Hi,
Today we (the OONI team) released a post which explains our methodology when examining internet blackouts through public data sources.
You can find the post here: https://ooni.torproject.org/post/examining-internet-blackouts/
This also includes an ipython network which shows how to automatically analyze Google traffic data with the aim of identifying internet blackouts.
We hope you find this useful!
Please contact us with any questions or suggestions you may have (while bearing in mind that we're attending RightsCon this week and may be slow in replies).
All the best,
~ The OONI team.