New Zeland Geography
Just a small portion of a continent almost half of Australia’s size or approximately the size of Western Europe (almost four million square kilometers) most of New Zealand’s land area (continent) known as Zealandia is 93 per cent underwater.
The actual continent is uncommonly thin and long. It extends from the nineteenth degree latitude south (New Caledonia’s tropical north) up to fifty six degrees south (in NZ’s south in the austere islands of sub-antarctic).
The deep ocean basin floors consist of dense volcanic basalt rocks. These rocks are made on extending ridges in the center of bodies of oceans.
Ridges that spread have large cracks in the crust of the earth that squeeze out molten rock. These rocks cool and spread in outward direction on the ridge’s sides weaving its way across the floor basin. Moving at the same speed as the growth of a fingernail, the cooled rocks travel in the direction of the corners of the oceans. The further away they travel from the ridge. the heavier. colder. and older they become.
Upon reaching the boundary of the plate, the rocks on the ocean floor may subduct or sink into the interior of the earth. Continents are very stable as compared to ocean basins.
After the rocks have sunk into the interior of the earth, the residue that has deposited on the ocean floor for millions of years is scoured off onto the surface of the continent. Almost 10 times older than the most ancient oceanic rocks, continental rocks are mostly really old. Continents are actually formed over hundreds of millions of years. starting from sediments from the ocean that are painstakingly added to basin’s edge over a really long period of time. Generally. continents are twenty five to thirty kilometers thick. and are buoyant and light that they float on the mantle of the earth, that layer of rock that is semi-molten that lies beneath the crust of the earth. Because of the general thickness and bouyancy of continents. they usually ride high on the earth’s mantle. above the water level of oceans.
Because it is pushed by the continuously moving ocean basins, a large portion of New Zealand’s shallow sea beds are moving too. The seabed is ripped apart by submarine faults either oozing out hot fluids rich in minerals, push the seabed together to build a new mass of land, or tear it apart sideways. Movements of faults create earthquakes that cause submarine landslides a whole lot more intense than those that occur on land.
The continent of New Zealand is primarily made up of 2 virtually parallel ridges. These are mostly underwater and move towards the north-west through the Pacific Ocean’s southern region. Included in the western ridge are the Campbell Plateau and Lord Howe Rise. The eastern ridge is narrower and forms Norfolk Ridge, New Caledonia. the Chatham Rise. and the New Zealand Northland peninsula. Both the western and eastern ridges form a sea floor approximately a thousand to a thousand and a half meters deep. with the occasional rising above of rocky islets in the water. These new islands help outline the edge of the huge Exclusive Economic Zone of New Zealand.