storms which swept over France, Germany and Switzerland in December
1999 caused major damage to hundreds of monuments. A few months previously,
several earthquakes had struck the Mediterranean countries, damaging
in particular the cultural sites of Istanbul and Athens. In 1997, Umbria
and the Italian Marches were hit by five earthquakes. The Basilica of
St Francis of Assisi, which lost whole sections of its structure, including
frescoes by Cimabue and Giotto, was their most famous victim. Fires
and flooding also regularly cause destruction to monuments.
Each biotope has its own particular form of deterioration - Egypt's
limestone is eroded by sandstorms, the granite of the Celtic megaliths
by sea salt. Bacteria, algae, lichens and insects are all elements of
nature which leave their traces on monuments.
It is also true that nothing - not even a masterpiece - is eternal.
The most incorruptible materials age. Paintings buckle, the frameworks
of buildings sag, varnishes lose their brilliance, woods and marbles
acquire a patina.
Does this mean that we cannot withstand the destructive forces of nature
and the passage of time? Not altogether. Nowadays, innovative technologies
offer new weapons of prevention, protection and restoration to those
in charge of heritage.
1986, the European Union has been supporting the biggest international
research programme dedicated to damage caused to our cultural heritage
by the environment. The projects concerned encourage a multidisciplinary
approach and cross-border cooperation. Climatologists, biologists and
chemists work in concert with engineers, architects, archaeologists
and curators of various countries to analyse the state of conservation
and the damage suffered by monuments and works of art.
In Europe and throughout the world, the safeguarding of cultural treasures
is nowadays a highly important sector of economic activity. Synergies
with industry lead to innovations, often based on technologies or materials
used for other purposes. This field of research is in fact particularly
valuable in terms of technology transfers from areas as diverse as the
aerospace industry, pharmacy, medicine, geology, etc. Progress in all
these fields is helping to renew preservation strategies. One example,
unique in Europe, is the facility for testing earthquake-proof construction
technologies at the ELSA Laboratory, part of the Joint Research Centre
in Ispra (Italy), where numerous tests of the technologies for protecting
historical monuments have been conducted.
Earthquake-proof surgery in Assisi
Shaken by earthquakes in 1997, the Basilica of St Francis has been
subjected to various anti-earthquake treatments. Among these, a project
led by an Italian SME, together with the Joint Research Centre of
Ispra (IT) and other universities and research centres in Italy, Greece
and Portugal, has made it possible to supply a new type of reinforcement:
an alloy of nickel and titanium belonging to the shape memory alloy
family. As this material is capable of dissipating energy when movement
it should increase by at least 50% the resistance of structures to
earthquakes where it has been inserted.
When wood suffers from the climate
Wooden components of historical architecture that are sensitive to humidity
are deteriorating. European scientists have analysed climatic variables
(temperature, rainfall, etc.) at different German, Polish, Swedish and
Norwegian sites where some of these wooden monuments are located. The
development of a new type of sensor has made it possible to assess the
state of preservation and damage suffered. The scientists then drew
up a "map of climatic hazards" which provides a knowledge
base on which appropriate protective measures can be based.
Fragile archaeological testimonies
A multidisciplinary team of archaeologists, geologists, microbiologists,
osteologists, geochemists, mineralogists and others are analysing bones
at various excavation sites and the soil samples surrounding them. Indications
as to their condition and state of conservation will make it possible
to establish a quality scale for the subterranean environment. For many
researchers, these testimonies to our pre-history and history ought,
as far as possible, to be preserved in situ.