Time lapse imagery of the calving front of Ryder Glacier, Northern Greenland, August 2019

Felicity Holmes, Nina Kirchner, Abhay Prakash

This data set contains images of the calving front of Ryder Glacier taken every 5 seconds during the period 14⁠ – ⁠25th August 2019. The Ryder Glacier drains the northwestern sector of Northern Greenland Ice Sheet and calves in the Sherard Osborn Fjord.

The data can be used to identify calving events and monitor the frontal dynamics of Ryder Glacier during the aforementioned period. The data were collected in connection with the Ryder 2019 Expedition with Swedish icebreaker Oden.

The data was collected using a camera positioned on the fjord wall near Ryder glacier at 81.8° N, 50.4° W. In total, there are around 140,000 images. Some short periods have no data, and fog obscures the view of the glacier in some periods.

Scientific highlights

This dataset allows the identification and classification of calving events at the front of Ryder glacier. Through being able to classify the calving events, we can gain some insight into the processes operating at the calving front.

For example, around 55 % of calving events identified from this dataset show signs that they are initiated by waterline weaknesses and associated undercutting. This suggests that ocean temperatures play a significant role with regards to calving at Ryder glacier.

Sheet collapse events and waterline events

Examples of calving events related to waterline weaknesses are ’sheet collapse’ events (reasonably large events where ice spanning the entire height of the calving front falls into the water) and ’waterline events’ (where smaller pieces of ice break off from just above the waterline).

Ice fall events

Other types of calving events do not show a clear relation to water temperatures, for example ’ice fall’ events. In these type of events, ice falls off from near the top of the calving front.

Drivers of frontal ablation

When the timing and style of calving events is analysed in conjunction with other data sets, these time lapse images can help to elucidate the key drivers of frontal ablation at Ryder glacier.

Download data

You can download all files automatically using the software wget and the following single command.

wget -i https://bolin.su.se/data/data/ryder-2019-glacier-front-imagery.txt

You may need to download the software wget.

The command uses wget to download all files specified in a file list. A list of all files is available at https://bolin.su.se/data/data/ryder-2019-glacier-front-imagery.txt

Because of the large data volume, downloading all files can take can take long time and requires sufficent disk space on your system.

To download a selected subset, you can edit the file list and run wget with your revised list. Alternatively, you can select files for download in the file list below.

Data files

Click on the categories below to view the files. Click on the download button to download the files shown in the list. Depending on your connection speed it may take considerable time to download the data since it is rather big. Thus, it is not recommended to use the web browser to download more than one day (24 files) per batch. Please use wget to download larger batches, as described above.

Citation

Felicity Holmes, Nina Kirchner, Abhay Prakash (2021) Time lapse imagery of the calving front of Ryder Glacier, Northern Greenland, August 2019. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/oden-ryder-2019-glacier-front-imagery-1

References

Jakobsson M, Mayer LA, Farrell F, Ryder 2019 Scientific Party (2020) Expedition report: SWEDARCTIC Ryder 2019, Swedish Polar Research Secretariat, 455 pp, ISBN 978-91-519-5132-4

Holmes FA, Kirchner N, Prakash A, Stranne C, Dijkstra S, Jakobsson M (2021) Calving at Ryder glacier, Northern Greenland. Journal of Geophysical Research: Earth Surface, 126, e2020JF005872. https://doi.org/10.1029/2020JF005872

Data description

The dataset consists of images files of the calving front of Ryder glacier.

The data were collected using a Canon Rebel T6 camera with an 18⁠ – 55 mm lens, controlled by a Digisnap Pro intervalometer. The camera system was visited twice for maintenance.

Note that the time when each photo was taken is shown in the computer's local time zone setting in the file time stamp, while it is given in UTC in the internal image metadata.

Images are stored as JPEG (.JPG) file.

Each JPEG file around 5 MB. The total size of the data set is about 700 GB.

Comments

Please cite the article by Holmes et al. (in preparation) when using images from this dataset.

The Ryder 2019 Expedition was an Explorers Club Flag Expedition carrying Flag #51. It was multidisciplinary with a broad range of data collected.