Regional variations in the shapes and mechanical properties of ocean basins mean that this can sometimes be far higher in parts. The Arctic Ocean, for example, has had its barystatic sea level rise underestimated by up to 1 millimeter (0.04 inches) per year.
Pushing down the oceanic crusts of every single major oceanic basin in the world is no small feat, and it’s something that will worsen over time as climate change continues to accelerate. At the very least, it’s masking just how badly we’re affecting the planet, and this study attempts to pull away this veil for the first time.
Calculating such a major geological change isn’t easy either. In order to do this, the team used the best estimates possible of how much land-based ice and water is making its way into the oceans. They plugged these numbers into a series of computer models and watched as their virtual oceans bent and pushed at the creaking oceanic crust.
“To increase the accuracy of sea level estimates, the effect of ocean bottom deformation should be taken into account,” the researchers stress in their study.
They suggest using a satellite system similar to the now-terminated GRACE mission. By detecting small localized changes in gravity, the barystatic sea level rise could be properly quantified.
Far stranger things are happening to the planet due to this redistribution of water. As noted by a 2016 study, it’s also altering how Earth rotates on its axis. The northern end of this rotational axis – the North Pole, essentially – is drifting eastwards as a result, and it’s heading toward London.