Shifting website from m.example.com to responsive layout. How to best tackle SEO for already cached links?

Question

I have a website which has a desktop version & a mobile version. Recently We completed the development of the new responsive design, hence forth the mobile website is not required anymore. Since this website has been live for more than 6 years & has close to 600K+ mobile pages cached in search engines for the mobile site. how can i shut down the mobile site without affecting my website traffic & not hurting the SEO.

Note:

• The new responsive designs inherits the Same URL as that of the previous website. So we are not worried about the desktop version of the site.
• Programming language used is ASP.NET.

Answer 1

If both "old" site and "new" site have exactly the same URL structure and new site is SEO friedly, Search Engines will crawl the new site if it is allowed in its Robots.txt file (or meta). The Search Engine cache will be update accordingly.

If URLs are different you should implement:

A 301 redirect which is a permanent redirect which passes between 90-99% of link juice (ranking power) to the redirected page.

You could get more information on Google crawling process and inform when you update your website using Google Web Master tool or another services.