"From the observation of satellite imagery, there has been a deformation of 64 hectares of Gunung Anak Krakatau, especially on the southwest slope," BMKG Head Dwikorita Karnawati noted in a statement in Jakarta on Monday.
Deformation or change in shape on the surface of the body of Gunung Anak Krakatau is a collapse caused by the vibration or tremor from volcanic activity.
This condition is also exacerbated by extreme weather that occurs in the form of waves and high rainfall. BMKG has issued an early warning the day before.
"This phenomenon is reinforced by an analysis of four tide gauge models that show that the tsunami`s energy source originates from the South of Mount Anak Krakatau," Karnawati explained.
The tsunami struck Banten and Lampung on Saturday night (Dec 22) without being preceded by an earthquake, so that it was thought to have occurred due to volcanic activity of Mount Anak Krakatau.
Reporting by Desi Purnamasari
EDITED BY INE
(T.A014/B/KR-BSR/S012) 24-12-2018 22:10:29