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Flashcards in cenozoic climate change 2 Deck (18)
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1

what happened in the eemian?

127-118 thousand yrs ago

penultimate warm period

slighlt=y warmer than present

sea level 4-9m higher

wasnt just one warn event - short lived colder events

2

what is terminal moraine

debris accumulated and pushed to front edge of glacier - deposited and unsorted rock

shows visible footprint of glaciers

3

describe what is was like during glacial perids

cold dry
-120m lower sea level as water in ice
land bridges between continents

boreal
taiga
tundra

4

describe what is was like inter during glacial perids

warm
humid

savanna
deserts
rainforests

5

the last glacial maximum

23-19,000 yrs ago

coldest period of last 100,000 yrs

temps 7 degrees lower than beginning og glaciation

23 degrees cooler than present greenland
5 degrees cooler than present tropics

sea surface temps 4-5 degrees lower

seal level 120m below present

6

what does bluemarble 3000 show

shows earth at last glacial maximum 21,000 yrs ago and end 1000 yrs into future

based of co2 emissions 2100

7

which hemisphere ice sheet cover was impacted the mostno

northern hemisphere

8

what was the very cold period called in the LGM

Younger Dryas - loch lomand

9

the younger dryas

12,900 - 11,500 yrs ago

very cold short spell

hypothesis - outburst of flood path from lake agassiz in arctic. freshwater into oceans, impacted thermohaline current as its driven by desnity and stopped over turning circulaton which interuppted warm gulfstream

10

what factors caused the spread of trees in early holocene

climate change

distance of glacial refuge ice

role of biotic factors - comp/soil/dispersal rates

11

describe sequnece of trees in early holocene

pre boreal
boreal - warmer
atlantic - warmest period
sub-boreal - cooler
subatlantic

12

what makes up the mid holocene climatic optimum

boreal and subboreal

13

in the subatlantic phase what made there be an increase in veg and grases

humans
pasture
agricutlture

wood used for building

charcoal use-

14

when did humans start impacting the world

20-40,000 yrs ago

15

average weight of humans on earth

470 mill tonnes

16

average weight of skeletons

75 million tonnes

17

anthropocene

new epoch and geological time period makring commence of significant human imapct on ecosystems

18

evidence of anthropocene

altered isotope due to atomic bomb

plastic bottles