Increased seismicity at Agung, as well as the severity of past eruptions, prompted PVMBG to raise the Alert Level to 2 (on a scale of 1-4).
The report noted that volcanic earthquakes (VA) began to be recorded on 10 August and shallow volcanic earthquakes (VB) began to be recorded on 24 August.
Local tectonic earthquakes were also recorded and began to increase consistently on 26 August.
PVMBG warned the public to stay at least 3 km away from the crater.
On 13 September a climber observed a sulfatara plume rising from the bottom of the crater as high as 50 m above the crater rim.
During 14-18 September four earthquakes centered around Agung were felt.
On 18 September PVMBG reported that the number of VA and VB events continued to increase; the Alert Level was increased to 3.
The exclusion zone was increased to 6 km, with an additional expansion to 7.5 km in the N, SE, and SSW directions.
Elevations above 950 m were also restricted.
A VEI 5 eruption during 1963-64 produced pyroclastic flows and lahars that caused extensive damage and resulted in more than 1,100 deaths.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)