The Canterbury region of New Zealand experienced a sequence of significant earthquakes during 2010 and 2011. These earthquakes occurred on 2010-09-04, 2011-02-22, 2011-06-13 and 2011-12-23. The coordinates in this layer account for all significant movements relating to these, so should be consistent with any observations made after the last earthquake to affect a given area (neglecting localised deformation such as that due to liquefaction). **Users may also be interested in the more comprehensive data in the companion layer [Canterbury Earthquake Geodetic Marks (2010, 2011) - Comprehensive](http://data.linz.govt.nz/layer/1588).** These coordinates are only provisional. Analysis is ongoing as further data is collected. Coordinates were calculated using SNAP v2.3.61. Stations were constrained using coordinates calculated by GNS Science. Some coordinates were calculated from data provided by Christchurch City Council. No precise levelling data has been used. The estimated accuracy is 0.02m horizontally and 0.03m vertically. The deformation model igns2011_working.grd calculated from a model (v4) provided by GNS Science on 28 April 2011 was used to remove secular deformation. These coordinates are suitable for use in surveys and other geospatial activities in Canterbury and Christchurch. **For further information about this dataset, see [the Canterbury earthquake information](http://www.linz.govt.nz/survey-titles/canterbury-earthquake/canterbury-earthquake/geodetic-survey-control-coordinates) on the LINZ website.**

The DUN58-NZGD2000 grid enables the conversion of normal-orthometric heights from the Dunedin 1958 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights. DUN58-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Dunedin 1958 vertical datum (168.4° E to 171.3° E, 43.9° S to 46.5° S). The conversion value is represented by the attribute “delta”, in metres. This grid is a combination of New Zealand Quasigeoid 2016 [NZGeoid2016](https://data.linz.govt.nz/layer/3418) and the [DUN58-NZVD2016](https://data.linz.govt.nz/layer/3428) height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the DUN58-NZVD2016 grid models the difference between the Dunedin 1958 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

The TNK70-NZGD2000 grid enables the conversion of normal-orthometric heights from the Taranaki 1970 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights. TNK70-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Taranaki 1970 vertical datum (173.6° E to 176.4° E, 38.3° S to 41.1° S). The conversion value is represented by the attribute “delta”, in metres. This grid is a combination of New Zealand Quasigeoid 2016 [NZGeoid2016](https://data.linz.govt.nz/layer/3418) and the [TNK70-NZVD2016](https://data.linz.govt.nz/layer/3444) height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the TNK70-NZVD2016 grid models the difference between the Taranaki 1970 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

The STI77-NZVD2016 grid enables the conversion of normal-orthometric heights from the Stewart Island 1977 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016). The conversion value is represented by the attribute “O”, in metres. This conversion and NZVD2016 are formally defined in the LINZ standard [LINZS25009](http://www.linz.govt.nz/regulatory/25009). STI77-NZVD2016 is published on a two arc-minute grid (approximately 3.6 kilometres) extending over the benchmarks that nominally define the extent of the Stewart Island 1977 vertical datum (167.2° E to 168.8° E, 46.5° S to 47.5° S). The height conversion grid models the difference between the Stewart Island 1977 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy of STI77-NZVD2016 is better than 18 centimetres (95% Confidence interval). More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

The WGN53-NZVD2016 grid enables the conversion of normal-orthometric heights from the Wellington 1953 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016). The conversion value is represented by the attribute “O”, in metres. This conversion and NZVD2016 are formally defined in the LINZ standard [LINZS25009](http://www.linz.govt.nz/regulatory/25009). WGN53-NZVD2016 is published on a two arc-minute grid (approximately 3.6 kilometres) extending over the benchmarks that nominally define the extent of the Wellington 1953 vertical datum (174.4° E to 176.4° E, 39.1° S to 41.6° S). The height conversion grid models the difference between the Wellington 1953 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy of WGN53-NZVD2016 is better than 2 centimetres (95% Confidence interval). More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

This layer details the movement of survey marks due to the Canterbury Earthquake Sequence (CES). The movements include the impact of 5 major earthquakes on 4 September 2010, 22 February 2011, 13 June 2011, 23 December 2011 and 14 February 2016. Note that these movements apply only at the survey mark. Nearby land may have moved differently, especially in areas impacted by substantial shallow ground movement. For further earthquake information, see **[the Canterbury earthquake information](http://www.linz.govt.nz/land/surveying/canterbury-earthquakes )** on the LINZ website. **Scope** Movements do not include the regular tectonic movement (not related to earthquakes) of approximately 5cm per year. As well as Christchurch, the data covers Lyttelton, Spencerville, Kaiapoi, Pines Beach, Woodend, Pegasus and Waikuku Beach. **Mark Movement Calculations** Observed mark movements have been calculated from geodetic and cadastral survey data collected at the same physical survey mark before and after the earthquakes. Various filters have been applied to ensure as far as practicable that the movements reflect real-world earthquake-related movements of marks. For example, only non-boundary marks that have been directly measured (rather than adopted) are included. Modelled mark movements have been calculated using models of the tectonic-scale movements resulting from each earthquake, supplied by GNS Science, supplemented with more detailed modelling carried out by LINZ. These models typically represent deep-seated movement only. They do not include shallow movement, such as that resulting from liquefaction. Therefore the difference between the post-earthquake observed and post-earthquake modelled position generally represents shallow ground movement. The difference between the post-earthquake modelled and pre-earthquake observed position generally represents deep-seated movement. The difference between the post-earthquake observed position and pre-earthquake observed position represents total movement due to the earthquakes. **Accuracy** The uncertainty of the coordinate changes is 0.1m at a 95% confidence interval. **Layer Attributes** - nod_id_post_eq: Landonline node id for the latest post-earthquake node (mark) - code_post_eq: Geodetic code for the latest post-earthquake node - name_post_eq: Mark name for the latest post-earthquake node - nod_id_pre_eq: Landonline node id for the pre-earthquake node (mark) - code_pre_eq: Geodetic code for the pre-earthquake node - name_pre_eq: Mark name for the pre-earthquake node - de_mod_obs: East change from modelled post-earthquake to observed post-earthquake position - dn_mod_obs: North change from modelled post-earthquake to observed post-earthquake position - hz_mod_obs: Horizontal change from modelled post-earthquake to observed post-earthquake position - bg_mod_obs: Bearing from modelled post-earthquake to observed post-earthquake position - de_pre_mod: East change from observed pre-earthquake to modelled post-earthquake position - dn_pre_mod: North change from observed pre-earthquake to modelled post-earthquake position - hz_pre_mod: Horizontal change from observed pre-earthquake to modelled post-earthquake position - bg_pre_mod: Bearing from observed pre-earthquake to modelled post-earthquake position - de_pre_obs: East change from observed pre-earthquake to observed post-earthquake position - dn_pre_obs: North change from observed pre-earthquake to observed post-earthquake position - hz_pre_obs: Horizontal change from observed pre-earthquake to observed post-earthquake position - bg_pre_obs: Bearing from observed pre-earthquake to observed post-earthquake position

