Jökull - 01.01.2019, Blaðsíða 108

Remote sensing of snow patches on Tröllaskagi Peninsula, N-Iceland
Table 1. Number of available optical satellite images for the Tröllaskagi Peninsula. – Framboð gervi-
tunglamynda af Tröllaskaga.
Cloud Landsat-5 Landsat-7 Landsat-7 Landsat-8 Sentinel-2
Cover (gaps)1
Low (< 20%) 4 4 8 3 2
Still suitable (< 30%) 1 2 1 2
1Landsat-7 images after 2003, when the Scan Line Corrector failed.
Table 2. Landsat-5/-7/-8 and Sentinel-2 images which were used for the six study areas. Almenningar and
Úlfsdalir are presented together, as they are covered by the same images. – Gervitunglamyndir sem notaðar
voru fyrir hvert svæði og dagsetningar þeirra.
Almenningar and Úlfsdalir Brimnesdalur Kerling Búrfellsdalur Sakka
Date Satellite Date Satellite Date Satellite Date Satellite Date Satellite
17.09.1984 L-5 17.09.1984 L-5 17.09.1984 L-5
14.09.1986 L-5 14.09.1986 L-5 14.09.1986 L-5 14.09.1986 L-5
16.09.1986 L-5 16.09.1986 L-5 16.09.1986 L-5 16.09.1986 L-5 16.09.1986 L-5
09.08.1987 L-5 09.08.1987 L-5 09.08.1987 L-5
10.08.1988 L-5 10.08.1988 L-5 10.08.1988 L-5 10.08.1988 L-5
08.08.1990 L-5 08.08.1990 L-5 08.08.1990 L-5 08.08.1990 L-5
13.09.1994 L-5
20.09.1994 L-5 20.09.1994 L-5 20.09.1994 L-5 20.09.1994 L-5
18.08.1999 L-7 18.08.1999 L-7 18.08.1999 L-7 18.08.1999 L-7 18.08.1999 L-7
21.10.1999 L-7 21.10.1999 L-7 21.10.1999 L-7 21.10.1999 L-7 21.10.1999 L-7
20.08.2000 L-7 20.08.2000 L-7 20.08.2000 L-7
07.10.2000 L-7
07.08.2001 L-7 07.08.2001 L-7 07.08.2001 L-7
24.09.2001 L-7 24.09.2001 L-7 24.09.2001 L-7 24.09.2001 L-7 24.09.2001 L-7
19.10.2001 L-7 19.10.2001 L-7
17.08.2002 L-7 17.08.2002 L-7 17.08.2002 L-7
09.09.2002 L-7
10.09.2013 L-8 10.09.2013 L-8 10.09.2013 L-8
19.08.2014 L-8
28.08.2014 L-8 28.08.2014 L-8 28.08.2014 L-8 28.08.2014 L-8
20.09.2014 L-8 20.09.2014 L-8 20.09.2014 L-8 20.09.2014 L-8 20.09.2014 L-8
30.07.2015 L-8
23.09.2015 L-8 23.09.2015 L-8 23.09.2015 L-8
07.10.2015 L-8
14.07.2016 L-8
08.08.2016 L-8 08.08.2016 L-8 08.08.2016 L-8 08.08.2016 L-8 08.08.2016 L-8
24.08.2016 L-8 24.08.2016 L-8 24.08.2016 L-8 24.08.2016 L-8
09.09.2016 L-8 09.09.2016 L-8
18.09.2016 L-8 18.09.2016 L-8 18.09.2016 L-8 18.09.2016 L-8
12.09.2017 L-8
14.10.2016 S-2 14.10.2016 S-2 14.10.2016 S-2 14.10.2016 S-2 14.10.2016 S-2
30.08.2017 S-2 30.08.2017 S-2 30.08.2017 S-2 30.08.2017 S-2
has melted, hence facilitating the detection of PSPs
(Table 1). Only a few satellite images were suitable
for the whole peninsula whereas significantly more
images fitted the selection criteria for the six study
areas (Table 2), covering a period of 31 years for
Almenningar–Úlfsdalir, Brimnesdalur, and Búrfells-
dalur and 33 years for Kerling and Sakka.
The governmental company Landmælingar Ís-
lands (LMI) provides online access to aerial photos
acquired between 1977 and 2000 (LMI) with a spa-
tial resolution of 0.5 m and DEM with spatial res-
olution of 25 m. Aerial images from 1988 (Úlfs-
dalir, Brimnesdalur and Kerling) and 1994 (Brimnes-
dalur, Kerling, Búrfellsdalur and Sakka) were geo-
JÖKULL No. 69, 2019 107