Roundup of Global Volcanic Activity – New Activity for the week of 1 August – 7 August 2018
Ambae | Vanuatu : According to news articles and the Vanuatu Red Cross, residents of Ambae began to evacuate the island during 1-8 August under the governments orders due to the effects of significant ashfall from the ongoing eruption at Lake Voui. The Red Cross noted that by 8 August over 3,000 people had been moved to Espiritu Santo (W) and Maewo (NE) islands. Video from 3 August showed lahars blocking roads in S Ambae.
Etna | Sicily (Italy) : Based on two field inspections and webcam data, INGV reported that during 30 July-5 August activity at Etna was characterized by gas emissions at the summit craters and Strombolian activity. Three vents at the bottom of the Bocca Nuova crater were active, with gas emissions rising from two vents and sporadic Strombolian activity occurring at a third. Three vents were also active at the bottom of Northeast Crater (NEC); one produced ash emissions, one steam emissions, and Strombolian explosions at the third ejected incandescent material as high as the crater rim. After several months of quiet conditions, explosive activity resumed at the E crater on the E flank of the New Southeast Crater (NSEC). The activity began at 0608 on 1 August with a brownish-gray ash emission that rose several hundred meters above the summit. The event was followed by more ash emissions and then Strombolian activity in the evening.
Krakatau | Indonesia : PVMBG reported that on 2 August multiple events at Anak Krakatau generated ash plumes that rose as high as 300 m above the summit and drifted N. A dense, black ash plume from an event at 1757 rose 200 m and drifted N. During 5-7 August dense gray ash plumes rose 200-600 m above the summit, and summit incandescence was visible at night. The Alert Level remained at 2 (on a scale of 1-4); residents and visitors were warned not to approach the volcano within 1 km of the crater.
Nevados de Chillan | Chile : Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) and ONEMI reported continuing activity through 6 August associated with growth of the Gil-Cruz lava dome in Nevados de Chillán’s Nicanor Crater. Seismicity was at moderate-to-high levels, and consisted of long-period events and tremor. The Alert Level remained at Orange, the second highest level on a four-colour scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-colour scale) for the communities of Pinto, Coihueco, and San Fabián.
Sierra Negra | Isla Isabela (Ecuador) : IG reported that the eruption at Sierra Negra continued during 1-7 August. Incandescence from active lava flows was visible daily. An increase of tremor began at 2220 on 3 August and lasted two hours, signifying a new pulse of activity on the N flank. Small gas emissions were visible on 4 August, and steam-and-gas emissions were noted on 6 August.