Scientists say we could be witnessing the birth of a major new split in the tectonic plates that cover the Earth's surface.
They say evidence for this has come from earthquakes in Indonesia, the BBC reports.
The Indonesian island of Sumatra was sent into panic by two huge earthquakes on 11 April this year and the shaking from the biggest - a magnitude 8.7 - was felt across Asia.
Many thought it would generate a massive tsunami, but it didn't because the seafloor broke in a lateral motion that can't disturb the water above.
Scientists now believe the April quakes signal a breaking apart of the Indo-Australian tectonic plate - a vast slab of the Earth's exterior shell.
However, they stress it is not something that's imminent, as a full split is likely to take millions of years.
Scientists give the assessment in this week's Nature journal.