Geoscience Reference
In-Depth Information
8
The impact of the earthquake activity in
Western Europe from the historical and
architectural heritage records
THIERRY CAMELBEECK, PIERRE ALEXANDRE, ALAIN SABBE, ELISABETH
KNUTS, DAVID GARCIA MORENO, AND THOMAS LECOCQ
Abstract
This chapter presents and discusses the impact of the earthquake activity in
the plate interior region of Western Europe extending from the Lower Rhine
Embayment to southern England. The present study is based on methodologies
combining the historical and architectural heritage records to better quantify
moderate and extensive damage from past earthquakes. These methodologies
have been applied to seven destructive earthquakes with magnitudes ranging
from 4.5 to 6.0, characteristic of the seismic activity of this area.
The extremely high seismic vulnerability of this region is illustrated by
the destruction resulting from small shallow earthquakes such as the 1983
M
Colchester (England) earthquakes
and the elevated financial losses produced by the 1992 M
=
4.6 Liege (Belgium) and 1884 M
=
4
¾
5.3 Roermond
(the Netherlands) earthquake, despite the low observed intensities. This vul-
nerability is directly related to the very high density of population and to the
substantial fraction of poorly constructed masonry dwellings in the building
inventory in most of the cities of Western Europe. Indeed, the consequences of
arareM
=
6.0 seismic event, such as the Verviers (Belgium) 1692 earthquake,
could certainly be catastrophic in terms of victims and destruction.
Comparing the damage caused by past earthquakes in large structures such as
churches or castles and classical dwellings provides information on their source
and regional site effects. On the one hand, the earthquakes that caused moderate
to heavy damage to large structures located far away from the epicentre had
magnitudes greater than 5.0. On the other hand, the observation that churches
were damaged in some localities of the Lower Rhine Embayment or the Brabant
Massif while typical houses located in the same localities suffered less or had
no damage appears to be related to the presence of a sedimentary cover with a
