Archaeoseismology and Palaeoseismology in the Alpine ... - Tierra

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are of lower slip‐rates (Pollino 0.3 mm/yr; Volturara 0.3 mm/yr). Sensitivity Analysis A sensitivity analysis was carried out to determine the way different isoseismal dimensions influence the shaking frequency maps. As a result, a new shaking frequency map has been constructed by increasing the dimensions of isoseismal IX from a 12.5 km radius to a 20 km radius (Fig.3); which is an extreme upper value for a Ms=6.5 earthquake in the southern Apennines. Fig.3 :Map showing how many times a locality receives enough energy to shake at intensities ≥IX in 18 kyrs, assuming homogenous bedrock geology, a circular pattern of energy release and a 20 km radius of isoseismal IX which is an extreme upper value for a Ms=6.5 earthquake in the southern Apennines. By implementing larger dimensions for the intensity IX isoseismals the affected area, as expected, has been enlarged. In order to: i) quantify the differences in terms of frequency of earthquake shaking between Figures 2 and 3, and ii) delineate how these differences are distributed spatially; a third map has been constructed and presented in Figure 4. In a few words, Figure 4 maps the differences by subtracting the shaking frequency map constructed with a 12.5 km radius of isoseismal IX from the shaking frequency map constructed using a 20 km radius of isoseismal IX. The highest difference is observed in the area of the stepover between the Vallo di Diano and the Maratea faults, where more than 50 additional events (up to 58) are calculated (Fig. 4). This is a substantial ten fold increase between the hazard map constructed using a 12.5 km radius of isoseismal IX and the map constructed with a 20 km radius of isoseismal IX. When applying a 20 km radius, each isoseismal occupies 156% more area compared to the area covered by a 12.5 km radius isoseismal (1256 km 2 instead of 491 km 2 ). However, there is only a 75% increase in the maximum frequency value (63 instead of 36). Hence, it should be noted that this increase of frequency values is not distributed uniformly in the study area. For example, in the stepover of the Vallo di Diano and the Val' D' Agri 1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archaeology and Palaeoseismology) 104 faults, there is almost a ten fold increase (1000%) in frequency values, whereas in other areas such as the hangingwall centres of the Val' D' Agri, the Monte Alpi and the San Gregorio faults there is only a 10‐25% increase. Therefore, it is clear that the hazard pattern is modified in a non‐spatially uniform way so that the 156% increase of the area affected from a single isoseismal can not be extrapolated uniformly to the entire map. Fig.4: Map showing the frequency differences between Fig. 2 and 3 by subtracting the hazard map constructed with a 12.5 km radius from the hazard map using a 20 km radius of isoseismal IX. THE ESI 2007 Traditional intensities from which attenuation laws are extracted are based on human parameters. However, when using the effects on man and manmade environment to assess the macroseismic intensity, then intensity will tend to reflect mainly the economic development and the cultural setting of the area that experienced the earthquake, instead of its “strength” (Serva, 1994). The Earthquake Environmental Effects (EEE) are not influenced by human parameters as the traditional intensity scales (MCS, MM, EMS 1992, etc) predominantly imply. The ESI 2007 provides a quantitative analysis and description of the EEE offering a more credible documentation and has already been easily applied in several events worldwide (Lalinde and Sanchez, 2007, Papathanassiou and Pavlides 2007, Serva et al., 2007, Papanikolaou et al., 2009). Among other advantages this scale: i) allows the accurate assessment of intensity in sparsely populated areas, ii) provide a reliable estimation of earthquake size with increasing accuracy towards the highest levels of the scale, where raditional scales saturate and ground effects are the only ones that permit a reliable estimation of earthquake size and iii) allows the comparison among future, recent and historical earthquakes (Michetti et al., 2004).
