Canterbury Region Data - Page 7

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 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

Index Tiles ONLY, for actual orthophotos see layer Christchurch 0.075m Urban Aerial Photos (2015-16)

Orthophotography in the Christchurch City Council area taken in the flying season (summer period) 2015-16.
Coverage is of the urban areas within Christchurch City and Banks peninsula.

Imagery was captured for the ‘Christchurch City Council' by AAM NZ Limited, 6 Ossian St, NAPIER, New Zealand.

Data comprises:

• 6,993 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:500 tile layout.
  
• Tile layout in NZTM projection containing relevant information.
  

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:500 tiles.

Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 7.5cm pixel resolution (0.075m GSD), 3-band (RGB) uncompressed GeoTIFF.

The final spatial accuracy is ±0.2m @ 90% confidence level in clear open spaces.

Index Tiles ONLY, for actual orthophotos see layer Waimakariri 0.075m Urban Aerial Photos (2015-16)

Orthophotography in the Waimakariri District Council area taken in the flying season (summer period) 2015-16.
Coverage is of urban areas within the Waimakariri District.

Imagery was captured for the ‘Waimakariri District Council' by AAM NZ Limited, 6 Ossian St, NAPIER, New Zealand.

Data comprises:

• 1,116 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:500 tile layout.
• Tile layout in NZTM projection containing relevant information.
  

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:500 tiles.

Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 7.5cm pixel resolution (0.075m GSD), 3-band (RGB) uncompressed GeoTIFF.

The final spatial accuracy is ±0.2m @ 90% confidence level in clear open spaces.

Orthophotography in the Waimakariri District Council area taken in the flying season (summer period) 2015-16.
Coverage is of urban areas within the Waimakariri District.

Imagery was captured for the ‘Waimakariri District Council' by AAM NZ Limited, 6 Ossian St, NAPIER, New Zealand.

Data comprises:

• 1,116 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:500 tile layout.
  
• Tile layout in NZTM projection containing relevant information.
  

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:500 tiles.

Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 7.5cm pixel resolution (0.075m GSD), 3-band (RGB) uncompressed GeoTIFF.

The final spatial accuracy is ±0.2m @ 90% confidence level in clear open spaces.

Index tiles for this dataset are available as layer Waimakariri 0.075m Urban Aerial Photos Index Tiles (2015-16)

Orthophotography in the Christchurch City Council area taken in the flying season (summer period) 2015-16.
Coverage is of the urbans areas within Christchurch City and Banks Peninsula.

Imagery was captured for the ‘Christchurch City Council' by AAM NZ Limited, 6 Ossian St, NAPIER, New Zealand.

Data comprises:

• 6,993 ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:500 tile layout.
  
• Tile layout in NZTM projection containing relevant information.
  

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:500 tiles.

Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 7.5cm pixel resolution (0.075m GSD), 3-band (RGB) uncompressed GeoTIFF.

The final spatial accuracy is ±0.2m @ 90% confidence level in clear open spaces.

Index tiles for this dataset are available as layer Christchurch 0.075m Urban Aerial Photos Index Tiles (2015-16)

The DUN58-NZVD2016 grid enables the conversion of normal-orthometric heights from the Dunedin 1958 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.

DUN58-NZVD2016 is published on a two arc-minute grid (approximately 3.6 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 height conversion grid models the difference between the Dunedin 1958 vertical datum and NZVD2016 using the LINZ GPS-levelling marks. From the GPS-levelling marks the expected accuracy of DUN58-NZVD2016 is better than 2 centimetres (95% Confidence interval).

More information on converting heights between vertical datums can be found 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 and the DUN58-NZVD2016 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.

Coordinates computed from surveys undertaken after the 14 February 2016 Canterbury earthquake. These should be consistent with any observations made after this earthquake (neglecting any localised deformation such as that due to liquefaction).

For further information about this dataset, see the Canterbury earthquake information.

These coordinates are only provisional. Analysis is ongoing as further data is collected. Coordinates were calculated using SNAP v2.5.33. Stations were constrained using coordinates of distant PositioNZ continuous GNSS stations that were unaffected by the earthquake.

The standard deviations of coordinates are 0.01m horizontally and 0.02m vertically, relative to the PositioNZ network.

Coordinate changes due to the earthquake have been calculated by comparing pre and post-earthquake coordinates. Pre-earthquake coordinates were calculated relative to public and private continuous GNSS stations. These continuous GNSS stations had data processed for several days early in 2016 (before the earthquake). Other pre-earthquake geodetic data was then readjusted with the continuous GNSS data. Note that this means these coordinate changes may differ slightly from those that would be calculated by comparing the post-earthquake coordinates with those currently in the Geodetic Database.

These coordinates are suitable for use in surveys and other geospatial activities in Canterbury and Christchurch.

Orthophotography for the Canterbury region taken in the flying season (summer period) 2014 - 2015. Coverage encompassed the Hurunui, and Kaikoura council areas.

Imagery was captured for the ‘Environment Canterbury’ by Aerial Surveys Ltd, Unit A1, 8 Saturn Place, Albany,0632, New Zealand.

Data comprises:
•1,661 x ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:5,000 tile layout
•Tile layout in NZTM projection containing relevant information.

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:5,000 tiles. Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 30cm pixel resolution (0.3m GSD), 3-band (RGB) uncompressed GeoTIFF. The final spatial accuracy is +/-0.6m.

Index tiles for this dataset are available as layer Canterbury 0.3m Rural Aerial Photos Index Tiles (2014-15)

Index Tiles ONLY, for actual orthophotos see layer Canterbury 0.3m Rural Aerial Photos (2014-15)

Orthophotography for the Canterbury region taken in the flying season (summer period) 2014 - 2015. Coverage encompassed the Hurunui, and Kaikoura council areas.

Imagery was captured for the ‘Environment Canterbury’ by Aerial Surveys Ltd, Unit A1, 8 Saturn Place, Albany,0632, New Zealand.

Data comprises:
•1,661 x ortho-rectified RGB GeoTIFF images in NZTM projection, tiled into the LINZ Standard 1:5,000 tile layout
•Tile layout in NZTM projection containing relevant information.

The supplied imagery is in terms of New Zealand Transverse Mercator (NZTM) map projection. The products are tiled into NZTopo50 1:5,000 tiles. Please refer to the supplied tile layout shape file for specific details, naming conventions, etc.

Imagery supplied as 30cm pixel resolution (0.3m GSD), 3-band (RGB) uncompressed GeoTIFF. The final spatial accuracy is +/-0.6m.