No. They can occur in any body of water, and are actually more common in the Pacific. It is only that the worst tsunami in living memory occurred in the Indian Ocean. The Pacific actually had a tsunami warning system decades before the Indian Ocean did.
There are two main reasons. First, at the time, there was no tsunami warning system for the Indian Ocean, only for the Pacific. Second, most people, even most educated Western tourists, did not know the warning signs of a tsunami.
Pacific Ocean
The Pacific Ocean has the most tsunami warning centers because it is the most seismically active ocean. These warning centers help monitor and track seismic activity that could potentially generate tsunamis in the Pacific region.
The Indian Tsunami Early Warning Centre (ITEWC) is located in Hyderabad, India. It is operated by the Indian National Centre for Ocean Information Services (INCOIS) and serves as the primary agency responsible for detecting and issuing tsunami warnings for the Indian Ocean region.
The Pacific Tsunami Warning System is located in Honolulu, Hawaii. It is operated by the National Oceanic and Atmospheric Administration (NOAA) and provides monitoring and warnings for tsunamis in the Pacific Ocean region.
It could be in Japan. Because in Japan had often Tsunami
The Pacific Tsunami Warning Center is headquartered at Ewa Beach, Hawaii, USA. It has responsibility for most of the Pacific Ocean. It has responsibilities for receiving and analysing input from all tsunami monitoring stations and making the projections and ultimately issuing warnings. It is the operational headquarters for the Pacific Tsunami Warning System. It is one of two warning systems operated by the US National Oceanic and Atmospheric Administration (NOAA).
No, the 2004 Indian Ocean tsunami did not hit Molokai in Hawaii. Molokai is located in the central Pacific Ocean and was not affected by the tsunami.
There are two reasons. First, tsunamis are not as common in the Indian Ocean as they are in the Pacific, which has had a warning system since 1949. This meant there was less motivation to build such a system. Second, the Indian Ocean is surrounded largely by countries that are not well economically developed and likely were unable to build such a system. The Pacific, by contrast, is bordered by a number of wealthy nations, most notably the United States, Canada, and Japan.
No. At the the time there was no tsunami warning center in the Indian Ocean. They received no warning. The first indication anyone in Indonesia got was the ocean receding before the tsunami struck, but most people did not know that this was a sign of a tsunami.
Seismometers or earthquake sensors placed near fault zones. They do not make a judgment that a tsunami is coming, but indicate that it is possible. The tsunami's travel across deep water almost invisible, but generate astounding heights when coming ashore in shallow water. That is why some warnings are issued and no tsunami appears. It takes certain things to happen to generate a tsunami.