The Semeru presented in this first half of April gas emissions with a gray-white plume at 200-400 meters above the crater Jonggring Seloko, interspersed by eruptions, with gray plumes at 400-600 meters above the summit .
On April 16 at 9:04 a.m. local time, an eruption was reported with an ash plume at 4,076 meters asl, according to a ground observer.
This April 17 at 06:08 WIB, Dr. Devy Kamil Syahbana reports a pyroclastic flow traveling 2,000 meters south, with an imprint on the seismogram of 7 mm amplitude and a duration of 481 sec.
Seismology is further characterized by 2 eruption earthquakes with a magnitude of 10-11 mm and a duration of 25-85 sec., An avalanche earthquake with an amplitude of 2 mm and a duration of 60 sec. ., and 14 blast earthquakes, of 2-5 mm amplitude and of a duration of 50-56 sec.
The eruptive activity and the continuous gas bursts in the crater of Jonggring Seloko of G. Semeru shows that there is a supply or a pressure of magma accompanied by an increase of fluid (gas, liquid and solids) to a depth weaker. The appearance of harmonic tremors without accompanying volcanic earthquakes (shallow volcanic or deep volcanic) indicates that the system is now open. The gray color in the eruption column indicates the presence of rocky materials brought to the surface. The intervals of seismic eruption are quite dense shows that so far, there has been no accumulation of energy having the potential of eruptions with greater intensity.
Sources: PVMBG, Magma Indonesia & Dr. Devy Kamil Syahbana
The activity of Anak Krakatau continues.
Magma Indonesia reports an eruption on April 16 at 2:47 p.m. local (07:47 UTC). The height of the plume could not be observed.
VAAC Darwin issued an orange VONA, following continuous ash emissions.
A new eruption is reported this Friday April 17, 2020 at 07:49 am IWST. No visual observation of the eruption could be made. This eruption was recorded on a seismograph with a maximum amplitude of 40 mm and a duration of 50 seconds.
Mirova has reported thermal anomalies between 11 MW and 60 MW in the past 4 days.
Alert levels remain constant.
Sources: PVMBG, Magma Indonesia, VAAC Darwin, Mirova
In Nevado del Ruiz, Colombia, seismicity related to fluid dynamics, inside volcanic conduits, showed an increase in the number of events and the seismic energy released, during the week of 6 to April 13.
The seismicity generated by the fracturing of the rocks presented a slight decrease in the number of earthquakes and increase in the seismic energy released, compared to the previous week. This kind of seismicity was located mainly in the Arenas crater and in the south-southwest, northwest and northeast sectors of the volcano, at depths varying between 0.3 and 6.3 km.
The occurrence of several seismic events of the drum-beat type, associated with fracturing of rocks were recorded on April 9, 10 and 12.
Small gas and ash emissions have been confirmed by cameras and reports from officials in Los Nevados National Natural Park, as well as by the VAAC Washigton VAAC, with a plume of gas and vapor reaching max. 1,300m above the summit on April 9.
The deformation of the volcanic surface, measured from GNSS stations (Satellite System of Global Navigation), showed no significant change
By monitoring the information provided on Mirova and NASA, low energy thermal anomalies at the volcano over the past week.
The alert remains at 3, Amarillo / Change in behavior of volcanic activity.
In Nevado del Huila, a total of 353 seismic events were recorded during the week of April 6 to 13, of which 188 were related to rock fracturing processes (VT type) and 165 to fluid dynamics in conduits volcanic.
The images obtained during the week by the webcams of Caloto, Tafxnú, Maravillas and La Palma showed a weak degassing of the volcanic system, while the sensors for monitoring the deformation of the ground, magnetic fields and infrasonic waves do not have not recorded variations associated with changes in volcanic activity. The alert remains at 3.
Source: SGC weekly report.