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The standard global model to define shallow site properties (Vs30) comes from the USGS Global Vs30 model https://earthquake.usgs.gov/data/vs30/. Currently the site model assumes a fixed Vs30, but it would be critical that the global Vs30 database can be used (as was the case for the previous shakyground library). However, no WEB API exists to query and download the Vs30 data, meaning that the data would need to be extracted from the global raster. This is problematic as the global raster is approximately 1 Gb in size, which would either need to be included in the code itself or can be retrieved easily from an online service.

Some points to consider:

1. The 1 Gb global raster covers the entire globe at 30 arc-seconds, including oceanic regions that effectively have no Vs30. If the raster were sliced into tiles and stored in an hdf5 file this could i) allow us to cut out about 2/3 of the data, ii) possibly make extracting the Vs30 values faster. But even in the best case this would still result in a data file of a couple of hundred Mb and extracting from tiles can be problematic for events on the edges of the tiles

2. An alternative would be to develop a lightweight API service that could allow users to access the site model information from GFZ's own files. This has the advantage that we could store all of the relevant site data (including other properties beyond just Vs30) in a single database or hdf5 and the user can download the site model information in one command. But the concerns here would be security, volume of usage etc.