The 18 September 1692 Earthquake in the Belgian Ardenne and Its Aftershocks - Historical Seismology: Interdisciplinary Studies of Past and Recent Earthquakes - page 218

and are not real aftershocks, but represent seismic activity triggered there by the
strong mainshock. Even for Aftershock 4, only reported in Aachen not very far
from the main shock epicenter, it is impossible to certify if it is a real aftershock or
an event that occurred along the border fault zone of the Roer Graben, very close to
Aachen.
On the other hand, due to the geographical repartition of its felt area and the
description in Soiron, aftershock 6 appears as a real one.

7 Conclusion

The knowledge of the 18 September 1692 September has greatly improved during
the last ten years by the numerous new documents found in different record-offices
in Belgium, Germany, The Netherlands and France. In this publication, we propose
a new macroseismic map of the earthquake in terms of the EMS-98 macroseismic
scale, from which it is suggested a better epicenter location, than in previous inves-
tigations, within the area of Verviers-Soiron-Herve-Montzen. However this conclu-
sion should be revisited in the light of possible new discoveries in the archives for
localities in the Belgian Ardenne and the Eifel mountains.
With a magnitude between 6 and 6 1 / 4 , it is the largest known historic earthquake

which occurred in Northwest Europe. Thus, it is an earthquake of reference for the
assessment of seismic hazards and risks. For the purpose of evaluating the risks
on buildings, it is now important to undertake investigations on the vulnerability
of typical constructions of the end of the 17th century to more precisely assign
intensities in the epicentral area.
The earthquake had a strong impact on patrimonial buildings, destroying chur-
ches, and castles in the epicentral area, but provoking also heavy damage at larger
distances. It is important to analyse these damages and destructions more carefully
to improve the knowledge on the effects of earthquakes to the patrimonial build-
ings with the objective of incorporating paraseismic design when a costly repair is
undertaken on a specific building.

Acknowledgments This study results from scientific investigations conducted in the frame-
work of the European Commission projects SAFE (EVG1-CT-2000-00023) and the project of
the Belgian Federal Public Planning Service Science Policy MO/33/010: “Recherche et analyse
systematique des sources historiques concernant les tremblements de terre destructeurs de nos
regions entre 1350 et 1900”.
We would like to thank the scientists and scholars who contributed to our research:
Dr.G.Grunthal, from the GeoForschungsZentrum Postdam, who supplied a copy of the Ungl ucks-
Chronica; Mrs S. Boulvain and M-P. Rahier, MM. E. Chefneux, J. Delsupexhe, B. Dumont,
Chr. Dury, P. Eppe, M. Fanon, J. Flick, J.A. Fraipont, K. Gommes, P. Guerin, C. Meessen, A. Ozer,
E. Schepens and R. Wilkin who all brought new data to our attention.
We greatly thank M. Demecheleer and H. Kempson, from the Universite Libre de Bruxelles,
who translated in English the original historical sources.
We are also very grateful to Dr. A. Levret and Dr. K. Hinzen who made helpful comments that
improved the manuscript.