Glacier Changes in Iceland From ∼1890 to 2019

Abstract

The volume of glaciers in Iceland (∼3,400 km3 in 2019) corresponds to about 9 mm of potential global sea level rise. In this study, observations from 98.7% of glacier covered areas in Iceland (in 2019) are used to construct a record of mass change of Icelandic glaciers since the end of the 19th century i.e. the end of the Little Ice Age (LIA) in Iceland. Glaciological (in situ) mass-balance measurements have been conducted on Vatnajökull, Langjökull, and Hofsjökull since the glaciological years 1991/92, 1996/97, and 1987/88, respectively. Geodetic mass balance for multiple glaciers and many periods has been estimated from reconstructed surface maps, published maps, aerial photographs, declassified spy satellite images, modern satellite stereo imagery, and airborne lidar. To estimate the maximum glacier volume at the end of the LIA, a volume–area scaling method is used based on the observed area and volume from the three largest ice caps (over 90% of total ice mass) at 5–7 different times each, in total 19 points. The combined record shows a total mass change of −540 ± 130 Gt (−4.2 ± 1.0 Gt a−1 on average) during the study period (1890/91 to 2018/19). This mass loss corresponds to 1.50 ± 0.36 mm sea level equivalent or 16 ± 4% of mass stored in Icelandic glaciers around 1890. Almost half of the total mass change occurred in 1994/95 to 2018/19, or −240 ± 20 Gt (−9.6 ± 0.8 Gt a−1 on average), with most rapid loss in 1994/95 to 2009/10 (mass change rate −11.6 ± 0.8 Gt a−1). During the relatively warm period 1930/31–1949/50, mass loss rates were probably close to those observed since 1994, and in the colder period 1980/81–1993/94, the glaciers gained mass at a rate of 1.5 ± 1.0 Gt a−1. For other periods of this study, the glaciers were either close to equilibrium or experienced mild loss rates. For the periods of AR6 IPCC, the mass change rates are −3.1 ± 1.1 Gt a−1 for 1900/01–1989/90, −4.3 ± 1.0 Gt a−1 for 1970/71–2017/18, −8.3 ± 0.8 Gt a−1 for 1992/93–2017/18, and −7.6 ± 0.8 Gt a−1 for 2005/06–2017/18.

Microplastics in Glaciers: First Results from the Vatnajökull Ice Cap

“…Around 30 km west of the location is the active volcano Grímsvötn. Vatnajökull is the largest glacier in Iceland, covering around 8% of the country [35], and by volume, it is the largest glacier in Europe. The study location was chosen in a remote area in a central part of the ice cap.…”

“…Location of Sampling Samples were taken from the central part of the Vatnajökull ice cap in southeast Iceland (see Figure 1). The sampling site coordinates are 64.43415 • N and 16.43670 • W.Vatnajökull is the largest glacier in Iceland, covering around 8% of the country[35], and by volume, it is the largest glacier in Europe. The study location was chosen in a remote area in a central part of the ice cap.…”

Vatnajökull Mass Loss Under Solar Geoengineering Due to the North Atlantic Meridional Overturning Circulation

“…The uncertainty estimates in radiative flux observations are about 10%, so while these discrepancies are larger than hoped, there is little that can be done given the limitations of models. Typically, uncertainties in SMB on Icelandic ice caps (Aðalgeirsdóttir et al, 2020) and the Greenland ice sheet (Mouginot et al, 2019) are 10%. Thus, uncertainty in radiative flux makes significant, but not ruinous errors in estimates of SMB.…”

“…The Vatnajökull ice cap (VIC) is the largest nonpolar ice cap in Europe with an area of ~7,700 km 2 and a volume of ~2,870 km 3 (Aðalgeirsdóttir et al, 2020). VIC is near the southeastern coast of Iceland and has a maximum surface elevation of ~2,100 m above sea level (Figure 1).…”

“…We address this by using downscaling and bias correction methods that take the ESM climate fields and modify them according to high-resolution surface topography, along with in situ and satellite observations of albedo and glacier mass balance. There are advantages in this methodology for Iceland and VIC in particular, which has been well studied for many decades with a wealth of meteorological and glaciological observations (e.g., Aðalgeirsdóttir et al, 2020;Jóhannesson et al, 2020).…”