Tracking the world's biggest iceberg by BBC News

The world's biggest iceberg - more than twice the size of Greater London - is on the move. A23a, as it’s known, broke away from the Antarctic coastline way back in 1986, yet for more than three decades, it remained stuck in the Weddell Sea, anchored to the seafloor. It recently broke free, embarking on a remarkable 2,000-mile journey across the Southern Ocean, an odyssey that has captivated scientists and researchers alike.

This feature chronicles A23a’s incredible voyage, using satellite imagery to track its movements through one of the most remote and hostile regions on Earth. In the absence of ground-based observations, satellite imagery became our indispensable tool. We used iceberg tracking data from the US National Ice Center, but also digitised dozens of optical and radar satellite images (one per month) to complement this dataset. This was then animated with one frame per month, as to show the actual journey with the iceberg rotating and speeding up. The basemap shows bathymetry data (seafloor topography) to highlight how the iceberg follows the seafloor ridge of the Antarctic Peninsula.

In another animated video, historic iceberg tracking data is used to show the usual journey of icebergs, and how they are pushed by ocean currents to disintegrate and melt next to South Georgia island.

Through a series of graphics, this piece aims to convey the sheer size of the iceberg, larger than 29 different countries. 3D style illustrations delve into the mechanics of its formation, highlighting the forces that shaped it over decades, and the gradual erosion it now faces, weathered by relentless waves, wind, and temperature changes as it is moving northward.

This weekend long read feature used innovative and creative data visualisations to report on an otherwise forgotten part of the world.