Authorship Shake-up — December 19, 2013
As predicted by Matt Cutts at Pubcon Las Vegas, authorship mark-up disappeared from roughly 15% of queries over a period of about a month. The fall bottomed out around December 19th, but the numbers remain volatile and have not recovered to earlier highs.
Unnamed Update — December 17, 2013
Almost all global flux trackers registered historically high activity. Google would not confirm an update, suggesting that they avoid updates near the holidays. MozCast also registered a rise in some Partial-Match Domains (PMDs), but the patterns were unclear.
The Biggest SERP Flux Since Penguin 2.0 (Dejan SEO)