On edge

Dr Hamish Campbell

GNS Science

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Seaward Kaikoura Range

Hope Fault

Kaikoura

GNS Science

Banks Peninsula, looking west

Christchurch

GNS Science

Kaikoura

Christchurch

Alpine Fault

Hope Fault

GNS Science

South Island

GNS Science

Regional Context

GNS Science

Kevin Furlong

GNS Science Photo: Nicola Litchfield, GNS Science

GNS Science

Darfield Earthquake

7.1

Saturday 4 September

4:36 am

GNS Science

Acceleration records from Greendale

-5

-4

-3

-2

-1

0

1

0 5 10 15 20 25 30

Time (s)

Ac

ce

lera

tio

n (

g)

305

215

VERT

`

GNS Science

“There’s a sandhill in the middle of my house… it’s wrecked.”

GNS Science

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Fault Rupture (breakage)

source: www.GeoNet.org.nz

GNS Science

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Greendale Fault Surface Rupture Displacement

GNS Science

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Faults within basement rocks of the Chatham Rise

Wood, Andrews & Herzer (1989): NZGS Basin Studies 3: Chatham Rise, Map 4

GNS Science

90 Ma

(million years ago)

GNS Science

Bathymetric map

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Aftershocks: 4 – 21 September, 2010

GNS Science

February 22, 2011 Christchurch

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Comparison of Vertical and Horizontal Ground

Shaking

Vertical

Horizontal

500 yr code 0.30g

2,500 year 0.54g

GNS Science

Actual vs. Previously Mapped Hazard

Extent of liquefaction from 22 Feb 2011.

Orange = major liquefaction.

Yellow = minor / trace / isolated small liquefaction areas

2004 Liquefaction Hazard Map

GNS Science

Predicted vertical contours and fault slip model (transparent)

Subsidence

up to 15 cm

along much of

the Avon, with

uplift >30 cm

of river mouth

and estuary

GNS Science

New Zealand Historical Atlas 1997 p.55

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Photo: Dougal Townsend

Mohaka Fault looking NE to Waipawa River and Wakarara Range

GNS Science

Mars and its faults: normal (red) and reverse (black)

Lada Dimitrova (PhD, Stony Brook, USA)

GNS Science

MARS

S pole N pole

GNS Science

Full moon

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Earthquakes occur on plate boundaries

GNS Science

NEIC

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IRIS

22 Feb

Japan - 20000 x more energy

4 Sept - 30 x more energy

Globally there‟s about one/year M>8.0

GNS Science

Globally, the 5th largest earthquake since 1900.

Magnitude 8.9 NEAR THE EAST COAST OF HONSHU, JAPAN Friday, March 11, 2011 at 05:46:23 UTC

7.8

8

8.2

8.4

8.6

8.8

9

9.2

9.4

9.6

1900 1920 1940 1960 1980 2000 2020

Ma

gn

itu

de

Year

Great (M > 8) Earthquakes Since 1900 Chile 1960

Alaska 1964

Sumatra 2004

Chile 2010

Japan 2011

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Wairarapa Fault

Featherston

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Wairarapa Fault

raised beaches

at

Cape Turakirae

Cook Strait

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Wellington Fault

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Wellington Fault

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Pondard and Barnes, JGR, 2010

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Marlborough Sounds, South Island

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Wanganui Basin

Cook Strait

Marlborough Sounds

„lithospheric sag‟

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Understanding our subduction thrust

• Geophysical – remote sensing

• Drilling – IODP

GNS Science

Seismicity in NZ for a 10 year period (1990s)

GNS Science

GPS: Global Positioning System

satellite receiver

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Total slip in the Kapiti 2003 and Manawatu 2004/2005

SSEs was equivalent to Mw 7.26, and occurred along the

down-dip edges of inter-seismic coupling

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Comparison of Japan with North Island

GPS tells us where the subduction zone is “stuck”

– building up stress to be relieved in a future earthquake

GNS Science

Comparison of Japan with North Island

GNS Science

Edgecumbe Earthquake February 1987: looking NE

GNS Science

Taupo Volcanic Zone

(TVZ)

A rift with at least 8

calderas or

super-volcanoes

E-W stretching of

>9.0 mm per year

at Rotorua

GNS Science

Looking NE at

Mt Edgecumbe

over

Waimungu

Lake Rotomahana

Mt Tarawera

Photo: Lloyd Homer,

GNS Science

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Tarawera, Ruawahia, Wahanga (domes)

Photo: Lloyd Homer, GNS Science

GNS Science

Kaharoa Eruption

of Mt Tarawera

1314 AD +/- 12

by David Lowe,

Waikato University

GNS Science

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Acknowledgements • Helen Anderson

• Phil Barnes (NIWA)

• John Beavan (GNS Science)

• John Begg (GNS Science)

• Neil Campbell (Kiwi Rail)

• Russ van Dissen (GNS Science)

• Kevin Furlong (Penn. State, USA)

• Ken Gledhill (GeoNet, GNS Science)

• Gavin Hayes (USGS)

• Stuart Henrys (GNS Science)

• Lloyd Homer

• James Jackson (Cambridge University)

• Graeme McVerry (GNS Science)

• Andy Nichol (GNS Science)

• Nico Pondard (GNS Science)

• Martin Reyners (GNS Science)

• Warwick Smith (GeoNet, GNS Science)

• Mark Stirling (GNS Science)

• Dougal Townsend (GNS Science)

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GNS Science

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National Seismic

Hazard Model

PGA = peak ground

acceleration