From Science Europe Data Glossary
Definition: a data archive is a professional institution for the acquisition, preparation, preservation, and dissemination of research data.
Explanation: the term is commonly used in the humanities and social sciences, and is less common in the natural and life science, where data centre seems to be the preferred term. The first data archives in the social sciences were founded in the early 1960s.
References: http://en.wikipedia.org/wiki/Data_archive; http://en.wikipedia.org/wiki/Scientific_data_archiving; http://mitpress.mit.edu/books/scholarship-digital-age; http://datasupport.researchdata.nl/en/start-de-cursus/i-definitions/data-jargon/