On April 2016, a NASA research came to declare that Earth’s irregular rotation not due to melting of ice sheets, but other droughts across planet. They calculated how much mass was involved in water cycling between Earth’s land areas and its oceans from 2003 to 2015, and the extent to which the mass losses and gains pulled and pushed on the spin axis. Around the year 2000, Earth’s spin axis took an abrupt turn toward the east and is now drifting almost twice as fast as before, at a rate of almost 17 centimeters (7 inches) a year.
I beg to differ with the outcome of NASA research as variations in water and ice levels have been the constant norm all the time without a tangible impact on the Earth axis of rotation getting drifted or wobbled. In my research and as explained on the Earth Magnets page of this site https://planet-earth-2017.com/the-true-source-of-earth-magnetic-field/, I came to conclude that although there is an induced south polarity magnetic fields at each of the Northern and Southern pole regions due to the Outer Core helically flowing electrons, there is also a presence of a stronger dipole magnetic field, and that the source of such a dipole magnet can only be the Inner Core. Under extreme pressure and high temperature, the Inner Core became ductile and its two magnetic poles are not synchronously aligned to each other at the geo pole regions of Earth. In other words, the imaginary line connecting the two magnetic poles does not pass through the centre point of Earth.
According to http://wdc.kugi.kyoto-u.ac.jp/poles/polesexp.html, the magnetic pole in the North has moved from 81.0N-109.6W in the year 2000 to 86.4N-166.3W in the year 2016. And, the magnetic pole in the South has moved from 64.7S-138.3E in the year 2000 to 64.2S-136.4E in the year 2016. As both magnetic poles keep moving eastward, it is expected that the centre of gravity of the Inner Core to also move to the east. Such a move could explain why the spin axis has drifted to the east as quoted by NASA: “a massive eastward drift of our axis over past 16 years”. A precise comparison of the eastward movement of the centre of gravity of the Inner Core where density is 13 gm/ cm3 to the rebalance of ice and water where the density is a mere 1 gm/ cm3, could tell which one of us is correct.