1 upvotes, 2 direct replies (showing 2)
View submission: Is the Earth rotating faster?
Does melting of glaciers have any noticeable (edit: in the graph, not in person of course!) effect? Melting results in the water being at lower altitude than before, which should reduce the Earth's moment of inertia slightly, right?
Comment by dukesdj at 04/08/2022 at 17:05 UTC
1 upvotes, 1 direct replies
A person would not notice it but we can measure length of day variation. We can point at processes and say "that will alter the length of day due to xyz mechanism" and we can measure the length of day variation. However, the measured length of day variation is the combination of all relevant processes. So it would be very difficult to quantify how much each process contributes in an accurate way. Even if you know exactly how much ice has melted it is difficult to know where it has been distributed. One could use the hydrostatic approximation but then you have to include to bathymetry and potentially other effects such as salinity and temperature. I imagine the error bars would be much larger than the measured change!
Comment by bluesbrother21 at 05/08/2022 at 19:14 UTC
1 upvotes, 0 direct replies
I can't comment on the specific impact on rotational speed, but the melting of polar ice caps has resulted in a measurable movement of mass from the poles to lower latitudes, which should slow down the rotation slightly. I'd imagine the movement of mass from high-altitude glaciers to lower altitudes would have a lesser effect than the larger-scale movement of water in the oceans.