Term 2 - Theme 3 (1)

Question 1

Observed sea level has increased around

Answer 1

10cm since 1970s.

Question 2

Glaciers are driven by climate

Answer 2

Snow and ice accumulation, ablation through radiative forcing.

Question 3

IPCC, 2001 + 2007

Answer 3

glaciers re the clearest indicators of what is currently happening to the climate of the earth… the fact that they are thinning and retreating at historically unprecedented rates should be a concern to us all.

Question 4

Mass balance equation

Answer 4

MB = accumulation - ablation (-iceberg calving)

Question 5

The cryosphere consists of

Answer 5

Northern hemisphere - Greenland, Arctic glaciers, Alaska, alps, himalayas (7m potential SLR).
Southern hemisphere - Antarctica - 57m potential SLR and the andes.

Question 6

Change in glacier length

Answer 6

indirect, delayed sign of change in climate

Question 7

Air temperature role

Answer 7

Related to radiation balance and solid/liquid precipitation ratio.

Question 8

Climatic sensitivity of a glacier depends on

Answer 8

local topographic effects.

Question 9

Response/lag time

Answer 9

Occur because the signal must be transferred from accumulation area to the snout of the glacier.

Question 10

Response/lag time controlled by

Answer 10

glacier size, gradient and flow velocity. Lay, low gradient, slow glaciers will have a long lag time. Short, steep and fast glaciers will have a short lag time.

Question 11

Monitoring frontal variations of glaciers

Answer 11

Direct measurement, image comparison.

Question 12

Mass balance measurement of glaciers

Answer 12

Direct measurements of accumulation and ablation, remote sensing methods.

Question 13

Global glacier changes (length)

Answer 13

General glacier recession shown in Little Ice Age. Intermittent readvances on decadal timescales. Strong glacier retreat in the 1920s and 1940s.

Question 14

Glacier frontal variations

Answer 14

Most visible component of glacier response to climate change. May be studied over long time scales. All related to changes in total glacier mass balance.

Question 15

global glacier change (mass balance)

Answer 15

mass balance is the different between mass gained and mass lost. Mountain glaciers are losing mass all the time + this has increased in the last decade.

Question 16

Glacier fluctuation - Africa

Answer 16

occur on Rwenzari, Mount Kenya and Kilimanjaro In 1906 Rwenzari had 43 glaciers with a total area of 7.5km2. By 2005, this was about 1.5km2.

Question 17

Glacier fluctuations - New Zealand

Answer 17

Most glaciers located along the Southern Alps . Overall retreat over the past 150 years, with intermittent Alpine radius in the 1890s, 19202, 70/80s and 1985. Ice cover estimated to have diminished by about 35% from 1850 to 1970s and another 22% by 2000.

Question 18

Glacier fluctuations - Antarctica

Answer 18

Majority of glaciers and ice caps located on the Antarctic Peninsula. Cook et al (2005) showed that 87% of the glaciers have retreated over the last 6 decades. Glaciers on S Georgia receded overall since 9th Century.

Question 19

Antarctic glacier change

Answer 19

Increasing atmospheric + oceanic temp. Air temps rose by 2.5 degrees in the northern antarctic peninsula. 1950-2000. Collapse of ice shelves. Acceleration of ice streams + outlet glaciers.

Question 20

Glacier surface lowering

Answer 20

More surface lowering in the north related to greater temp increases. The thinning is likely to be related to glacier acceleration and increasing calving rates.

Question 21

Prediction of future glacier changes are important for

Answer 21

understanding contribution to SLR, Managing water resources, mitigation against hazards such as GLOFs.

Question 22

Prediction of future changes difficult due to

Answer 22

Uncertainty of future climate scenarios. Uncertainty as to how glaciers will retreat in future changes in climate. Local factors such as aspect and sliding.

Question 23

Equilibrium line altitude (ELA) increased

Answer 23

in a warmer climate.

Question 24

Prediction: topography

Answer 24

Steeper glaciers more likely to survive longer into a period of continental warming. Rise in eLA translated to a smaller zone of ice transferring from the accumulation to ablation zone.

Question 25

The WAIS: marine ice sheet instablility

Answer 25

Major concern about the West Antarctic ice sheet size -much of the sheet is below sea level.

Question 26

Nesje, A + Dahl, S, O (2000) the equilibrium line altitude marks

Answer 26

the area or zone on the glacier where accumulation is balanced by ablation.

Question 27

Kieffer et al, 1994

Answer 27

The EOS has been developed to build uniform database of most glaciers in the world and monitor changes in glaciers on a periodical basis.

Question 28

Paterson, 1994

Answer 28

The response time is defined as the time a glacier takes to adjust to a change in mass balance.

Question 29

Johannesson et al, 1989

Answer 29

The response time is defined as the time a glacier takes to adjust to a change in mass balance.

Question 30

During the Quarternary glacial periods, ice sheets were extensive, covering bout

Answer 30

30% of the Earth’s land area.