HOW HAS THE JAPAN EARTHQUAKE SHORTENED DAYS ON EARTH?
From a marine scientist perspective, we can understand how the earthquake was formed and what changes took place in the tectonic plates that were involved in the quake. The movement of the plates was due to subduction of the Pacific Plate under the Philippine plate and the friction resulted in an earthquake. Because the subduction was so abrupt, everything on the plates also shifted which decreased the diameter of the earth by a very small amount but still large enough to shorten the day slightly. This is explained further lower down using diagrams to illustrate the shifting of the plates.
The earth is divided in layers of different composition so different structures. The crust is the superficial layer therefore the one we are in contact with. It is divided in two main parts the oceanic crust and the continental crust(that forms the tectonic plates), they have respectively a density of 3g.mol-1 and 2.7g.mol-1. Considering these densities and the amount of the crust; we can easily come to the conclusion that the masses involved are huge and a small movement can change a lot of things as the axis the Earth
From the physics point of view, it was explained how a change in the diameter of the solid spherical earth causes a change in the earths's period, that is, the length of the day on earth.
From a marine scientist perspective, we can understand how the earthquake was formed and what changes took place in the tectonic plates that were involved in the quake. The movement of the plates was due to subduction of the Pacific Plate under the Philippine plate and the friction resulted in an earthquake. Because the subduction was so abrupt, everything on the plates also shifted which decreased the diameter of the earth by a very small amount but still large enough to shorten the day slightly. This is explained further lower down using diagrams to illustrate the shifting of the plates. The earth is divided in layers of different composition so different structures. The crust is the superficial layer therefore the one we are in contact with. It is divided in two main parts the oceanic crust and the continental crust(that forms the tectonic plates), they have respectively a density of 3g.mol-1 and 2.7g.mol-1. Considering these densities and the amount of the crust; we can easily come to the conclusion that the masses involved are huge and a small movement can change a lot of things as the axis the Earth
From the physics point of view, it was explained how a change in the diameter of the solid spherical earth causes a change in the earths's period, that is, the length of the day on earth.
A lower R(new) value (new radius) will give us a lower T(new) value (new period) and vice versa. This explains how, due to the reduced radius of the earth, the length of the day, that is, the Period of the earth was also reduced.
