Source: GNS Science
The maps cover the bathymetry (shape of the ocean floor) and the tectonic origins of Earth’s eighth continent – the 5 million square kilometre Te Riu-a-Māui / Zealandia on which New Zealand sits.
They can also be accessed through a new interactive website called E Tūhura – Explore Zealandia (TEZ) – http://data.gns.cri.nz/tez. TEZ is designed for exploring onland and offshore geoscience data in and around Te Riu-a-Māui / Zealandia.
“These maps are a scientific benchmark – but they’re also more than that. They’re a way of communicating our work to our colleagues, stakeholders, educators and the public,” lead author of the maps, geologist Dr Nick Mortimer says.
“We’ve made these maps to provide an accurate, complete and up-to-date picture of the geology of the New Zealand and southwest Pacific area – better than we have had before.
“Their value is that they provide a fresh context in which to explain and understand the setting of New Zealand’s volcanoes, plate boundary and sedimentary basins.”
The TEZ website presents a wealth of maps, graphics and other information on the continent compiled in GNS Science research programmes.
Programme Leader Vaughan Stagpoole says TEZ provides the perfect way for users to explore geoscience data from the comfort of their homes or offices.
“Users can zoom and pan around different thematic geoscience webmaps of the region. They can readily view and interrogate the maps and turn layers on or off. They can also query features in the layers and generate custom maps of their own,” Dr Stagpoole says.
As more research results become available, GNS Science will update the maps and add more information to the interactive website.
The authors of the maps are Nick Mortimer, Belinda Smith Lyttle, and Jenny Black. The project team for the TEZ website is Phil Scadden, Andrew Boyes, Vaughan Stagpoole and Jenny Black.
The tectonic map
This highlights the 5 million sq km Te Riu-a-Māui / Zealanda continent, a small part of which is on land, but most of which is under the sea. The colours show continental crust in red, orange, yellow and brown hues and oceanic crust in blues. Island arc crust is pink and large igneous province crust is green. (A large igneous province is a large accumulation of igneous rocks resulting from magma travelling through the crust towards the surface).
The bathymetric map
This map uses the GEBCO 2019 grid, the first output of the Seabed2030 project which is a global initiative to map the ocean floor of the entire world by 2030. The project is a collaboration between The Nippon Foundation in Japan and the General Bathymetric Chart of the Oceans (GEBCO). NIWA, GNS Science and Land Information New Zealand are jointly leading the South and West Pacific Ocean Regional Data Assembly and Coordination Centre, based in Wellington.
Availability of maps
Copies of the printed maps are available either as flat or folded at $15 each ($25 the pair). PDF files can be downloaded at no cost. Both maps and PDFs are available through the GNS Online Store. An accompanying GNS Science Report 2020/01 lists the data sources used to compile the map posters. The GIS layers from the posters are also available through the TEZ interactive website.
E Tūhura – Explore Zealandia interactive website http://data.gns.cri.nz/tez
This consists of three maps with multiple layers. The Geoscience data webmap shows a compilation of research data. Geology layers include GNS Science’s 1:250 000 onland geology and Petlab database sample locations. Users can add further layers to customise their maps.
The Tectonic webmap displays interpretations of the types and age of crust, major faults, plate and microplate boundaries, plate motion vectors, subducting slab depths, basement geology, and sedimentary basins. It also shows locations of ancient and modern volcanoes.
The Bathymetric web map shows the shape of the solid land and seabed in a seamless colour scheme with a hillshade background. It also depicts coastlines, territorial limits and names of major undersea features.