Tsunami
Sea level readings indicated that a tsunami was generated. A total of 4 tsunami alerts were issued in 24 hours. After the first, and largest, earthquake, the Pacific Tsunami Warning Centre issued a tsunami alert for much of the Indian Ocean basin. A tsunami approximately 1 metre high was reported at Padang, Indonesia. A small tsunami, some 15 cm high, was reported at the Cocos Islands. Sumatra was taken off tsunami alert after two hours.
Tsunami warnings were also issued in India and other countries around the Indian Ocean soon after the earthquake. The Government of India asked the states of Tamil Nadu, Kerala, Andhra Pradesh and the union territories of Andaman and Nicobar Islands and Puducherry to be on high alert. By late 12 September, the tsunami warning was recalled. Similarly, a tsunami alert was issued in Peninsular Malaysia at 20:50 (local time) for the coastal areas of Perlis, Kedah, Perak and Penang; the alert was lifted two hours later. However, Malaysian authorities had detected a 1-3m high tsunami heading away from the epicenter of the earthquake.
Read more about this topic: September 2007 Sumatra Earthquakes