The 2017, MD = 4.0, Casamicciola Earthquake: ESI-07 Scale Evaluation and Implications for the Source Model

On 21 August 2017 at 20:57 (local time) a very shallow (H = 1.2 km), moderate (Md = 4.0), earthquake hit the volcanic island of Ischia (Southern Italy), causing the death of two people. The study of the damage to the buildings with the European Macroseismic Scale 98 (EMS-98), carried out immediately after the earthquake, highlighted that hilly area of Casamicciola Terme, on the northern side of the Mt. Epomeo, was the most damaged part of the island with locally quite relevant damage (I = VIII EMS). This seismic event is the first damaging earthquake in Ischia during the instrumental era. In fact, this provides, for the first time, the opportunity to integrate historical seismicity, macroseismic observations, instrumental information, and detailed mapping of the geological coseismic effects. In this work we evaluate the effects induced by the 2017 Casamicciola earthquake on the environment using the Environmental Seismic Intensity 2007 (ESI-07) macroseismic scale. This macroseismic analysis, together with the superficial coseismic faulting characteristics and the available geophysical information, allows us to reconsider the source model for the 2017 earthquake and the previous damaging historical earthquakes in the Casamicciola Terme area. The application of the ESI scale to the Casamicciola Terme earthquake of 21 August 2017 and the assignment of seismic intensity offers better spatial resolution, as well as an increase of the time window for the assessment of the seismic hazard, allowing to reduce the implicit uncertainty in the intensity attenuation laws in this peculiar volcano-tectonic setting. Since intensity is linked to the direct measure of damage, and it is commonly used in hazard assessment, we argue that building damage at Casamicciola Terme is strongly influenced by earthquake surface faulting and near field effects, and therefore controlled by the geometry of the seismic source.

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Developing the First Intensity Prediction Equation Based on the Environmental Scale Intensity: A Case Study from Strong Normal-Faulting Earthquakes in the Italian Apennines

Seismological Research Letters ◽

10.1785/0220200044 ◽

2020 ◽

Vol 91 (5) ◽

pp. 2611-2623 ◽

Cited By ~ 2

Author(s):

Maria Francesca Ferrario ◽

Franz Livio ◽

Stefano Serra Capizzano ◽

Alessandro M. Michetti

Keyword(s):

Time Window ◽

Near Field ◽

Seismic Hazard Assessment ◽

Prediction Equation ◽

Seismic Intensity ◽

Intensity Prediction ◽

Empirical Relations ◽

Italian Apennines ◽

Local Intensity ◽

Esi Scale

Abstract Earthquakes produce effects on the built and natural environment, the severity of which decays with distance from the epicenter. Empirical relations describing the intensity attenuation with distance are fundamental for seismic hazard assessment and for deriving parameters for preinstrumental events. Seismic intensity is usually assigned based on damage to buildings and infrastructures; this can be challenging for intensity degrees higher than X or when macroseismic fields of multiple events close in time are overlapping. A complementary approach is the study of earthquake environmental effects (EEEs), which are used to assign intensity on the environmental scale intensity (ESI) scale. However, a quantitative comparison between the ESI and traditional scales, and an equation describing the ESI attenuation with distance are still lacking. Here, we analyze 14 historical and instrumental events (time window 1688–2016) in the central and southern Apennines (Italy), comparing ESI and Mercalli–Cancani–Sieberg (MCS) intensities. Our results show that ESI consistently provides higher intensity near the epicenter and the attenuation is steeper than MCS. We derive the first intensity prediction equation for the ESI scale, which computes local intensity as a function of distance and epicentral intensity value. We document that, in the near field, the MCS attenuation for shallow crustal events occurred in the twenty-first century is steeper than previous events, whereas the ESI attenuation shows a consistent behavior through time. This result questions the reliability of current empirical relations for the investigation of future events. We recommend including EEEs in intensity assignments because they can guarantee consistency through time and help in evaluating the spatial and temporal evolution of damage progression during seismic sequences, thus ultimately improving seismic risk assessment.

