Effect of time-dependence on probabilistic seismic hazard maps and deaggregation for the central apennines, Italy

Abstract We produce probabilistic seismic-hazard assessments for the central Apennines, Italy, using time-dependent models that are characterized using a Brownian passage time recurrence model. Using aperiodicity parameters, α of 0.3, 0.5, and 0.7, we examine the sensitivity of the probabilistic ground motion and its deaggregation to these parameters. For the seismic source model we incorporate both smoothed historical seismicity over the area and geological information on faults. We use the maximum magnitude model for the fault sources together with a uniform probability of rupture along the fault (floating fault model) to model fictitious faults to account for earthquakes that cannot be correlated with known geologic structural segmentation. We show maps for peak ground acceleration (PGA) and 1.0 Hz spectral acceleration (SA 1 ) on rock having 10% probability of exceedence in 50 yr. We produce maps to compare the separate contributions of smoothed seismicity and fault components. In addition we construct maps that show sensitivity of the hazard for different α parameters and the Poisson model. For the Poisson model the addition of fault sources to the smoothed seismicity raises the hazard by 50% at locations where the smoothed seismicity contributes the highest hazard and up to 100% at locations where the hazard from smoothed seismicity is low. For the strongest aperiodicity parameter (smallest α ), the hazard may further increase 60%–80% or more or may decrease by as much as 20% depending on the recency of the last event on the fault that dominates the hazard at a given site. In order to present the most likely earthquake magnitude and/or the most likely source-site distance for scenario studies, we deaggregate the seismic hazard for SA 1 and PGA for two important cities (Rome and L’Aquila). For PGA both locations show the predominance of local sources having magnitudes of about 5.3 and 6.5, respectively. For SA 1 at a site in Rome, there is significant contribution from local smoothed seismicity and an additional contribution from the more distant Apennine faults having magnitude around 6.8. For L’Aquila the predominant sources remain local. In order to show the variety of impact of different α values, we also obtained deaggregations for another three sites. In general, as α decreases (periodicity increases), the deaggregation indicates that the hazard is highest near faults with the highest earthquakes rates. This effect is strongest for the long-period (1 sec) ground motions.

[1]  F. Galadini,et al.  ANALISI PALEOSISMOLOGICHE LUNGO LA FAGLIA DEL M. MARINE (ALTA VALLE DELL'ATERNO): RISULTATI PRELIMINARI , 2002 .

[2]  Mark D. Petersen,et al.  Time-independent and Time-dependent Seismic Hazard Assessment for the State of California: Uniform California Earthquake Rupture Forecast Model 1.0 , 2007 .

[3]  N. Pino,et al.  Geodetic and seismologic evidence for slip variability along a blind normal fault in the Umbria-Marche 1997–1998 earthquakes (central Italy) , 2003 .

[4]  Paolo Galli,et al.  The Holocene paleoearthquakes on the 1915 Avezzano earthquake faults (central Italy): implications for active tectonics in the central Apennines , 1999 .

[5]  M. Tesauro,et al.  Modeling coseismic displacements resulting from SAR interferometry and GPS measurements during the 1997 Umbria-Marche seismic sequence , 2000 .

[6]  R. Camassi,et al.  LOOKING FOR “NEW” EARTHQUAKE DATA IN THE 17th-18th CENTURY EUROPEAN “NEWSSELLERS” NETWORK , 2004 .

[7]  P. Galli,et al.  Quaternary basin evolution and present tectonic regime in the area of the 1997-1998 Umbria-Marche seismic sequence (central Italy) , 2002 .

[8]  David D. Jackson,et al.  Seismic hazards in southern California: probable earthquakes, 1994 to 2024 , 1996 .

[9]  L. Malagnini,et al.  Seismic hazard estimate in the Alps and Apennines (Italy) using smoothed historical seismicity and regionalized predictive ground-motion relationships , 2004 .

[10]  Luca Malagnini,et al.  Ground-Motion Scaling in the Western Alps , 2006 .

[11]  F. Galadini,et al.  New paleoseismological data from the Gran Sasso d'Italia area (central Apennines) , 2002 .

[12]  S. Harmsen,et al.  Documentation for the 2002 update of the national seismic hazard maps , 2002 .

[13]  Francesca Romana Cinti,et al.  Investigation of the active Celano–L'Aquila fault system, Abruzzi (central Apennines, Italy) with combined ground‐penetrating radar and palaeoseismic trenching , 2003 .

[14]  S. P. Nishenko,et al.  A generic recurrence interval distribution for earthquake forecasting , 1987 .

[15]  F. Sabetta,et al.  Estimation of response spectra and simulation of nonstationary earthquake ground motions , 1996, Bulletin of the Seismological Society of America.

[16]  M. Frezzotti,et al.  Palaeoseismicity in the Gran Sasso Massif (Abruzzo, Central Italy) , 1995 .

[17]  Morgan T. Page,et al.  Methodologies for Earthquake Hazard Assessment: Model Uncertainty and the WGCEP-2002 Forecast , 2006 .

