The Earth´s rotation turns more slowly, and not every day are the same
length, producing speed variations for different reasons. The most influential
is that the Moon by its gravitational effect and especially by tidal movements
it causes is gradually slowing the speed of rotation of our planet at an
average of approximately 55 nanoseconds per day.
There are other imbalances that advance or delay the Earth sporadically, in
cases such as earthquakes, hurricanes and even thaws. For example, according to
a further analysis of NASA, the Japanese earthquake that devastated Fukushima,
produced several effects, the axis shifted 10 cm land, moved the Japanese
island 2.4 meters and 1.6 microseconds accelerated rotation Earth globe.
But the greatest influence until today dynamic measurement corresponds to
the earthquake that triggered the Indian Ocean tsunami of 2004, with an
acceleration of 6.8 microseconds in the Earth's rotation.
For humanity today, we rely increasingly on technology and its accuracy is
vital to maintain the accuracy and especially the coordination of time, for
which we use 3 different temporal coordinates, UT1, the TAI and UTC is known
that we know and handle, and 3 must be perfectly coordinated.
