LINZ Data Service :: tag:data.linz.govt.nz,2008-10:feed:layers:category=301266:sort=rLand Information New Zealandhttps://data.linz.govt.nz//NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014)tag:data.linz.govt.nz,2016-12:layers:535322016-12-09T00:12:37.161798+00:002017-01-30T20:25:10.197743+00:00
<a class="kxThumbnail" href="https://data.linz.govt.nz/layer/53532-nz-airborne-gravity-free-air-anomalies-at-ground-surface-2013-2014/" title="Details for NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014)"><img src="//tiles-cdn.koordinates.com/services/tiles/v4/thumbnail/layer=53532.162271,style=auto/90x70.png" alt="NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014) thumbnail"/></a><br />
<br /><strong>Updated with new data on 30 Jan 2017</strong><br />
<p><strong>Warning:</strong> 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. </p>
<hr>
<p><strong>Introduction</strong><br>
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).</p>
<p><strong>Description</strong><br>
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.</p>
<p>These free-air anomalies show values which include gravitation impact of the topography.</p>
<p>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.</p>
<p>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).</p>
<p>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.</p>
<p><strong>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</strong> <a href="https://data.linz.govt.nz/layer/3530">NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014)</a> and <a href="https://data.linz.govt.nz/layer/3531">NZ Airborne Gravity Flight Lines at Elevation (2013-2014)</a>.</p>
<p>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.</p>
From: <a href="https://data.linz.govt.nz/group/ngo/" title="Profile for National Geodetic Office">National Geodetic Office</a><br />
Added: 09 Dec 2016<br />
Updated: 30 Jan 2017<br />
NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014)tag:data.linz.govt.nz,2016-12:layers:535302016-12-08T20:35:54.652419+00:002017-01-30T20:24:06.956781+00:00
<a class="kxThumbnail" href="https://data.linz.govt.nz/layer/53530-nz-airborne-gravity-bouguer-anomalies-at-ground-surface-2013-2014/" title="Details for NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014)"><img src="//tiles-cdn.koordinates.com/services/tiles/v4/thumbnail/layer=53530.162270,style=auto/90x70.png" alt="NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014) thumbnail"/></a><br />
<br /><strong>Updated with new data on 30 Jan 2017</strong><br />
<p><strong>Warning:</strong> 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. </p>
<hr>
<p>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.</p>
<p>This dataset provides a 1 arc minute raster image of the Bouguer anomalies, which have been downward continued to the ground surface (McCubbine et al, 2017).</p>
<p>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.</p>
<p><strong>Users may also be interested in other layers created for the free-air anomalies at ground surface and the along track observations from the gravity flight lines at flight elevation</strong> <a href="https://data.linz.govt.nz/layer/3532">NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014)</a> and <a href="https://data.linz.govt.nz/layer/3531">NZ Airborne Gravity Flight Lines at Elevation (2013-2014)</a>.</p>
<p>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 ZealandJournal of Geology and Geophysics.</p>
From: <a href="https://data.linz.govt.nz/group/ngo/" title="Profile for National Geodetic Office">National Geodetic Office</a><br />
Added: 08 Dec 2016<br />
Updated: 30 Jan 2017<br />
NZ Airborne Gravity Flight Lines at Elevation (2013-2014)tag:data.linz.govt.nz,2016-12:layers:535312016-12-09T00:29:32.039382+00:002017-01-30T20:28:46.994761+00:00
<a class="kxThumbnail" href="https://data.linz.govt.nz/layer/53531-nz-airborne-gravity-flight-lines-at-elevation-2013-2014/" title="Details for NZ Airborne Gravity Flight Lines at Elevation (2013-2014)"><img src="//tiles-cdn.koordinates.com/services/tiles/v4/thumbnail/layer=53531.162272,style=auto/90x70.png" alt="NZ Airborne Gravity Flight Lines at Elevation (2013-2014) thumbnail"/></a><br />
<br /><strong>Updated with new data on 30 Jan 2017</strong><br />
<p><strong>Introduction</strong><br>
This dataset provides gravity observations, reductions and metadata for New Zealand’s national airborne gravity survey at flight elevation. A full description of each field in this dataset is available in the accompanying pdf <a href="https://data.linz.govt.nz/document/1825">NZ Airborne Gravity Flight Lines at Elevation (2013-2014) Description</a>. </p>
<p><strong>Description</strong><br>
New Zealand’s 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. </p>
<p>Gravity observations can be used to compute gravity anomalies: differences between measured gravity and an ellipsoidal model of the Earth’s gravity field. 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. </p>
<p>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. </p>
<p><strong>Users may also be interested raster layers created for each of the free-Air and Bouguer Anomalies which have been downward continued to ground surface</strong> <a href="https://data.linz.govt.nz/layer/3532">NZ Airborne Gravity Free-Air Anomalies at Ground Surface (2013-2014)</a> and <a href="https://data.linz.govt.nz/layer/3530">NZ Airborne Gravity Bouguer Anomalies at Ground Surface (2013-2014)</a>.</p>
From: <a href="https://data.linz.govt.nz/group/ngo/" title="Profile for National Geodetic Office">National Geodetic Office</a><br />
Added: 09 Dec 2016<br />
Updated: 30 Jan 2017<br />