tivity on the carmel faul

world in order to chronologically reconstruct principal paleoseismic events and to estimate the
maximum earthquake possible in a given seismogenic area.
1.2.1 Previous studies
A number of studies are of particular relevance to this discussion. Postpischl et al. (1991)
took samples of growth anomalies in stalagmites from the “Grotta Del Cervo” and the “Grotta
a Male” (caves in central Italy), and dated them using 14 C and U/Th radiometric methods.
Observing the anomalies, they found they are always related to earthquakes or other tectonic
events. They also found that collapsed stalagmites presented preferential azimuths,
demonstrating an involvement of the entire karst area and therefore, the tectonic character of
the event which generated a particular collapse. They associated these collapse formations with
four different seismic periods of ac<strong>tivity</strong>, the youngest of which is most probably related to the
December 1456 earthquake that occurred in central Italy.
Morinaga et al. (1994) inferred paleo-seismicity from paleo-magnetic dating of
speleothems in western Japan. Those researchers claimed that in areas of active seismicity,
earthquakes can contribute to a condition in which blocks are “ready to collapse”. Using data
on weak, yet stable remnant magnetization of speleothems, they determined the Paleo-Secular
Variation (PSV) of a geomagnetic field, which they then compared to a standard curve in order
to establish the time of growth. In that study three stalagmites, which were perched on
collapsed limestone blocks, yielded three ages interpreted to indicate dates of past earthquakes.
In order to validate this research method, Lemeille et al. (1999) conducted research in
regions where earthquakes are studied and known from historic based catalogues. A regional
study was carried out in the vicinity of Basel (Switzerland), the area of the greatest damage
during the historically dated earthquake of 1356 CE. They explored and analyzed growth
anomalies and displacements of speleothems in two karstic caves. Battlerloch Cave yielded a
fallen block from which dating samples of re-growth phases were taken in order to confirm
their seismic origins. Dieboldslochli Cave revealed a large number of broken stalagmites; the
offset of re-growth on the fault plane is assumed to be related to a number of events, all of
which could have been caused by earthquakes. Moreover, some preliminary data on ages of
these anomalies corresponded to the 1356 CE earthquake.
Similar studies were carried out by Gilli et al. (1999), who investigated eight caves near
St. Paul de Fenouille in the eastern Pyrenees (France), following an earthquake of magnitude
5.2 in February 1996. That kind of study has the advantage of knowing the age of the damage
and the accurate magnitude of an event. Collapsed soda straw stalactites and small rocks were
observed and attributed to the earthquake. Other more ancient damage was also noted. A
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