This can be called the Vatnajökull Polygon:
At three corners of the main polygon the mantle convection rolls form, there are very famous volcanic sites, Grímsvötn, Kverkfjöll and Öræfajökull. Esjufjöll are found close to the center of the polygon. But the polygon is very unlike the next polygons to the NW and W which are in a rift zone. The Vatnajökull Polygon is very active, but no rifting is taking place within it. The polygon should still move partly as a whole, and therefore activity at Bárðarbunga and especially Grímsvötn and Kverkfjöll might affect Öræfajökull. It is obvious how this polygon provides the main area for Vatnajökull. The line from Öræfajökull to the NE also marks the eastern edge of the glacier. So, the convection rolls far below give us a framework to explain the appearance of the wonder world of Vatnajökull.
