In Merapi, on Java, the life of the dome generates a lot of collapse and avalanches of incandescent blocks.
For the adjournment of January 5, 2021, the PVMBG notes:
- 86 collapse earthquakes, with an amplitude of 3-41 mm and lasting between 10 and 158 seconds.
- 53 blast / emission earthquakes, with an amplitude of 2 to 15 mm and of variable duration between 7 to 36 seconds.
- 230 hybrid / multiphase earthquakes, with an amplitude of 3-31 mm, S-P 0.3-0.5 seconds and a duration of 4-12 seconds.
- 57 shallow volcanic earthquakes, with an amplitude of 34 to 75 mm and the duration of the earthquake was 11.9 to 41 seconds.
- 1 distant tectonic earthquake.
The activity level remains at 3 / siaga.
Source: PVMBG, Magma Indonesia
The activity of Etna during the week of 28,12,2020 to 03,01,2021 was marked by a Strombilian activity of variable intensity and emissions of ash at the summit craters: the SEC, the NEC, the VOR and BN.
In more detail, the Southeast Crater (SEC) was characterized on the morning of December 29, from 06:50 UTC, by a gradual intensification of Strombolian explosive activity at the eastern vent with associated emission of ash that the Strong winds at high altitude quickly dispersed towards the ENE.
At approximately 08:00 UTC this activity intensified further producing the launch of coarse pyroclastic material above the crater rim which fell copiously on the east side of the SE crater cone. As of 09:00 UTC, the intensity of Strombolian explosive activity significantly decreased as well as the emission of ash.
In the following days, the explosive strombolian activity continued at the SE crater mainly at the eastern vent, of varying intensity, accompanied by sporadic emissions of diluted ash and secondarily and discontinuously from the mouth of the saddle.
The Voragine crater (VOR) was affected by continuous strombolian intracratera activity which intensified from December 30, producing the launch of pyroclastic material beyond the crater rim.
Finally, the strombolian intracrateric activity remained unchanged at the craters of Bocca Nuova (BN) and at the Northeast crater (NEC) accompanied by sporadic emissions of dilute ash.
The seismic activity of fracturing remains average; the amplitude of the volcanic tremor is mainly at the intermediate level.
The infrasound activity remains moderate.
No significant change to report at the strain level.
Regarding geochemistry, the flow of sulfur dioxide remains at an average level, as does the flow of HCl
Soil CO2 flux is at medium-low levels.
Source: INGV OE
Kilauea Halema'uma'u - The HVO flyby of Halema'uma'u crater shows the newly exposed lava channel entering the lava lake. Lava also continues to enter the lava lake through the tube, which produces the small domed fountain at the margin of the lake below (lower center). - USGS photo taken by B. Carr on Jan.5, 2021.
Kilauea Halema'uma'u - the recent changes to the domed fountain at the entrance to the west vent into the lava lake. - USGS photos by M. Patrick.
In Kilauea, lava activity is confined to Halemaʻumaʻu crater with lava erupting from vents on the northwest side of the crater. On Monday afternoon (January 4), the lava lake was 191 m (627 feet) deep and was perched above its edge. SO2 emission rates were still high. in the order of 3,000 to 6,500 t / d since last Sunday.
The eruption of the western vent of Halema’uma’u crater continues at the summit of Kīlauea. Nighttime images from January 2 (left) and January 4 (right) compare recent changes to the domed fountain at the entrance to the west vent into the lava lake. On January 4, the small domed fountain is more uniform and less elongated.
The HVO's flyby over Halema'uma'u on January 5, 2021 shows the newly exposed lava channel entering the lava lake. Lava also continues to enter the lava lake through the tube, which produces the small domed fountain at the margin of the lake below (lower center).