Over the past eight days, the temperature at Mount Ruapehu Crater Lake (Te Wai ā-moe) has increased further, from ~32°C to ~36°C. Our modeling suggests that the temperature increase corresponds to ~460 MW of heat entering the lake. The temperature and heat input are within the typical range of a heating cycle.
Volcanic tremor levels remain elevated and, after a slight increase over the past week, are now among the highest levels we have seen in the past nine years.
Water and gas sampling from the crater lake and an aircraft gas measurement flight were completed last week. Analysis of water and gas samples from the lake do not indicate any significant changes in the geothermal system feeding the lake. The amount of gas released from the lake has increased compared to previous measurements, but remains within the generally observed long-term trends. The crater lake has taken on a battleship gray color as upwelling has disturbed the sediments at the bottom of the lake. Sulfur sheets are present on the surface of the lake.
The results to date are typical for the start of a heating cycle except that the dither values are abnormally high. Current data indicates that normal processes observed at the crater lake are occurring. Gas and fluids from the shallow magma below the volcano interact with the geothermal system of the crater lake, causing the lake to heat up, volcanic tremors and increased gas emissions to the surface.
The interpretation of this activity is consistent with high volcanic unrest and therefore the Volcanic Alert Level remains at Level 2. The Aviation Color Code remains at Yellow.
Active eruptive activity continues at Otake crater on Suwanosejima.
The number of explosions increased to 34 times per day, then 76 times per day, and up to 122 times during the last observation period (preliminary figures).
The eruptive plume rose a maximum of 2,800 m above the crater rim.
The ash falls were confirmed 5 km away, on the village of Toshima.
The large volcanic bombs disperse on a trajectory up to about 900 m from the center of the crater.
Volcanic tremors occurred throughout the period, and inflation is measured.
Source: JMA (subject to correct translation)
The I.G.Peru informs us of the activity of Sabancaya between March 28 and April 3, 2022; it remained at moderate levels, with an average of 41 daily explosions, accompanied by plumes of gas and ash up to 2,000 meters above the summit.
During this period, 205 volcanic earthquakes associated with the circulation of internal magmatic fluids were detected, as well as VT earthquakes linked to rock fracturing. The deformation does not show any significant anomalies; Two thermal anomalies, max. 11 MW, are linked to the presence of a lava body on the surface of the crater.
The alert level is maintained at Naranja, associated with an inaccessible zone of 12 km radius around the crater.
Source: I.G.Peru bulletin posted on 05.04.2022
An image from Planet documents the Fukutoku-Okanoba decoloration aera on April 4, 2022; its core is only 150 meters in diameter.