all questions Flashcards
what is palaeolimnology the study of?
lake sediments
the stable isotope of 16O/18O is used as a proxy for what?
ppt
how much higher were temps during the last interglacial compared to now?
2°C
which oceanic sector are Heinrich events recorded from?
N Atlantic
by how much has the conc of atm CO2 increased since the end of the LGM to now?
200 ppm
approx how many cold cycles have been recorded over the past 2.6 mil years?
100
what is a stadial?
a period of low temps characterised by high global ice vol
approx when were Neanderthals thought to have become extinct?
24,000 y/a
abrupt c.c. in the Late-glacial and early Holocene are thought to be a consequence of which natural factor?
freshwater injection into the N Atlantic
annual temps in Britain during the LGM were though to have been?
-10°C
the last mammoth pop in N Siberia are thought to have become extinct when?
4000 Cal yr BP
what bought water to earth?
carbonaceous chondrite meteorites
what is the earliest evidence for some form of photosynthesis on earth?
13C-depleted carbon in graphite
where do Island arcs form?
above subduction zones where ocean plates converge
what did Lovelock propose as a generic signature of life on a planet?
disequilibrium in the mixture of atmospheric gases
what happens to the temp on Daisyworld when both daisies are coexisting and the solar luminosity increases?
it decreases
how long in total will our sun spend on the main sequence?
10 billion years
which process causes a long-term removal of O2 from the atm?
oxidative weathering of ancient organic carbon
when did the first animal fossils form?
580 Ma
what could plausibly have cooled the climate. and triggered the Neoproterozoic snowball earth events?
equatorial distribution of continents causing high weathering rates
what describes the immediate aftermath of a snowball earth?
hot and wet caused by low albedo and high atm CO2 levels
which glacial period did the first non-vascular plants colonise the land?
ordovician
which was the biggest extinction in the Phanerozoic record?
end permian
approx how much C was released to the atm at the PETM?
2000 GtC
