glaciation sg5 Flashcards
what glacier did lake palcacocha come from
palcaraju glacier in the peruvian andes
what are the names of the valley and and river flowing from lake palcacocha
valley: cajup valley
river: rio paria
what is the name of the town at end of valley
huaraz
describe the human activity taking place (dam)
- 8m dam built in 1974
- reinforce terminal moraine
- includes concrete overflow spilling
describe the human activity taking place (pipes)
- lake lowered by 3m since 2010
- water is siphoned off through drainage pipes
temp increase since 1940?
from 3^C to 5^C
how much has lake increased in volume since 1940
3000%
how much has lake increased in potential energy since 1940
10,000% increase
impact of 1941 GLOF (glacial lake overflow flood)
- carried blocks of ice, large rocks, boulders & liquid mud down valley
- 6000-7000 ppl killed
how has human activity impacted potential energy stored in lake
- 47% decrease
less energy converted to kinetic energy = reduced inpact in case of GLOC
how has human activity impacted sedimentation in lake (description, advantage & disadvantage)
- lack of water flow = lack of energy = deposition of sediment on lake bed
- only clear water containing fine rock flour is transported down stream = huaraz has more cleaner water for their needs
- however: if sedimentation increases = reduced lake capacity = increased risk of GLOF
effect of human activity on lake palcacocha
- mean depth won’t exceed 30m
- less fluctuations in size
effect of human activity on rio paria
during dry season, meltwater can be siphoned from lake into river, increasing its volume, so river is less effected by dry season
effect of human activity on cojup valley
increased channel erosion = wider and deeper valley
