LOWER HUTT, NEW ZEALAND — The hidden continent of Zealandia has fascinated scientists ever since the mid-1990s. Now, researchers from GNS Science in New Zealand have mapped the submerged land mass in great detail, showing how tectonic and seismic activity have shaped its evolution.
The islands of New Zealand and New Caledonia are the only visible remnants of Zealandia, which was declared a distinct geological continent in a 2017 paper published in the Geological Society of America’s journal.
Zealandia is a fragment of the supercontinent Gondwana, which began to separate from the northern supercontinent Laurasia around 180 million years when the Atlantic Ocean formed between what are now North America and Africa.
Zealandia separated from Gondwana beginning in the Late Cretaceous period. It is argued that it is a continent because it possesses a distinct and well-defined area and is composed of continental crust, not oceanic crust.
However, as it began its journey eastward, most of it slid beneath the ocean. Today, 94 percent of Zealandia is submerged. Its highest point is Aoraki, or Mount Cook, in New Zealand, at 3,724 meters, or 12,218 feet.
GNS Science is a geoscience research and consultancy organization owned by the government of New Zealand.
In a statement, Nick Mortimer, a geologist and lead author of the maps, said:
"We’ve made these maps to provide an accurate, complete and up-to-date picture of the geology of the New Zealand and southwest Pacific area — better than we have had before," he said. "Their value is that they provide a fresh context in which to explain and understand the setting of New Zealand’s volcanoes, plate boundary and sedimentary basins."
