OVPDLF reported an eruption from Piton de la Fournaise on 21 September. Lava flows issued from a fissure about halfway up the W wall of Dolomieu crater and ponded at the bottom. A strong concentration of sulfur dioxide was detected near the edge of the crater. On 22 September, Pele's hair was found scattered around the summit area and the lava flow rate decreased. This marked the first eruptive activity in the Dolomieu crater since the major collapse in April 2007 that enlarged the crater to 800 by 1,100 m wide and 340 m deep.

Geological Summary. Piton de la Fournaise is a massive basaltic shield volcano on the French island of Réunion in the western Indian Ocean. Much of its more than 530,000-year history overlapped with eruptions of the deeply dissected Piton des Neiges shield volcano to the NW. Three scarps formed at about 250,000, 65,000, and less than 5,000 years ago by progressive eastward slumping, leaving caldera-sized embayments open to the E and SE. Numerous pyroclastic cones are present on the floor of the scarps and their outer flanks. Most recorded eruptions have originated from the summit and flanks of Dolomieu, a 400-m-high lava shield that has grown within the youngest scarp, which is about 9 km wide and about 13 km from the western wall to the ocean on the E side. More than 150 eruptions, most of which have produced fluid basaltic lava flows, have occurred since the 17th century. Only six eruptions, in 1708, 1774, 1776, 1800, 1977, and 1986, have originated from fissures outside the scarps.

Source: Observatoire Volcanologique du Piton de la Fournaise (OVPF)