A 15-year circum-Antarctic iceberg calving dataset derived from continuous satellite observations

• Published in: Earth System Science Data
• Main Authors: M. Qi, Y. Liu, J. Liu, X. Cheng, Y. Lin, Q. Feng, Q. Shen, Z. Yu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: geo; envir; Antarctic; The Antarctic; Antarc*; Ice Sheet; Ice Shelf; Ice Shelves; Iceberg*
• Online Access: https://doi.org/10.5194/essd-13-4583-2021; https://essd.copernicus.org/articles/13/4583/2021/essd-13-4583-2021.pdf; https://doaj.org/article/71c72b4f99aa483ca15722ffdf11008e

Iceberg calving is the main process that facilitates the dynamic mass loss of ice sheets into the ocean, which accounts for approximately half of the mass loss of the Antarctic ice sheet. Fine-scale calving variability observations can help reveal the calving mechanisms and identify the principal processes that influence how the changing climate affects global sea level through the ice shelf buttressing effect on the Antarctic ice sheet. Iceberg calving from entire ice shelves for short time intervals or from specific ice shelves for long time intervals has been monitored before, but there is still a lack of consistent, long-term, and high-precision records on independent calving events for all of the Antarctic ice shelves. In this study, a 15-year annual iceberg calving product measuring every independent calving event larger than 1 km2 over all of the Antarctic ice shelves that occurred from August 2005 to August 2020 was developed based on 16 years of continuous satellite observations. First, the expansion of the ice shelf frontal coastline was simulated according to ice velocity; following this, the calved areas, which are considered to be the differences between the simulated coastline, were manually delineated, and the actual coastline was derived from the corresponding satellite imagery, based on multisource optical and synthetic aperture radar (SAR) images. The product provides detailed information on each calving event, including the associated year of occurrence, area, size, average thickness, mass, recurrence interval, and measurement uncertainties. A total of 1975 annual calving events larger than 1 km2 were detected on the Antarctic ice shelves from August 2005 to August 2020. The average annual calved area was measured as 3549.1 km2 with an uncertainty value of 14.3 km2, and the average calving rate was measured as 770.3 Gt yr−1 with an uncertainty value of 29.5 Gt yr−1. The number of calving events, calved area, and calved mass fluctuated moderately during the first decade, followed by a dramatic ...