744748
Description
Mind Map by Sharondeep, updated more than 1 year ago
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Created by Sharondeep
about 10 years ago
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Glacial/Interglacial cycles
- Glacials
- protracted (Extended time) climatic cold periods (ice ages)
- ice sheets form in mid-latitude lowlands or low-latitude
mountain areas, polar caps extend out to sea.
- ice sheets form in mid-latitude lowlands or low-latitude
mountain areas, polar caps extend out to sea.
- global climates were colder and drier than interglacials.
- Modifies atmospheric and oceanic circulation.
- Evidence that the world was more arid, subtropical desert margins
more extended towards the equator, savannah grasslands more
extensive, restricting the extent of tropical rainforests.
- Increased ice volume in northern hemisphere forced polar
front closer to the equator, limiting Gulf stream northern
penetration and NADW formation weakening.
- protracted (Extended time) climatic cold periods (ice ages)
- Interglacials
- phases of warm climate between glacials
where ice has retreated, temperate forests
replace tundra veg in northern hem.
- Current interglacial period = Holocene, 10.000 years.
- Eamian Interglacial period 125,000 years warmer (marine oxygen isotope stage 5b)
- Past 2.5 myr (millions on years) 100 glacial/interglacial periods formally indentified.
- In marine records, assigned numbers (odd=inter) we're in Stage 1,
Stage 100 taken as marking the beginning of the Quaternary
period when there was a massive buildup of ice in northern hem.
- oscillations in global climate have continued over a
much longer period of time but before 2.5 Ma overall
climate warmer, restricting glaciations to polar regions
and high-latitude mountains.
- In marine records, assigned numbers (odd=inter) we're in Stage 1,
Stage 100 taken as marking the beginning of the Quaternary
period when there was a massive buildup of ice in northern hem.
- phases of warm climate between glacials
where ice has retreated, temperate forests
replace tundra veg in northern hem.
- climates may oscillate between g/I periods calling for further subdivision
- Stadial short cold phase within an interglacial.
Not cold enough to permit full gl conditions local
ice advances generally occur.
- Interstadial - short warm phase within a
glacial. Temps not as high as interglacial
period. In lowland mid-latitude regions the
climax veg was boreal woodland.
- Stadial short cold phase within an interglacial.
Not cold enough to permit full gl conditions local
ice advances generally occur.
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