USGS Trusted Digital Repositories: What They Are and Why They Matter

Federal mandates and the USGS's own Fundamental Science Practices require publicly funded scientific data, publications and derived work to be openly accessible. Open access makes these data assets easier to find, reproduce and reuse — getting more from the public's investment — and makes the way data were collected and analysed transparent, protecting scientific integrity.

USGS programmes, science centres and projects keep their data assets in many USGS and non-USGS repositories. To make sure the USGS systems are trustworthy, reliable and secure, the Bureau's Fundamental Science Practices Advisory Committee runs an evaluation; a system that passes is certified as a USGS Trusted Digital Repository (TDR).

Figure 1. The mass storage system for the USGS Earth Resources Observation and Science (EROS) Center data archive, a USGS Trusted Digital Repository. USGS photograph.

What a Trusted Digital Repository is

A TDR is a USGS data system certified by the Bureau — after a rigorous panel review of what its manager submits — as meeting internationally accepted standards for digital repositories. It must show that USGS data are preserved, accessible, documented and backed up to those standards, meeting federal mandates to keep and deliver science to researchers and the public over the long term.

Besides published products, TDRs keep and openly share the raw data and information behind them — field observations and measurements, analysis and modelling, laboratory results — and make it easier to combine data products. That improves availability, supports reproducibility and gives evidence of a dataset's legitimacy for later work. TDR standards set common practices for managing, archiving and sharing data, and apply the FAIR principles — findable, accessible, interoperable, reusable: persistent identifiers, rich metadata, version control, and telling users about changes, licences and related work.

Why TDRs exist

In 2016 the USGS published its Public Access Plan — Public Access to Results of Federally Funded Research at the U.S. Geological Survey — setting out how to make its data and publications usable, discoverable and widely available. It calls for repositories that:

1. provide reliable, secure infrastructure to manage, preserve and openly share assets;
2. follow sustainable data management, so data are properly cared for after the projects that collected them end;
3. keep data available in stable environments for the long term.

The USGS must also make it possible to integrate data held in separate subject databases, to study the Earth's critical zone and Earth systems across disciplines; common practices in TDRs make that easier.

The plan answers several federal directives: the OPEN Government Data Act (2019); the 2013 Office of Science and Technology Policy memo Increasing Access to the Results of Federally Funded Scientific Research; Executive Order 13642, Making Open and Machine Readable the New Default for Government Information (2013); and Office of Management and Budget memo M-13-13, Open Data Policy (2013).

What owners and managers must do

• have a mission to preserve USGS science data;
• take responsibility for long-term care of digital resources for depositors and users;
• support the repository's long-term viability, and show it is financially and managerially sustainable;
• design it to common conventions and standards for management, access and security;
• have it evaluated to meet the community's expectations of trustworthiness;
• tell users about changes to data or metadata;
• manage metadata for all datasets in line with National Archives and Records Administration, Department of the Interior and USGS policies.

Examples

Figure 3. Lake Erie during a harmful algal bloom in September 2017, preserved in the EROS Center data archive. USGS and NASA.

Why seek certification

USGS policies require released publications and data to be kept in repositories that meet the Public Access Plan. TDR status shows a system can meet long-term preservation requirements and demonstrates the USGS's commitment to delivering science to the public over the long term.

USGS data may also go into accepted outside repositories that pool worldwide research — such as IRIS for seismic and geophysical data, GenBank for genetic sequences, and AmeriFlux for carbon, water and energy flux measurements — but authoritative copies, including every version, must also be kept in USGS systems.

How certification works

1. Repository staff tell the USGS TDR working group they want certification.
2. They complete a self-assessment, scoring themselves from 0 (low) to 4 (high) on infrastructure (governance, finances, staffing), management of digital objects (quality and integrity, persistent identifiers and citations, documented processes) and technology (technical infrastructure, security and risk). Anything not applicable, or only minimally met, must be documented.
3. The working group reviews it with the applicant in an iterative, collaborative process, discussing gaps and asking for more information. A score of 2 or below on any element blocks certification, but the group keeps working with the applicant on a path to it; strong areas can outweigh weaker ones during the implementation phase.
4. Once certified, the system keeps developing to promote preservation and reuse.
5. Repositories are recertified every 3 years, through the USGS process or the international CoreTrustSeal process, whose 16 criteria the USGS follows; the aim is eventually to apply directly to CoreTrustSeal.

Figure 4. Inside one of the USGS's high-speed, high-capacity tape libraries: a robot fetches a cartridge, loads it into a drive to be read, then puts it back. USGS photograph.

Why it matters

Repository managers are accountable for assets bought with public money. Some data — from studies of natural hazards, endangered species, aerial surveys and other costly work — could never be collected again, because conditions change and costs are high. Self-assessment and peer review give assurance that a system can keep such data secure for the long term, and, with disciplined data management, TDRs preserve and deliver the science that serves the USGS mission.

Sources

• Latysh, N., Kirk, K.G., and Faundeen, J., 2020, Purpose and benefits of U.S. Geological Survey Trusted Digital Repositories: U.S. Geological Survey Fact Sheet 2020–3032. https://pubs.usgs.gov/publication/fs20203032
• The certification steps, figures and captions come from the fact sheet's PDF, which the web version breaks up. A stock banner photograph and a picture of the Public Access Plan's cover are not reproduced.
• Rewritten in hubnx's own words.