Why did the island of tebua disappear under the pacific ocean?

Answer 1

Longer explanation:

Its easy to say rising sea level, but no way to prove it without doing geodetic measurements (which have not been done) and there are very valid geologic reasons why the subsidence of Tebua under the sea may not be related to change in sea level. This island is constantly cited as a casualty of rising sea level by those who do not take the time to understand the geology of islands like Tebua.

All of the Cook Islands were formed by volcanic activity. As volcanoes get older, especially seamounts, they move off of the hot spot that formed them and begin cooling. As they cool, they shrink. Even the Hawaiian islands experience this and the island of Kauai is known to be sinking gradually as it moves away from the Hawaiian hotspot. Some Pacific Islands have built up hundreds of feet of coral deposits that are formed by coral reefs growing upward at the same rate that the volcanic mountain underneath them subsides. Seismic measurements on Bikini Atoll showed that 1.8 km of coral reef had accumulated as the volcanic rocks beneath the island sank.

One reason that many of the atolls in the Pacific are arc shaped or even circular in shape with a deep lagoon in the middle is that they formed on the tops of volcanoes. These volcanoes are no longer active and have sunk beneath the sea leaving only the rim of the volcanic crater exposed. This is what has formed the island, and in most cases, will continue to subside. They will eventually subside below sea level and then they will depend on the growth of coral reefs to keep them from subsiding even deeper. In the case of Tebua, it is a future location of a coral reef.

See the related link.

So, it can be said that it is rising sea level, but one cannot say it isn't sinking land, which is a totally different story. By ignoring the natural cycle of volcanic islands that always includes significant subsidence, the stories that claim this island is being drowned by rising sea levels are only telling half of the story.

Shorter explanation:

Rising sea Levels