In other earthquake news

Our science guy put us on the trail of this story; how the earthquake in Chile impacted the rotation of the earth and, hence, the "shortening" of each day.

The Time magazine site had a good explanation. I like their clarifying sports analogy at the end:

Earthquakes alter planetary speed in two ways. Shifting plates rearrange the distribution of the Earth's mass, causing it to bulge imperceptibly in spots it didn't bulge before and contract in others. That rearrangement should further shift the Earth's inclination, or figure axis (the axis around which the Earth's mass is balanced, which is slightly different from the north-south axis around which the Earth rotates) — in the case of the Chile earthquake, by about 3 inches. The law of conservation of angular momentum, however, requires that even under these exigent circumstances, the Earth's angular momentum stays constant, which means the planet must step on the gas (or the brake) to accommodate shifting mass. The same thing happened in 2004 with the 9.1 Sumatran earthquake that triggered the tsunami. That earthquake should have shifted the Earth's figure axis by 2.76 inches and shortened its day by 6.8 millionths of a second, according to computer models.

If the physics seems a bit arcane, consider that you probably spent much of the last two weeks seeing the angular momentum principle in action — at least if you watched the Olympics. Earthquakes change the Earth's rotation the same way a twirling figure skater changes hers — by extending or tucking her arms in, for instance, to slow down or speed up accordingly. The only difference is that the skater does so decidedly more elegantly.