A new "major explosion" was recorded on August 18 on Stromboli by the National Institute of Geophysics and Volcanology (INGV). In particular, at 17:08 (local time), an intense explosion involved the mouths of the south-central zone located on the crater terrace. The explosion produced a small cloud of ash, which dispersed rapidly, and the ejection of coarse pyroclastic material, which fell mainly on the crater terrace and on top of the Sciara del Fuoco. The seismic signal associated with the event lasted a little over 4 minutes. Subsequently, the volcano returned to its normal Strombolian activity.
As we know, these explosive events are characterized by greater energy compared to the "ordinary" strombolian activity that characterizes this volcano on a daily basis.
Source: INGV Catania
The seismicity of Anak Krakatau was particularly high on August 18, characterized by 578 earthquakes of eruption, 80 earthquake of emission / breath, and a continuous tremor of dominant 2 m.
On August 19, the number of eruptions earthquakes was only 248, and that of emission earthquakes 118, for a continuous tremor of identical dominance
Some details on the earthquakes of Lombok on August 19, 2018:
To the two episodes reported yesterday (1 & 2), 4 additional episodes should be added, according to a joint report by BMKG and PVMBG.
1. The first earthquake occurred at 11:06:13 WIB, the epicenter lying at the coordinates of 8.29LS and 116.62BT with a magnitude of 5.4 SR at a depth of 10 km, a distance of 25 km at northeast of East Lombok, NTB.
2. The second earthquake occurred 4 minutes later at 11:10:22 WIB with the epicenter at 8.24 LS and 116.66BT, with a magnitude greater than 6.5 SR at 10 km depth, 32 km northeast of Lombok Est.
3. The third earthquake occurred at 21:56:27 WIB with a central location at 8.28LS and 116.71BT (30 km northeast of East Lombok), at a depth of 10 km, with a magnitude from 7.0 SR
4. The fourth earthquake occurred at 22:16:37 WIB at 8:35 AM and 116.51BT (18 km northwest of East Lombok), at a depth of 10 km, with a magnitude of 5.6 SR
5. The fifth earthquake occurred at 22:28: 59 WIB at the location of 8.30LS and 116.56BT (23 km northwest of East Lombok), at a depth of 10 km, a magnitude of 5, 8 SR
6.The sixth earthquake took place at 23:25 on the coordinates of numbers 8.50LS and 116.85BT, at a depth of 10 km with a magnitude of 5.0 S.R.
Based on the position and depth of the seismic source, the earthquakes are associated with the Flores back arc Thrust area, of west-east direction.
The feeling zone includes a part of Java, the island of Bali and up to East Nusa Tenggara.
The electricity was interrupted on Lombok, buildings collapsed and fires were triggered following circuit-breakers on Bugin Island.
Sources: PVMBG, BNPB, BMKG, Magma Indonesia