Based on observations made on Sunday at between midnight and 6 a.m. local time, the lava avalanche of Mount Merapi slid toward southwest, Head of BPPTKG Hanik Humaida said in a statement.
During the observation period, Mount Merapi also experienced 43 earthquake avalanches with an amplitude of 3-23 mm for 12-188 seconds and six times a multi-phase earthquake with an amplitude of 3-5 mm for 5-8 seconds.
The volcano also spewed thick white cloud at height of up to 50 meters above the crater peak.
Previously, during the observation period on Saturday (16/1) at between 6 p.m. and midnight, Mount Merapi spewed incandescent lava for 20 times, with a maximum distance of 1,000 meters toward the southwest.
Based on observations over the past week, from January 8 to 14, 2021, the BPPTKG concluded that the volcanic activities of Mount Merapi remained quite high, hence the agency maintained the volcano's alert status at Level III.
The potential hazards due to the eruption of Merapi are estimated to cover an area within a radius of five kilometers from the top of the mountain.
The BPPTKG has recommended that mining activities in rivers that originate in Mount Merapi, tourism activities and climbing in the disaster-prone zones, must be halted.