official data

IERS: Earth's pole still wandering — Chandler/annual wobble measured, not a reversal

Aug 27, 2026, 11:11 PM EDTLane: ecdo

The International Earth Rotation and Reference Systems Service (IERS) publishes daily polar motion: two coordinates, x and y, that locate Earth’s rotation axis relative to the crust. The Rapid Service product finals2000A.daily gives Bulletin A final values for 27 August 2026 (Modified Julian Date 61279): x = 0.212992 arcseconds, y = 0.342431 arcseconds. Those numbers are Earth-orientation measurements. They are not a geomagnetic reversal, a crustal flip, or proof of ECDO.

IERS Earth Orientation Centre plot of polar motion since 2006, with a 180-day prediction in yellow — IERS Earth Orientation Centre Figure 1: polar motion since 2006 (Chandler wobble plus the annual wobble), with a 180-day prediction in yellow. Official IERS illustration of the motion — not a Doom Signals plot, not a reversal forecast, and not a substitute for the dated x/y snapshot above. File hosted by IERS EOP-PC. IERS Earth Orientation Centre

Product date: Aug 27, 2026 (MJD 61279)
x-pole: 0.212992 arcseconds
σ(x): 0.000091 arcseconds
y-pole: 0.342431 arcseconds
σ(y): 0.000091 arcseconds
Type: Bulletin A final (not a prediction row)

The motion of the rotation axis of the Earth relative to the crust is represented by the Earth Orientation Parameter x and y. It has two major components: (i) a free oscillation with period about 435 days (Chandler wobble) and (ii) an annual oscillation forced by the seasonal displacement of air and water masses.
IERS Earth Orientation Centre, polar motion page

Chandler wobble is the free wobble of Earth’s rotation axis relative to the crust. The IERS Earth Orientation Centre describes it as a free oscillation with a period of about 435 days. IERS’s useful-constants table lists the Chandler period in the terrestrial frame as 433.1 ± 1.7 mean solar days (Vicente and Wilson 1997, as cited by IERS). This site does not invent an amplitude or a single exact period.

Polar motion is the combination

What IERS measures day to day is polar motion: the combination of Chandler wobble, an annual wobble forced mainly by seasonal air and water-mass shifts, and smaller terms (including a slow drift of the mean pole). The daily x and y in finals2000A.daily are that combined series, in arcseconds, not a Chandler-only amplitude.

This snapshot (IERS, 27 Aug 2026)

Product: finals2000A.daily (IAU2000A), IERS Rapid Service / Prediction Centre.
Bulletin A final (type final, not prediction) for 27 August 2026, MJD 61279.
x-pole = 0.212992 arcseconds (sigma 0.000091); y-pole = 0.342431 arcseconds (sigma 0.000091).
The ASCII product file on the IERS datacenter was last modified 27 Aug 2026, 1:15 PM EDT (17:15 UTC).
URL: https://datacenter.iers.org/products/eop/rapid/daily/finals2000A.daily

What this is not

This is not a pole-reversal forecast. The World Magnetic Model (WMM) is a separate NOAA National Centers for Environmental Information (NCEI) navigation model of the main geomagnetic field; it is not a reversal clock. Geomagnetic Kp from NOAA’s Space Weather Prediction Center (SWPC) is a separate space-weather index. Official Earth-orientation data stays separate from the ECDO hypothesis tracked on this lane.

Why it matters

Polar motion is a routine geodetic series. Some ECDO and pole-reversal discussions treat Chandler wobble as a countdown. Official IERS x and y are where the rotation axis sits relative to the crust on that date. They do not confirm a magnetic reversal, a true polar wander event, or ECDO. ECDO remains a tracked hypothesis, not proven science, and is kept off this official-data note. The pole is not nailed in place; the official x/y series is that wander, not a countdown to a flip.

Sources

Official data. Not a forecast. Endtimes badge not used on this note.

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