Image:Muir Glacier.jpg

From Global Warming Art

Contents

Description

Map showing the thinning of mountain glaciers worldwide since 1970.
Map showing the thinning of mountain glaciers worldwide since 1970.

Comparison photos of Muir and Riggs Glaciers in Glacier Bay National Park and Preserve, Alaska. Muir glacier, parts of which were greater than 65 meters thick in 1941, has retreated out of the image in 2004 (towards the upper left). The distance to the visible Riggs glacier in 2004 is ~3 km. During this time, the Muir Glacier retreated more than 20 km (Benson and Field 1995).

The Muir and Riggs glaciers are part of the Glacier Bay ice field. In the 1700s, during the little ice age, most of the regional glaciers were merged into a single ice mass that extended ~110 km south of Muir's present location into the Icy Strait of Cross Sound. By 1890, the ice tongue for which Muir was the largest component had already retreated 60 km north (Hall et al. 1995). Tidewater glaciers, i.e. those terminating in channels open to the ocean but sufficiently thick to avoid floating, tend to be unstable when pushed into retreat. If thinned sufficiently, they will start to float off the bottom of the channel and allow sea water infiltration underneath the glacier, which can trigger rapid and prolonged retreat until the glacier reaches a position that is again stable (e.g. Vieli et al. 2002). Because Muir glacier and many other glaciers in the Glacier Bay complex are tidewater glaciers, it is not known how much of the present retreat is a response to recent warming, and how much is the consequence of unstable conditions created by previous warming that has not yet resolved itself (Hall et al. 1995).

Sources

Copyright

This composition was prepared by Robert A. Rohde from the two sources noted above. The composition itself is released under the Global Warming Art license.


float
Global Warming Art License

This image is an original work created for Global Warming Art.

Permission is granted to copy, distribute and/or modify this image under either:

It is expected that reusers of this image will:

  1. Acknowledge Global Warming Art and/or the specific author of this image, as the source of the image.
  2. Provide a link or reference back to this specific page:
    http://www.globalwarmingart.com/wiki/Image:Muir_Glacier_jpg
  3. Allow any modifications made to the image to also be reused under the terms of one or both of the licenses noted above.

Those interested in commercial and/or higher quality reproduction should also refer to information for professional republishers.


References

  • Hall, Dorothy K., Carl S. Benson and William O. Field (1995). "Changes of Glaciers in Glacier Bay Alaska, Using Ground and Satellite Measurements". Physical Geography 16 (1): 27-41. 
  • [abstract] Vieli, Andreas, Jacek Jania, and Lezek Kolondra (2002). "The retreat of a tidewater glacier: observations and model calculations on Hansbreen, Spitsbergen". Journal of Glaciology 48 (163): 592-600. 

Metadata

This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified image.

Orientation Normal
Horizontal resolution 300 dpi
Vertical resolution 300 dpi
Software used Roxio PhotoSuite
File change date and time 18:39, 15 October 2004
Y and C positioning 1
Exif version 2.2
Date and time of data generation 18:39, 15 October 2004
Meaning of each component 1230
Image compression mode 1.1

File upload and version history

Click on date to see the file uploaded on that date.

Retrieved from "http://www.globalwarmingart.com/wiki/Image:Muir_Glacier_jpg"
Sea Level Explorer New!
Random image