External Reading

Question 1

Who researched Antarctic glaciation and the associated changes in ocean circulation at the Eocene-Oligocene transition?

Answer 1

Goldner et al., 2014

Question 2

What were the two hypotheses raised by Goldner et al., 2014 for global cooling and the abrupt growth of the Antarctic Ice Sheet 34 MYA? and which of the two has evidence

Answer 2

1. Thermal insolation of Antarctica as a result of the opening of the Southern Ocean gateway
2. Declining atmospheric CO2 – EVIDENCE FOR THIS

Question 3

What influence did the growth of the AIS 34MYA have on ocean circulation? (With Citation)

Answer 3

Caused a northwards transport of Antarctic Intermediate Water (AIW), which invigorated the formation of Antarctic Bottom Water (ABW) (Goldner et al., 2014)

Question 4

What was the +ve and -ve feedback that occurred due to the formation of the AIS 34MYA? (With Citation)

Answer 4

+ve: Increased sea ice and increased primary production

-ve: Stronger southward heat transport and localised high-latitude warming

(Goldner et al., 2014)

Question 5

Who modelled the collapse of the THC and what restricted the research?

Answer 5

Vellinga and Wood, 2002

Limited knowledge of the THC so pre-inudsutrial climate variables were used

Question 6

Name 4 changes to the climate as a result of a collapse in the THC (With Citation)

Answer 6

1. Cooling in the N.Hemisphere and a dryer climate
2. Weak warming in the S.Hemisphere
3. Southwards shift of the ITCZ
4. 5% reduction in vegetation primary productivity

(Vellinga and Wood, 2002)

Question 7

After how many years would the THC recover? (With Citation)

Answer 7

100 years

Vellinga and Wood, 2002

Question 8

Who found that the Greenland Ice Core only covers the last glacial cycles compared to Antarctica which covers 800,000 years?

Answer 8

Andersen et al., 2008

Question 9

What did Barker et al., 2015 conclude with regards to icebergs and North Atlantic Cold events?

Answer 9

That although the freshwater derived from melting icebergs may provide a +ve feedback for enhancing and/or prolonging stadial (cold) conditions but it doesn’t trigger Northern Stadial events

Question 10

Who took a new deep ice core from Southern Greenland and compared the oxygen isoptoes to deep-sea forams dating back 90,000 years?

Answer 10

Dansgaard et al., 1982

Question 11

At which interglaical did Dansgaard et al., 1982 suggest there was a dramatic termination?

Answer 11

Eem/Sangoman IG

Question 12

When was the first reconstruction of SST at the LGM?

Answer 12

In the 70s and 80s by CLIMAP

Question 13

What did the MARGO project (2009) do?

Answer 13

An updated synthesis of SST for 19-23kya – it was a multiproxy apporach and integreated microfossil and geochemcial reconsturctions of SST

Question 14

What did the MARGO project revela about SST?

Answer 14

That there was a presence of large longitudinal gradients in SST in all ocean basins at the LGM

Question 15

Which 3 climate indices have been identified by Hays et al. (1976) with their periodicity and contribution to climatic vacation?

Answer 15

Obliquity - 42,000 years (25%)
Precession - 23,000 years (10%)
Eccentricity - 100,000 years (50%)

Question 16

What did Hays et al. (1976) conclude about the Earths orbital geometry?

Answer 16

That is is a fundamental cause of the succession of Quaternary Ice Ages

Question 17

What were the 2 scenarios raised by Borecker (1982) to explain lower CO2 content in the oceans during peak glacials?

Answer 17

1. Storage and erosion of Phosphorus leaving residues from shelf seas
2. C/P ratio changes for the organic debris falling to the deep-sea

Question 18

What did Clark et al. (1999) say about ice sheet activity?

Answer 18

That ice sheets can actively interact with the ret of the climate by amplifying and potentially driving global climate change over several timescales

Question 19

Antarctic temperaturen have been positively correlated with what over millennial scale climate cycles? (With Citation)

Answer 19

CO2 Concentrations

Ahn and Brook, 2008

Question 20

What link does CO2 have with the Southern Ocean? (With Citation)

Answer 20

CO2 increases when the Southern Ocean Stratification decreases during Northern Hemisphere Stadials
(Ahn and Brook, 2008)

Question 21

Who said that glacier terminations during the late pleistocene are associated with changes in insolation?

Answer 21

Barker et al., 2010

Question 22

On what timescales is there a a strengthening of the AMOC? (With Citation)

Answer 22

Millenial Scale

Barker et al., 2010

Question 23

What happened to NADW export during expansion of the Atlantic? (With Citation)

Answer 23

It was greater than it was in the IG

Barker et al., 2010

Question 24

Who said that the relationship between millennial scale temperature changes over Greenland and Antarctica during the LGM has led to the bipolar seesaw?

Answer 24

Barker et al., 2009

Question 25

What role does the Southern Ocean play in deglacial climate change? (With Citation)

Answer 25

Links to increased atmospheric CO2 and outgassing

Barker et al., 2009