Introducing Ice

Ice Sheet

A large body of ice over 50000 sq. Km in extent.

Ice Cap

A smaller body of ice (less than 50000 km in extent), usually found in mountainous regions

Glacial

A period of ice advance associated with falling temperatures.

• 80,000 to 100,000 years

• Sometimes caused an ice age

Glacier

A river of ice usually extending downhill from an ice cap occupying a valley

Interglacial

A period of ice retreat associated with rising temperatures.

• 10,000 to 15,000 years (in the past 2.6M years)

• Also called Quarternary warm periods

Impact of ice

• Climate

• Landscapes

• Ecosystems

• Human Civilisation

Impact of the Last Glacial Period

• Earth's Crust: During the last glacial period, huge ice sheets up to 3000 metres thick covered the continents in the northern hemisphere, causing the Earth's crust to sink.

• Vast areas of floating sea ice also formed.

• Sea Levels: Because so much water was locked in the ice sheets, sea levels dropped by over 100 metres.

Formation of Glaciers

• In cold environments and high altitudes, snow falls layer upon layer

• Over time, the layers get compacted to ice

• If the ice doesn't melt and snow continues to fall, the ice becomes bigger and heavier

• When it becomes very heavy, gravity causes it to start moving down very slowly

• As the glacier moves, it erodes and changes the landscape

• Glacier melts or falls away, evaporates and the cycle repeats

Label the diagram:

• Avalanches

• Snowfall

• Melting

• Calving

• Evaporation

Accumulation

Inputs to the glacial budget, such as snowfall and avalanches

Ablation

Outputs from the glacier budget, such as melting

Temperature change every 100m

1 degree celsius

Which part of the glacier is the 'snout’?

The end

What accumulates to form a glacier?

Snowfall

As a glacier advances, what does it do to the landscape?

Erodes/carves

How long ago did the last ice age finish?

10,000 to 15,000 years

Cycle that affects the Earth's climate causing glacial and interglacial periods

Milankovich Cycles

Countries with glaciers

France, China, India, Pakistan, Chile, etc.

Define:

• Erosion

• Transportation

• Deposition

• Wearing away of the land

• Moving or carrying something

• Putting something down

Plucking

When ice freezes around rocks under the glacier and then the glacier tugs them out

Freeze- thaw weathering

When water freezes in cracks expanding them so the crack becomes bigger

Striations

The indentation the glacier makes as it scratches the rock beneath it

Abrasion

When rocks grind against other rocks wearing it away like sand paper

Corrie

• Glaciers form a hollow on the mountain where they've been forming

• The hollow deepens through plucking, abrasion and freeze-thaw weathering

• Carries are revealed whne the glacier melts, often with a lake in them

Tarn

The corrie fills with water, forming a tarn.

Arete

Corries sometimes form side by side, forming an Arete

Pyramidal Peak

Three/four corries around a mountain lead to the formation of a pyramidal peak.

U-Shaped Valleys

Glaciers erode V-shaped valleys, making them less steep and forming U-shaped valleys

Truncated Spurs

As glaciers flow, they erode the valleys and bulldoze the interlocking spurs, truncating them.

Misfit Streams

A narrow river in a wide valley

Ribbon Lakes

• Ice erodes the valley floor unevenly

• This is because of different rock types

• As the glacier melts, meltwater fills the valley, forming ribbon lakes

Hanging Valley

A hanging valley is a smaller side valley left 'hanging' above the main U-shaped valley formed by a tributary glacier.

Erosion

• Freeze-thaw weathering

• Abrasion

• Plucking

Erratics

• Large rocks or boulders

• Found on their own

• Unusual shapes and sizes

• Not native to the area they've been dumped

Drumlins

• Elongated hills of glacial deposits

• 1km long and almost 500m wide

• group: Drumlin swarm or basket of eggs

• Part of the sediment acccumulated by the glacier until it was overloaded

• they then got deposited

Moraine

• Created when a glacier deposits the till it's been carrying

• Made of unsorted angular rocks

• Types:

  • Lateral

  • Medial

  • Terminal

  • Ground

Link between CO₂ Levels and Atmospheric Temperature

• Evidenced by ice core

• Increased burning of fossil fuels and methane released from permafrost has contributed to higher CO₂ levels.

Increase in CO Particles per Million

• Gradual increase from 1800

• 106 particles per million from 1800 to 2008

• Biggest increase: 1980 to 2008 (49 ppm)

Which end of a glacier points in the direction of glacial advance?

Elongated end

Alps: Location

• Span 1200km across Europe

• They span France, Switzerland, Monaco, Italy, Liechtenstein, Austria, Germany, and Slovenia.

• The highest point is Mont Blanc which is situated on the France/ Italy border and is 4808 metres above sea level.

• Rivers like the Rhine, the Rhône, the Inn, and the Po originate here.

• They flow into the North Sea, the Mediterranean Sea, the Adriatic Sea and the Black Sea.

Alpine Lifestyle

Traditionally: farming and agriculture.

• Because of the fertile land in the lower regions caused by factors associated with glaciation.

• Good supply of fresh water as well as minerals eroded from the mountain by the glaciers themselves.

Positive Social Impact: Alpine Toursim

Young people stay in villages because of increased oppurtunities

Negative Social Impact

• Traditional culture is eventually lost

• Residents may become hostile towards tourists

Positive Economic Impact

• Tourists put money into the economy by spending

• Extra money can be reinvested into the infrastructure

• Jobs are created in the summer months as well

• Jobs are created in the lower slopes

• Jobs other than the service sector are created

Positive Environmental Impact

Money generated can be reinvested to help improve biodiversity

Negative Environmental Impact

• Large amounts of energy used

• Noise from machinery scares away wildlife

• Increase in vehicles= Increase in CO2

• Skiing over thin ice damages vegetation and land

• Deforestation

• Vegetation is destroyed

Extreme Tourists

• Young (late 20s to early 30s): have the time, energy and motivation

• Often Unmarried: no commitments or attachments = more freedom

• Both have good jobs: high income helps fund expensive trips

• DINKS: noone to look after, more time, more freedom

Why is Antarctica extreme?

• Located on the South Pole

• Continent about 5M square miles wide

• Emptiness: uninhabited until 1897, now about 200-1000 people

• Temperatures -30 to 0 degrees Celsius

• Wilderness: Few people and buildings, limited wildlife

Reasons for visiting Antarctica

• Comfort: easier than in the past

• Ease of access: more tour each year

• Wilderness: Antarctica is still unspoilt

• Ecotourism: people want to visit places with as little environmental impact as possible

• Financial: young people with big incomes + recently retired people

Things to do in Antarctica

• Fly over the ice

• Climb rock and ice faces

• Visit research stations

• Hike

• Go underwater in underwater vehicles