Natural Features

Natural Features

1. Shark Alley- 2km long, 50m wide. Sheltered by Motuotau Is. and Moturiki Is. Wave refraction decreases erosion at shark alley- less steep profile than Mt. beach. Volcanism process + wave process

2. Mount Maunganui- Rhyolite lava dome. 2-5 million years old, 232m tall. East side has a wave cut platform formed by erosion. Soft material (soil layer) eroded away revealing hard rhyolite layer. interaction between volcanism and errosion. deposit of sand around mount is limited due to high wave erosion.

3. Moturiki Is. - Rhyolite rock, approx 3om tall. blow hole formed through abrasion and hydraullic action. main process- wave erosion. interaction- volcanism and erosion.

4. Tombolo- 20m long, 5m wide. deposition process- long shore drift (LSD), wave refraction, lack of beach erosion (sheltered from volcanism process). Interaction- deposition & volcanism & lack of wave erosion.

5. Mount Main Beach- 600/700m long, 60m wide. sand= quartzo-feldspathic from ancient eruptions. waves enter beach undisturbed by volcanic features = larger fetch than shark alley. constructive waves in summer, destructive in winter. Long shore drift occurs. more steep profile than S.A because of direct erosion from swell. deposition mainly from Kaimais. interaction- deposition & wave process

6. General beach- prevailing swell direction N.E. Prevailing wind during tropical cyclones is N.E. Predominant off-shore winds SW. Beach cusps= horns are made up of coarser finer material and the bays have finer sediment. wave crests rise at 1km from shore= decrease in wave length, slows down. linear patter of coast/dunes=linear patter on waves.