WASHINGTON (AP) — The Library of Congress says it’s amassed about 170 billion tweets since it began collecting an archive of all Twitter messages in 2010.

Twitter is donating its archive to the library, going back to the first one posted in 2006.

Library Director of Communications Gayle Osterberg wrote in a blog post Friday that the volume of tweets it receives has grown from 140 million daily in February 2011 to nearly half a billion tweets each day in late 2012.

Librarians have been developing a system to preserve and organize the collection. Now the library is shifting its focus to handle the technical challenges of making such a massive archive available to researchers.

The library may work with a private partner to provide access because its own search technology is slow.