Speaker
Prof.
Klaus-G. Hinzen
(Cologne University)
Description
Earthquakes cause ground motions and ground motions can cause damage to engineered structures. Engineering seismology’s main goal is to design structures that withstand such ground motions. Models for simulating ground motions, given that the seismic source and the travel path parameters can be assumed or are known, can be constructed which can help quantify damage scenarios. By applying a variety of models, the dynamic behavior of engineered structures can be calculated. In archaeoseismology, the timeline of operation is reversed. It is a discipline that includes time travel; i.e., to reconstruct the site when the damage occurred as opposed to merely modeling a contemporary structure and its associated geology. In addition to the geology, the only available data is the evidence of structural damage revealed by archaeological techniques in ongoing or completed excavations; in the latter case, documentation may be limited. Therefore, the task becomes one of starting with the damage, and then travel backwards in time, make models, evaluate possible non-seismic causes, estimate ground motion characteristics, and eventually conclude on the existence and character of the assumed earthquake source.
The tools available to the quantitative archaeoseismologist include Finite and Discrete Element techniques to virtually test structures and the considerable range of methods available to calculate synthetic site-specific seismograms. On-site data acquisition is often necessary to quantify parameters required for the models, and these include estimates for anthropogenic structures and the subsurface. The complexity of the problem introduces large uncertainties in the results; however, by continuously striving to quantify, these methods can also provide a reasonable estimation of uncertainty, more so than ‘common knowledge’ interpretations of archaeologically documented damage. We use field cases from Greece, Turkey, Israel and Italy to illustrate the quantitative concept.
Primary author
Prof.
Klaus-G. Hinzen
(Cologne University)
