It is called D15A, it covers 3,037 square kilometres, and it is parked off the East Antarctic coast at 66.63 degrees south, 81.93 degrees east. That is bigger than Luxembourg. It was last fixed by the US National Ice Center on 7 August 2026, and it is the largest of the 33 icebergs on that list today.
The biggest icebergs on Earth are always Antarctic, because only Antarctica has ice shelves wide enough to shed a slab the size of a small country in one piece. Greenland produces more bergs and smaller ones. So the answer to the world question comes from a southern list, and the list is public, free and updated weekly.
The top of the list
| berg | km² | where it is |
|---|---|---|
| D15A | 3,037 | 66.6 S, 81.9 E |
| B22A | 1,423 | 69.0 S, 172.1 E |
| A81 | 1,342 | 59.5 S, 50.8 W |
| C36 | 848 | 67.5 S, 146.5 E |
| D15B | 611 | 67.0 S, 81.6 E |
All 33 together come to 12,324 square kilometres. D15A alone is 24.6% of that. Add its three siblings, D15B, D15C and D15D, and the one family accounts for 3,820 square kilometres, close to a third of every tracked berg in the Southern Ocean. Iceberg area is not spread across a list. It sits in a handful of monsters and a long tail of rubble.
What the names mean
The letter is the quadrant of Antarctica the berg calved from. A is 0 to 90 degrees west, B is 90 to 180 west, C is 180 to 90 east, D is 90 east back round to 0. The number is the order in which the bergs of that quadrant were first tracked, and a trailing letter marks a fragment. So D15A is the first surviving piece of the fifteenth berg logged in the Indian Ocean sector, and its siblings D15B, D15C and D15D are three more.
The letter records where a berg was born, not where it is. B22A calved in the Amundsen Sea sector, which is the B quadrant, and today it sits at 172 degrees east, most of the way round the continent in the other direction. Read the name as a birth certificate rather than an address.
Of the 33 bergs on the list, 23 are separate families and five of those families have split. D15 and D33 have four surviving pieces each, B22 has three, B09 and C18 have two. Nearly a third of the list is debris from five original calvings.
What "tracked" means, and why it matters to the answer
The US National Ice Center list is a threshold list. A berg gets a name and a weekly position fix once it is big enough to matter to a ship, and it drops off when it breaks up or melts below that size. So "the largest iceberg in the world" is precisely "the largest berg currently large enough to be tracked", and a berg leaving the list is not the same event as a berg ceasing to exist.
This is why the title changes hands in jumps rather than smoothly. A berg does not shrink its way out of first place. It fractures, and the next one down inherits. The D15 family is the visible evidence: one calving, four surviving pieces, of which the largest still tops the world list and the smallest would not make the top ten.
It also means "largest iceberg in the world" is a weaker claim than it sounds, and anyone quoting it should say which list they mean and on what date. The published area carries two decimal places, D15A is logged as 3,037.47 square kilometres, which is more precision than the edge of a fracturing ice slab really supports, and the position is a single point for an object tens of kilometres across. Both are perfectly good for the job they exist to do, which is keeping ships away from them. Neither is a laboratory measurement and we do not round them as though they were.
Ten days of fixes, and almost no movement
We have been storing a daily snapshot of this list since 1 August, which lets us ask something the raw file cannot answer: how fast do these things actually move? Over eight snapshots from 1 to 10 August, 17 of the 33 bergs have exactly one position and 16 have exactly two. D15A is in the first group. It has not moved at all, and neither has its area.
That is mostly an artefact of the refix cadence rather than of the ice. Positions are updated about weekly, so ten days of daily snapshots can only ever contain one or two distinct fixes per berg. It is a displacement, not a track. Another three or four weeks of snapshots turns it into a path, and until then we are not drawing arrows and calling them drift. The honest statement today is that we have two dots for half the fleet.
Why a berg is not sea ice, and the mix-up is common
An iceberg is glacier ice. It fell as snow on the continent, was compressed over centuries, flowed to the coast and broke off, so it was already displacing its own weight of ocean the moment it floated. Sea ice is frozen sea water, a metre or two thick, forming and melting every year. The 16 million square kilometres of sea ice around Antarctica this month dwarfs the 12,324 square kilometres of tracked bergs by three orders of magnitude, and the two numbers answer different questions. Sea ice is a climate signal you can read weekly, which is why the daily extent figure is the number this site leads with. A berg is a single event with a name.
Both are on the live polar map, and every tracked berg has its own page here, including D15A. The underlying feed is the US National Ice Center tabular iceberg list, which is a plain CSV, needs no key, and is the same file every news story about a record iceberg is ultimately quoting.