Submap database &amp; web-tool milestones from their birth to their current state and future developments
Authors: Lallemand Serge , Cerpa Nestor , Peyret Michel , Heuret Arnauld , Arcay Diane , van Rijsingen Elenora 
Published: March 2024

Submap (www.submap.fr) is a web-tool for generating maps and cross-sections, and for displaying datasets of subduction zone areas. Maps and (cross-)sections rely on the (Py)GMT library and global geophysical databases. Submap is also a mean for sharing our own Submap database, which compiles data on subduction kinematics, on the characteristics of the convergent plates and on their geometry, as well as on the seismogenic characteristics of the subduction interface along 260 transects evenly distributed across all active oceanic subduction zones.What makes this tool so special is that one can access over 200 tectonic parameters for every transect with a single click. , as new studies are produced by the Submap team or by the wider community.The idea of developing such a tool arose from the subduction zone comparative study carried out by Arnauld Heuret during his PhD thesis in 2005. In a first version (2009), we proposed an aid to the rapid creation of MAPS and SECTIONS using global databases (topo-bathymetry, gravimetry, age of the seafloor, seismicity) using the GMT library in a way that was transparent to the user via a query page. We then added the possibility to extract a number of characteristic parameters for the 260 transects composing the Submap database (module Sub-DATA in 2013). This database has grown over years, incorporating, for instance, new parameters describing the seismogenic zone after we published a global study on this .In 2023, we decided to fully redesign the web-tool. A major effort has been made to facilitate the use on all types of screens (computers, tablets). We enhanced the range and the rendering of documents made available for download, and the tool was made accessible to all audiences. In terms of content, a new module called MAP-Subquake now allows to plot the rupture envelopes for selected subduction earthquakes together with the roughness of the subducting seafloor facing the ruptures. The latter dataset comes from Submap team publications in 2018. Moreover, several parameters were revised or added to the Submap dataset, such as the sediment thickness in the trench or in the subduction channel, and the kinematics. We are currently working on the geometric characteristics of the volcanic arcs and on a better representation of the strain in the upper plate, planning to update the database by the end of the year.Submap is primarily a useful working tool for research on subduction zones, as it lists and displays a vast amount of complementary data in an optimized format that facilitates comparative analysis. It is also a meaningful tool for teaching at secondary and higher-education levels, as a support for courses or as part of tutorials or individual work for high school and university students. It can be used to quickly obtain accurate documents to support workshops, for example to determine the best segmentation criteria in order to define the seismic hazard of a zone, or simply to study the lateral variations of certain parameters of a subduction zone.