Dents in Earth's gravitational field due to plumes

 作者:殳谥箅     |      日期:2019-03-06 08:15:12
ANCIENT pieces of continental crust that are falling to the bottom of the Earth’s mantle could explain mysterious dents in our planet’s gravitational field. The Earth’s field is not uniform because of density variations inside the planet. Weaknesses in the field are believed to be created by “slab graveyards” – ancient pieces of crust and sediment that were pushed down into the Earth when plates collided and are now falling through the mantle. The slabs are denser than the mantle and so have a stronger gravitational pull. As they fall, however,