The Dunedin-Bluff 1960 to NZVD2016 Conversion Raster provides users with a two arc-minute (approximately 3.6 kilometres) raster image of the conversion of normal-orthometric heights from the Dunedin-Bluff 1960 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016). The conversion value is represented by the attribute “O”, in metres. This conversion and NZVD2016 are formally defined in the LINZ standard [LINZS25009](http://www.linz.govt.nz/regulatory/25009). The height conversion grid models the difference between the Dunedin-Bluff 1960 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy is better than 2 centimetres (95% Confidence interval). More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

The Stewart Island 1977 to NZVD2016 Conversion Raster provides users with a two arc-minute (approximately 3.6 kilometres) raster image of the conversion of normal-orthometric heights from the Stewart Island 1977 local vertical datum to the New Zealand Vertical Datum 2016 (NZVD2016). The conversion value is represented by the attribute “O”, in metres. This conversion and NZVD2016 are formally defined in the LINZ standard [LINZS25009](http://www.linz.govt.nz/regulatory/25009). The height conversion grid models the difference between the Stewart Island 1977 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy is better than 2 centimetres (95% Confidence interval). More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

The STI77-NZGD2000 grid enables the conversion of normal-orthometric heights from the Stewart Island 1977 local vertical datum directly to New Zealand Geodetic Datum 2000 (NZGD2000) ellipsoidal heights. STI77-NZGD2000 is published on a one arc-minute grid (approximately 1.8 kilometres) extending over the benchmarks that nominally define the extent of the Stewart Island 1977 vertical datum (167.2° E to 168.8° E, 46.5° S to 47.5° S). The conversion value is represented by the attribute “delta”, in metres. This grid is a combination of New Zealand Quasigeoid 2016 [NZGeoid2016](https://data.linz.govt.nz/layer/3418) and the [STI77-NZVD2016](https://data.linz.govt.nz/layer/3442) height conversion grid. Where NZGeoid2016 is the reference surface for the New Zealand Vertical Datum 2016 (NZVD2016), while the STI77-NZVD2016 grid models the difference between the Stewart Island 1977 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. More information on converting heights between vertical datums can be found [on the LINZ website](http://www.linz.govt.nz/data/geodetic-services/coordinate-conversion/converting-between-nzvd2016-nzgd2000-and-local-vertical-datums).

**Note:** This layer has been provided to enable potential users to identify the coverage of photography for Mainland NZ flown on behalf of the Crown between 1936 and 2005. The layer shows the extent of each photograph taken. The [NZ Aerial Survey Footprints, Mainland NZ, (1936-2005) polygons layer](https://data.linz.govt.nz/layer/1000-nz-aerial-survey-footprints-mainland-nz-1936-2005-polygons) shows the extent of each survey undertaken, and the [Digitised Historic Aerial Surveys Available for Download (1936-2005)](https://data.linz.govt.nz/layer/2418) layer shows the extents of the surveys digitised and released by LINZ under open license. See [http://www.linz.govt.nz/about-linz/what-were-doing/projects/crown-historic-aerial-photo-archive-scanning-project](http://www.linz.govt.nz/about-linz/what-were-doing/projects/crown-historic-aerial-photo-archive-scanning-project) for direction on how to access the digitised photos. The photos are not downloadable from the LINZ Data Service. The Crown Aerial Film Negative Collection is managed for LINZ by Opus International.You can are order images from the Collection from Opus International in a number of formats, including: - contact prints - enlargements - digital files - precision scans for photogrammetric production - orthophotos You will need to tell Opus International the survey, run and photo number (values in the ‘SURVEY’ 'RUN' and 'PHOTO_NO' attributes) covering your area of interest. Opus International will be able to provide information about the cost of providing images in the various formats. Contact them at: photosales@opus.co.nz or 0800 680 690 There are also a large number of images which previously belonged to New Zealand Aerial Mapping and which are now are available for public use. The extents of these may be added to the LDS in future. You can order these images by contacting Opus International.