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  • For the purpose of studying the impact of the 5 March 2021 Kermadec tsunami in Tutukaka Harbor, Whangarei, New Zealand, and its neighbourhood, a high-resolution digital elevation model (DEM) of Tutukaka Harbor has been built using two different types of data (Roger, 2022). These are: - Digitized and georeferenced British Admiralty Nautical Chart (Cape Brett to Paepae-o-Tu / Bream Tail, 1:90,000 – Id: NZ300521 and Tutukaka Harbour, 1:12,000 - Id: NZ552121) - The New Zealand 8 m DEM (LINZ, 2012) for the land part The compilation of data has been interpolated to a regular spatial resolution of 0.00009° (~10m) between 174.5233364°W and 174.5797705°W and -35.6252705°S and -35.5979928°S using the krigging method. For more information about this method, see for example Oliver and Webster (1990). DOI: https://doi.org/10.21420/AQBF-Q453 Cite when using the DEMs: Roger, J. (2022). Digital Elevation Model of Tutukaka Harbor and neighbourhood, Whangarei District, New Zealand [Data set]. GNS Science. https://doi.org/10.21420/AQBF-Q453

  • For the purpose of studying the impact of the 10 February 2021 South Matthew Island tsunami in the southwest Pacific Ocean, a set of three digital elevation models (DEM) of Norfolk Island, Australia, including a high-resolution focus on Sydney Bay (on the south coast of the island) has been built using three different types of data. They include: - The global dataset 15 arcsec resolution GEBCO (2020); - The global dataset 1 arcsec resolution SRTM (2013); - Norfolk Island LiDAR 0.57m DEM (Gallant and Petheram, 2020); - Digitized and georeferenced nautical chart of Norfolk Island (Australian Hydrographic Office, 2019) and related charts (Australian Hydrographic Office, 2009a, b, c, d). The data showing the highest resolution has been kept in priority. The compilation of data has been interpolated to a regular spatial resolution of 0.005° (~500 m) for the coarser grid, 0.0005° (~50 m) for the medium grid, and to 0.0001° (~10 m) for the grid over Sydney Bay. The data interpolation processes have done using the kriging method. For more information about this method, see for example Oliver and Webster (1990). DOI: https://doi.org/10.21420/H889-5393 Cite when using the DEMs: Roger, J. (2022). Digital Elevation Model of Norfolk Island and Sydney Bay, Australia. [Data set] GNS Science. Accessed on [insert date]. https://doi.org/10.21420/H889-5393.

  • The Elevation Database contains a collection of separate datasets related to landscape morphology representing a visual snap shot of the earth’s surface. Different instruments and collection methods are used for the different datasets, and the spatial resolution of the datasets are variable. LiDAR data is open source data obtained from LINZ (https://data.linz.govt.nz/search/?q=LiDAR). GNS Staff, logged in to the Dataset Catalog can access details of the following datasets: o Fixed-wing Aerial Lidar https://data.gns.cri.nz/metadata/srv/eng/catalog.search#/metadata/95c0bb51-a0a6-4fcd-a478-57180881175e o Terrestrial Laser Scanning o UAV

  • Plot data Mc Nemar: To enable comparisons with the 1961 and 2004 survey results, the Lambert Conformal Conic projection from the 2004 survey was used to precisely georeference and trim the RGB image across a 1-m2 grid, generating a total of 3,458 1-m2 grid cells. For each grid cell moss, lichen, or algae/cyanobacteria cover was extracted as one of the four cover classes: Heavy (>40%), Patchy (10–40%), Scattered (less than 10%), and None (0%) for the survey years 1962, 2004 and 2018. Ground truthing: To test the overall accuracy of cover classifications and ensure consistency with 2004 survey methodologies, a ground-truthing approach was performed. Photographs were taken of individual cells along eight transects, running west to east across the plot at 0.5, 1.5, 15.5, 16.5, 28.5, 29.5, 116.5 and 117.5 m distance from the NW corner. Each grid cell could be identified individually with an x/y coordinate in the centre and was surrounded by a rectangular frame parallel to the outer edge of the plot. A total of 174 photographs were taken and archived with Antarctica New Zealand. For each photographed grid cell, the presence of each functional group of vegetation and their cover class was assessed visually. Orthomosaic image: Aerial images were obtained using a DJI Matrice 600 Pro hex-rotor remotely piloted aircraft system equipped with a Canon EOS 5Ds camera (image size: 8688×5792 pixels, focal length: 50 mm, pixel size: 4.14 μm) on November 28, 2018. The flight altitude was 30 m above ground level, and a total of 10 ground-control points were included to provide accurate geo-referencing. An orthomosaic photo and accompanying DEM was generated with the acquired aerial images using Agisoft PhotoScan (now known as Metashape by Agisoft LLC, https://www.agisoft.com/) RELATED PUBLICATION: https://doi.org/10.1029/2022EF002823 GET DATA: https://doi.org/10.7488/ds/3417