According to an extraordinary bulletin from the Popayan Observatory / Servicio Geológico Colombiano, there has been a major change in the activity of the Puracé volcano over the past two days.
As reported in the bulletins and communications of the previous months, there have been gradual changes in the behavior of this volcano, which from March 28 had a greater increase in recurrence, both in the events associated with the fracture of the rock in the volcanic edifice (type VT), presented in event trains and with magnitudes
up to 3.3 ML, than those of the LP and TR type.
On the other hand, changes have been observed by different monitoring techniques such as volcanic soil deformation and fluid geochemistry.
A change in activity level to level III is declared on March 30, 2022 / 09:00 local time.
The yellow activity level (or III) considers variations in the levels of parameters derived from monitoring that indicate that the volcano is above the base threshold and that the process is unstable and can evolve, increasing or decreasing these levels .
In Taal / Philippines, after a phreatomagmatic eruption recorded at 0226 on March 25, based on seismic data and webcam images, and which produced a 500 m high plume, a phreatomagmatic eruption from 07:22-08:59 on March 26 consisted of no less than 66 explosions and prompted PHIVOLCS to raise the Alert Level to 3 (on a scale of 0 to 5) midway through 0800. Eruption plumes reached 3 km. Wet ash falls with the smell of sulfur fell on the island of the Taal volcano, along the shores of Calauit and Alas-as, and on the shores of Lake Banyaga, Agoncillo, Batangas.
Phreatomagmatic events were recorded at 04:34 and 05:04 on March 27 by the seismic network and seen on webcam images, producing eruption plumes that rose to 800 and 400 m respectively and drifted SW.
Hot volcanic fluids continued to rise in the lake from March 26-29, generating plumes that rose up to 2.4 km and drifted southwest.
On March 31, Phivolcs reported a phreatomagmatic burst at 10:39 a.m. (VTMC Camera). Activity at the main crater was dominated by upwelling of hot volcanic fluids in its lake which generated 1,500 meter high plumes that drifted southwest.
Sulfur dioxide (SO2) emissions averaged 6,405 tonnes/day as of March 30, 2022.
Sources: Phivolcs, VAAC Tokyo and Global Volcanism Program
In Nishinoshima, in the Ogasawara Islands, an overflight by the Japan Coast Guards using an aircraft from the Haneda base on March 29, shows intense degassing at all the cracks in the lava field, which hide the crater. This activity seems to be linked to a rise in magma.
The previous flyby dates from March 14, when gas and steam emissions and high temperatures persisted in the summit crater.
Similarly, a brownish to yellowish discoloration is visible in the water along the coasts of the island, and extends into the surrounding area.
Source: Japan Coast Guards
Nishinoshima - strong degassing & discoloration of coastal waters, increasing activity - Doc. JCG 29.03.2022 - one click to enlarge
For the past two weeks, the crater lake of Mount Ruapehu (Te Wai ā-moe) has entered a new heating cycle, accompanied by high levels of volcanic tremor (volcanic earthquakes).
Over the past week, the lake has further warmed to ~32°C (compared to 31°C the previous week). The slow warming has been hampered by heavy rains on the volcano and the influx of cold water into the lake. The strong shaking reported last week continues.
A sustained high tremor, combined with the slow warming of the lake, continues to indicate that gas is flowing through the system. However, the slower than expected increase in lake temperature suggests that a partial blockage may exist in the vent below the lake, preventing hot gas from entering the lake. This could allow pressure to build up in the volcano.
The interpretation of this activity is consistent with elevated volcanic unrest and therefore the Volcanic Alert Level remains at Level 2. The Aviation Color Code has been raised to Yellow.
Mount Ruapehu is an active volcano and has the potential to erupt with little or no warning when in a state of high volcanic unrest.