Barrier Islandbarrage island
Greater Barrier Island (New Zealand)
Medlands area of Great Barrier Island at noon. The Great Barrier Island (GBI) is an island about 100 kilometres north east of New Zealand's Hauraki Gulf, located in the North Island of New Zealand. Aotea", known by the locals, is New Zealand's 6th biggest island.
Originally depleted for its richness in minerals and cauri tree species, the approximately 1,000 inhabitants now live mainly from farming and touring. GBI's rhythm of live is gradual, but his call to an old way of live isolates them from the turmoil of the outside environment.
Under little developmental pressures and almost 60% of its land under the leadership of New Zealand's Ministry of Conservation, GBI has largely preserved its night-time serenity. The isolation of the island from the shore by the Hauraki Gulf and the lack of electric current for exterior illumination protect these circumstances.
The typical darkness of the nightsky has become part of the island' s inhabitants' culture, as they begin to become conscious of the value of astro tourism, which consists in preserving the island' s largely untouched nightscape. The villagers now want to formalise the kind of practice they have been observing on a voluntary basis for decade-long periods and make the black nightsky over GBI a statute that deserves to be formally protected under the policy of the ruling Council of Auckland.
Effects of Mother Earth on Barrier Islands - Effects of Mother Earth on Barrier Islands
Accessible isles are always evolving. Wave - Surges continuously accumulate and move sediment away from the sea side of the island. Current - Streams created by diagonally encountering sea breezes can move the sands from one end of the island to the other. As an example, the sea current on the eastern US coastline tends to move away sands from the north ends of the barrier island and store them at the south ends.
Tide - The tide moves sediment into the saline meadows and finally fills them up. Thus, the soundwalls of barrier-sites are prone to be formed with the erosion of the ocean-sides. Wind - Winds are blowing sediment from the beach into the sand and swamps, contributing to their formation.
Changes in ocean floor height - Increasing ocean floor heights have a tendency to move barrier islets inland. Windstorms - Whirlwinds and other windstorms have the most tragic impacts on barrier isles, as they create flood plains and erosion sites and other parts of barrier isles. Windstorms affect barrier island depending on the characteristics of the windstorm (storm tide, waves) and the height of the barrier island on land.
The U.S. Geological Survey (USGS) has developed a "hazard scale" to measure the effects of windstorm damage: Inpact 1 - The shaft EDM is limited to the beaches. Eradicated sand is refilled in a few week to month and there is no significant system modification. Collision 2 - Shafts are eroding the dunes and causing the dunes to rear.
It is a semi-permanent or constant system modification. Collision 3 - The movement of the waves passes the height of the dunes, destroying the dunes and pushing sand out of the dunes towards land (approx. 300 yards/100 m), causing flooding. The system changes are driving the barrier islands towards land. Effpact 4 - The tide fully covered the barrier island, destroyed the dunes system and pushed sand deposits landwards (approx. 0.6 miles/1 km).
It is a constant modification of the barrier island or parts of it. Maps of coastal hazards.