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About / Mission Statement / Services / TRAC Certification



Chronopolis is a geographically distributed preservation network. All data in the network are replicated among three geographically dispersed partner sites. This geographic distribution ensures that no single catastrophic event will affect the content.

Chronopolis network partners map


Originally funded by the Library of Congress, the Chronopolis digital preservation network has the capacity to preserve hundreds of terabytes of digital data—data of any type or size, with minimal requirements on the data provider. Chronopolis comprises several partner organizations that provide a wide range of services. The partners include:

The project leverages high-speed networks, mass-scale storage capabilities, and the expertise of the partners in order to provide a geographically distributed, heterogeneous, and highly redundant archive system.

Features of the project include:

  • Three geographically distributed copies of the data
  • Curatorial audit reporting
  • Development of best practices for data packaging and sharing


Mission Statement

Chronopolis is a digital preservation program for the preservation of long-lived digital data collections. It accomplishes this through the development and implementation of a preservation data grid and its supporting human, policy, and technological infrastructure.  Chronopolis is intended as a model for valued digital collections with long-term impact from a variety of academic disciplines. The infrastructure is designed to be content-agnostic, to enable the ingest of collections of all types.

Chronopolis starts with the realization that partnership and collaboration among a specified group of like organizations is necessary to insure continuity for the life-time of a collection. Thus it has been designed with multiple organizations providing the preservation infrastructure, tool and software development, and management. This is key not only to providing a robust preservation environment, but also creating a sustainable organizational model, not dependent on any one group.



Chronopolis's preservation infrastructure, tool and software development, and management is provided by multiple organizations, creating both a robust preservation environment and a sustainable organizational model not dependant on any one group.

The Chronopolis Preservation Plan offers the following services:

  • Provide long-term preservation of a wide variety of digital content;
  • Operate a robust, grid-based storage environment for digital preservation;
  • Maintain appropriate preservation metadata relevant to all aspects of the object lifecycle;
  • Develop tools and services for digital preservation;
  • Devote resources to investigating and planning for new technologies and services;
  • Utilize and create community-based standards and systems.

Format obsolescence is not an immediate concern of the Chronopolis system. Instead, this is regarded as the responsibility of the data providers. The single, overriding commitment of the Chronopolis system is to preserve objects in such a way that they can be transmitted back to the original data providers in the exact form in which they were submitted.


TRAC Certification

The Center for Research Libraries (CRL) has certified Chronopolis as a “trustworthy digital repository,” meaning that it meets accepted best practices in the management of digital repositories. The primary metrics used by CRL in its assessment are derived from the Trustworthy Repositories Audit Certification (TRAC).

The TRAC criteria includes organizational infrastructure, digital object management, technologies, technical infrastructure, and security. These criteria represent best current practices and thinking about the organizational and technological needs of trustworthy digital repositories.

The certification process involved three broad steps:

  1. The Chronopolis team completed a "self-audit," answering all of the questions posed in the TRAC document. This self-audit was sent to CRL, who used it as the basis for their work. The Chronopolis self-audit is available here.
  2. Next, CRL analyzed the Chronopolis network and the self-audit, including a site visit to talk to Chronopolis staff, and a number of interviews with Chronopolis users and stakeholders. Based on input from this work, the audit team and Chronopolis began an interactive phase, discussing changes and recommendations.
  3. CRL released the final audit report. This report is available on the CRL site here.

UC San Diego Library Receives Mellon Grant to Develop Approaches to Preserving Digital Repositories

A one-year, $161,000 grant from the New York City-based Andrew W. Mellon Foundation will fund a joint project to support the effective communication and exchange of data between local and national digital preservation repositories. The project — a collaboration between the UC San Diego Library, UC Santa Barbara, Emory University, Northwestern University and DuraSpace — will design tools that will enable libraries and archives to seamlessly deposit content into distributed digital preservation systems (DDPs), update that content over time and reliably restore content if needed.

The design work will leverage Chronopolis, a UC San Diego-led digital preservation platform, to enable digital repository platforms from around the world to simplify the process for creating preservation copies of their data. By addressing a current gap between digital preservation platforms and digital libraries this project will increase the reliability and sustainability of digital archives. Read more.

The Digital Preservation Network (DPN) to Cease Operations

The Digital Preservation Network (DPN) has announced plans to cease operations. The individual nodes that collectively provided preservation services to DPN seek to reassure the DPN membership as well as the larger academic and digital preservation communities that we remain confident about the future of digital preservation. Read the announcement on the DuraSpace blog.

Texas Digital Library Joins Chronopolis

The Texas Digital Library (TDL), along with the Texas Advanced Computing Center (TACC) at The University of Texas at Austin, has joined the Chronopolis digital preservation network, becoming the first new node since the network’s inception in 2008. Read more.

Chronopolis Teams up with DuraSpace 

The TRAC-certified Chronopolis digital preservation network at the UC San Diego Library is collaborating with DuraSpace to offer the DuraCloud Enterprise Chronopolis subscription plan, which provides DuraCloud customers with a wide range of benefits. Read more here.