External Reading Flashcards
Who researched Antarctic glaciation and the associated changes in ocean circulation at the Eocene-Oligocene transition?
Goldner et al., 2014
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
- Thermal insolation of Antarctica as a result of the opening of the Southern Ocean gateway
- Declining atmospheric CO2 – EVIDENCE FOR THIS
What influence did the growth of the AIS 34MYA have on ocean circulation? (With Citation)
Caused a northwards transport of Antarctic Intermediate Water (AIW), which invigorated the formation of Antarctic Bottom Water (ABW) (Goldner et al., 2014)
What was the +ve and -ve feedback that occurred due to the formation of the AIS 34MYA? (With Citation)
+ve: Increased sea ice and increased primary production
-ve: Stronger southward heat transport and localised high-latitude warming
(Goldner et al., 2014)
Who modelled the collapse of the THC and what restricted the research?
Vellinga and Wood, 2002
Limited knowledge of the THC so pre-inudsutrial climate variables were used
Name 4 changes to the climate as a result of a collapse in the THC (With Citation)
- Cooling in the N.Hemisphere and a dryer climate
- Weak warming in the S.Hemisphere
- Southwards shift of the ITCZ
- 5% reduction in vegetation primary productivity
(Vellinga and Wood, 2002)
After how many years would the THC recover? (With Citation)
100 years
Vellinga and Wood, 2002
Who found that the Greenland Ice Core only covers the last glacial cycles compared to Antarctica which covers 800,000 years?
Andersen et al., 2008
What did Barker et al., 2015 conclude with regards to icebergs and North Atlantic Cold events?
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
Who took a new deep ice core from Southern Greenland and compared the oxygen isoptoes to deep-sea forams dating back 90,000 years?
Dansgaard et al., 1982
At which interglaical did Dansgaard et al., 1982 suggest there was a dramatic termination?
Eem/Sangoman IG
When was the first reconstruction of SST at the LGM?
In the 70s and 80s by CLIMAP
What did the MARGO project (2009) do?
An updated synthesis of SST for 19-23kya – it was a multiproxy apporach and integreated microfossil and geochemcial reconsturctions of SST
What did the MARGO project revela about SST?
That there was a presence of large longitudinal gradients in SST in all ocean basins at the LGM
Which 3 climate indices have been identified by Hays et al. (1976) with their periodicity and contribution to climatic vacation?
Obliquity - 42,000 years (25%)
Precession - 23,000 years (10%)
Eccentricity - 100,000 years (50%)
What did Hays et al. (1976) conclude about the Earths orbital geometry?
That is is a fundamental cause of the succession of Quaternary Ice Ages
What were the 2 scenarios raised by Borecker (1982) to explain lower CO2 content in the oceans during peak glacials?
- Storage and erosion of Phosphorus leaving residues from shelf seas
- C/P ratio changes for the organic debris falling to the deep-sea
What did Clark et al. (1999) say about ice sheet activity?
That ice sheets can actively interact with the ret of the climate by amplifying and potentially driving global climate change over several timescales
Antarctic temperaturen have been positively correlated with what over millennial scale climate cycles? (With Citation)
CO2 Concentrations
Ahn and Brook, 2008
What link does CO2 have with the Southern Ocean? (With Citation)
CO2 increases when the Southern Ocean Stratification decreases during Northern Hemisphere Stadials
(Ahn and Brook, 2008)
Who said that glacier terminations during the late pleistocene are associated with changes in insolation?
Barker et al., 2010
On what timescales is there a a strengthening of the AMOC? (With Citation)
Millenial Scale
Barker et al., 2010
What happened to NADW export during expansion of the Atlantic? (With Citation)
It was greater than it was in the IG
Barker et al., 2010
Who said that the relationship between millennial scale temperature changes over Greenland and Antarctica during the LGM has led to the bipolar seesaw?
Barker et al., 2009
What role does the Southern Ocean play in deglacial climate change? (With Citation)
Links to increased atmospheric CO2 and outgassing
Barker et al., 2009
