From UPSC perspective, the following things are important :
Prelims level : Zealandia
Mains level : Zealandia and its features
A new map has revealed the lost continent of Zealandia.
The ocean relief can be divided into various parts such as Continental Shelf, Continental Slope, Continental Rise or Foot, Deep Ocean basins, Abyssal plains & Abyssal Hills, Oceanic Trenches, Seamounts and Guyots.
Revise these ocean bottom relief features from your basic references.
Also revise India’s Deep Ocean Mission.
- Zealandia — or Te Riu-a-Māui, as it’s referred to in the indigenous Māori language — is a 2 million-square-mile (5 million square kilometres) continent east of Australia, beneath modern-day New Zealand.
- Scientists discovered the sprawling underwater mass in the 1990s, then gave it formal continent status in 2017.
- Still, the “lost continent” remains largely unknown and poorly studied due to its Atlantean geography.
- It is a group of submerged pieces of crust that separated from the ancient supercontinent Gondwana about 85 million years ago.
- Gondwana was formed when Earth’s ancient supercontinent, Pangea, split into two fragments.
- Laurasia was transformed into North America, Asia, and Europe, while Gondwana became Africa, South America, Australia, and Antarctica.
- But land masses continued to be rearranged afterwards, with Zealandia breaking off Gondwana.
Data revealed by the new map
- The new maps reveal Zealandia’s bathymetry (the shape of the ocean floor) as well as its tectonic history, showing how volcanism and tectonic motion have shaped the continent over millions of years.
- Data for the bathymetric map was provided by the Seabed2030 project — a global effort to map the entire ocean floor by 2030.
Why call it a continent?
- Zealandia was classified as a “microcontinent,” as the island of Madagascar, until 2017.
- But according to Mortimer, it has all the requirements to be classified as a continent.
- It has defined boundaries; it occupies an area of over one million square kilometres and is elected above the ocean crust.