Archaeoseismology and Palaeoseismology in the Alpine ... - Tierra

1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archeology and Paleoseismology
ARCHAEOSEISMOLOGY: PAST, PRESENT AND FUTURE
M. Sintubin (1), I.S. Stewart (2), T. Niemi (3) and E. Altunel (4)
(1) Department of Earth & Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B‐3001 Leuven. BELGIUM.
manuel.sintubin@ees.kuleuven.be
(2) School of Earth, Ocean & Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, U.K.
iain.stewart@plymouth.ac.uk
(3) Department of Geosciences, University of Missouri‐Kansas City, 5110 Rockhill Road, Kansas City, Missouri 64110‐2499, U.S.A.
niemit@umkc.edu
(4) Department of Geological Engineering, Eskişehir Osmangazi Üniversitesi, 26480, Eskişehir, TURKEY. ealtunel@ogu.edu.tr
Abstract: Reflecting on the burgeoning scientific discipline of archaeoseismology a clear trend can be discerned. What started as an
“extravaganza” in a good story (archaeological perspective) became a multidisciplinary effort to get a maximum amount of information on the
parameters of ancient earthquakes out of archaeological evidence (seismological and archaeoseismological perspective). A clear shift can be
observed from a more qualitative approach focussing on the extension of earthquake catalogues to a more quantitative approach concerning
site effects. But looking into the future, the vocation of archaeoseismology may lie elsewhere. Archaeoseismology could become a holistic
interdisciplinary discipline concerned with establishing the essential earthquake culture in a region (sociological perspective).
Key words: archaeology, earthquake, seismic culture
ARCHAEOSEISMOLOGY
Archaeoseismology is the study of ancient earthquakes
through traces left into archaeology the archaeological
record. In this respect it is commonly considered that this
burgeoning scientific discipline aims at bridging the gap
between instrumental and historical seismology on one
side and palaeoseismology and earthquake geology on
the other (e.g. Caputo and Helly, 2008).
To date, the scientific community remains rather sceptical
as to whether cultural material data – destruction layers,
structural damage to manmade constructions, displaced
manmade structures, indications of repair and
abandonment, and inscriptions – can reliably be used as
earthquake indicators at all. The extent to which this
research field can contribute to seismic‐hazard analysis
still remains to be proven.
PAST: AN ARCHAEOLOGICAL PERSPECTIVE
Archaeologists, like e.g. Arthur Evans (1928) or Claude
Schaeffer (1948), introduced earthquakes into
archaeology. Earthquakes were used rather
indiscriminately – as a ‘deus ex machina’ – to explain the
otherwise inexplicable, such as the sudden desertion of a
site or its destruction at a time when no marauders were
known. Earthquakes simply added drama and conjecture
to a site’s history. In such interpretations the basic
physical parameters of earthquakes are often ignored,
especially where imprecise age control leads to discrete
multiple seismic events being amalgamated, thereby
giving rise to seismological monsters (Guidoboni, 2002)
that are “beyond the limits of possible” (Ambraseys et al.
2002). While critics portray this approach as
neocatastrophism (Ambraseys, 2006), advocates see the
earthquake hypothesis as the simplest solution, referring
to Occam’s razor (Nur, 2008). The question should though
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be asked if calling upon earthquakes shouldn’t rather be
seen as an easy trap in earthquake‐prone regions.
PRESENT: A SEISMOLOGICAL PERSPECTIVE
An accurate catalogue of historical and prehistorical
earthquakes is a necessary tool for assessing the seismic
hazard of a region. And yet, the archaeological record
would seem ideal to augment the grossly incomplete
historical records of past seismicity. Historical catalogues
typically document only a few percent (Ambraseys et al.,
2002) of the damaging seismic shocks that have struck a
region over centuries to millennia. The missing population
of earthquakes clearly tempers reliable seismic‐hazard
assessment, but information on seismic effects at
archaeological sites can extend the earthquake record
beyond written sources, and consequently, ought not to
be neglected (Kovach and Nur, 2006). So it seems
perplexing that archaeological data have thus far been
largely neglected by seismic‐hazard practitioners.
But once again some pitfalls are to be avoided that adds
to the scepticism by seismologists with respect to
archaeoseismology. On the one hand, the danger exists
that the anomalous or “rogue” earthquakes, supposedly
proven by archaeologists, will be used by seismologists as
real events in a seismic‐hazard analysis (Ambraseys et al.,
2002). On the other hand, confronting historical
earthquake catalogues and archaeological data also
carries a risk. The correlation of archaeological evidence –
often with a poor temporal resolution – with documented
earthquakes in a catalogue produces circular reasoning
(Niemi, 2008)
Seismic‐hazard practitioners need exact dates and
magnitudes of past earthquakes. The question can be
asked if archaeological evidence can actually provide the
seismologist this information.