Kaldalonsjökull -- emergence of a hidden landscape

 

Satellite image of the 2025 Kaldalonsjökull.  This is a composite image with some rough joins.......

Two annotated close-ups from the same satellite imagery.

Sad though it is to comment on the death of a glacier, it is fascinating to record the emergence of a landscape that might not have seen daylight for more than a hundred thousand years. On the other hand, there is an active debate in the literature about the survival or disappearance of Drangajokull and its outlet glaciers duringt the Holocene.  The drift of specialist opinion now seems to be that the ice cap melted away during the Holocene and was absent duting the "Neoglacial" period, to be regenerated around 2,000 years ago, reaching its greatest extent in the Litrtle Ice Age.  Watch this space........

 This is a high resolution satellite image from Google Maps, taken this year.  If you zoom in even closer, you can see the individual boulders littering the ground surface.........

As I pointed out in a previous post, this is a complex landscape of rocky knolls, platforms controlled by flat-lying basalts, wide gorges and narrow meltwater channels.  Some of the undulating terrain still supports patches of dead ice -- elsewhere the ice has gone altogether, to be replaced nowadays just by a seasonal snowcover which changes from year to year in respose to precipitation totals and the directions of snowdrifting.  There are traces of pitted moraine, fluted moraine and ridged moraine, probably related to recent glaciological conditions -- ie ice wastage within the last few decades.

One of our photos from 1960.  The beginning of the end.......

Dave at the exit of the Morilla River from the glacier snout.

If Kaldalonsjökull really is only 2,000 years old, then we can infer that the "hidden landscape" represents a complex history of  waxing and waning, disappearance and regeneration.  In other words, there have been multiple phases of growth and decline, including catastrophic ice wastage and powerful meltwater flow at times.  No wonder this hidden landscape is so complex....... 

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Abstract
The status of Icelandic ice caps during the early Holocene provides important constraints on North Atlantic climate and the mechanisms behind natural climate variability. A recent study postulates that Drangajökull on Vestfirðir, Iceland, persisted through the Holocene Thermal Maximum (HTM, 7.9–5.5 ka) and may be a relic from the last glacial period. We test this hypothesis with a suite of sediment cores from threshold lakes both proximal and distal to the ice cap's modern margin. Distal lakes document rapid early Holocene deglaciation from the coast and across the highlands south of the glacier. Sediment from Skorarvatn, a lake to the north of Drangajökull, shows that the northern margin of the ice cap reached a size comparable to its contemporary limit by ∼10.3 ka. Two southeastern lakes with catchments extending well beneath modern Drangajökull confirm that by ∼9.2 ka, the ice cap was reduced to ∼20% of its current area. A continuous 10.3ka record of biological productivity from Skorarvatn's sediment indicates local peak warmth occurred between 9 and 6.9 ka. The combination of warm and dry summers on Vestfirðir suggests that Drangajökull very likely melted completely shortly after 9.2 ka, similar to most other Icelandic ice caps.

from Harning et al, 2016:

https://www.sciencedirect.com/science/article/abs/pii/S0277379116303924?via%3Dihub

Early Holocene deglaciation of Drangajökull, Vestfirðir, Iceland
October 2016
Quaternary Science Reviews 153
DOI:
10.1016/j.quascirev.2016.09.030