Geoscience Reference
In-Depth Information
(a)
46
°
30'
k
0
kilometres
10
Wa shi ngt on
Washington
Mount St Helens
Mount St Helens
Mount St Helens
Kid Va lley
Kid Valley
e
T
Castle Rock
Si l v er
Silver
Lake
Lake
46
15'
Sp i r i t
Spirit
Lake
°
Castl e
Castle
Lake
Lake
Lake
Mount
St H el en s
Mount
St H el en s
St Helens
R
Kelso
Longview
Merrill
Merrill
Lake
Lake
Cougar
Swift
Reser voi r
Sw i f t
Ya l e
Ya l e
Lake
Reser voi r
Reservoir
123
°
00' W
123
°
30'
123
°
15'
122
°
00'
46
°
00' N
Lake
Area altered by debris avalanche
from the 18 May 1980 eruption
Gauging station
10000
(b)
(c)
1000
SRS
100
10
1.0
0.1
0.01
1980
1984
1998
1992
1996
2000
Water year
North Fork Toutle River (KID)
Muddy River (MUD)
South Fork Toutle River (SFT)
Green River (GRE)
Toutle River (TOW)
Case Fig. 2.2
Impacts of the 1980 Mount St Helens eruption. (a) Location map showing main river systems. (b) North Fork
Toutle River Valley, 1989. (c) Annual suspended sediment yields in Mount St Helens rivers. The vertical line (SRS) is the location
of the sediment retention structure. The horizontal line is mean sediment yield value for western Cascade Range rivers
(Source: Major et al. 2000; reproduced with permission
Geological Society of America
.)