[18]  Gianluca Valensise,et al.  Paleoseismology along the 1980 surface rupture of the Irpinia Fault: Implications for earthquake recurrence in the southern Apennines, Italy , 1993 .

[19]  Luca Malagnini,et al.  Characteristics of the Ground Motion in Northeastern Italy , 2002 .

[20]  Mark D. Petersen,et al.  Discrepancy between Earthquake Rates Implied by Historic Earthquakes and a Consensus Geologic Source Model for California , 2000 .

[21]  Mark D. Petersen,et al.  Model Uncertainties of the 2002 Update of California Seismic Hazard Maps , 2005 .

[22]  L. Sykes,et al.  "Probabilities of occurrence of large plate rupturing earthquakes for the San Andreas, San Jacinto, and Imperial faults, California,1983–2003"" , 1984 .

[23]  B. Gutenberg,et al.  Seismicity of the Earth and associated phenomena , 1950, MAUSAM.

[24]  P. Galli,et al.  ARCHAEOSEISMOLOGY IN ITALY: CASE STUDIES AND IMPLICATIONS ON LONG-TERM SEISMICITY , 2001 .

[25]  Kelin Wang,et al.  Thermal models of the Middle America Trench at the Nicoya Peninsula, Costa Rica , 2002 .

[26]  Massimiliano Stucchi,et al.  Active tectonics and seismicity in the area of the 1997 earthquake sequence in central Italy: A short review , 1999 .

[27]  Paolo Messina,et al.  Plio-Quaternary changes of the normal fault architecture in the Central Apennines (Italy) , 2001 .

[28]  Integration of geological and geophysical data along a section crossing the region of the 1997-98 Umbria-Marche earthquake (Italy) , 2002 .

[29]  A. Frankel.  Mapping Seismic Hazard in the Central and Eastern United States , 1995 .

[30]  Allan G. Lindh,et al.  Preliminary assessment of long-term probabilities for large earthquakes along selected fault segments of the San Andreas fault system, California , 1983 .

[31]  A. Tertulliani,et al.  Earthquakes in Rome during the past one hundred years , 1995 .

[32]  Mark D. Petersen,et al.  A Time-Dependent Probabilistic Seismic-Hazard Model for California , 2000 .

[33]  P. Galli,et al.  Paleoseismology of silent faults in the Central Apennines (Italy): the Mt. Vettore and Laga Mts. faults , 2003 .

[34]  Walter H. F. Smith,et al.  New, improved version of generic mapping tools released , 1998 .

[35]  E. Möbius,et al.  Charge states of energetic (≈0.5 MeV/n) ions in corotating interaction regions at 1 AU and implications on source populations , 2002 .

[36]  D. Perkins,et al.  National Seismic-Hazard Maps: Documentation June 1996 , 1996 .

[37]  S. Harmsen,et al.  Geographic Deaggregation of Seismic Hazard in the United States , 2001 .

[38]  Mark D. Petersen,et al.  A Monte Carlo approach in estimating uncertainty for a seismic hazard assessment of Los Angeles, Ventura, and Orange counties, California , 1996, Bulletin of the Seismological Society of America.

[39]  D. Weichert,et al.  Estimation of the earthquake recurrence parameters for unequal observation periods for different magnitudes , 1980 .

[40]  Sensitivity analysis for seismic source characteristics to probabilistic seismic hazard assessment in central Apennines (Abruzzo area). , 2002 .

[41]  C. Cornell,et al.  Disaggregation of seismic hazard , 1999 .

[42]  Luca Malagnini,et al.  Ground-Motion Scaling in the Apennines (Italy) , 2000 .

[43]  J. Bommer,et al.  PREDICTION OF HORIZONTAL RESPONSE SPECTRA IN EUROPE , 1996 .

[44]  C. Collettini,et al.  Connecting seismically active normal faults with Quaternary geological structures in a complex extensional environment: The Colfiorito 1997 case history (northern Apennines, Italy) , 2005 .

[45]  F. Galadini,et al.  Early–Middle Pleistocene eastward migration of the Abruzzi Apennine (central Italy) extensional domain , 2004 .

[46]  G. Lavecchia,et al.  Defining a model of 3D seismogenic sources for Seismic Hazard Assessment applications: The case of central Apennines (Italy) , 2004 .

[47]  R. Basili,et al.  The Database of Individual Seismogenic Sources (DISS), version 3: Summarizing 20 years of research on Italy's earthquake geology , 2008 .

[48]  M. Grasso,et al.  Structural setting of the Apennine-Maghrebian thrust belt , 2003 .

[49]  William L. Ellsworth,et al.  A Brownian Model for Recurrent Earthquakes , 2002 .

[50]  Luca Malagnini,et al.  Ground-Motion Scaling in the Region of the 1997 Umbria-Marche Earthquake (Italy) , 2000 .

[51]  Salvatore Stramondo,et al.  Slip distribution of the 1997 Umbria‐Marche earthquake sequence: Joint inversion of GPS and synthetic aperture radar interferometry data , 2002 .

[52]  Yosihiko Ogata,et al.  Estimating the hazard of rupture using uncertain occurrence times of paleoearthquakes , 1999 .

