GEOGRAPHIC RESEARCH - The Coastal Environment of Muriwai
Use the information on this page to help you become familiar with Muriwai and Maori Bay AND to help you with your research.
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On the right is a glossary of words related to Coastal Environments. Refer to it online. DO NOT print it, as it is 57 pages long!!
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Processes at Muriwai
GEOLOGICAL PROCESSES
Formed 15 – 22 million years ago 20km off the present day coast.
Had diameter of 50km and was 3000km high (sea bed to summit.
Today’s Waitakere Ranges are the eroded remnants of this volcano.
A distinctive geological feature at Muriwai is the pillow lava in the cliffs above Maori Bay.
Pillow lava is the rock type formed when lava emerges from an underwater volcanic vent or a lava flow enters the ocean.
Formed 15 – 22 million years ago 20km off the present day coast.
Had diameter of 50km and was 3000km high (sea bed to summit.
Today’s Waitakere Ranges are the eroded remnants of this volcano.
A distinctive geological feature at Muriwai is the pillow lava in the cliffs above Maori Bay.
Pillow lava is the rock type formed when lava emerges from an underwater volcanic vent or a lava flow enters the ocean.
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LONG SHORE DRIFT
| long_shore_drift.doc |
SALTATION
| saltation_diagram.docx |
AEOLIAN PROCESSES
Animation of erosion at the coast. - click here.
Animation of Corrasion - click here.
Corrasion/abrasion is when waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff. It is
the most effective and rapid form of shoreline erosion.
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Corrosion is the dissolving of rock by carbonic acid in sea water. Carbonic acid is a name given to solutions of carbon dioxide in water. Carbonic acid slowly dissolves away minerals in rock, especially the carbonate minerals that make up limestone and marble. The rock is broken down by the crystallising salt spray to create a powdery surface that looks like a layer of dust on the rock. This is also called FRITTERING
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Hydraulic Action
Air may become trapped in joints and cracks on a cliff face. When a wave breaks, the trapped air is compressed which weakens the cliff and causes erosion |
OTHER INFORMATION
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Extra information about coastal environments (and ideas for research) - click here.
Videos about Muriwai
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Coastal Field Work Resources
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Examples of field work in a Coastal Environment - click here How to create a beach profile - click here |
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