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Stochastic Source Model for Strong Motion Prediction

International Journal of Geotechnical Earthquake Engineering ◽

10.4018/ijgee.2018070101 ◽

2018 ◽

Vol 9 (2) ◽

pp. 1-22

Author(s):

S. Sangeetha ◽

S.T.G. Raghukanth

Keyword(s):

Near Field ◽

Source Parameters ◽

Strong Motion ◽

Seismic Source ◽

Source Model ◽

Spectral Density Function ◽

Correlation Lengths ◽

Rupture Area ◽

Power Spectral ◽

Finite Fault

The article aims at developing a stochastic model which simulates spatial distribution of slip on the fault plane. This is achieved by analysing a large dataset of 303 finite-fault rupture models from 152 past earthquakes with varying fault mechanisms and in the magnitude range of 4.11-9.12. New scaling relations to predict the seismic source parameters such as fault length, fault width, rupture area, mean and standard deviation of slip have been derived for distinct fault mechanisms. The developed methodology models the spatial variability of slip as a two-dimensional von Karman power spectral density function (PSD) and correlation lengths are estimated. The proposed stochastic slip model is validated by comparing the simulated near-field ground response with the recorded data available for the 20th September 1999 Chi-Chi earthquake, Taiwan.

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Seismic hazard estimate from background seismicity in southern California

Bulletin of the Seismological Society of America ◽

10.1785/bssa0860051372 ◽

1996 ◽

Vol 86 (5) ◽

pp. 1372-1381 ◽

Cited By ~ 1

Author(s):

Tianqing Cao ◽

Mark D. Petersen ◽

Michael S. Reichle

Keyword(s):

Seismic Hazard ◽

Southern California ◽

Seismic Source ◽

Source Model ◽

Historical Seismicity ◽

Rational Approach ◽

Smoothing Function ◽

Background Seismicity ◽

Seismic Source Model ◽

Seismicity Catalog

Abstract We analyzed the historical seismicity in southern California to develop a rational approach for calculating the seismic hazard from background seismicity of magnitude 6.5 or smaller. The basic assumption for the approach is that future earthquakes will be clustered spatially near locations of historical mainshocks of magnitudes equal to or greater than 4. We analyzed the declustered California seismicity catalog to compute the rate of earthquakes on a grid and then smoothed these rates to account for the spatial distribution of future earthquakes. To find a suitable spatial smoothing function, we studied the distance (r) correlation for southern California earthquakes and found that they follow a 1/rµ power-law relation, where µ increases with magnitude. This result suggests that larger events are more clustered in space than smaller earthquakes. Assuming the seismicity follows the Gutenberg-Richter distribution, we calculated peak ground accelerations (PGA) for 10% probability of exceedance in 50 yr. PGA estimates range between 0.25 and 0.35 g across much of southern California. These ground-motion levels are generally less than half the levels of hazard that are obtained using the entire seismic source model that also includes geologic and geodetic data. We also calculated the overall uncertainty for the hazard map using a Monte Carlo method and found that the coefficient of variation is about 0.24 ± 0.01 for much of the region.

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Seismic Intensity Attenuation for Intraplate Earthquakes in Brazil with the Re‐Evaluation of Historical Seismicity

Seismological Research Letters ◽

10.1785/0220190120 ◽

2019 ◽

Vol 90 (6) ◽

pp. 2217-2226 ◽

Cited By ~ 2

Author(s):

Lúcio Quadros ◽

Marcelo Assumpção ◽

Ana Paula Trindade de Souza

Keyword(s):

Earthquake Hazard ◽

Historical Earthquakes ◽

Seismic Intensity ◽

Historical Seismicity ◽

Qualitative Description ◽

Intensity Data ◽

Intraplate Earthquakes ◽

Intensity Attenuation ◽

Hypocentral Distance ◽

Root Mean Square Residual

ABSTRACT Intensity evaluation attempts to quantify a qualitative description of the effects observed in an earthquake ranked in terms of how strong it was felt and the amount of damage. Despite its qualitative nature, intensity data are essential to study both historical and recent earthquakes such as in earthquake hazard studies and in which dense accelerometric data are missing. The magnitude of historical earthquakes in Brazil has been determined with relations involving magnitude and felt area. Intensity attenuation equations (decay of intensity as a function of magnitude, depth, and distance) determined in other regions of the world are intrinsically dependent on the crustal tectonic characteristics and cannot be applied to Brazil without proper evaluation. We determined an intensity attenuation equation using 20 earthquakes in Brazil and neighboring intraplate areas, in the magnitude range mb 3.5–6.2 and hypocentral distances up to 720 km. The best attenuation model was I=0.995M−1.505logR−0.00116R+2.08 (standard deviation = 0.778), in which M is the magnitude (mb) and R is the hypocentral distance (in kilometers). The uncertainties of the estimated magnitudes using this equation are around mb±0.72 for events with 30 or more intensity points. We tested the new equation with intensity data from two important events: the 1939 offshore earthquake (mb 6) in southern Brazil and the 2018 Venezuela earthquake (mb 6.9). The fit was reasonable for both earthquakes, with a root mean square residual of 1.0 and 1.1 intensity units, respectively. We also re‐evaluated the 1861 earthquake in southeast Brazil. The new epicenter was 23.1° S 44.7° W with a magnitude of mb 5. The epicenter was located onshore, but the estimated uncertainties include a large offshore region. Given that, the location of the 1861 event remains uncertain.

