Geology & Geography Faculty Work

Title

Generating a Supraglacial Melt-Lake Inventory Near Jakobshavn, West Greenland, Using a New Semi-Automated Lake-Mapping Technique

Document Type

Article

Publication Date

2019

Publication Title

Polar Geography

Volume Number

42

Issue Number

2

DOI

10.1080/1088937X.2019.1578289

Abstract

We analyze Landsat-7 imagery spanning a 13-year period (2000–2012) for the Jakobshavn Ablation Region (JAR) along the west coast of Greenland. In addition, we introduce a new semi-automated technique for the mapping of melt-lakes using FoveaPro image-processing software (plug-in to Adobe Photoshop™), greatly simplifying the process, and resulting in more-precise spatial melt-lake statistics over existing manual methods. We found a total mean melt-lake area of 0.30 ± 0.12 km2 (±1σ), with maximum melt-lake area increasing at an average rate of 0.032 km2 d−1 across the study periods. Additionally, we note a yearly seasonal increase (∼1.8 m d−1) in the overall mean lake elevation (∼200 m per season) as well as an optimal elevation of the largest-area melt-lakes of ∼1320 ± 20 m (±1σ). We also found an increase in the maximum average melt-lake elevation (MAME) of ∼3.8 m a−1 (∼50 m). Based on data recorded at nearby automated weather stations, the mean seasonal temperature increased ∼1.6°C over the 13-year period at an average rate of 0.125°C a−1. Although temperature is a driver for meltwater production, we conclude that mechanisms related to the surface topography are more likely modulating the spatial pattern and characteristics of melt lakes in the ablation zone.

ISSN

1939-0513

First Page

89

Last Page

108

Link Out URL

https://doi.org/10.1080/1088937X.2019.1578289

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