Adrian Luckman

@adrianluckman.bsky.social

Polar scientist studying ice dynamics using satellite data. I create and share animations of icy activity from satellite images

More than 30 years of satellite observations reveal changing glacier dynamics in Svalbard ❄️ By combining @esa.int Heritage Mission data with modern satellite observations, researchers found glacier surge frequency in Svalbard has increased threefold since 2015. earth.esa.int/eogateway/su...

Heritage data uncover glacier surges across Svalbard - Earth Online

Decades of archived radar data from ESA’s Heritage missions, combined with recent satellite measurements, are shedding new light on the dynamics of Svalbard’s glaciers.

earth.esa.int

End days for Iceberg A23. The two largest remaining fragments - A and K - had major blowouts on or just after the 28th of March. The largest chunks are ~50 sq km. A23 calved from the Filchner-Ronne Ice Shelf in 1986. Quite the journey it's had over four decades.

2 April. A23k after fragmentation event (Nasa)2 April. A23a after fragmentation event (Nasa)

The last two big fragments of the once mighty A23 iceberg. The US National Ice Center calls the bottom-left object A23k and the top-right, A23a. Its latest report (20/3/26) said both were about 140 sq km. Latitude is roughly 50 deg S.

Image by Nasa/Terra/Modis 26/3/2026

Thwaites Eastern Ice Shelf heading for collapse. Monthly average velocities Jan 2025 to Feb 2026 derived from EU Copernicus Programme Sentinel-1 SAR data. Grounding lines in black and yellow from NASA MEaSUREs

Iceberg A23a today (17 Feb). A totally clear sky. Utterly stunning. Still refusing to die. Still 500 sq km in area. Image from the Modis instrument on the venerable Aqua satellite, another oldie that's still plugging away.

Iceberg A23a, 17 Feb 2026, Aqua/Modis

💥 Boom! And it's just happened. The huge volumes of meltwater that had collected on the surface of iceberg A23a have triggered a massive and catastrophic hydrofracture event. Much of the berg has turned to mush. Three major segments remain, the largest about 500 sq km.

NASA Aqua Modis 11 January

One big paddling pool becomes three. Today's view of iceberg A23a (left) and a view from the end of December (right). Notice how the raised rim effect, holding in surface meltwater, has re-established on all three main segments of the broken berg. A23a is turning to slush puppie.

NASA Modis

Check out this time-lapse video of waves eroding an ice front from an experiment conducted in our cryogenic wave tank at the University of Wisconsin-Madison. The tank is housed in a walk-in freezer, and the waves are precisely controlled. This video captures about an hour of wave erosion.

Jakobshavn Isbrae (Ilulisat Glacier) produces 10% of Greenland's icebergs (Wikipedia). Ten years of @esa.int Copernicus #Sentinel-1 SAR data shows ice pouring into Baffin Bay. Winter advance and summer retreat of the ice front show how calving is controlled by seasonal freeze-up of fjord ice melange

Sentinel-1 has finally got a clear view of iceberg A23a (13/6/25). The berg is much diminished as it skirts around South Georgia. And the US National Ice Center has updated its stats: A23a is now only the world's second biggest berg at 829.79 sqNM, or 2846,11 sqKM.

PolarView 13/5/25

Nested glacier surges! This is Liestolbreen in Svalbard, surging into Nathorstbreen (which itself surged from 2008), and then being surged into by Doktorbreen. All brought to you by the magic of Sentinel-1 SAR

The movement of iceberg A23a over the past seven days. It's moved about 80km to the southeast of the position where it grounded off the coast of South Georgia in early March. Zoomed in animation from Meteosat-12.

With days shortening at South Georgia (it's about 8 hours from sunrise to sunset), optical satellite coverage in the region is getting more restricted. Not so for Meteosat, which images the Europe/Africa hemisphere regardless of season. Hence we get a few views of iceberg A23a. Still grounded.

Meteosat view of South Georgia and iceberg A23a. 30/5/25

There was a spectacular view of iceberg A23a on 3 May. Clear skies over the berg and South Georgia. By my measurement, A23a is no longer the world's biggest iceberg. At ~2850 sq km, it's now bested by D15a - but only just. The US National Ice Center will be the final judge on the matter.

Iceberg A23a on 3 May. Copernicus / Sentinel-3

The journey of Iceberg A23a (largest, oldest, 'living' berg) since the beginning of 2024, as seen by NASA MODIS, including its five-month pirouette on the Taylor Column, short embrace by the pack ice in August, grounding on South Georgia's shelf in April, and baby calf. Watch this space for updates!