Volcanos

Roundup of Global Volcanic Activity - New Activity for the week 4 January - 10 January 2023

Ijen - Eastern Java : PVMBG reported that beginning in July 2022 the seismic network at Ijen began detecting increasing numbers of shallow volcanic earthquakes and earthquake signals characteristic of emissions, indicating increasing pressure at shallow depths within the hydrothermal system. The number of shallow volcanic earthquakes again increased on 1 January. The temperature of the crater lake water rose from 16 degrees Celsius in December 2022 to 45.6 degrees Celsius on 5 January 2023. During a field visit on 5 January scientists noted that the color of the lake water was light green, dense white solfatara plumes were visible rising from vents, and the sulfur odor was strong. Increased activity at the volcano is often characterized by a change in the lake water color from green to whitish-green due to the resuspension of disturbed lake-bottom sediments from increased gas emissions.

Kaitoku Seamount - Volcano Islands (Japan) : Discolored water around the Kaitoku Seamount was visible in 1 and 6 January Sentinel satellite images. Concentric circles of discolored water radiated out from the vent area and a plume drifted W. The plume of discolored water extended S in the 6 January image.

Kilauea - Hawaiian Islands (USA),: Small earthquake swarms were recorded at Kilauea on 30 December 2022 and 2 January 2023, with heightened seismicity in between those dates. Increased seismicity and changes in the pattern of deformation began to be recorded during the morning of 5 January. At around 1500 both the rate of deformation and seismicity dramatically increased indicating magma moving towards the surface. Incandescence seen in webcam images at 1634 on 5 January indicated that an eruption began in Halema’uma’u Crater, prompting HVO to raise the Volcano Alert Level to Warning (the highest level on a four-level scale) and the Aviation Color Code to Red (the highest color on a four-color scale). Vents opened in the E central portion of the crater floor and produced multiple lava fountains and flows. Fountain bursts ejected lava as high as 50 m during the initial phase of activity, though in general fountaining was consistently 10 m high. By 1930 lava had covered most of the crater floor (an area of about 120 hectares) to a depth of 10 m. A higher-elevation island that formed during the initial phase of the December 2020 eruption remained exposed (and appeared darker in images) along with a ring of older lava around the lava lake that was active prior to December 2022. Overnight during 5-6 January the lava fountains became less vigorous, rising to 5 m, and lava effusion slowed. The sulfur dioxide emission rate was about 12,500 tonnes per day. Lava continued to erupt from the vents during 6-8 January, though the footprint of the active area had shrunk, which has been common during the early stages of recent eruptions within Halema’uma’u. By 9 January only one dominant fountain was visible that continued to be active at least through 10 January.

Marapi - Central Sumatra : PVMBG reported that an explosive eruption at Marapi began at 0611 on 7 January, generating a dense white-and-gray ash plume that rose 300 m above the summit and drifted SE. Images posted with the report showed jets of dark material rising from the crater. Emissions continued to periodically rise form the crater; at 0944, 1034, and 1451 dense white or white-to-gray ash plumes rose 200-250 m above the summit and drifted SE. Seismic signals indicated that eruptive events also occurred at 1135, 1144, 1230, 1715, and 1821, but no ash emissions were visually observed. At 1250 on 8 January a dense white ash plume rose 150 m and drifted SE and at 1300 a dense white-to-gray ash plume rose 200 m and drifted E. Seismic signals indicated eruptive events at 0447, 1038, and 1145, but again no ash emissions were visually observed. At 0634 on 9 January a dense white ash plume rose around 250 m and drifted E and SE. The eruption was preceded by an increase in the number of deep volcanic earthquakes beginning on 25 December 2022 and summit inflation.

Semisopochnoi - Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s Mount Young, formerly Mount Cerberus, was ongoing during 4-10 January. Daily minor steam emissions were visible in webcam views. Seismicity was above background levels; low-level explosive activity was detected in geophysical data during 4-5 January with elevated seismicity and infrasound signals observed on local stations. Volcanic tremor was detected during 7-9 January, and very weak explosive activity was detected in seismic and infrasound data on 9 January.