Selected geological features near the Brennisteinsfjöll volcanic system (approximate outline in red). Clicking on the image enables mouse-over with more detail where shading also shows: other '"`UNIQ--templatestyles-00000000-QINU`"'fissure swarms, '"`UNIQ--templatestyles-00000001-QINU`"'central volcanoes, '"`UNIQ--templatestyles-00000002-QINU`"' calderas '"`UNIQ--templatestyles-00000003-QINU`"'subglacial terrain above 1,100m (3,600ft), '"`UNIQ--templatestyles-00000004-QINU`"'seismically active areas between 1995 to 2007.