It is possible that a portion of this variation in the data that introduces the large uncertainty in the attenuation laws stems from the way macroseismic effects have been assessed. Thus, wherever feasible, by reconstructing the macroseismic field of historical earthquakes, through the use of the ESI 2007 scale, uncertainties may be significantly reduced (Papanikolaou et al., 2009). DISCUSSION Sensitivity analysis showed that the error introduced by the implied uncertainty in the dimensions of modelled isoseismals is significantly larger than the fault slip‐rate error of ± 20 %. This is remarkable because it shows that input parameters such as the isoseismal dimensions which themselves are derived from empirical attenuation relationships, influence the results more significantly than the uncertainty implied from the fault slip‐rate data, which govern the earthquake recurrence. Herein, it should be noted that the complication and uncertainty in earthquake ground motion and consequently in the attenuation/amplification relationships is not only related to the way intensity values have been assigned and isoseismal lines have been drawn, but also emerges from several other factors, which are critical but not accurately known. In particular, uncertainty in the seismic hazard assessment stems from factors such as the fault geometry, slip‐rates, the earthquake occurrence model etc. Moreover, there is also an intrinsic variability in seismic shaking caused by basin‐ edge induced surface waves, focusing and defocusing effects and scattering in general that cannot be reduced in any model (e.g. Field et al., 2000). Therefore, there is little hope that all uncertainties implied by the attenuation/amplification relationship can be fully reduced. However, it is also probable that part of this uncertainty stems out of the intensity evaluation, whereas the application of the ESI 2007 scale could limit the uncertainties. CONCLUSIONS Seismic hazard maps are highly sensitive to the attenuation relationship used, forming a major source of uncertainty and in several cases they overshadow all the other factors of uncertainty, even slip‐rates which govern the earthquake occurrence. Earthquake Environmental Effects provide higher objectivity in the process of assigning intensity values, so that the ESI 2007 scale is the best tool to compare recent, historic and pre‐historic earthquakes as well as earthquakes from different tectonic settings. A re‐ appraisal of recent and historical earthquakes so as to constrain the ESI 2007 scale and the extraction of ESI‐ based attenuation laws, may prove beneficial for the seismic hazard assessment by reducing the present day large uncertainty implied in the attenuation laws. References Bolt, B.A., 1999. Earthquakes. W.H. Freeman and Company, New York, 366pp. Coburn, A. and Spence, R. 2002. Earthquake protection. 420p. John Wiley&Sons, Ltd, West Sussex, England. 1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archaeology and Palaeoseismology) 105 D’Amico, V., Albarello, D., & Mantovani, E. (1999). A distribution‐ Free Analysis of Magnitude‐Intensity Relationships: an Application to the Mediterranean Region. Phys. Chem. Earth 24, 517‐521. Grandori, G., Drei, A., Perotti, F. and Tagliani, A. (1991). Macroseismic intensity versus epicentral distance: the case of Central Italy. Tectonophysics 193, 165‐171. Field, E.H., and the SCEC Phase III Working group, (2000). Accounting for site effects in probabilistic seismic hazard analyses of southern California: Overview of the SCEC Phase III report. Bulletin of the Seismological Society of America 90, S1‐ S31. Lalinde, C‐P. and Sanchez J.J. (2007). Earthquake Environmental Effects in Colombia during the past 35 years: INQUA scale Project. Bulletin of the Seismological Society of America 97, 646‐654. Lee, K., & Kim, J‐K. (2002). Intensity Attenuation in the Sino‐ Korean Craton. Bulletin of the Seismological Society of America 92, 783‐793. Michetti, A.M., Esposito, E., Gurpinar, A., Mohammadioun, B., Mohammadioun, J., Porfido, S., Rogozhin, E., Serva, L., Tatevossian, R., Vittori, E., Audemard, F., Comerci, V., Marco, S., McCaplin, J. and Morner, N.A. (2004). The INQUA scale: An innovative approach for assessing earthquake intensities based on seismically‐induced ground effects in natural environment. Sp. paper Mem. Descr. Carta Geologica D’ Italia LXVII, pp.118 Roma. Michetti, A.M., Audemard, F.A. and Marco, S. (2005). Future trends in paleoseismology: Integrated study of the seismic landscape as a vital tool in seismic hazard analyses. Tectonophysics 408, 3‐21. Michetti, A.M. et al. (2007). Intensità scale ESI 2007. In Guerrieri L.and Vittori, E. (Eds): Mem. Descr. Carta Geol. d’ Italia 74, Servizio Geologico d’ Italia‐Dipartimento Difesa del Suolo, APAT, Rome Italy. Papanikolaou, I. D. (2003). Generation of high‐resolution seismic hazard maps in extensional tectonic settings through integration of earthquake geology, fault mechanics theory and GIS techniques. Unpublished PhD thesis, University of London. 