This is a differential interferogram generated from a pair of Sentinel-1 SAR imagery dated 28 August and 21 September 2017 downloaded from the Sentinel Data Hub and processed using SNAP software. It appears that along with the increased seismicity, there is also some slight ground surface deformation in the volcano edifice, which is depicted by the color fringes.
To be clear, it’s still uncertain at this point if the volcano will really erupt, much harder is to tell when the eruption will be. Though from what I understand from the reports is that, so far all signs do indicate that Agung may erupt soon.
Download the kmz file here.
Dr. Tim Wright replied to my tweet and pointed out that radar signals in Agung are prone to atmospheric delays, which can be mistaken as deformation signals. He is absolutely right, and I have to emphasize here that this interferogram is preliminary. So I’ll have to wait for other imagery to confirm, or try additional processing to minimize the atmospheric effects.