• Earthquakes and Structures
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• v.8 no.1
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• pp.153-184
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• 2015

Most damaging earthquakes come as complex sequences characterized by strong aftershocks, sometimes by foreshocks and often by multiple mainshocks. Complex earthquake sequences have enormous seismic hazard, engineering and societal implications as their impact on buildings and infrastructures may be much more severe at the end of the sequence than just after the mainshock. In this paper we examine whether historical sources can help characterizing the rare earthquake sequences of pre-instrumental times in full, including fore-, main- and aftershocks. Thanks to the its huge documentary heritage, Italy relies on one of the richest parametric earthquake catalogues worldwide. Unfortunately most current methods for assessing seismic hazard require that earthquake catalogues be declustered by removing all shocks that bear some dependency with those identified as mainshocks. We maintain that this requirement has led most modern historical seismologists to focus mainly on mainshocks rather than also on the fore- and aftershocks. To shed light onto major earthquake sequences of the past, rather than onto individual mainshocks, we investigated 10 damaging earthquake sequences ($M_w$ 4.7-7.0) that hit the L'Aquila area and central Abruzzo from the 14th to the 20th century. We find that most of the results of historical research are important for modern seismology, yet their rendering by the current parametric catalogues causes most information to be lost or not easily transferred to the potential users. For this reason we advocate a change in current strategies and the creation of a more flexible standard for storing and using all the information made available by historical seismology.

• Journal of the Korean earth science society
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• v.33 no.7
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• pp.637-644
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• 2012

The Seoul metropolitan area is densely populated with 40 percent of Korean people and quite weak to the seismic hazard. According to the analysis of historical documents, the largest earthquake occurred in this area is MMI VIII-IX acompanying with a large shaking, collapse of stone walls, collapse of houses, and many casualties. Two times of damaging earthquakes occurred in the first century (A.D. 27, 89), and there was a long quiet period of about 1430 years. Another big earthquakes re-occurred three times in the 16-17 century (1518, 1613, 1692) and then a quiet period has continued to the present time. Just after Seoul earthquake in 1518, aftershocks occurred almost 19 days consecutively and many triggered earthquakes occurred not only in Seoul metropolitan area but also in Hwanghae province, northern Korea. It indicates that the largest potential earthquake in and around Seoul is MMI VIII-IX with a long occurrence period of about 1400-1500 years.