However, the recent loss of ice due to climate change is an increasing concern in Icelandic society.
Data that was gathered over many years in the 1890s, or even by the first complete aerial photographic survey between 1945 and 1946 is difficult to compare to the richer satellite studies and the on the ground measurements possible since the 1990's but such comparisons have been attempted.
Two different definitions of a glacier are usually used in current research and much Iceland work is closer to the definition:[3]: 7 A perennial mass of ice, and possibly firn and snow, originating on the land surface by the recrystallization of snow or other forms of solid precipitation and showing evidence of past or present flowAn ice cap is a mass of glacial ice that covers less than 50,000 km2 (19,000 sq mi) of land area covering a highland area and they feed outlet glaciers.
When volcanic activity occurs under the glacier, the resulting meltwater can lead to a sudden glacial lake outburst flood, known in Icelandic as a jökulhlaup.
In order to fit the criteria glaciers need to be thick enough to sink and move under their own weight, which any ice remaining of Okjökull can not do.
[3]: 1 Some outlet glaciers have shown marked surges over relatively short periods of time resulting in growth in glacial size.
[3]: 4 This has only changed the recent overall trend to smaller total area of glacial ice for a brief period in 1963–1964 from a surge in Brúarjökull.