Glaciation JC Geography

What is an ice age?

A period during which large parts of several continents are covered by ice sheets.

When did the last ice age affecting Ireland end?

Roughly 12,000 years ago.

What causes an ice age related to Earth's orbit?

The Earth's orbit changes from oval to circular, influencing climate over tens of thousands of years.

How does carbon dioxide affect global temperatures?

Less CO2 in the atmosphere can lead to a drop in global temperatures.

What is plucking in glacial erosion?

The process where meltwater from a glacier refreezes around rocks, which are then pulled away as the glacier moves.

What is abrasion in glacial erosion?

The scratching and scraping of the underlying rock by rocks attached to the glacier, leaving striations.

What is a cirque?

A basin-shaped hollow in a mountain, often containing a lake, formed by accumulating snow and moving ice

How is a cirque formed?

Snow accumulates in a hollow, compresses into ice, and erodes the sides of the mountain through plucking and abrasion.

Cirque example

Devil's Punchbowl, Co. Kerry

How do glaciers transport their load?

Glaciers transport material by pushing it in front, carrying it on top, rolling it along the sides, or allowing it to fall through crevasses.

What happens when a glacier reaches lowland areas?

The warmer temperature causes the glacier to melt and deposit its load, forming landforms of glacial deposition.

What are drumlins?

Oval-shaped hills made of boulder clay formed by the deposition of material from a glacier. Example

How do drumlins indicate glacier movement?

The steep slope (stoss end) shows the direction the glacier came from, while the gentle slope (lee slope) indicates the direction it was traveling.

Drumlin example

Co. Cavan

What are fluvio-glacial features?

Landforms created by meltwater from glaciers, including eskers and outwash plains.

What are some benefits of glaciation?

Benefits include fertile soil for agriculture, tourism opportunities, hydroelectric power from glacial lakes, and natural routeways.

What are some negative influences of glaciation?

Negative impacts include poor agricultural land in upland areas, poor drainage leading to bogs, and flooding due to melting glaciers.

What is the Golden Vale known for?

The Golden Vale in Munster is known for its fertile boulder clay soils and agriculture.

What is the 'basket of eggs' landscape?

A landscape formed by clusters of drumlins, resembling a basket of eggs.