geo sac 2: melting ice sheets + glaciers

what % of earth's land is covered by glaciers and ice sheets?

around 10% (15 million km2)

how much of earth's freshwater is stored in glaciers and ice sheets?

around 75%

where are ice sheets found?

antarctica and greenland

where are glaciers found globally?

on every continent except australia

where are glaciers typically located?

high altitude mountain regions (Andes, Himalayas)

what are the main factors controlling glacier distribution?

climate (cold temps + snowfall) and latitude (mostly above 60º N/S, also alpine areas)

accumulation

the process of gaining ice on a glacier

ablation

the process of melting ice on a glacier

glacial advance

ice gained is greater

glacial retreat

ice lost is greater

terminus

the end of a glacier where most melt occurs

equilibrium line

divides zone of accumulation (where the ice builds up) and zone of ablation (where ice is lost)

what controls whether a glacier grows or shrinks?

the mass balance between accumulation and ablation

what is the spatial association between human activity and glacier melt?

moderate association

where do most human causes of climate change occur?

urban/industrial areas

where does glacier melt mainly occur?

remote and alpine polar regions

how are human activity and glacier melt connected?

greenhouse gases -> global warming -> glacier melt worldwide

key SAC sentence for spatial association

human activity and glacier melt are spatially associated but functionally interconnected thought the global climate system

how do variation in solar energy affect glaciers?

changes in solar output affect earth's temp; more sunspots = warming

what are milankovitch cycles?

long-term orbital changes that affect climate

eccentricity

the shape of the earth's orbit, changes the lengths of seasons

obliquity

the tilt of the earth's axis- 23.5 degrees, causes the seasons, larger tilt means less ice and smaller tilt means more ice

procession

the 'wobble' of the earth caused by tidal forces, causes more intense seasonal contrasts in one hemisphere and less intense in the other

what do milankovitch cycles control?

ice ages and warming periods

how does volcanic activity affect glaciers?

ash causes clooking; gases cause warming

how does ocean circulation affect glaciers?

moves heat around earth; warmer currents increase melting

how do tectonics affect glaciers?

mountain building influences glacier formation; volcanic heat can increase melting

where is the quelccaya ice cap located?

tropical south america, near the equator, in the andes mountains

why is the quelccaya ice cap significant?

it's the largest tropical ice cap in the world

what global pattern does peru fit into?

a cluster of developing countries

what's the main human cause of ice melt in peru?

increases greenhouse gases causing global warming

how much has peru warmed comapred to the global average?

1.5ºC (faster than global average)

how does warming affect glaciers?

increases ablation and decreases accumulation

how does el nino contribute to glacier melt?

warmer temps and less snowfall increase melting

what is cryoconite and how does it affect melting?

dust from central asian deserts and particulate matter from volcanic eruptions in iceland land on the ice. dark dust lowers albedo, increasing heat absorption and melting

environmental impacts of glacier melt

positive: more vegetation in some areas

negative: sea level rise, habitat loss, increased heat absorption

social impacts of glacier melt

positive: tourism jobs and short-term water supply

negative: long-term water shortages, flood risks, loss of traditional lifestyles

economic impacts of glacier melt

positive: short-term farming benefits and tourism growth

negative: crop losses, reduced hydropower (70% of energy), expensive infrastructure

environmental issues from glacier melt

rising sea levels and loss of land

social issues from glacier melt

food and water insecurity

economic issues from glacier melt

job loss and cost of adaptation

what technology is used to monitor glaciers in peru?

ASTER satellite (NASA)

strengths of geospatial technologies

accurate, large-scale monitoring and helps predict hazards

weaknesses of geospatial technologies

not real-time, cannot detect small cracks, affected by weather (clouds)