Avatele Oneonepata Beach is a White Sand Beach at Niue.
White sand beaches are very seldom on this island, because of the vulcanic orign most beaches are black sand beaches.
Take a look around and I'll tell you something about building a beach.
At first glance, the sand looks like a large soft mass - in fact, it is made up of tiny rocks that have been used to grind the sea and its elements into fine grains over thousands of years. Waves carry rock constantly from the bottom of the sea to the coast, and that against the current.
The length of the waves determines, from which depth of water sand is washed to the beach. In Niue they can be over 50 meters long, so they dig much deeper than short waves. Whether the beach is constructed of coarse or fine sand determines the slope on the seabed off the coast. The lower the inclination, the smaller the stones. The current throws the stones to the shore, rubbing them there even finer and smaller, to grains of sand with a diameter of 0.063 to two millimeters.
The type of rock or mineral finally decides what color the beach has: In Niue, the beach-goers have to the sand grain size crushed remains of coral and shells under their feet. The white dream beaches are made of lime.
No matter what color he has, a sandy beach always looks the same. But in fact he is constantly changing his face: waves are breaking down over him, wind, rain and sun are closing in on him.
The four sections of most beaches
Swash zone: is alternately covered and exposed by wave run-up.
Beach face: sloping section below berm that is exposed to the swash of the waves.
Wrack line: the highest reach of the daily tide where organic and inorganic debris is deposited by wave action.
Berm: Nearly horizontal portion that stays dry except during extremely high tides and storms. May have sand dunes.
Erosion at Avatele Oneonepata Beach
Where volcanism is adding material, erosion takes it away again.
Types of erosion are:
- fluvial erosion - e.g. rivers cutting their own valleys
- glacial erosion - by glaciers
- aeolian erosion - wind blowing away sand and dust
- marine erosion - caused by surf and breakers
Quartz at Avatele Oneonepata Beach
Quartz is a mineral composed of silicon and oxygen atoms in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.
Quartz crystals are chiral, and exist in two forms, the normal α-quartz and the high-temperature β-quartz. The transformation from α-quartz to beta-quartz takes place abruptly at 573 °C (846 K). Since the transformation is accompanied by a significant change in volume, it can easily induce fracturing of ceramics or rocks passing through this temperature limit.
There are many different varieties of quartz, several of which are semi-precious gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings.
Sustainable Coastal Development policy in Niue
This policy explicitly addresses the coastal area as a system that has natural and human aspects and components that are inter-related and dependent on one another. The diversity and productivity of coastal ecosystems is interwoven with the safety and growth of livelihoods and development for the people of Niue.
Year after year, large parts of the few beaches are eroded away by erosion, waves and wind and washed into the sea. Effective coastal protection here on Avatele Oneonepata Beach should counteract this.
Tasks:
1. Describe the sections of the beach with your own words! Can you discover the area where shells and fossilized corals lie? What is this area called? Is it a fine sandy beach or rather grainy?
2. Describe in your own words how it came to this erosion. Will the erosion go on?
3. What kind of coastal protection the government of Niue installed here at the beach to prevent (or slow) further erosion? (Little help: look on the right side of the bay). Are there also natural geological barriers in the water? (Little help: look on the left side of the bay).
4. A picture of your team, your mascot or GPS at Avatele Oneonepata Beach is mandatory.
You are welcome to log your answers straight away but please message or Email me with your answers. I'll let you know if anything is unclear. Please don't forget: the answers must be received within 10-14 days or the log may be deleted.
There is an information sign, but it is not needed to answer the questions.
Caution: It is not necessary to go or swimm at Avatele Oneonepata Beach to answer the questions, even if it is worth. Swimming and snorkelling is possible during low tide.
Enjoy your stay