Roundup of Global Volcanic Activity
Etna (Sicily, Italy): Since Wednesday (3 Aug) evening, the New SE crater has been producing intermittent small ash emissions. This activity has become more intense yesterday and seems to have decreased again today. Weaker and rarer emissions had also occurred during 21-27 July and then again ceased. Thermal imagery shows that the ash is of low temperature only, which probably means that the origin are internal collapses rather than explosions of fresh magma inside the conduit. Volcanic tremor is currently low.
Bagana (Bougainville Island, Papua New Guinea): Minor ash emissions were reported this morning by Darwin VAAC. A gas plume with possibly light ash content is visible on this morning’s satellite image extending WSW from the volcano.
Gamalama (Halmahera): Small ash emissions from the volcano have continued yesterday and in the night. Due to the hazard of new ash falls, the airport remains closed today and is scheduled to reopen tomorrow morning at 11:00 am local time. The Indonesian authorities keep the status level of the volcano at 2 (on a scale of 1-4, 4 being highest). No evacuations were ordered, but an exclusion zone of 1.5 km radius around the crater is in place. Ash falls were reported in several villages including Salero, Soa Sio, Sangaji, Dufa-Dufa, and in some parts of Central Ternate. Based on information from the local volcano observatory, the ash from yesterday’s activity reached 1,700 to 2,500 meters above sea level. Seismic data show no significant earthquake activity associated with the activity, but a weak constant tremor signal.
Sinabung (Sumatra, Indonesia): Explosions continue to occur at the volcano almost daily. One this morning at 06:53 local time was relatively strong, producing a vertical ash column that rose 3000 m above the volcano’s summit where a lava dome continues to grow slowly. Another, but smaller explosion was reported yesterday morning at 10:20.
Kilauea (Hawai’i): No significant changes have occurred over the past week. As of yesterday, lava from the 61G flow was still flowing into the sea at the Kamokuna ocean entry, but the rate of lava reaching it has been relatively low recently. A small delta of new coastal land (extremely dangerous to approach as it is prone to sudden collapse) has by now formed there. The lava lake at Halemaʻumaʻu Crater remains active, but has dropped recently and was 41 m (135 ft) below the Overlook crater rim as of yesterday. HVO reports background levels of seismicity and deformation.
Pavlof (Alaska Peninsula, USA): AVO lowered the alert level of the volcano back to advisory and the Aviation Color Code to yellow and declared that “the eruptive activity that was observed intermittently since July 28 has ended or paused. Over the past several days there has been no evidence for continued ash emissions or signs of near surface magma in satellite data.”
Santiaguito (Guatemala): After several weeks of relative calm, another strong explosion occurred from the Caliente lava dome yesterday at 10:45 local time, the 75th vulcanian explosion in 2016. Due to the currently bad weather (passing tropical storm Earl), there were no direct observations, but it could be inferred from ash falls observed in San Marcos, Loma Linda Palajunoj and Quetzaltenango city. The ash plume was estimated to have reached 5,000 meters asl. Due to the heavy rainfalls, the risk of lahars (violent mud flows) through river beds draining from the volcano is elevated.