Háalda
Háalda – pronounced how-aaldaa, lit. ‘high wave’ – is a large glacier ridge (wave) formed during the 1727 eruption of the volcano Öræfajökull, itself a sub-glacier of Vatnajökull. In geological parlance, this is known as a dead-ice terrain.
In the second image, the glacial tongue Kotárjökull is seen extending downward.