Fragile Environments Flashcards
What 3 types of services do glaciated areas provide?
Provisioning
Regulating
Cultural
What do provisioning services provide within glaciated areas?
Fisheries
Wild foods
Freshwater
Genetic resources
What do regulating services provide within glaciated areas?
Climate regulation
Carbon sequestration
What do cultural services provide within glaciated areas?
Natural beauty
Culture preservation
Spiritual value
Describe the importance of provisioning services in glaciated areas
Arctic + Southern Ocean fisheries have local + international value
Seasonal seal hunting for indigenous tribes
Freshwater stores in ice caps + glaciers
Describe the importance of regulating services in glaciated areas
Large carbon + peat stores in Arctic soil
Warming may release large volumes of CO2 + CH4
Arctic + Antarctic regulate global environment
Describe the importance of cultural services in glaciated areas
Travellers enjoy unspoilt wilderness
Ecosystems have cultural merit to certain tribes + need maintaining
What is a carbon sink?
Natural or artificial resevoir that absorbs more carbon than it releases, leading to carbon accumulation
Describe the environmental role + importance of glaciated areas
Regions of permafrost + tundra peat are major areas for soil carbon storage
Arctic regions act as weak carbon sink
How can permafrost accelerate environmental damage?
Melting due to positive feedback
Soils release carbon + upset balance
What are the 3 main natural hazards to glaciated upland landscapes?
Avalanches
Lahars
Glacial Outburst Floods (GOF)
What is the main cause of a glacial outburst flood?
Sudden discharge of a sub-glacial lake or ice moraine dammed lake
In how many ways can a glacial outburst flood be triggered?
6
List the ice dam related causes of a GOF
Overflow + melting of ice dam
Breakdown due to tectonic activity
Enlargement of underlying tunnels due to increased water pressure
List the water related cause of a GOF
Increased floatation of ice due to rising water levels
List the moraine dam related causes of a GOF
Irreversible overtopping of moraine dam by tsunami style wave
Dam failure due to melting ice within or removal of sediment
Give a historical example of a GOF
Iceland 1996
Grimsvotn erupted, caused large peak discharge
Resulted in $15m damages
What is a lahar?
Mixture of water, mud + rock fragments
How does a lahar occur?
Volcanic activity and/or glacial melting
Give a historical example of a lahar
1985, Columbia (Nevado Del Ruiz)
Volcanic activity resulted in large scale glacial melting
What were the impacts of the Nevado Del Ruiz lahar?
Moved 50km downstream
3-8m mud deposits in places
23,000 killed almost instantly
When does an avalanche occur?
When stress exceeds strength of mass of snow located on a slope
How does an avalanche occur?
Snow becomes strong + cohesive
Breaks away from underlying slope
