2017 questions

Question 1

how old is the oldest ocean crust in the NW Atlantic and W Pacific?

Answer 1

180-200 Myr

Question 2

what do plumes underneath continental crust create at the surface?

Answer 2

massive outpourings of lava called large igneous provinces

Question 3

which is not an argument against the Gaia hyp?

Answer 3

organisms cannot change the composition of the atm

Question 4

what is the largest reservoir of carbon?

Answer 4

carbonate in sedimentary rocks

Question 5

what describes the earth’s oxygenation state after the origin of oxygenic photosynthesis but before the great oxidation?

Answer 5

reducing atm, oxygenated surface ocean, anoxic deep ocean

Question 6

what is a source of evidence for the great oxidation?

Answer 6

the disappearance of mass independent fractionation of sulphur isotopes

Question 7

when was the earth’s second oxygenation event?

Answer 7

600-400 Ma

Question 8

where would be the safest place during a snowball earth?

Answer 8

a geothermal heated oasis on land

Question 9

what glaciations are said to have been caused by the rise of the first non-vascular plants?

Answer 9

Ordovician glaciations

Question 10

what ocean based mechanism counteracts declines in atm oxygen?

Answer 10

increased ocean anoxia promotes phosphorous recycling from ocean sediments fueling marine productivity and organic carbon burial

Question 11

what do mesozoic sediments tell us about atmospheric oxygen levels?

Answer 11

the presence of charcoal indicates O2 >15% of the atm

Question 12

how did the c cycle respond at the end cretaceous extinction?

Answer 12

collapse of the marine biological pump added CO2 to the atm

Question 13

what is the age of the Neogene-Quaternary transition?

Answer 13

2.6 ma

Question 14

how long does one complete eccentricity cycle take?

Answer 14

100,000 years

Question 15

what was a major factor to the build-up of large ice sheets in the N Hemisphere that defines the quaternary likely to have been?

Answer 15

closure of the Isthmus of Panama

Question 16

the total number of MIS stages identified in the deep ocean sediment records in the quaternary now exceeds:

Answer 16

100

Question 17

when did H Erectus emigrate out of Africa?

Answer 17

1.8 Ma

Question 18

what was the last glacial in Britain?

Answer 18

devenisian

Question 19

how much lower was the temp during the LGM?

Answer 19

5°C

Question 20

where were the youngest mammoth remains found in Britain?

Answer 20

Candover, Shropshire

Question 21

when was the YD/Holocene transition in the Greenland ice core?

Answer 21

~11,700 y/a

Question 22

which MIS is thought to be most comparable to the Holocene?

Answer 22

MIS 11

Question 23

when was H. floresiensis thought to have become extinct?

Answer 23

~ 50,000 y/a

Question 24

what is the limit of radio carbon dating?

Answer 24

50,000 years

Question 25

what is a key forcing factor of global climate over multi-decadal timescales during the holocene?

Answer 25

solar variability