There are a number of outlet glaciers in the ice cap within the area of the central volcano which clockwise from north are: Breiðamerkurjökull, Fjallsjökull, Hrútárjökull, Bræðrajökull, Kviarjökull, Hólárjökull, Stórhöfðajökull, Gljúfursárjökull, Rótarfjallsjökull (which has a western branch called Kotárjökull), Grænafjallsjökull, Falljökull, Virkisjökull, Svinafellsjökull and Skaftafellsjökull.

[2] The deposits closer to the central volcano are rhyolytic but the more distal lava flows which can extend for 20 km (12 mi) from the caldera are alkali olivine basalt and both have been erupted in the Holocene.

[4] The eruption sequence lasted for several months, being from a medium-potassium alkali rhyolite and has been assigned a VEI of 6 although dense-rock equivalent volume may be less than previous estimates at 1.2 km3 (0.29 cu mi).

[10] Increased earthquake activity in the form of small tremors ranging from a depth of 1.5–10 km beneath the summit crater, began in August 2017 according to the Icelandic Meteorological Office.

The Aviation Colour Code of the United States was raised to yellow on 17 November 2017, after the appearance of an ice cauldron inside the main crater and increased geothermal activity under the glacier.

[12] In 2013 due to paraglacial slope failure, a large landslide affecting an area of 1.7 km2 (0.66 sq mi) occurred, that deposited debris on the volcano's Svínafellsjökull outlet glacier.