According to a recent study published in Tectonics, scientists have completed the mapping of Zealandia, a largely submerged continent located below the Pacific Ocean roughly between New Caledonia and New Zealand. Zealandia covers an area of approximately 1.9 million square miles, nearly half the size of Australia. Only 5 percent of the continent is above water. The continent was first discovered seven years ago, but this study has provided a comprehensive map of its boundaries.

By analyzing rock samples and magnetic maps, researchers were able to gain insights into how Zealandia formed and separated from nearby landmasses. The granite samples collected from the northern portion of Zealandia contained zircon crystals, which hold valuable information about the continent’s geology. Through radiometric dating, scientists determined that these crystals formed around 100 million years ago, coinciding with the breakup of the supercontinent that once contained Zealandia.

Magnetic mapping was also used to provide a broader understanding of Zealandia’s shape and structure. The researchers found that highly magnetic rocks were aligned with fracture zones in the oceanic crust, indicating the stretching of the supercontinent’s crust prior to the breakup. This analysis helped confirm Zealandia’s geological connection to Antarctica and Australia.