A group of scientists from 12 countries has returned from a nine-week exploration of the seafloor between New Zealand and Australia to learn more about the mysterious sunken continent called Zealandia. A paper published by a team of geologists brought the existence of Zealandia to the fore when they argued that an eighth continent exists below sea level. The result of the recently-concluded seafloor analysis is now hoped to unveil new insights into the Earth’s history.
What is Zealandia and what is the expedition about?
Geologists and researchers have been pushing for Zealandia’s recognition as a continent in the past 20 years. According to the Guardian, the term was first coined by geophysicist and oceanographer Bruce Luyendyk in 1995. However, it was the latest paper published in GSA Today that further solidified claims of Zealandia being the lost eighth continent. Co-author Nick Mortimer said that their study is the first peer-reviewed scientific paper on Zealandia.
Zealandia has much of its landmass buried 3,280 feet below sea level. According to Fox News, among the evidence presented to back claims of Zealandia’s existence is the shallow crust that makes up the continent, which is much shallower than its surrounding ocean crust. Its geological makeup is similar to that of a continent than an oceanic crust. Moreover, there’s a narrow strip of oceanic crust between Australia and Zealandia, which means these two landmasses were split apart.
Following the exploration, Jamie Allan, program director of the U.S. National Science Foundation’s Division of Ocean Sciences, described Zealandia as a “sunken continent long lost beneath the oceans.” It is said to hold untapped information about the Earth’s history. Through scientific ocean drilling, scientists aim to uncover many of the Earth’s 60 million-year-old secrets.
Among the particular fields scientists are looking at include “mountain-building in New Zealand to the shifting movements of Earth’s tectonic plates to changes in ocean circulation and global climate.”
Researchers drilled as far as 860 meters below the sea floor in six different areas all over Zealandia.
Fossil specimens gathered
The team managed to gather 8,000 specimens and around a hundred fossils by drilling through ice cores. Gerald Dickens, the co-chief scientist of the expedition, reported the discovery of microscopic shells of organisms that lived in warm, shallow waters as well as spores and pollen from plants that used to grow on land, which means Zealandia wasn’t originally thousands of feet underwater.
Why did Zealandia sink?
It was suggested that Australia, Zealand, and Antarctica formed one mega-continent some 100 million years ago. Rupert Sutherland, a co-chief scientist of the study, noted that it was generally suspected that Zealandia started to sink around 80 million years ago when it broke off from Australia and Antarctica. Its current geological landscape was shaped by significant volcanic activity that took place between 40 million and 50 million years ago.
Linking the past and the future
The data gathered from the Zealandia exploration will help develop global climate models and improve predictions on changes in climate.
[Featured Image by World Data Center for Geophysics & Marine Geology/Wikimedia Commons Public Domain]