Land tides

1996/10/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Geologia

The soil at our feet twice a day ascends and falls about thirty centimeters, due to the oscillations that the Moon produces when attracting the elastic zone of our planet. The total surface of the Earth supports these rises, but we do not feel them.

Richard Ray and his NASA collaborators analyze these land tides by measuring very weak perturbations affecting geodesic satellites. It is calculated that the oscillations of the Earth occur about 40 seconds after the force it exerts. This delay is due to the viscosity of our Earth.

However, in the oscillation a huge amount of energy is consumed: 83.000 megawatts. It is a huge amount, but, however, in the tides of the Oceans 30 times more energy is lost.