437pp. Papanikolaou, I.D. and Roberts G.P. (2007). Geometry, kinematics and deformation rates along the active normal fault system in the Southern Apennines: implications for fault growth. Journal of Structural Geology 29, 166‐188. Papanikolaou, I.D. Papanikolaou, D.I, and Lekkas, E.L. (2009). Advances and limitations of the environmental seismic intensity scale (ESI 2007) regarding near‐field and far‐field effects from recent earthquakes in Greece. Implications for the seismic hazard assessment. From Reicherter, K., Michetti, A.M., and Silva, P.G. (eds), Paleoseismology: Historical and Prehistorical Records of Earthquake Ground Effects for Seismic Hazard Assessment. Special Publication of the Geological Society of London 316, 11‐30. Papathanassiou, G. and Pavlides, S. (2007). Using the INQUA scale for the assessment of intensity. Case study on the 2003 Lefkada (Ionian Islands), Greece earthquake. Quaternary International 173‐174, 4‐14. Roberts, G.P., Cowie, P., Papanikolaou, I. and Michetti, A.M. (2004). Fault scaling relationships, deformation rates and seismic hazards: An example from the Lazio‐Abruzzo Apennines, central Italy. Journal of Structural Geology 26, 377‐ 398. Serva, L. (1994). Ground effects in the intensity scales. Terra Nova 6, 414‐416. Serva, L., Esposito, E., Guerrieri, L., Porfido, S., Vittori, E. and Commerci, V. (2007). Environmental effects from five historical earthquakes in southern Apennines (Italy) and macroseismic intensity assessment: Contribution to INQUA EEE Scale project. Quaternary International 173‐174, 30‐44. Yeats, R.S. and Prentice, C.S. (1996). Introduction to special section: Paleoseismology. Journal of Geophysical Research 101, 5847‐5853.
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Abstracts Volume Archaeoseismology
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Edita e imprime: Sección de Public
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1 st INQUA‐IGCP‐567 Internation
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the importance of performing absolu
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indicative of strike‐slip faultin
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DISCUSSION Based on detailed field
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Table 1: Source parameters used in
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elations. However, the attenuation
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mostly concentrated on the DST in I
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continuous support. N. Shalev, G. G
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The tumulus initial morphology show
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our understanding and prediction of
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spans, with a threefold increase fr
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Nevertheless the lack of research,
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earthquake. In uncertain cases, as
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The site reconnaissance successfull
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Table 1: Surface faulting extent re
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The graben has a markedly asymmetri
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are a valuable addition to the rout
Page 55 and 56: to 400 m) the calculated values for
Page 57 and 58: RISK ANALYSIS The created hazard ma
Page 59 and 60: 290 m water depth the basin accumul
Page 61 and 62: CONCLUSIONS From the palaeostress a
Page 63 and 64: Fig. 2: Geological map of the study
Page 65 and 66: 1 st INQUA‐IGCP‐567 Internation
Page 71 and 72: however, the massive 1995 earthquak
Page 73 and 74: mapped on the slopes above Qiryat
Page 77 and 78: interpreted as either an expression
Page 79 and 80: The Shepran Cave is located on the
Page 87 and 88: properties. The mean value of speci
Page 91 and 92: excavated a deep trench, thus provi
Page 99 and 100: Fig. 8: Seismic ground shaking may
Page 101 and 102: elevant qualitative criteria are po
Page 103 and 104: CONCLUDING REMARKS The exposed exam
Page 105: produced by significantly different
Page 109 and 110: In addition, the Database of histor
Page 111 and 112: were published by IGME (1983) and E
Page 115 and 116: The city collapsed and it was aband
Page 119 and 120: Fig. 4: Slipped lintel in a window
Page 121 and 122: to overcome shear resistance and in
Page 123 and 124: Newmark, N.M. (1965). Effects of ea
Page 125 and 126: associated with various tsunamis (<
Page 129 and 130: this method, the magnitude of the e
Page 133 and 134: etween pieces. Fragments have not f
Page 137 and 138: on the exact date of the earthquake
Page 139 and 140: THE ARCHAEOLOGICAL ZONE COLOGNE Aft
Page 143 and 144: affecting the Alcázar was about 50
Page 147 and 148: archaeoseismology could instead bec
Page 149 and 150: In the area later occupied by Vilni
Page 155 and 156: Fig. 2: Assemblage of landforms ass
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Fig. 8: Data and regression for mag
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Fig. 3: Relationships among magnitu
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CONCLUSIONS 1. Spatial distribution
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The stratigraphic sequence (Fig. 4)
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especially in the zones of hanging
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interpretations are based on relati
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Fig. 5: Gray‐scale value laser im
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(~40 cm), F‐ rotated building str
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Index 1 st INQUA‐IGCP‐567 Inter
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