ANTWERPEN (BE)

Intensity of a municipality or a cell (CII, Community Internet Intensity) is computed as follows:

• I if no answer reports that the earthquake was felt;
• F earthquake felt, but fewer than 3 answers kept per municipality or cell;
• II–IX computed from 3 answer(s) kept: CII = 3.40 ln(CWS) − 4.38 (Wald et al., 1999), applied to the weighted sum (CWS) of the mean indexes of the answers; at least II if felt, at most IX.

Answers kept (USGS method, as applied by the ROB): reliability of 80 or more, given on the ground floor up to the 4th floor (or unknown floor), without those more than two standard deviations from the mean. The “felt” index is weighted by the answer to “Did others nearby feel it?”.

Distribution by intensity: macroseismic intensity (MI) recorded for each answer.

Cells: 5 or 10 km squares of the Belgian Lambert 72 grid, each answer placed at its geocoded address or at the point it placed on the map, otherwise at the centre of its municipality. The positions of the answers are published only rounded to about 1 km, in “Arrival of the answers”. Grid cell method: Van Noten et al. (2017), Solid Earth 8, 453–477, doi:10.5194/se-8-453-2017.

Arrival of the answers: time each answer of reliability 80 or more was sent, duplicates removed; position rounded to 0.01° (about 1 km), geocoded or otherwise at the centre of the municipality, where several answers may therefore pile up. Answers without a usable sending time or position, not shown: 2.

Depth not determined: distances measured from the epicentre.

Answers without a known municipality, left out of the map and the chart: 2.

Answers read on 2026-11-09 09:53.