[53]  Rodolfo Console,et al.  A simple and testable model for earthquake clustering , 2001 .

[54]  Eser Durukal,et al.  Earthquake hazard in Marmara region , 2003 .

[55]  W. Ellsworth.  Characteristic earthquakes and long-term earthquake forecasts: Implications of central california seismicity , 1995 .

[56]  Ezio Faccioli,et al.  Treatment of ground-motion predictive relationships for the reference seismic hazard map of Italy , 2005 .

[57]  Chris H. Cramer,et al.  A seismic hazard uncertainty analysis for the New Madrid seismic zone , 2001 .

[58]  C. Bosi.  Osservazioni preliminari su faglie probabilmente attive nell'Appennino centrale , 1975 .

[59]  B. Papazachos,et al.  Time-Independent and Time-Dependent Seismic Hazard in Greece Based on Seismogenic Sources , 2000 .

[60]  Eser Durukal,et al.  Earthquake hazard in Marmara Region, Turkey , 2004 .

[61]  William A. Bryant,et al.  Probabilistic seismic hazard assessment for the state of California , 1996 .

[62]  N. Abrahamson,et al.  On the Use of Logic Trees for Ground-Motion Prediction Equations in Seismic-Hazard Analysis , 2005 .

[63]  P. Galli,et al.  Active Tectonics in the Central Apennines (Italy) – Input Data for Seismic Hazard Assessment , 2000 .

[64]  L. Malagnini,et al.  Uncertainty analysis for seismic hazard in Northern and Central Italy , 2005 .

[65]  K. Olsen,et al.  3D Ground-Motion Estimation in Rome, Italy , 2006 .

[66]  A. Pizzi,et al.  Methods for determining the Pleistocene–Holocene component of displacement on active faults reactivating pre-Quaternary structures: examples from the Central Apennines (Italy) , 2000 .

[67]  Yan Y. Kagan,et al.  Random stress and earthquake statistics: spatial dependence , 1987 .

[68]  Paolo Scandone,et al.  Il terremoto del 1456 e la sua interpretazione nel quadro sismotettonico dell\'Appennino meridionale , 1988 .

[69]  T. Kumamoto.  Seismic Hazard Maps of Japan and Computational Differences in Models and Parameters , 1999 .

[70]  Robert W. Simpson,et al.  A physically-based earthquake recurrence model for estimation of long-term earthquake probabilities , 1999 .

[71]  Paolo Galli,et al.  Surface faulting in Norcia (central Italy): a “paleoseismological perspective” , 2005 .

[72]  Bruno Pace,et al.  Layered Seismogenic Source Model and Probabilistic Seismic-Hazard Analyses in Central Italy , 2006 .

[73]  M. Giardino,et al.  Geological Evidence of recent fault evolution. Examples from Campo Imperatore (l'Aquila - Central Apennines) , 1992 .

[74]  Dario Slejko,et al.  Empirical Ground-Motion Attenuation Relations for the Eastern Alps in the Magnitude Range 2.5–6.3 , 2005 .

[75]  R. Mcguire.  Probabilistic seismic hazard analysis and design earthquakes: Closing the loop , 1995, Bulletin of the Seismological Society of America.

[76]  J. C. Savage.  Criticism of some forecasts of the national earthquake prediction evaluation council , 1991, Bulletin of the Seismological Society of America.

[77]  Paleoseismology of silent faults in the Central Apennines (Italy): the Campo Imperatore Fault (Gran Sasso Range Fault System) , 2003 .

[78]  P. Pieruccini,et al.  Quaternary normal faults, intramontane basins and seismicity in the Umbria-Marche-Abruzzi Apennine Ridge (Italy): contribution of neotectonic analysis to seismic hazard assessment , 2002 .

[79]  D. Pantosti,et al.  Paleoseismicity of the Ovindoli‐Pezza fault, central Apennines, Italy: A history including a large, previously unrecorded earthquake in the Middle Ages (860–1300 A.D.) , 1996 .

[80]  D. Perkins,et al.  Uncertainties in probability of occurrence of strong earthquakes for fault sources in the Central Apennines, Italy , 2008 .

[81]  D. Wells,et al.  New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement , 1994, Bulletin of the Seismological Society of America.

[82]  The Holocene paleoseismicity of the Aremogna-Cinque Miglia Fault (Central Italy) , 2001 .

[83]  F. Scherbaum,et al.  On the Conversion of Source-to-Site Distance Measures for Extended Earthquake Source Models , 2004 .

[84]  Gianluca Valensise,et al.  Defining seismogenic sources from historical earthquake felt reports , 1999, Bulletin of the Seismological Society of America.

[85]  Giuliano Milana,et al.  Seismogenesis in Central Apennines, Italy: an integrated analysis of minor earthquake sequences and structural data in the Amatrice-Campotosto area , 2004 .

[86]  D. Pantosti,et al.  Geomorphology of the Gubbio Basin (Central Italy): understanding the active tectonics and earthquake potential , 2003 .

[87]  Charles S. Mueller,et al.  Documentation for the 2008 update of the United States National Seismic Hazard Maps , 2008 .