Geoscience Reference
In-Depth Information
Figure 15.3
Mass balance and related flow
characteristics of (a) a valley
glacier, (b) an ice sheet and (c)
an ice shelf. Mass transfers
and basal velocity are
proportional to the size of the
arrows.
Source: After Sugden and John
(1976)
(a)
Equilibrium line
(b)
Maritime
Inland
ELA
Calving
(c)
Calving
Grounding line
Flow
velocity
Flow
line
Accumulation
Ablation
soft coastlines as it is deformed and moved by waves and
currents. It is less likely to do so where
fast ice
is literally
held fast in fjords or other enclosed locations and is more
effective in the
pack ice
along open coasts.
%
%
100
0
100
0
50
50
50
50
Ground ice (permafrost)
50
50
0
100
%
0
100
%
Annual snowpack ice and glacier ice can insulate their
substrates from the full severity of winter cold. In cold arid
climates, where snowfall is inadequate for glacier growth,
the ground itself may be perennially frozen to great
depths. Attention then shifts to the forms and effects of
ground ice. A cold wave penetrates the ground once
surface temperature falls below 0
%
100
0
100
0
Net radiation
Conduction
Cold, polar
glaciers
Sub-polar/
Sub-temperate
Temperate,
alpine glaciers
to principal energy sources and sinks.
Source: After Andrews (1975)
C. What happens next
