|
||||||
|
|
||||||
 |
 |
 |
 |
|
|
|
|
||
 |
A researcher investigates the terminus of Hole-in-the-Wall Glacier as it pushes debris in front of it and knocks over trees. This photograph dates from 1959, when the glacier had already been surging for nearly 20 years.
(Source: Unattributed photograph at the World Data Center for Glaciology, Boulder)
