Living with Earthquakes - Earthquake Engineering for Structural Design - page 62

The World's third strongest of 9.0 M recorded earthquake as magnitude (after
Chile and Alaska earthquakes), the 2004 Indian Ocean earthquake (Wikipedia,
nd) (also called Great Sumatra-Andaman earthquake) occurred in one of the most
seismically active zones on Earth (Fig. 2.18), the West coast of Sumatra, due to the
subduction of the India tectonic plate under the Eurasia tectonic plate. The
earthquake caused major damage to buildings and infrastructure, predominantly in
North Sumatra. But the great disaster was caused by the tsunami, whose origin was
due to the fact that the epicenter was located in the open sea. It catastrophically
affected Indonesia, Sri Lanka, India, Thailand and the Maldives. Damage and
deaths were also produced on the East African coast (Somalia, Tanzania, and
Kenya) and in Bangladesh, Burma, the Seychelles and Malaysia. The great number
of fatalities was mainly due to the lack of an alarm system. It is very interesting to
notice that the following 2005 great earthquake, which occurred practically in the
same place, with a magnitude close to that of the 2004 earthquake (see Table 2.5),
did not give any sign of a possible tsunami.
Interplate
subduction
fault
(a)
Figure 2. 18 (continues)