This brief report updates the ‘Two-part Seabed Geomorphology classification scheme’ of Dove et al. (2016) and presents a new glossary (Part 1) of Seabed Morphology features. This Morphology glossary is intended to provide marine scientists with an accurate and robust way to characterise the seabed. Each glossary entry includes a feature definition and a representative schematic diagram to support clear and consistent classification. Feature terms and definitions are primarily drawn from the IHO guide for undersea feature names, which are herein modified and augmented with additional terms to ensure the final feature catalogue and glossary encompasses the diversity of morphologies observed at the seabed, while also minimising duplication and/or ambiguity. This updated classification system and new glossary are the result of a collaboration between marine geoscientists from marine mapping programmes/networks in Norway (MAREANO), Ireland (INFOMAR), UK (MAREMAP), and Australia (Geoscience Australia) (MIM-GA). A subsequent report will present the (Part 2) Geomorphology feature glossary. <b>Citation:</b> Dove, Dayton, Nanson, Rachel, Bjarnadóttir, Lilja R., Guinan, Janine, Gafeira, Joana, Post, Alix, Dolan, Margaret F.J., Stewart, Heather, Arosio, Riccardo, & Scott, Gill. (2020). <i>A two-part Seabed Geomorphology classification scheme (v.2); Part 1: Morphology Features Glossary.</i> Zenodo. https://doi.org/10.5281/zenodo.4071939

<div><em>Seabed geomorphology</em> describes the shape and evolution of underwater landscapes. These landscapes interact with ocean currents to create diverse marine habitats. Similar to geological maps on land, maps of seabed geomorphology are vital for making informed decisions to support the sustainable growth of our Ocean Economy.</div><div><br></div><div>As we gather more detailed seabed data and face increasing ocean pressures, there's a need for new, standardised maps that support consistent decision making at multiple scales and between administrative jurisdictions. Dr Rachel Nanson and an international team have developed a new seabed geomorphology classification system that is designed to simplify complex seabed interpretations into a map format that is accessible to a broad range of end users.</div><div><br></div><div>This approach is being adopted internationally and is currently being implemented by Geoscience Australia. We are using the method to map parts of Australia’s extensive Marine Park network and to support government to make informed decisions regarding Australia’s rapidly expanding Offshore Renewable Energy sector</div>