This article involves an original method to classify low magnitude sei
smic events recorded in France by a network of seismometers. This meth
od is based on the merging of high-level data with possibly incomplete
low-level data extracted from seismic signals. The merging is perform
ed by a multi-layer neural network. A fuzzy coding is applied to the n
eural network's inputs to process efficiently incomplete data. The res
ults reveal that the fuzzy coding coupled with the data merging increa
ses the correct classification rate to more than 90% even when the dat
abase contains missing values.