NZ Quasigeoid 2016 Raster

Licence

Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

4194
177
Added
25 Jul 2016

This dataset was first added to LINZ Data Service on 25 Jul 2016.

New Zealand Quasigeoid 2016 Raster, provides users with a one arc-minute gridded (approximately 1.8 kilometres) raster image of the New Zealand Quasigeoid 2016 (NZGeoid2016).

The relationship between the GRS80 ellipsoid and the New Zealand Vertical Datum 2016 (NZVD2016) is modelled by [NZGeoid2016] and is represented by the attribute “N”, in metres.(data.linz.govt.nz/layer/3418).
NZVD2016 is formally defined in the LINZ standard LINZS25009.

Users may also be interested in transforming heights to any of the 13 historic local vertical datums used in New Zealand using the appropriate datum relationship grid displayed in the NZ Height Conversion Index.

More information on these transformations is available on the LINZ website.

Layer ID 53447
Data type Grid
Resolution About 1579.000m
Services Raster Query API, Catalog Service (CS-W), data.govt.nz Atom Feed

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

Licence

Creative Commons Attribution 4.0 International

You may use this work for commercial purposes.

You must attribute the creator in your own works.

3937
73
Updated
30 Jan 2017

This dataset was last updated on LINZ Data Service on 30 Jan 2017.

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 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) and NZ Airborne Gravity Flight Lines at Elevation (2013-2014).

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.

Layer ID 53532
Data type Grid
Resolution About 1579.000m
Services Raster Query API, Catalog Service (CS-W), data.govt.nz Atom Feed
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