 |
 |
Dirty Glaciers
Name: Victoria H.
Status: Other
Grade: Other
Location: NJ
Country: United States
Date: March 2009
Question:
Why does snow in a glacier or iceberg look dirty from a
cruise ship?
Replies:
Victoria,
The ice in a glacier or iceberg looks dirty because
it is dirty.
First, snow crystals usually form on a tiny
nucleus of soil, pollutant particle, or salt.
Second, when snow falls from the cloud to the ground
it "scavenges" soil, pollutants, salt, etc. from the
air , although not as efficiently as rain does.
Third, soil pollutants, salt, etc. naturally falls
from the air onto a glacier.
The accumulation of all of this "dirt" on the glacier
over many years makes it look dirty. Also, the more
the glacier melts or evaporates, the more concentrated
the dirt layer on top becomes, making it look even dirtier.
David R. Cook
Meteorologist
Argonne National Laboratory
It looks dirty because it is dirty. Glaciers advance and scrape the bedrock
(the rock beneath the ice). As the rock is scraped, the fragmented bedrock
gets incorporated in the ice. Glaciers calve (break) and form icebergs that
float out into the ocean. The icebergs carry the sediment and thus look dirty.
If you would take a closer look you would see that the icebergs look rocky, not
just dirty, because of the sediment incorporated in the ice.
Leslie Kanat, Ph.D.
Professor of Geology
Department of Environmental Sciences
Click here to return to the Environmental and Earth Science Archives
| |
Update: June 2012
|
|
