Taken by Oleg Volynets, eruption in 1975.
After the eruption of Plosky Tolbachik for the first time in 36 years, I thought it might be useful to have a quick background look at the volcano. When looking at the previous eruption history eruptions were spaced more closely together prior to 1975 and were generally smaller in nature than the VEI 4 category of the 1975 eruption (pictured to the right). It certainly has a rich amount of activity stretching back several thousand years.
As ever eruptions blog has provided information and will likely give regular updates on the eruption. I highly recommend taking a look at the Russian website for Kamchatkan activity (KVERT) where there is a nice overview of various volcanoes not just Plosky Tolbachik (here I link to Plosky Tolbachik). By looking at the following link on the same website, you can see images of the summit area taken at different times over the past few years. The most recent was taken during August 2012 and I note the visible absence of steam from the volcano. Suggesting (tentatively) that at this stage there may have been no evidence of a reawakening at the summit.
Furthermore, when looking at the seismic activity this seemed only to increase a few days prior to the eruption, as detailed on Volcano Discovery. All this illustrates that there can be a minimum amount of activity detected prior to the eruption of a volcano!
Personally I find the volcanoes of Kamchatka fascinating and it will be thoroughly interesting to see how this eruption develops over the coming months and potentially longer.