Roundup of Global Volcanic Activity – New Activity for the week of 12 December – 18 December 2018

Ambrym | Vanuatu : The Vanuatu Meteorology and Geo-hazards Department (VMGD) reported that a fissure eruption in the ESE part of the Ambrym summit caldera near the Lewlembwi crater (4 km SE of Marum) began at 0600 on 15 December, heralded by elevated seismicity detected by the seismic network and ash emissions visible in the webcam. A notice issued later that day by VMGD stated that lava flows and lava fountains were visible, and explosions were occurring. John Tasso, a local guide, visited the caldera a few hours after the new activity started and observed lava fountains from a fissure eruption; his video was posted to his website. The lava fountains were about 40 m high; lava flows spread to the E part of the caldera. Although partially obscured by a steam plume directly above the eruption site, infrared imagery from the Sentinel-2 satellite on 15 December showed lava filling much of the 500 x 900 m Lewlembwi crater and a lava flow almost as large a few hundred meters SW of that crater. VMGD raised the Alert Level to 3 and stated that the eruption was characterized as “small scale.” The eruption continued during 16-17 December, though reports on 17 December only described ongoing ash-and-gas emissions.

Cleveland | Chuginadak Island (USA) : A small explosion at Cleveland was recorded by the seismic network at 1155 on 8 December. A second small explosion with a higher peak amplitude was detected at 1153 on 12 December, prompting AVO to raise the Aviation Color Code to Orange and the Volcano Alert Level to Watch. No ash cloud was observed, though weather clouds obscured views of the volcano. Elevated surface temperatures were visible in satellite data on 15 December. A small explosion which occurred at 0737 on 16 December generated a minor ash cloud that drifted NE.

Planchon-Peteroa | Central Chile-Argentina border : Observatorio Volcanológico de los Andes del Sur (OVDAS)-SERNAGEOMIN and ONEMI reported increased activity at Planchón-Peteroa beginning in the morning of 16 December. Low-intensity pulses of tremor were detected by the seismic network and associated with pulsating grayish gas emissions which rose no higher than 800 m above the vent rim. Webcams recorded crater incandescence during the night of 15-16 December. The Alert Level remained at Yellow (the middle level on a three-color scale) for the volcano, and ONEMI maintained Alert Level Yellow for the communities of Molina (66 WNW), Curicó (68 km NW), Romeral (75 km NW), and Teno (68 km NW).

Soputan | Sulawesi (Indonesia) : PVMBG reported that seismic activity at Soputan rapidly and significantly increased at 1700 on 15 December. An eruption began at 0102 on 16 December though dark and foggy conditions prevented views of emissions. The event lasted for almost 10 minutes, and thunderous sounds were heard at the Soputan Volcano Observation Post located in Silian Raya (about 10 km SW). The conditions improved about two hours later, and a dense ash plume was visible rising 3 km above the summit and drifting SE. Incandescence from the summit was also visible. An event that began at 0540 produced dense gray-to-black ash plumes that rose as high as 7 km above the summit and drifted SE. The event lasted for 6 minutes and 10 seconds based on the seismic network. Ash plumes from events at 0743 and 0857 rose as high as 7.5 km and drifted SW. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.

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