what caused the tsunami in the indian ocean
2004 Indian Ocean earthquake and tsunami The 2004 Indian Ocean earthquake occurred at 00:58:53 UTC on 26 December with the epicentre off the west coast of Sumatra, Indonesia. The shock had a moment magnitude of 9.1–9.3 and a maximum Mercalli intensity of IX (Violent). The undersea megathrust earthquake was caused when the Indian Plate was subducted by the Burma Plate and triggered a series of devastating tsunamis along the coasts of most landmasses bordering the Indian Ocean, killing 230,000–280,000 people in 14 countries, and inundating coastal communities with waves up to 30 metres (100 ft) high. It was one of the deadliest natural disasters in recorded history. Indonesia was the hardest-hit country, followed by Sri Lanka, India, and Thailand.
2011 Tōhoku earthquake and tsunami The earthquake took place at 14:46 JST (UTC 05:46) around 67 km (42 mi) from the nearest point on Japan's coastline, and initial estimates indicated the tsunami would have taken 10 to 30 minutes to reach the areas first affected, and then areas farther north and south based on the geography of the coastline.[127][128] Just over an hour after the earthquake at 15:55 JST, a tsunami was observed flooding Sendai Airport, which is located near the coast of Miyagi Prefecture,[129][130] with waves sweeping away cars and planes and flooding various buildings as they traveled inland.[131][132] The impact of the tsunami in and around Sendai Airport was filmed by an NHK News helicopter, showing a number of vehicles on local roads trying to escape the approaching wave and being engulfed by it.[133] A 4-metre-high (13 ft) tsunami hit Iwate Prefecture.[134] Wakabayashi Ward in Sendai was also particularly hard hit.[135] At least 101 designated tsunami evacuation sites were hit by the wave.[136]