Question:
How does the Geo-zone tool determine the earthquake data according to DIN EN 1998‑1?
Answer:
The raw data comes from DIN EN 1998‑1/NA:2021 07, including the additional digital content. The GPS coordinates and the response acceleration S-aP, R in the plateau area of the response spectrum are available in the form of an Excel table. It shows the GPS coordinates for the latitude and longitude in decimal degrees with an accuracy of 0.1°. The geo-zone tool also works with a grid size of 0.1°×0.1°. The values from the additional digital content are defined as a center of each cell. The result of the search query is then taken from the corresponding cell. Intermediate values are not interpolated nor extrapolated. Therefore, it may happen that the color range does not correspond the result from the cell, because the curves do not follow the grid, but lie on a separate layer.
Example:
City: Ludolf Camphausen Street in Cologne
As you can see in the image, the location in the cell is located at 6.9° east and 50.9° north. Thus, the location you are looking for gets a response acceleration of 1.7144 m/s², as it is not interpolated.