<story><title>Humans have pumped enough groundwater to change the tilt of the Earth</title><url>https://e360.yale.edu/digest/groundwater-depletion-earths-axis</url></story><parent_chain><item><author>mjfl</author><text>2 trillion tons = 1&amp;#x2F;3 of 1 billionth of the mass of the earth. the distance from the ground to the surface is around 5 millionths of the radius of earth (like 100ft)&lt;p&gt;So you&amp;#x27;re talking about a change in angular momentum that is on the order of 10^(-20) times the angular momentum of earth (mr^2 \omega).&lt;p&gt;A change in the pole of earths rotation by 31 inches (10^(-7) times the radius of earch) corresponds to a change in angular momentum on the order of 10^(-14). So we seem to be off by 7 orders of magnitude.&lt;p&gt;I call bullshit.</text></item></parent_chain><comment><author>adrian_b</author><text>Your computation is very wrong, as explained in the actual research paper and in another comment here. The water is not moved only from under the ground to the surface and the effect on the axis is not due to raising, but mainly to horizontal movement.</text></comment>
<story><title>Humans have pumped enough groundwater to change the tilt of the Earth</title><url>https://e360.yale.edu/digest/groundwater-depletion-earths-axis</url></story><parent_chain><item><author>mjfl</author><text>2 trillion tons = 1&amp;#x2F;3 of 1 billionth of the mass of the earth. the distance from the ground to the surface is around 5 millionths of the radius of earth (like 100ft)&lt;p&gt;So you&amp;#x27;re talking about a change in angular momentum that is on the order of 10^(-20) times the angular momentum of earth (mr^2 \omega).&lt;p&gt;A change in the pole of earths rotation by 31 inches (10^(-7) times the radius of earch) corresponds to a change in angular momentum on the order of 10^(-14). So we seem to be off by 7 orders of magnitude.&lt;p&gt;I call bullshit.</text></item></parent_chain><comment><author>wcoenen</author><text>&amp;gt; &lt;i&gt;the distance from the ground to the surface is around 5 millionths&lt;/i&gt;&lt;p&gt;The water from aquifers is not just lifted a short distance up to the surface. It is used, ends up in rivers, and spreads around the world&amp;#x27;s oceans. And the places where we are pumping groundwater are not uniformly distributed around the Earth. We are essentially moving mass to the Pacific.</text></comment>