Antarctica/ Greenland Basic

Question 1

Introduction

Answer 1

Eq line

PMB
NMB

Question 2

Temps rising

Answer 2

Region of

6x

• 2.5 (Tuner et al., 2005)
• 9oC (Morris and Vaughan, 2003)

Oscillation (van den Broeke and van Lipzig, 2004)

Pressure patterns

Question 3

Measuring changes in climate

Answer 3

Ice core (Augustin et al, 2004)

Methane and carbon dioxide (Solomon et al., 2007).

Question 4

Ice shelves are collapsing

Answer 4

Removal of ice shelf (Glasser and Scambos, 2008)

Meltwater on the surface (Glasser and Scambos, 2008)

Incursion of warm ocean currents (Viela et al., 2010)

Iceberg calving by hydrofracture (Sheperd et al., 2003)

Question 5

Larsen Ice Shelf

Answer 5

Summer of 2002

Stable throughout the Holocene

Question 6

Pine Island Glacier

Answer 6

Warmed from below

Interior

Primary driver Pritchard et al. (2012)

Troughs on the continental shelf

Question 7

Glaciers are accelerating

Answer 7

Easier to float

Pritchard and Vaughan (2007)

Question 8

Sea level is rising

Answer 8

3 mm per year (Solomon et al., 2007)

Question 9

Impact of climate on glaciers

Answer 9

Small size and northerly latitude (Vaughn et al., 2003).

High snowfall but high melt (Pritchard and Vaughan, 2007)

It interrupts the Circumpolar Westerlies

Question 10

Everything Antarctica

Answer 10

Introduction

The main difference between the East and West Antarctic Ice Sheets

Temperatures are rising:

Measuring changes in climate

Ice shelves are collapsing

Larsen Ice Shelf

Pine Island Glacier

Glaciers are thinning

Glaciers are accelerating

Sea level is rising

Impact of climate on glaciers

Measuring mass balance

Question 11

The main difference between the East and West Antarctic Ice Sheets

Answer 11

The East Antarctic Ice Sheet (EAIS) has about 9 times the volume of the West Antarctic Ice Sheet (WAIS).

The EAIS has an average thickness of 2226m compared with the WAIS maximum of 1306m.

The EAIS reaches a higher elevation (over 4000m at Dome Argus) than the WAIS, and the EAIS reaches a maximum thickness of 4776m.

In contrast with the EAIS, the WAIS sits on bedrock that is mostly below sea level (lowest bed elevation of 2496m below sea level).

Question 12

What are ice shelves?

Answer 12

These are areas where part of an ice sheet extends into the sea and floats because ice is less dense than water.

The lack of frictional resistance with bedrock causes the ice in ice shelves to move at a high velocity, up to 3km per year, and glacier ice is discharged to the sea as the edges of the ice shelf break off and float away as icebergs (a process termed ‘calving’).

Question 13

What are significant parts of the Antarctic being lost?

Answer 13

The Ross Ice Shelf and the Ronne-Filchner Ice Shelf each cover an area larger than the British Isles. Smaller ice shelves along the Antarctic Peninsula are losing mass as a result of climate change

Question 14

In addition to transporting ice, glaciers shape the land through erosion and deposition, ice streams are particularly important in this regard.

Answer 14

Glacial plucking and glacial abrasion they deepen and widen their valleys

As a major valley is widened, the spurs of tributary valleys become worn back to form truncated spurs.

Glacial erosion that is concentrated on two or more sides of an area of high relief leads to the formation of arêtes and pyramidal peaks.

Question 15

Where is much of the glacial ice transported?

Answer 15

Since much of Antarctica’s glacier ice reaches the coastline and beyond, much of the material carried in Antarctic ice is taken to the sea and deposited as ice rafted debris.

However, moraines can be seen around the margins of glaciers that terminate inland, such as glaciers that terminate in the Dry Valleys.

Question 16

GL Introduction

Answer 16

Surface mass balance (Box et al., 2006).

Question 17

GL Effect of temperature (melt)

Answer 17

(Diamond, 1960).

At higher elevations, an increase in winter snow accumulation has partially offset the melt.

Question 18

GL The individual basins response to heat is therefore likely to be characteristic of what?

Answer 18

(Sicart et al., 2008).

Question 19

GL Effect of sea contact

Answer 19

(Rignot et al., 2008).

Question 20

GL The mass balance of the polar ice sheets is affected by numerous factors, including…

Answer 20

Changes in precipitation and snowfall patterns

Summer melting of snow

Changes in ice sheet albedo

Changes in the extent of supraglacial lakes

Submarine melting of the floating ice shelves at the tongue of marine outlet glaciers (Wouters et al., 2015)

Icebergs breaking off of glaciers

Question 21

Greenland is losing mass…

Answer 21

34 billion tonnes lost per year over the period 1992–2001 to 215 billion tonnes lost per year over the period 2002–2011.

In 2012, an exceptional loss estimated at more than 500 billion tonnes was recorded.

Question 22

Atmospheric effects

Having said this,

Answer 22

(Fettweis et al., 2013)

Increased atmospheric moisture content, the effect of this being an increase in solid accumulation.

Question 23

Everything Greenland

Answer 23

Introduction

Effect of temperature

Individual basins

Effect of sea contact

Mass balance of the polar ice sheets is affected by numerous factors

Greenland is losing mass…

Atmospheric effects

Having said this,

Question 24

EVERYTHING

Answer 24

Introduction

The main difference between the East and West Antarctic Ice Sheets

Ice flow in East Antarctica

Climate in East Antarctica

Temperatures are rising

Measuring changes in climate

Ice shelves are collapsing

Larsen Ice Shelf

Pine Island Glacier

Glaciers are thinning

Glaciers are accelerating

Sea level is rising

Impact of climate on glaciers

Measuring mass balance

Introduction

Effect of temperature

Individual basins

Effect of sea contact

Mass balance of the polar ice sheets is affected by numerous factors

Greenland is losing mass…

Atmospheric effects

Having said this,

Question 25

Ice flow in East Antarctica

Answer 25

The East Antarctic Ice Sheet has a complex configuration, with ice velocity being slow near the ice divide, but feeding out into a number of ice streams. Many of these ice streams end in ice shelves, floating glacier ice that is no longer in contact with the bed. Many of these ice shelves receive snow and ice in their own right, from freezing sea water below or from snow falling on them from above. One of the largest ice streams in East Antarctica is the Lambert Glacier System, which drains around 16% of the ice sheet by area 2.

Question 26

Climate of the East Antarctic Ice Sheet

Answer 26

Although there has been rapid ice sheet thinning observed in West Antarctica and on the Antarctic Peninsula, so far, this has not been observed around East Antarctica 9.

In fact, parts of the East Antarctic Ice Sheet are thickening, especially deep in the interior, which contrasts strongly with the observed rapid thinning of the West Antarctic Ice Sheet

Some of the glaciers of the East Antarctic Ice Sheet are thinning and receding. These glaciers include Totten Glacier, the largest discharger of ice within the ice sheet

The East Antarctic Ice Sheet is currently cooling slightly 12, probably as a result of changes in the circumpolar vortex.

Some models predict that continued climate change will actually result in increased snowfall around East Antarctica.