Lecture 21 Flashcards
climatologists
Take the statistics of the earth system
What are the isotopes of water?
Isotope 18 and 16
What factors influence the ratio of oxygen isotopes in ocean water?
Evaporation and Condensation
What are the major glaciation periods of earth’s history?
Huronian Glaciation(2.4-2.2 bya) Late Preterozoic glaciation (0.8-0.6 bya) Late Ordovician glaciation(440 mya) Permo-carboniferous glaciation(280 mya) Pleistocene glaciation(1.8mya-10,000 ya)
The past 100,000 years has been marked by a period of?
Cold
When did short-term variations in glacial activity occur?
The Pleistocene
When was the warmest interval in the Halocene(our current time period)?
4000-6000 years ago
What are the causes of various climate fluctuations?
Major Glaciations and warm spells
Medium range variability
Short Term Variability
Major Glaciations and warm spells
- Changing continental positions
- continental uplift/erosion and/or
- co2 variations
- superplumes
medium range variability
- changes of earth’s orbit
- changes in solar output
Short term variability
- Volcanoes
- Solar cycles
Snowball Earth
Earth oscillates between planetary snowball and a giant hothouse as a result of long-term oscillations in atmospheric CO2 driven by the carbonate-silicate global cycle
Interstellar Dust Hypothesis
Earth protected from interstellar dust by solar wind, when heliosphere(solar wind) interacts with a cosmic dust cloud the heliosphere may partially collapse
Superplume
Superplume of magma releases CO2
Milankovich Cycles
- Changes in eccentricity of earth’s orbit
- Variability in earth tilt
- Procession
