Geology Reference
In-Depth Information
(A)
(B)
VOLUMETRIC WATER CONTENT (%)
20
40
60
80
DEPTH
(cm)
20-50
0
median
-20
Surface
50-75
-40
75-100
-60
100-125
125-150
-80
Frost line
150-175
-100
175-200
-120
200-225
-140
1994
1995
1996
1997
1998
1999
Year
Figure
8.3.
Thermokarst subsidence at Mayo, Yukon Territory, Canada. (A) Typical volumetric
water content in the upper 2.25 m of glaciolacustrine sediment. (B) Ground subsidence (1994-1999)
observed following surface disturbance. From Haeberli and Burn (2002). Reproduced by permission
of CABI Publishing.
Figure
8.4.
Photograph showing thermal erosion along an ice-wedge system near Sachs Harbour
(Ikaahuk), Banks Island. Gullying developed followed vehicle disturbance and snowmobiles in late
spring 1973. Photograph taken in July 1975.
ice the following winter. Many tundra lakes that drain rapidly are thought to have been
effected by thermal erosion operating along ice wedges (Mackay, 1988b). Beaded drainage
patterns may also result from channel enlargement located at the intersection of ice
wedges.
