<div>The International Seabed Geomorphology Mapping Working Group's Seabed Geomorphology Classifier (ISGM-SGC) is used to support the implementation of the ISGM marine and coastal mapping approach. Part 1 of this approach (Dove et al., 2020) is used to map and define the seabed shape using bathymetry and derivative data; Part 2 (Nanson et al., 2023; in press) classifies these shapes with their geomorphic interpretation.</div><div><br></div><div>ISGM-SGC implements the Part 2 geomorphic classification framework (including physiography) by classifying and attributing the geomorphology of mapped seabed features using a standardised nomenclature structure. Seabed geomorphology maps provide critical baseline information for a wide range of Ocean Economy stakeholders. To bring greater consistency and value to diverse mapping efforts, it is essential to standardise the terminology used to classify seabed features. To address this need, geoscience agencies from the United Kingdom (British Geological Survey), Norway (Geological Survey of Norway), Ireland (Geological Survey Ireland and University College Cork), and Australia (Geoscience Australia) formed the International Seabed Geomorphology Mapping Working Group (ISGM) and collaborated to develop a standardised, two-part approach to seabed geomorphology mapping. </div><div><br></div><div>ISGM-SGC was developed as an Esri ArcGIS Pro Python tool using Python 3+. ISGM-SGC assigns five levels of geomorphology classification attributes for selected seabed features. The tool is composed of a series of drop-down lists and several free text entries. Depending on the user choices at the drop-down lists of higher classification levels, options at the drop-down list of lower classification levels are updated accordingly. In addition, 16 additional attributes can be assigned to describe the geomorphic interpretation of selected features. </div><div><br></div><div>The system and data format requirements of ISGM-SGC are described in the tutorials and user guide that accompany the tool, which also include sampled data and step-by-step examples of their application. ISGM-SGC is designed to operate as a standalone GIS tool for the consistent application of the Part 2 classification framework, while also integrating with broader seabed geomorphology mapping workflows, including those supported by complementary tools developed for Part 1 morphology mapping (Arosio et al., 2024; Huang et al., 2023). Further details of this tool, including its description, graphic illustrations and example applications, are also available in its metadata. </div><div><br></div><div>Arosio, R., Gafeira, J., De Clippele, L.H., Wheeler, A.J., Huvenne, V.A., Sacchetti, F., Conti, L.A. and Lim, A., 2024. CoMMa: A GIS geomorphometry toolbox to map and measure confined landforms. Geomorphology, 458, p.109227.</div><div><br></div><div>Dove, D., Nanson, R., Bjarnadóttir, L., Guinan, J., Gafeira, J., Post, A., Dolan, M.; Stewart, H.; Arosio, R, Scott, G. (October, 2020). A two-part seabed geomorphology classification scheme (v.2); Part 1: morphology features glossary. Zenodo. http://doi.org/10.5281/zenodo.4075248</div><div><br></div><div>Huang, Z., Nanson, R., McNeil, M., Wenderlich, M., Gafeira, J., Post, A. and Nichol, S., 2023. Rule-based semi-automated tools for mapping seabed morphology from bathymetry data. Frontiers in Marine Science, 10, p.1236788</div><div><br></div><div>Nanson, R., Arosio, R., Gafeira, J., McNeil, M., Dove, D., Bjarnadóttir, L., Dolan, M., Guinan, J., Post, A., Webb, J., & Nichol, S. (2023). A two-part seabed geomorphology classification scheme; Part 2: Geomorphology classification framework and glossary (Version 1.0) (1.0). Zenodo. https://doi.org/10.5281/zenodo.7804019</div><div><br></div><div>Nanson, R., Arosio, R., Gafeira, J., McNeil, M., Dove, D., Bjarnadóttir, L.R., Dolan, M.F.J., Post, A., Nichol, S., Huang, Z., Guinan, J., Bialik, O.M., Webb, J., Wells, J. and Carroll, A.G. (in press). Coastal to deep-marine geomorphic classification: a standardised framework and review of terms to support globally consistent mapping. Earth-Science Reviews.</div>