Disconnection of outlet glaciers and vulnerability of Harding Icefield, Southcentral Alaska

The Harding Icefield on Kenai Peninsula, southcentral Alaska, is the largest icefield in the United States and a key freshwater resource in southern Alaskan watersheds. Using Landsat imagery from 1986 to 2024 and a red/SWIR band-ratio mapping method with manual correction, this research created the highest-temporal-resolution glacier extent record yet for the icefield. Total glacierized area decreased from 1,944 ± 34 km2 in 1986 to 1,511 ± 26 km2 in 2024, a 22.3 ± 2.3 % loss. Retreat rates accelerated sharply after 2010, increasing from 6.1 km2 yr−1 to 32.1 km2 yr−1. A total of 124 glacier disconnections were identified (61 total and 63 partial) across 26 glaciers, with most occurring between 2009 and 2018, and concentrated on the eastern side of the icefield. Disconnected glaciers lost an average of 28.8% of their 1986 area, substantially more than glaciers without disconnection. Statistical analyses show that retreat rates more than doubled following the first disconnection event (–0.79to –1.64 % yr−1; p = 0.047) and continued to accelerate after subsequent events. However, the retreat did not appear to accelerate after each disconnection. These results demonstrate that the Harding Icefield has entered a new phase of rapid retreat but glacier disconnections are not causing the retreat. The findings underscore the need for high temporal and spatial resolution monitoring to further investigate the impact of glacier disconnections on icefield retreat and assess the future icefield vulnerability to climate forcings.

Grantor dc:publisher

Temple University. Libraries

Year dc:date.issued

2025

Author dc:creator

• Miller, Roberta Beck Connolly

Advisor dc:contributor.advisor

• Muto, Atsuhiro

Committee members dc:contributor.committeemember

• Buynevich, Ilya V. (Ilya Val)
• Davatzes, Alexandra K.

• Geology
• Remote sensing
• Climate change
• Glaciology

Statement dc:rights

• IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

eng

Repository record dc:identifier.uri

https://scholarshare.temple.edu/handle/20.500.12613/12111

OAI identifier oai:identifier

oai:scholarshare.temple.edu:20.500.12613/12111