Operational iceberg A68 monitoring with remote sensing and information services

Abstract

Iceberg A68 is a supersized iceberg that calved from Larsen C Ice Shelf in July 2017. The area of Iceberg A68, when it was calved from the ice shelf, was about 5800 square kilometers which accounts approximately for 12% of the area of Larsen C Ice Shelf. Iceberg A68 is currently the largest iceberg in Antarctica. Due to the split with Iceberg A68, the flow velocity of Larsen C Ice Shelf may change, which can change the oceanic outflow of the ice sheet and cause a change to the sea level. In addition, the occurrence of a supersized iceberg can affect the surrounding marine ecosystem and the sea ice forms, so continuous and constant monitoring for the iceberg is necessary. The Korea Polar Research Institute (KOPRI) have monitored Iceberg A68 and the changes in the surrounding environment by using satellite remote sensing and provided the iceberg information from the satellites through a web-based services. High-resolution SAR image enables precise surface observation without being affected by weather conditions and sun altitudes. Changes in the area and drift of Iceberg A68 are monitored by using Sentinel-1 and KOMPSAT-5 SAR images. The split with iceberg A68 may result in a change in the ice flow velocity of Larsen C Ice Shelf. The flow velocity of Larsen C Ice Shelf is monitored by offset tracking of Sentinel-1 SAR images. Using CryoSat-2 altimetry observations, changes in the thickness of iceberg A68 is monitored. The thickness is estimated by using the freeboard height of the iceberg observed monthly through the satellite altimeter. This provides basic information that can be used in various research fields such as predicting global environmental change, sea-level change, oceanography, biology, and glaciology through the satellite observations of the iceberg A68.