Great Barrier Island lies in the outer Hauraki Gulf, New Zealand, 100 kilometres (62 mi) north-east of central Auckland. With an area of 285 square kilometres (110 sq mi) it is the sixth-largest island of New Zealand and fourth-largest in the main chain. Its highest point, Mount Hobson, is 627 metres (2,057 ft) above sea level. The local authority is the Auckland Council.
Barrier islands are coastal landforms and a type of dune system that are exceptionally flat or lumpy areas of sand that form by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action, but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend uninterrupted for over a hundred kilometers, excepting the tidal inlets that separate the islands, the longest and widest being Padre Island of Texas. Sometimes an important inlet may close permanently, transforming an island into a peninsula, thus creating a barrier peninsula. The length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range, wave energy, sediment supply, sea-level trends, and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.
The Hauraki Gulf / Tīkapa Moana is a coastal feature of the North Island of New Zealand. It has an area of 4000 km2, and lies between, in anticlockwise order, the Auckland Region, the Hauraki Plains, the Coromandel Peninsula, and Great Barrier Island. Most of the gulf is part of the Hauraki Gulf Marine Park.
The Coromandel Peninsula on the North Island of New Zealand extends 85 kilometres (53 mi) north from the western end of the Bay of Plenty, forming a natural barrier protecting the Hauraki Gulf and the Firth of Thames in the west from the Pacific Ocean to the east. It is 40 kilometres (25 mi) wide at its broadest point. Almost its entire population lives on the narrow coastal strips fronting the Hauraki Gulf and the Bay of Plenty. In clear weather the peninsula is clearly visible from Auckland, the country's biggest city, which lies on the far shore of the Hauraki Gulf, 55 kilometres (34 mi) to the west. The peninsula is part of the Thames-Coromandel District of the Waikato region.
Waitematā Harbour is the main access by sea to Auckland, New Zealand. For this reason it is often referred to as Auckland Harbour, despite the fact that it is one of two harbours adjoining the city. The harbour forms the northern and eastern coasts of the Auckland isthmus and is crossed by the Auckland Harbour Bridge. It is matched on the southern side of the city by the shallower waters of the Manukau Harbour.
Moturoa / Rabbit Island is a small island that lies across the southernmost part of Tasman Bay / Te Tai-o-Aorere, on the northern coast of New Zealand's South Island. The long narrow island runs east–west for 8 kilometres (5 mi), and covers 15 km2 (5.8 sq mi).
Cape Colville is the northernmost point of the Coromandel Peninsula in New Zealand's North Island. It lies 85 kilometres north of Thames, and 70 kilometres northeast of the city of Auckland, on the other side of the Hauraki Gulf. The small settlements of Port Jackson and Fletcher Bay lie immediately to the west and east respectively of the cape.
The Colville Channel is one of three channels connecting the Hauraki Gulf with the Pacific Ocean to the northeast of Auckland, New Zealand. It is the easternmost channel, lying between the southern end of Great Barrier Island and Cape Colville at the northern tip of the Coromandel Peninsula. The tiny Channel Island lies in the centre of the channel.
The Mercury Islands are a group of seven islands off the northeast coast of New Zealand's North Island. They are located 8 kilometres (5 mi) off the coast of the Coromandel Peninsula, and 35 kilometres (22 mi) northeast of the town of Whitianga.
The Jellicoe Channel is one of three channels connecting the Hauraki Gulf with the Pacific Ocean to the northeast of Auckland, New Zealand. It is the westernmost channel, lying between Cape Rodney on the North Auckland Peninsula and Little Barrier Island.
Little Barrier Island, or Hauturu in Māori language, lies off the northeastern coast of New Zealand's North Island. Located 80 kilometres (50 mi) to the north of Auckland, the island is separated from the mainland to the west by Jellicoe Channel, and from the larger Great Barrier Island to the east by Cradock Channel. The two aptly named islands shelter the Hauraki Gulf from many of the storms of the Pacific Ocean.
