Elements at muriwai for use with the muriwai workbook.

1. Elements at Muriwai
Pg 16 and 17

2. ELEMENTS
CURRENTS
• Strong rip currents due to high energy beach
• Force of waves sideways affect seafloor
TIDES
• Highest tide is 4.3m (compared to 3.3m at St Leonards)
• Occurs when sun and moon are in line and the gravitational pull is the
greatest (full moon)
SEDIMENT
• 2 main types – black iron sand (titanomagnetite) and lighter coloured
white sand (quartz and feldspar). Only 5% produced by erosion, majority
brought in by longshore drift from volcanic regions in the South
• Iron sand is smaller in diameter (0.25mm) compared to quartz grains
(0.5mm)
• Both are light enough to be picked up by the wind

3. ELEMENTS
ROCK TYPE
• The headland is composed of Manuka Breccia which is a
conglomerate (mixture) of sandstone with volcanic intrusions
BIOTA
• Headland vegetation is pohutukawa, manuka trees and flax
which have adapted to extreme weather conditions
• Sand dunes have minimal vegetation. Spinifex, pingao and
marram grass grow on the dunes trapping sediment
• Endangered tohera shellfish beds
• Gannet colony on Motutara Stack
• Fur seals on Oaia Island

4. WATER ELEMENTS

5. LAND ELEMENTS

6. CLIMATIC ELEMENTS

7. BIOTIC ELEMENTS

8. Wind Rose pg 17
• A wind rose is a diagram that tell us information about wind in
an area. It tells us
– Direction of wind
– Force or speed of wind
– How long the wind blew at that speed/direction

9. How to draw a wind rose pg 17
• Draw a small circle (or an octagon if you prefer) in
the middle of page or area given
• Mark in your 4 main compass points with dashes
• Calculate a scale e.g. 1cm = 5 knots
• Draw a key e.g.
3-15 knots
Over 15 knots
• Rule out bars in the direction wind blew for the
length of time (%) it blew. Shade in bar the
appropriate wind speed

10. Climate Graph pg 18
• Plot the information given in the table at the
top of page 18 on to the climate graph outline
• Look for some reminders of appropriate
conventions of a climate graph on the next
slide….

11. Left hand axis
shows temp,
axis is
labelled with
degrees
celsius
Title includes
LOCATION and
GRAPH TYPE
Points for the temperature are
plotted in the MIDDLE of a column
and joined with a SMOOTH curve
Temperature is
shown using a
LINE graph and is
done using RED
Right hand
axis shows
rainfall. Axis
is labelled
with mm
Rainfall is shown using a BAR graph
and is shaded in BLUE
Months are represented down the
bottom with a letter

12. Significance of climate
• Below the climate graph write 2-3 sentences
describing the significance of climate to the
natural environment at Muriwai.