Power of the earthquake
The total energy released by the earthquake in the Indian Ocean has been estimated as 2.0 exajoules (2.0×1018 joules)
[16]. This is enough to boil 150 litres (40 US gallons) of water for every person on Earth. It is estimated to have resulted in an oscillation of the Earth's surface of about 20 to 30 cm, equivalent to the effect of the tidal forces caused by the Sun and Moon.
[17] The shock waves of the earthquake were felt across the planet - as far away as Oklahoma, vertical movements of 0.12 in (3 mm) were recorded.
[18]
The shift of mass and the massive release of energy very slightly altered the Earth's rotation. The exact amount is yet undetermined, but theoretical models suggest the earthquake shortened the length of a day by 2.68 microseconds (2.68 µs) (or about one billionth of the length of a day) [19]
[19] due to a decrease in the oblateness of the Earth. It also caused the Earth to minutely "wobble" on its axis by up to 2.5 cm (1 inch) in the direction of 145° east longitude
[20],
[21]) or perhaps by up to 5 or 6 cm
[22]). However, due to tidal effects of the Moon, the length of a day increases by 15 µs every year, so any rotational speedup due to the earthquake will be quickly lost. Similarly, the natural Chandler wobble of the Earth can be up to 15 m (50 ft).
More spectacularly, some of the smaller islands southwest of Sumatra may have moved southwest by up to 20 m (66 ft). The northern tip of Sumatra, which is on the Burma Plate (the southern regions are on the Sunda Plate), may also have moved up to 36 m (118 ft) southwest. Movement was likely both vertical as well as lateral; some coastal areas may now be below sea level, making their reoccupation very unlikely. Measurements using GPS and satellite imagery are being used to determine the extent and nature of actual geophysical change.[23]
