In total, Icelandic ice caps contain ~3600 km3 of ice,
which if melted would raise sea level by ~1 cm. Here, we
present an overview of mass changes of Icelandic ice masses
since the end of the 19th century. They have both gained and
lost mass during this period. Changes in ice volume have
been estimated both through surface mass balance measurements (performed annually since ~1990) and differencing
of digital elevation models derived from various satellite
and airborne observations. While the glaciers showed little
mass loss as the 20th century began, losses increased
rapidly after 1925, peaked in the 1930s and 1940s, and
remained signi?cant until the 1960s. After being near-zero
or even positive during the 1980s and early 1990s, glacier
mass budgets declined considerably, and have since the
mid-1990s shown an average annual loss of 9.5?1.5 Gt/yr,
contributing ~0.03 mm/yr to sea level rise. Since 1995
interannual variability in mass loss is high, ranging from
2.7 to 25.3 +/- 1.5 Gt/yr , corresponding to surface mass
balances of -0.2 to -2.2 +/- 0.15 m we/yr. This variability is
driven by climate ?uctuations and also by transient reduction
of albedo due to volcanic eruptions.
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