Data Access
Presentation
The product “Glacier Surface Flow Velocity” for the period 2017-2018 comes from the study of Millan et al. (2022). This is the first comprehensive mapping of the ice flow velocities for more than 200,000 world’s glaciers outside the ice sheets. This dataset provides a better understanding of the flow dynamics of glaciers, and was used to estimate of the distribution of ice thicknesses (cf. product “ice thickness”). Glacier flow velocities are distributed at a horizontal resolution of 50 m and represent an average over the period 2017-2018.
Data and Methods
The glaciers mapped are based on the Randolph Glacier Inventory 6.0.
The estimate of glacier surface flow velocities comes from image cross-correlation applied on optical and radar satellite observations, primarily Sentinel-2 (S2), Landsat-8 (L8) and Sentinel-1 (S1). These sensors make systematic acquisitions with a revisit period ranging from 2 to 16 days. Surface flow velocities are calculated using all possible image pairs, for time interval ranging from 5 (S2), 6 (S1) ou 16 days (L8), up to more than a year. The displacement fields obtained for different time interval (defined by the date of acquisition of the images) are averaged over the entire 2017-2018 period in order to ensure exhaustive coverage of the glaciers.
More scientific information is available in Millan et al., 2019, doi: 10.3390/rs11212498 and Millan et al., 2022 in Nature Geoscience and its supplement.
The products can be downloaded by tiles at maps.theia-land.fr. Bulk downloading is also available at the Sedoo site of Observatoire Midi-Pyrénées.
Contact
Romain Millan
Université Grenoble Alpes, CNRS, IRD | IGE
@R. Millan
Jérémie Mouginot
Université Grenoble Alpes, CNRS | IGE
@J.Mouginot
Mathieu Morlighem
Dartmouth College, Hanover, USA
@M.Morlighem
References
Millan, R., Mouginot, J., Rabatel, A., Jeong, S., Cusicanqui, D., Derkacheva, A., & Chekki, M. (2019). Mapping surface flow velocity of glaciers at regional scale using a multiple sensors approach. Remote Sensing, 11(21), 2498. doi: 10.3390/rs11212498
Millan, R., Mouginot, J., Rabatel, A., & Morlighem, M. Ice velocity and thickness of the world’s glaciers. Nature Geoscience, (2022) doi: 10.1038/s41561-021-00885-z