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NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014)

**Warning:** This raster is a grid of a floating-point values; not a surface. To derive an accurate height transformation value, this raster grid must be downloaded in terms of NZGD2000 and then converted into a surface using bilinear interpolation.

_________________________


**Introduction**

This dataset provides a 1 arc minute raster image of the free-air gravity anomalies, which have been downward continued to the ground surface (McCubbine et al, 2017).


**Description**

Gravity anomalies are differences between measured gravity (from the airborne gravity dataset) and an ellipsoidal model of the Earth’s gravity field (GRS80). Gravity anomalies correspond to un-modelled density variations within the Earth’s crust and upper mantle. They are used to investigate concealed geological structures and for quasigeoid modelling.


These free-air anomalies show values which include gravitation impact of the topography.


The national airborne gravity dataset is comprised of more than 50,000 linear km of flight observations, covering the three main islands of New Zealand and up to 10km offshore.


As the airborne gravity dataset was measured at flight altitude, the observations have been reduced to the ground surface (a process known as downward continuation).


The national airborne gravity dataset was collected as a joint project between Toitū Te Whenua Land Information New Zealand (LINZ), GNS Science (GNS) and Victoria University of Wellington (VUW). The airborne survey was completed in a total of eight months, over two campaigns: August – October 2013, and February – June 2014.


**Users may also be interested other layers created for Bouguer anomalies at ground surface and the along track observations from the gravity flight lines at flight elevation** [NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014)]( https://data.linz.govt.nz/layer/3530 ) and [NZ Airborne Gravity Flight Lines at Elevation (2013-2014)]( https://data.linz.govt.nz/layer/ 3531).


McCubbine, J. Stagpoole, V. Caratori-Tontini, F. Amos, M. Smith, E. and Winefield, R. (2017). Gravity anomaly grids for the New Zealand region. Manuscript submitted for publication New Zealand Journal of Geology and Geophysics.

Simple

Identification info

Date (Publication)
2016-12
Purpose

Purpose of this dataset is to supply the national airborne gravity dataset for use in geophysical research and mapping.

Credit

GNS Science

Credit

Victoria University of Wellington

Credit

Toitū Te Whenua Land Information New Zealand

Status
Completed
Point of contact
Role Organisation Electronic mail address
Point of contact

Toitū Te Whenua Land Information New Zealand

customersupport@linz.govt.nz

Resource provider

Toitū Te Whenua Land Information New Zealand

customersupport@linz.govt.nz

Spatial resolution

Spatial resolution
1.8 km
Topic category
  • Geoscientific information

Extent

Geographic identifier
nzl

Title

ANZMet Lite Country codelist

Date (Publication)
2009-03-31
Edition

Version 1.0

Edition date
2009-03-31
Citation identifier
http://asdd.ga.gov.au/asdd/profileinfo/anzlic-country.xml#Country

Cited responsible party
Role Organisation Electronic mail address
Custodian

ANZLIC the Spatial Information Council

Extent

N
S
E
W


Maintenance and update frequency
Monthly

Resource format

Title

*.xml

Date
Edition

Unknown

ANZLIC Jurisdictions
  • New Zealand

ANZLIC Search Words
  • GEOSCIENCES-Geophysics

  • LAND-Geodesy

Resource constraints

Classification
Unclassified

Resource constraints

Use limitation

Copyright 2016 Crown copyright (c)


Toitū Te Whenua Land Information New Zealand and the New Zealand Government.


All rights reserved

Use constraints
Copyright

Resource constraints

Use limitation

Released under Creative Commons Attribution 4.0 International with:


Following Attribution:

If you publish, distribute or otherwise disseminate this work to the public without adapting it, the following attribution to Toitū Te Whenua Land Information New Zealand should be used.'CC BY 4.0 Toitū Te Whenua Land Information New Zealand'


If you adapt this work in any way or include it in a collection, and publish, distribute or otherwise disseminate that adaptation or collection to the public, the following attribution to Toitū Te Whenua Land Information New Zealand should be used.'Contains data sourced from the LINZ Data Service and licensed for reuse under CC BY 4.0.'


If 'attribution stacking' problems exist then the requirement to display the above attribution statements is waived and in lieu the attribution statement is to be made in any terms or conditions associated with the work/product/application/ etc.

Use constraints
License
Language
English
Character encoding
UTF8

Distribution Information

OnLine resource

https://data.linz.govt.nz/layer/53532-nz-airborne-gravity-free-air-anomalies-at-ground-surface-2013-2014/

Resource lineage

Statement

This dataset is comprised of the downward continued free-air anomalies from the national airborne gravity survey. The downward continued process was completed using least squares collocation, a process which grids the dataset while reducing the data observed at elevation to the ground surface.


The airborne survey was observed over a period of eight months, over two campaigns: August – October 2013, and February – June 2014.

Hierarchy level
Dataset
Other

dataset

Reference System Information

Reference system identifier
4167

Metadata constraints

Classification
Unclassified

Metadata constraints

Use limitation

Copyright 2016 Crown copyright (c)


Toitū Te Whenua Land Information New Zealand and the New Zealand Government.


All rights reserved

Use constraints
Copyright

Metadata constraints

Use limitation

Released under Creative Commons Attribution 4.0 International

Use constraints
License

Metadata

Metadata identifier
cca2de2c-5f44-bfa5-be36-e1209a08e22c

Language
English
Character encoding
UTF8
Contact
Role Organisation Electronic mail address
Resource provider

Toitū Te Whenua Land Information New Zealand

customersupport@linz.govt.nz

Type of resource

Resource type
Dataset
Name

dataset

Date info (Revision)
2017-02-03

Metadata standard

Title

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Edition

1.1

 
 

Spatial extent

N
S
E
W


Keywords

ANZLIC Jurisdictions
New Zealand
ANZLIC Search Words
GEOSCIENCES-Geophysics LAND-Geodesy

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Access to the catalogue
Read here the full details and access to the data.


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