This continues the trend of earthquakes making Earth less oblate. Less oblate means more round. They also found the earthquake decreased the length of the day by 2.68 microseconds. (A microsecond is one millionth of a second.) In other words, Earth spins a little faster than it did before. This change in spin is related to the change in oblateness. It's like a spinning skater drawing arms closer to the body resulting in a faster spin. None of these changes have yet been measured--only calculated. But Chao and Gross hope to detect the changes when Earth rotation data from ground based and space-borne sensors are reviewed. Editor's note: The earthquake discussed in this story spawned deadly tsunamis that killed many tens of thousands of people and left an even greater number hurt and homeless.