[dennis baker (OP)]

The boxing day tsunami did it newbielink:http://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_and_tsunami [nonactive]

the japan tsunami did it newbielink:http://www.popularmechanics.com/science/environment/natural-disasters/how-the-japan-earthquake-made-the-day-shorter [nonactive]

Will the redistribution of mass associated with the polar ice caps melting induce a shift in the planets rotation to achieve dynamic balance ?