Scientists prepare to drill into ‘lost continent’ Zealandia
A $120 million drilling programme into the sea floor around New Zealand will reveal the massive natural forces at work, and help explain how the mostly underwater continent of Zealandia formed.
Scientists from around the world are to join their New Zealand colleagues on six voyages during the next 18 months on 143-metre long international research ship Joides Resolution. Its drill can get to depths of 8235m below the ocean surface.
The research is being funded by the 23-nation International Ocean Discovery programme, which operates the ship.
The first voyage, which starts next week and takes two months, will drill six holes under the Tasman Sea to learn about how one tectonic plate starts being subducted under another.
‘‘This expedition will answer a lot of lingering questions about Zealandia,’’ said expedition cochief scientist Gerald Dickens, professor of Earth, environmental and planetary science at Rice University, in Texas.
Drilling will be done at depths ranging from 1000-5000m, with cores being collected from 300-800m into the sea floor. The cores will contain samples of sediments deposited over millions of years, and will include fossils that can be used to assemble a detailed record of Zealandia’s past.
The expedition will examine a shift that happened about 50 million years ago in the direction of movement of the enormous Pacific Plate northeast of Zealandia. The expedition refers to this shift as ‘‘the most profound subduction initiation event and global plate-motion change’’ in the past 80 million years.
The research could also answer many questions about the way Earth’s climate evolved in the past 60 million years, Dickens said.
GNS Science said other expeditions in the research programme included voyages to:
Target slow-slip earthquakes and submarine landslides off the coast of Gisborne.
Investigate seafloor hydrothermal systems at Brothers volcano northeast of Bay of Plenty, where highly acidic fluids at more than 300 degrees Celsius are belching into the ocean.
Probe the seafloor off the Ross Ice Shelf to improve understanding of the stability of the West Antarctic Ice Sheet through cycles of warming and cooling during the past 20 million years.