Google Search Ranking Algorithm Update On March 12 & 13th

I am seeing plenty of signs from the SEO community, the tracking tools and so on that there was and is a Google algorithm update going on right now. It started on March 12th, yesterday and is continuing on today. It is early on, this is not confirmed by Google, but I am seeing plenty of chatter and signals of an update.

The last update we reported on was also unconfirmed and was on March 1st, before that February 27th and February 22nd.

The ongoing WebmasterWorld forums have these comments from SEOs:

I mean today. The last 5 hours. I think google made huge adjustments in the medicine sector.

People are seeing changes?

Yes, big flux going on here in USA. Should be interesting to see what Google does for ecommerce. The last update was horrible. Google can’t take away anymore converting traffic because it’s all gone. Google is dead….

yes, I can see also a improvment arround 10-20% and we made NO changes.
For example we have lost our (non commercial) main keyword on EAT in august. Drop from position 1 to 8. This keyword and a few more are now back to position 2.