WE ARE HERE
WE ARE HERE A N AT L A S O F A O T E A R OA C HR I S M C D OWA L L & T I M D E N E E
Contents
A Place for Maps
10
Te Whenua Introduced by Dan Hikuroa
12
Water and Air Introduced by Veronika Meduna
36
Living Things Introduced by James Russell
60
Places Introduced by Ben Schrader
82
People Introduced by Tze Ming Mok
114
Government Introduced by Andrew Geddis
142
Movement and Energy Introduced by Patrick Reynolds
168
Heart and Memory Introduced by Nadine Anne Hura
196
Afterword 220 Appendix One: Tools and Software
222
Appendix Two: Technical Notes and Data Sources
223
Contributors 234 Acknowledgements 236 Index 238
Te Whenua
Drowned Continent
16
Te Waipounamu
18
Te Ika-a-MÄ ui
20
Deep Earthquakes
28
Rock Ages
22
Most Ancient Rocks
24
Origins and Faults
26
Shallow Earthquakes
30
The Sinking City
32
Land Cover
34
Lightning Strikes
40
Rivers and Channels
42
Wet and Dry
44
Dry Spells
48
Scale of Irrigation
50
Rising Temperatures
52
Water and Air
A Year of Weather
46
Te Whenua An examination of Aotearoa’s physical form and foundations. Landscapes moving in slow motion, with occasional sudden lurches.
Origins and Faults Rocks form in three main ways. Igneous rocks form when melted rock cools and crystallises. Sometimes magma solidifies in the Earth’s crust and later finds its way to the surface through geological uplift or erosion. Other times, molten rock flows to the surface through vents and fractures, or erupts out of a volcano as lava and pumice. Sedimentary rocks form through the gradual accumulation of tiny loose pieces of rock, shells, plants and animal remains. Over many years the sediments compact together so densely that they become rocks. Metamorphic rocks form when igneous, sedimentary or other metamorphic rocks undergo intense heat and pressure, which transforms them into a new type of rock. These maps show where rocks of different origins are found throughout New Zealand. Note how fault lines often mark the boundary between rocks of different origin.
26
The Alpine Fault marks the boundary of the Australian and Pacific plates. The fault follows the Southern Alps’ north-west edge
Formed when molten rock crystallises and solidifies Young igneous rocks (less than 2.5 million years old) Older igneous rocks Formed by the accumulation of sediments Young sedimentary rocks (less than 2.5 million years old) Older sedimentary rocks Transformed by heat, pressure and chemical processes Older metamorphic rocks
Active fault
The TaupĹ? Volcanic Zone remains active after two million years of eruptions
Data source GNS Science 27
Australian Plate
Under the North Island, and north-east of New Zealand, the Pacific Plate is diving below the Australian Plate
Fa ul t
Pacific Plate
Under Fiordland, the Australian Plate is getting pushed beneath the Pacific Plate
ne pi l A
200 km
28
Deep Earthquakes The surface of the Earth is made of a series of huge, slow-moving slabs of rock called tectonic plates. Aotearoa lies on the boundary between the Australian Plate and the Pacific Plate — two of the world’s largest geological features. The motions of these plates along their New Zealand boundary is complicated. In the North Island, the Pacific Plate is getting pushed beneath the Australian Plate. At the bottom of the South Island, the reverse is happening. Along the Alpine Fault, the Australian Plate is sliding horizontally as the Pacific Plate pushes up, forming the Southern Alps. Along much of their boundary, the plates do not slide smoothly past one another. Instead they push together until the stress becomes too much, some part of the crust ruptures, and an earthquake occurs. This usually happens along a pre-existing fault. How to read This map shows 10 years of deep earthquakes between 2008 and 2018. Larger circles represent bigger earthquakes. The darker the circle, the deeper the earthquake. Note the bands of colour in the top half of the map, with deeper quakes in the west. This is due to the earthquakes following the slope of the plate boundary as it dips down into the subduction plate.
Quake magnitude 7
Depth 40–60 km 60–80 km 80–100 km 100–150 km
6 5 4 3
150–200 km Over 200 km below ground
Data source GNS Science 29
Water and Air An exploration of water, wind, weather and climate.
2009
Dry Spells New Zealand’s reliance on agriculture makes the country particularly sensitive to drought. Any lack of water causes cascading negative effects. Crops dry out. Livestock do not have enough to eat. Farm finances come under pressure. There is a loss of income to the region. Communities experience financial and emotional stress. The charts on these pages plot 10 years of NIWA’s New Zealand drought index. Each row shows the rhythm and intensity of water shortages for a single place. Some droughts start suddenly, going from near normal to severe drought within weeks. Others grow slowly, sometimes subsiding before returning again. All exert pressure and hardship. Most climate change scenarios forecast an increase in drought frequency and severity.
2010
2011
2012
2011
2012
At the time, 2009–10 was Northland’s worst drought in 60 years
Far North
Waikato
Taupō
Gisborne
Hastings
South Taranaki
Manawatū
Masterton
How to read Severe drought
Nelson
Intensity
Drought Extremely dry Very dry
Greymouth
Dry Near normal Duration
Christchurch
Far North
Mackenzie Basin Waikato Taupō South Taranaki Manawatū Nelson Greymouth Central Otago
Gisborne Hastings Masterton
Central Otago
Christchurch Mackenzie Basin
Gore
Gore Stewart Island
Data source NIWA
Stewart Island 2009
48
2010
2013
2014
2015
2016
2017
2018
2019
Much of Northland, Auckland and Coromandel experienced the driest first half of the year on record in 2019
The 2012–13 drought affected most of the North Island. Ministry of Primary Industries estimated it cost the country at least $1.3 billion
2013
2014
2015
2016
2017
2018
2019
Scale of Irrigation By international standards, Aotearoa receives plentiful rainfall. Yet in some places there is not always enough to go around. There are increasing demands from agriculture and urban areas. The unpredictability of climate change compounds issues around water supply. Rather than relying on rainfall alone, many farmers in the east of New Zealand rely on irrigation to grow crops and maintain grasslands.
Methven
In 2017, irrigated land covered 794,000 hectares of New Zealand, accounting for 3 per cent of the country’s land area. This map shows 345,000 hectares of irrigated farmland in Central Canterbury. This is 43 per cent of all irrigated land in the country. Irrigation has environmental effects. Diverting water from rivers and lakes reduces downstream flow and threatens fragile environments. Irrigation also enables more intensive land uses, which require the use of fertilisers. Excess water can carry dissolved fertiliser nitrates into groundwater aquifers. Managing these issues is an ongoing cause of tension between farmers, councils and environmental groups. How to read This map provides a sense of scale of irrigation in Canterbury. Small plots of irrigated land are shaded darker and larger fields are lighter. Colour is used to help readers distinguish individual fields.
Ōr
ar
ive
r
Geraldine
Central Canterbury
Temuka
Data sources Ministry for the Environment Land Information New Zealand Manaaki Whenua — Landcare Research 50
iR
Timaru
Darfield
Christchurch
Rolleston
hven
Ra
ka ia
Riv er
Rakaia
Lake Ellesmere (Te Waihora)
Ashburton
10 km
51