New research suggests the mountainous island of Oahu, in Hawaii, will one day be flat.
Geologists at Brigham Young University say groundwater beneath the island's mountains is "dissolving" the island from the inside, and this, combined with the usual erosion mountains experience from streams on their exterior, means they will eventually disappear.
"We tried to figure out how fast the island is going away and what the influence of climate is on that rate," said geologist Steve Nelson.
"More material is dissolving from those islands than what is being carried off through erosion."
Eventually the mountains are likely to completely dissolve, flattening the island. Although plate tectonics is pushing Oahu northwest, causing it to slowly rise in relation to sea level over the next 1.5 million years, the groundwater will "eventually triumph and the island will begin its descent to a low-lying topography".
The results of the two-month study have been published in journal Geochimica et Cosmochimica Acta.