The Seabed 2030 project is a collaboration between the Nippon Foundation in Japan and the internationally backed General Bathymetric Chart of the Oceans.
The work will be coordinated by four regional centres around the globe, with NZ's National Institute of Water and Atmospheric Research, GNS Science, and Land Information New Zealand jointly governing the south and west Pacific Ocean regional data assembly and coordination centre.
The centre will be based at NIWA in Wellington and look after an area equivalent to a quarter of the world's oceans, covering the Pacific Ocean from South America to Australia, north of latitude 50 degrees south to 10 degrees north of the Equator and the western part of the northern Pacific Ocean to Japan.
The area includes the world's two deepest trenches - the Mariana and Kermadec trenches, both of which are more than 10km deep.
The aim of the project is to combine all existing bathymetric data into a unified database, promote efforts to collect new data on the ocean floor and generate maps of all ocean floor features larger than 100m.
Less than 15% of the world's ocean floor is adequately mapped, Nippon Foundation said.
The foundation said the project was aiming for 100% coverage by 2030 by compiling data from around the globe and turning it into publicly available digital maps. The project will also identify gaps where data is lacking.
It plans to contribute $18.5 million for the first 10 years of the project.
"The topography of the ocean floor is far less known than the surfaces of Mercury, Venus, Mars, and the moons of several planets including Earth's," the foundation said this week.
Knowledge of the shape of the seafloor is crucial for understanding ocean circulation patterns that distribute heat between the tropics and the poles - a key component of Earth's climate system.
Detailed measurements of ocean depth were also crucial for modelling tsunami inundation of coastal areas.
Ocean bathymetry is also important for the study of tides, wave action, sediment transport, underwater geohazards, fisheries management, military applications, cable and pipeline routing, oil and gas exploration and the establishment of sovereign rights over the seafloor, which can be particularly important for resolving disputes such as that between Australia and East Timor over the Greater Sunrise fields.
NIWA marine geologist Dr Geoffroy Lamarche said the work would require close collaboration and involvement of all coastal states coordinated by the centre.
"Such information is critical to enable coastal states to properly manage and protect the benthic (at and near the seafloor) environment from the coast to the greatest abyssal depths of the ocean," he said.
NIWA and GNS Science have a strong shared experience of working on international projects.
Between 1996 and 2007 they led the New Zealand Continental Shelf Project for the successful submission to the UN Commission on the Limits of the Continental Shelf.
As a result, NZ has sovereign rights over more than 5.7 million sq.km of ocean floor, the fourth largest area in the world as defined by the Exclusive Economic Zone and Extended Continental Shelf.
GNS marine geoscience manager Dr Vaughan Stagpoole said NZ's participation in the project would help develop international collaborations and lead to technological innovation for mapping in areas where data could not be collected efficiently using existing technologies.
"Already, 24 government and research organisations, institutions, universities, and businesses around the world have agreed to participate in this project, and this number is expected to grow significantly," Stagpoole said.