris embedded in the base of the glacier.

There are 4 main processes that could be observed in cold environments.

Plucking

The ripping of material from the bedrock of a glacier

It occurs when there is a large downwards pressure from the weight of glacier. As the glacier moves downwards, friction between the basal ice of the glacier and the rock below causes melting. This water freezes to obstacles, which are then 'plucked' from the bedrock.

Abrasion

The sandpaper effect

It occurs when there is material present at the base or sides of the glacier. This material is dragged along the rock, erasing it. This process may cause grooves called striations to be formed. The larger and more angular material causes the most erosion.

Freeze-thaw

The weathering of rock with water

It occurs when water, which has penetrated cracks or fractures in rock, freezes. Water expands approximately 9% when it freezes so this expansion puts pressure on the rock. Repeated freezing and thawing (over many years) can lead to fracturing. As this process relies on fluctuating temperatures, it is mainly seen in periglacial areas.

Chemical weathering

The weathering of carbonate rocks by carbonic acid

It occurs when CO2 in the air dissolves into rainwater, forming a weak carbonic acid. CO2 is more soluble at lower temperature, so therefore the water becomes more acidic. This acid then reacts with carbonate rocks, such as limestone, dissolving them.

 

Cold environments 5

Read the describtion below and complete by missed term

_____________causes an alteration to the chemical composition of rock due to a reaction. Water that is slightly acidic can disolve rock. An example of this would be slightly acidic rain changing the chemical composition of limestone to form a limestone pavement. This occurs on the surface and along the joints and bedding planes of limestone. You can also see evidence of this on buidlings made from limestone.

There are 4 main processes that could be observed in cold environments.

Plucking

The ripping of material from the bedrock of a glacier

It occurs when there is a large downwards pressure from the weight of glacier. As the glacier moves downwards, friction between the basal ice of the glacier and the rock below causes melting. This water freezes to obstacles, which are then 'plucked' from the bedrock.

Abrasion

The sandpaper effect

It occurs when there is material present at the base or sides of the glacier. This material is dragged along the rock, erasing it. This process may cause grooves called striations to be formed. The larger and more angular material causes the most erosion.

Freeze-thaw

The weathering of rock with water

It occurs when water, which has penetrated cracks or fractures in rock, freezes. Water expands approximately 9% when it freezes so this expansion puts pressure on the rock. Repeated freezing and thawing (over many years) can lead to fracturing. As this process relies on fluctuating temperatures, it is mainly seen in periglacial areas.

Chemical weathering

The weathering of carbonate rocks by carbonic acid

It occurs when CO2 in the air dissolves into rainwater, forming a weak carbonic acid. CO2 is more soluble at lower temperature, so therefore the water becomes more acidic. This acid then reacts with carbonate rocks, such as limestone, dissolving them.

 

Cold environments 6

List in alphabetical order the names of all nowadays ice sheets of the Earth.

An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers (20,000 square miles). The two ice sheets on Earth today cover most of Greenland and Antarctica. During the last ice age, ice sheets also covered much of North America and Scandinavia.

Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth. The Antarctic Ice Sheet extends almost 14 million square kilometers (5.4 million square miles), roughly the area of the contiguous United States and Mexico combined. The Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice. The Greenland Ice Sheet extends about 1.7 million square kilometers (656,000 square miles), covering most of the island of Greenland, three times the size of Texas.

Cold environments 7

Choose one of the answers

What is the square of Greenland Ice Sheet?

Together, the Antarctic and Greenland ice sheets contain more than 99 percent of the freshwater ice on Earth. The Antarctic Ice Sheet extends almost 14 million square kilometers (5.4 million square miles), roughly the area of the contiguous United States and Mexico combined. The Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice. The Greenland Ice Sheet extends about 1.7 million square kilometers (656,000 square miles), covering most of the island of Greenland, three times the size of Texas.

Cold environments 8

Choose one answer.

We know that together Antarctic and Greenland Ice Sheets contains 99% of the freshwater ice on Earth. And the Antarctic Ice Sheet contains 30 million cubic kilometers (7.2 million cubic miles) of ice.

If in case of climate change the Antarctic Ice Sheet melted, how will be changed sea level?

Ice sheets contain enormous quantities of frozen water. If the Greenland Ice Sheet melted, scientists estimate that sea level would rise about 6 meters (20 feet). If the Antarctic Ice Sheet melted, sea level would rise by about 60 meters (200 feet).

Cold environments 9

How many square km at least does the ice field need to cover, to be called ice sheet.

If an ice field covers more than 50,000 square kilometers (20,000 square miles), it is defined as an ice sheet. Although ice sheets covered much of the Northern Hemisphere during a series of Pleistocene Ice Ages, the Earth now has just two major ice sheets, one on Greenland and one on Antarctica.

Cold environments 10

At present, both ice sheets are shrinking, but the rate is small. Chose correct missed part in next statement

In terms of sea level contribution, on the order of about __________ per year

At present, both ice sheets are shrinking, but the rate is small (in terms of sea level contribution, on the order of about 1 millimeter per year).

Cold environments 11

For what ice sheet these characteristics are most typical?

Ice shelves, with subglacial meltining. Iceberg calve off from ice shelves.

Cold environments 12

For what ice sheet these characteristics are most typical?

Melting on the lower part of the surface, icebergs calve off ice sheet edges into ice fjords and the sea.

Cold environments 13

Read definition and fill in missed term

Ice _____ a projection of the ice edge up to several km in length caused by wind and current; usually forms when a valley glacier moves very quickly into a lake or ocean.

Ice tongue -  a projection of the ice edge up to several km in length caused by wind and current; usually forms when a valley glacier moves very quickly into a lake or ocean.

Cold environments 14

Choose which catergory of ice shelves is most frequently occurs.

Ice shelves fall into three categories: (1) ice shelves fed by glaciers, (2) ice shelves created by sea ice, and (3) composite ice shelves (Jeffries 2002).
Most of the world's ice shelves, including the largest, are fed by glaciers and are located in Greenland and Antarctica.

Cold environments 15

Write down how many major ice shelf areas does Antarctica has.

Antarctica has 15 major ice shelf areas, and 10 of the largest appear in this map.

Cold environments 16

Choose correct specific characteristics of the Wilkins Ice Shelf.

Antarctica has 15 major ice shelf areas, and 10 of the largest appear in this map. The Wilkins Ice Shelf is an example of a composite ice shelf comprised of both glacier-fed ice and fast ice thickened by snowfall. The others are glacier-fed, but ice formed from direct snowfall accumulation is a significant part of all permanent ice shelves.

Cold environments 17

Which 2 types of events occuring on ice shelves have attracted the attention of scientists?

 

Which 2 types of events occuring on ice shelves have attracted the attention of scientists?

Two types of events occurring on ice shelves have attracted the attention of scientists. One kind is iceberg calving, a natural event. The other kind is disintegration, a newly recognized phenomenon associated with climate change.