IMO reported that the eruption between Stóra-Skógfell and Sundhnúkur, within the Reykjanes volcanic system, continued at the N end of the fissure during 27 August-3 September. By 29 August vigorous lava fountaining was concentrated at two main vents, though over the rest of the week the intensity of the eruption decreased. Lava slowly flowed mainly NW and to a lesser extent to the E. Subsidence was detected during the first part of the week; no deformation recorded during the second half of the week, suggesting that the rate of magma accumulation area under Svartsengi was similar to the rate of surface lava effusion. Plumes of sulfur dioxide gas from the eruption and smoke from vegetation fires started by lava caused significant pollution in areas downwind. According to Almannavarnadeild ríkislögreglustjóra, notable levels of sulfur dioxide gas concentrations (1,000 micrograms per cubic meter) were measured in Vogar on Vatnsleysustrand along the N coast on 30 August. The Aviation Color Code remained at Orange (the second highest level on a four-color scale).

Geological Summary. The Reykjanes volcanic system at the SW tip of the Reykjanes Peninsula, where the Mid-Atlantic Ridge rises above sea level, comprises a broad area of postglacial basaltic crater rows and small shield volcanoes. The submarine Reykjaneshryggur volcanic system is contiguous with and is considered part of the Reykjanes volcanic system, which is the westernmost of a series of four closely-spaced en-echelon fissure systems that extend diagonally across the Reykjanes Peninsula. Most of the subaerial part of the system (also known as the Reykjanes/Svartsengi volcanic system) is covered by Holocene lavas. Subaerial eruptions have occurred in historical time during the 13th century at several locations on the NE-SW-trending fissure system, and numerous submarine eruptions dating back to the 12th century have been observed during historical time, some of which have formed ephemeral islands. Basaltic rocks of probable Holocene age have been recovered during dredging operations, and tephra deposits from earlier Holocene eruptions are preserved on the nearby Reykjanes Peninsula.

Sources: Icelandic Meteorological Office (IMO), Almannavarnadeild ríkislögreglustjóra (National Commissioner of the Icelandic Police and Department of Civil Protection and Emergency Management)