The Mahurangi River is a tidal estuary in northern New Zealand that widens into the Mahurangi Harbour before opening into the outer Hauraki Gulf. The Mahurangi Harbour is accessible by all craft and is a sheltered anchorage in all weathers with many small bays and islands. The river itself is extremely tidal and ranges in depth from below approximately 50 centimetres (20 in) at the channel entrance to approximately 150 centimetres (59 in) further upstream. At high tide, the river is accessible by larger craft.
Mount Hobson is the highest mountain on Great Barrier Island, New Zealand. Located in the centre of the island, it rises 627 m (2,057 ft) above sea level.
Cuvier Island is a small uninhabited island off the east coast of the North Island of New Zealand. It lies on the seaward end of the Colville Channel, 15 km (9.3 mi) north of the Mercury Islands and approximately 23 km (14 mi) south-east of Great Barrier Island. The 195 ha island is a wildlife sanctuary, managed by the Department of Conservation and is the subject of an ongoing island restoration project to eliminate non-native mammals and restore the original ecosystem. It is also the location of the Cuvier Island Lighthouse which was constructed in 1889 and the wreck of the old HMNZS Philomel which was scuttled near the island on 6 August 1949 after decommissioning and being stripped of useful equipment.
The Wairahi River is a river of New Zealand's Great Barrier Island. It is the only river on the island — the island's other watercourses all having names ending is "stream". The Wairahi flows generally west, roughly paralleling the island's long southwestern shore, from its origins north of Whangaparapara Harbour. A walking track from Whangaparapara to Port Fitzroy follows the river for part of its length.
Harataonga Bay is a coastal feature and area on the northeast coast of Great Barrier Island in New Zealand's Hauraki Gulf, approximately 51 nautical miles northeast of central Auckland. Most of the area is in the Harataonga Recreation Reserve, with some of the hinterland forming the Harataonga Scenic Reserve.
Hapua is the Māori term for river-mouth lagoons on mixed sand and gravel (MSG) beaches which form at the river-coast interface where a typically braided, although sometimes meandering, river interacts with a coastal environment that is significantly affected by longshore drift. The lagoons which form on the MSG coastlines are common on the east coast of the South Island of New Zealand and have long been referred to as hapua by the Māori. This classification differentiates hapua from similar lagoons located on the New Zealand coast termed waituna. Hapua are often located on paraglacial coastal areas where there is a low level of coastal development and minimal population density. Hapua form as the river carves out an elongated coast-parallel area, blocked from the sea by a MSG barrier which constantly alters its shape and volume due to longshore drift. Longshore drift continually extends the barrier behind which the hapua forms by transporting sediment along the coast. Hapua are defined as a narrow shore-parallel extensions of the coastal riverbed. They discharge the majority of stored water to the ocean via an ephemeral and highly mobile drainage channel or outlet. The remainder percolates through the MSG barrier due to its high levels of permeability. Hapua systems are driven by a wide range of dynamic processes that are generally classified as fluvial or marine; changes in the balance between these processes as well as the antecedent barrier conditions can cause shifts in the morphology of the hapua, in particular the barrier. New Zealand examples include the Rakaia, Ashburton and Hurunui river-mouths.
Okiwi is a small settlement and rural community at the head of the Whangapoua Estuary, in Whangapoua Bay, on Great Barrier Island in New Zealand's Hauraki Gulf.
The 2021 Kermadec Islands earthquakes were a series of earthquakes with magnitudes of 8.1 and 7.4 that occurred at 19:28:31 UTC on 4 March 2021. The epicentres were located southeast of Raoul Island in the Kermadec Islands, part of the New Zealand outlying islands. The main magnitude 8.1 earthquake was preceded by a magnitude 7.4 foreshock and followed by a magnitude 6.1 aftershock. A separate, unrelated magnitude 7.3 earthquake occurred off the coast of the North Island of New Zealand, approximately 900 km to the south, several hours before the main quakes. As of January 2022, there have been thousands of aftershocks, with more than a dozen of them exceeding magnitude 6.
