Is it true our earth become smaller?

Technicly...yes it did, by a tiny fraction. What happened was when the two geological plates slipped causeing the earth quake..one slipeed down ward and under the other, shrinking the over all circumference. this in effect shortened toe rotation of the earth by 2 tenths of a millsecond. Another thing that happend as a result of the earthquake was the sudden displacement of the crust jarred the planet and tipped it by 3 inches. It's almost an unoticable difference in terms of astronimical size though Similar things have happened a number of times with other large earth quakes such as the Sumatra earthquake in 2004, the large quake in chile in 1960 and other notable enrmous quakes. It's just earth doing what earth does and really nothing to be worried about. We'll just have to start recalibrating our gps system a lttle to match it all.