Why seomoz.org still in Google index?

[Yosef]

I searched in Google, the number of URLs indexed left in the seomoz.org domain since it changed to moz.comI am surprised that after all this time more than 15,000 URLs indexed:https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=site%3Aseomoz.org%20inurl%3Aseomoz.org

If I clicked on any of the results it will be redirect (301) to the new domain, so it is working, but Google still keep these URLs in the index.
What could be the reason?Will not cause duplicated content issue on moz.com?

[Martijn_Scheijbeler]

Hi Yosef,

Seen this many times, it takes Google sometimes up to a year for bigger content sites to have all the content removed for the original domain in their index and have all links on the new domain indexed. This is not really a duplicate content case as Google should be able to follow the redirects to the new content and as with that the old content is not available anymore.

[Stramark]

maby you can try to use the function in webmastertools for the migration of domains. It seems the have updated it to fix this kind of issue https://support.google.com/webmasters/answer/83106?hl=en

[randfish]

Part of me thinks this is just because so many live pages still have links to these URLs, and while Google knows they 301, some part of its index maintains the old URLs due to the strength of their presence in the link graph. It might be a technical limitation too, where Google uses synthetic links/URLs in their indices to represent redirected stuff.

In any case, not a big concern for Moz, and shouldn't be for you either if you're redirecting a site. So long as the traffic to the pages from search goes back up and indexation looks solid, you should be fine.