Hubbard et al., 2009

Question 1

Hubbard et al., 2009

What does the model do?

Answer 1

Numerical modelling procedure to see the effect of ice streams, model looks at changes of air temperature and grounding lines.

Question 2

Hubbard et al., 2009

What does the model find?

Answer 2

The modelled BIIS is extremely dynamic, drained mainly by a number of transient but recurrent ice streams which dynamically switch and fluctuate in extent and intensity on a centennial time-scale.

A series of binge/purge, cycles are identified which correspond to alternating periods of relatively cold-based ice, and wet-based ice with a lower aspect ratio, characterised by streaming- of similar periodicity to Laurentide ice sheet.

Question 3

Hubbard et al., 2009

What do the phases of predominant streaming activity coincide with?

Answer 3

Periods of maximum ice extent and are triggered by abrupt transitions from a cold to relatively warm climate, resulting in major iceberg/melt discharge events into the North Sea and Atlantic Ocean.

Question 4

∼20 ka

Answer 4

maximum extent with fast-flowing ice across its western and northern sectors that extended to the continental shelf edge

Question 5

∼19 ka

Answer 5

deglaciation is achieved in less than 2000 years, discharging the freshwater equivalent of ∼2 m global sea-level rise.

Question 6

∼ 17 ka

Answer 6

a much reduced ice sheet centred on Scotland undergoes subsequent retrenchment and a series of advance/retreat cycles into the North Sea Basin

Question 7

∼ 13 to 11.5 ka

Answer 7

sustained Younger Dryas event

Question 8

∼ 10.5 ka

Answer 8

Modelled ice cover is persistent across the Western and Central Highlands until the last remnant glaciers disappear

Question 9

Time line overall

Answer 9

∼20 ka- maximum extent with fast-flowing ice across its western and northern sectors that extended to the continental shelf edge

∼19 ka- deglaciation is achieved in less than 2000 years, discharging the freshwater equivalent of ∼2 m global sea-level rise.

∼ 17 ka- a much reduced ice sheet centred on Scotland undergoes subsequent retrenchment and a series of advance/retreat cycles into the North Sea Basin

∼ 13 to 11.5 ka- sustained Younger Dryas event

∼ 10.5 ka- Modelled ice cover is persistent across the Western and Central Highlands until the last remnant glaciers disappear