Reid Wiseman / NASA
Earth has a concealed continent called 'Zealandia'
hidden in the Pacific Ocean and attached to New Zealand, according
to newly published research.
A team of 11 researchers found that New Zealand and New Caledonia
are actually part of a huge 4.9 million sq-km (1.89 million
square-mile) single slab of continental crust that is separate from
The study (Zealandia
- Earth's Hidden Continent), published by the
Geological Society of America, found that the region is 94
percent submerged, mostly as a result of crustal thinning before the
supercontinental break-up, using upgraded satellite-based elevation
and gravity map technology.
"The scientific value
of classifying Zealandia as a continent is much more than just
an extra name on a list," the scientists wrote.
"That a continent can
be so submerged yet unfragmented makes it a useful and
thought-provoking geodynamic end member in exploring the
cohesion and breakup of continental crust."
Simplified map of
Earth's tectonic plates and continents,
The team says it should be considered a geological continent, rather
than the previously-held theory that it was a collection of
continental islands and fragments.
"Based on various
lines of geological and geophysical evidence, particularly those
accumulated in the last two decades, we argue that Zealandia is
not a collection of partly submerged continental fragments but
is a coherent 4.9 Mkm2 continent," the study
As geologists count
Europe and Asia as one giant continent called 'Eurasia',
the new addition of Zealandia brings the total number of official
geologic continents to seven.
Spatial limits of Zealandia.
Zealandia's crust thickness typically ranges from 10 to 30km (six to
19 miles) and is roughly the size of India.
It's believed to have
broken off from Antarctica about 100 million years ago, and then
again from Australia about 80 million years ago.
Researchers behind the study are calling Zealandia a "realization"
rather than a "discovery", as New Zealand has been considered a
continent in its own right by some experts in the field for years.
"This is not a sudden
discovery but a gradual realization; as recently as 10 years ago
we would not have had the accumulated data or confidence in
interpretation to write this paper," the study's authors wrote.
"Zealandia illustrates that the large and the obvious in natural
science can be overlooked."