Randolph Glacier Inventory and infrastructure for glacier monitoring

(2014 – 2018)
WG co-chairs
Graham Cogley, Trent University, Peterborough, Canada
Regine Hock, University of Alaska Fairbanks, USA

Executive Committee (since Jan 2019)
Regine Hock, University of Alaska Fairbanks, USA
Fabien Maussion, University of Innsbruck, Austria
Frank Paul/Phillip Rastner, University of Zürich, Switzerland
Bruce Raup, National Snow and Ice Data Center, Boulder, USA

WG members
Etienne Berthier, CNRS-OMP-LEGOS, Toulouse, France
Andrew Bliss, University of Alaska Fairbanks, USA
Tobias Bolch, University of Zürich, Switzerland
and Technische Universität Dresden, Germany
Koji Fujita, University of Nagoya, Japan
Alex Gardner, Clark University, USA
Matthias Huss, University of Fribourg and ETH Zürich, Switzerland
Georg Kaser, University of Innsbruck, Austria
Christian Kienholz, University of Alaska Fairbanks, USA
Anil Kulkarni, Indian Institute of Science, Bangalore, India
Shiyin Liu, Cold and Arid Regions Environmental & Engineering Research Institute, Lanzhou, China
Christopher Nuth, University of Oslo, Norway
Ben Marzeion, University of Breme, Germany
Takayuki Nuimura, University of Nagoya, Japan
Valentina Radić, University of British Columbia, Canada
Bruce Raup, National Snow and Ice Data Center, Boulder, USA
Akiko Sakai, University of Nagoya, Japan
Donghui Shangguan, Cold and Arid Regions Environmental & Engineering Research Institute, Lanzhou, China
Arun Shrestha, International Centre for Integratred Mountain Development, Kathmandu, Nepal

The Randolph Glacier Inventory (RGI, Pfeffer et al., 2014) is a globally complete collection of digital outlines of glaciers, excluding the ice sheets. The RGI was created with limited resources by an ad-hoc group of scientists in a short period to meet the needs of the Fifth Assessment of the Intergovernmental Panel on Climate Change (IPCC) for estimates of recent and future glacier mass balance. Priority was given to complete coverage, if necessary at reduced quality, rather than to extensive attributes or documentary detail.

The RGI has proven highly valuable and has been used extensively since its first release in 2012. For example, the RGI has been used to compute regional and global glacier area (Gardner et al., 2013) and glacier volume (Huss and Farinotti, 2012; Marzeion et al., 2012; Grinsted, 2013; Radić et al., 2013) as well as thickness distributions (Huss and Farinotti, 2012) and area-altitude distributions (e.g. Radić et al., 2013). The completeness of the RGI has eliminated the need for upscaling (Radić and Hock, 2010) or simplifying assumptions, and has provided an indispensable basis for updated global-scale assessments and projections of glacier mass budgets (Marzeion et al., 2012; Gardner et al., 2013; Giesen and Oerlemans, 2013; Hirabayashi et al., 2013; Radić et al., 2013) that fed into the IPCC’s Fifth Assessment Report (Church et al., 2013; Vaughan et al. 2013).

Since 2000, glacier outlines have been archived at the U.S. National Snow and Ice Data Center (NSIDC) as part of the GLIMS (Global Land Ice Measurements from Space) initiative launched in 1995. Multi-temporal outlines are available, allowing glacier change detection. However, GLIMS outlines cover less than 75% of the world’s glacier area, and completion of GLIMS is not foreseen in the near future. Also, data retrieval from GLIMS on global/regional scales is not straightforward. Hence, we anticipate that, at least for regional/global glacier mass-balance studies, the RGI will remain the main data source until the two datasets are merged. The RGI Working Group provides the organizational framework to correspond to the existing framework within which GLIMS operates. The proposed work has the aim of further developing the RGI by increasing the accuracy of its outlines and the number of attributes attached to each outline. This will provide the glaciological community with the necessary base data for global-scale mass-balance studies, thus meeting the needs of upcoming assessments such as those of the IPCC in a timely way.

In the long term it does not make good sense for there to be two glacier databases with such similar content as the RGI and GLIMS. Thus one of the objectives of the Working Group is to oversee the gradual merger of these two databases. Their content is not identical, and the process of fusion requires consideration of how to retain the functionality and features of the RGI, expanded as outlined in the next section, as part of an expanded GLIMS. This is likely to require some time and may or may not be complete by the end of the Working Group’s term.


  • To maintain and develop the Randolph Glacier Inventory as a resource for global/regional-scale mass-balance assessments and projections
    a) Enlarge the set of attributes of the current RGI version 3.2, for example:
    topographic (hypsometry, slope, aspect, min/max elevation, area, length, …)
    glaciological (ice thickness, debris cover, climatic variables, glacier morphology (valley glacier vs ice cap), glacier type (lake/ocean-terminating, surge-type, …)
    hydrographic (drainage basins)
    political (national boundaries)
    sources, dates
    b) Improve the quality of glacier outlines where necessary
    c) Periodically release updated versions of the inventory
    d) Develop, document and make available tools for deriving inventory attributes
  • To work towards merging the RGI into GLIMS
    a) Ensure that there is no duplication or omission during merging, and that the functionality and features of the RGI (such as region-wide downloads and RGI-like representation of nunataks) are retained in the future GLIMS
    b) Advise GLIMS on enhancements of the GLIMS data model to facilitate global/regional-scale analysis
    c) Discuss and plan the eventual fusion of the two databases
  • To develop a model for medium-term support of the RGI, for example for purposes of the next IPCC assessment
    a) To explore prospects for increased funding to support the RGI
    b) To liaise with relevant organizations (e.g. GTN-G: GLIMS, NSIDC, WGMS) to optimize data submission and data provision for glaciological users

Deliverables and milestones

  • Updated versions of the RGI with enhanced attribute set (target dates for new releases: June 2014, and annually thereafter)
  • A technical document explaining in detail the derivation of the new attributes and their potential uses (released with each annually updated version)
  • A scientific publication reviewing glaciological achievements with the RGI, to be submitted during the second half of the Working Group’s term
  • An RGI-related session at a suitable international conference, for example, IUGG 2015 in Prague; we expect also that numerous peer-reviewed publications will rely on updated versions of the RGI, building on results already published (see section 1) and extending into fields such as glacier hydrology and water resources in which the RGI has not yet been exploited fully

Publications describing the RGI
Pfeffer, W.T., A.A. Arendt, A. Bliss, T. Bolch, J.G. Cogley, A.S. Gardner, J.O. Hagen, R. Hock, G. Kaser, C. Kienholz, E.S. Miles, G. Moholdt, N. Mölg, F. Paul, V. Radić, P. Rastner, B.H. Raup, J. Rich, M.J. Sharp and the Randolph Consortium (2014) The Randolph Glacier Inventory: a globally complete inventory of glaciers, J. Glaciol., 60 (221), 537-551 (doi: 10.3189/2014JoG13J176). Download pdf

RGI Consortium (2017). Randolph Glacier Inventory – A Dataset of Global Glacier Outlines: Version 6.0: Technical Report, Global Land Ice Measurements from Space, Colorado, USA. Digital Media. DOI: https://doi.org/10.7265/N5-RGI-60. Download here