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Seismic Source of 1746 Callao Earthquake from Tsunami Numerical Modeling

Journal of Disaster Research ◽

10.20965/jdr.2013.p0266 ◽

2013 ◽

Vol 8 (2) ◽

pp. 266-273 ◽

Cited By ~ 10

Author(s):

Cesar Jimenez ◽

◽

Nabilt Moggiano ◽

Erick Mas ◽

Bruno Adriano ◽

...

Keyword(s):

Numerical Simulation ◽

Seismic Source ◽

Source Model ◽

Trial And Error ◽

Rupture Directivity ◽

Computational Tools ◽

Macroseismic Observations ◽

Tsunami Numerical Modeling ◽

Seismic Source Model ◽

Forward Process

In this paper a model of slip distribution is proposed for the 1746 Callao earthquake and tsunami based on macroseismic observations written in historical documents. This is done using computational tools such as tsunami numerical simulation through a forward process by trial and error. The idea is to match historical observations with numerical simulation results to obtain a plausible seismic source model. Results show a high asperity from Cañete to Huacho, which would explain the great destruction in this area. The rupture directivity of the seismic source, from north to south, would explain the value of the arrival time of the first tsunami wave at Callao. A kinematic seismic source model was used as a first approximation of the event. The estimated magnitude was Mw9.0.

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A short introduction to historical earthquakes in Libya

Annals of Geophysics ◽

10.4401/ag-3320 ◽

2009 ◽

Vol 47 (2-3) ◽

Author(s):

A. S. Suleiman ◽

P. Albini ◽

P. Migliavacca

Keyword(s):

Historical Earthquakes ◽

Historical Seismicity ◽

Historical Sources ◽

Short Introduction ◽

North Central ◽

The North ◽

Lack Of Information ◽

Macroseismic Effects ◽

Instrumental Recording ◽

Earthquake Effects

As a result of the relative motion of the African and European plates, Libya, located at the north central margin of the African continent, has experienced a considerable intraplate tectonism, particularly in its northern coastal regions. If the seismic activity of the last fifty years, at most, is known from instrumental recording, macroseismic effects of those earthquakes which affected Libya in the past centuries are still imperfectly known. To try and partly overcome this lack of information, in this contribution we present a short introduction to historical earthquakes in Libya, focusing on the period up to 1935. According to the studies published in the last twenty years, the earliest records of earthquakes in Libya are documented in the Roman period (3rd and 4th century A.D.). There is a gap in information along the Middle and Modern Ages, while the 19th and early 20th century evidence is concentrated on effects in Tripoli, in the western part of nowadays Libya. The Hun Graben area (western part of the Gulf of Sirt) has been identified as the location of many earthquakes affecting Libya, and it is in this area that the 19 April 1935 earthquake (Mw = 7.1) struck, followed by many aftershocks. Further investigations are needed, and some hints are here given at historical sources potentially reporting on earthquake effects in Libya. Their investigation could result in the needed improvement to lay the foundations of a database and a catalogue of the historical seismicity of Libya.

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A new catalogue of earthquakes in the historical Armenian area from antiquity to the 12th century

Annals of Geophysics ◽

10.4401/ag-4134 ◽

1995 ◽

Vol 38 (1) ◽

Author(s):

E. Guidoboni ◽

G. Traina

Keyword(s):

Historical Earthquakes ◽

Historical Seismicity ◽

Seismic Events ◽

Specific Nature ◽

Present Contribution ◽

12Th Century ◽

Literary Sources ◽

New Localities ◽

History Of ◽

Catalogue Of Earthquakes

The present contribution describes the method of work, the types of source materia] used, and the historio- graphical and historico-eismic tradition of Armenia. The catalogue' s territorial frame of reference is that of socalled historical Armenia (which included part of present Eastern Turkey, and part of present Azerbaijan). The sources belong to different languages and cultures: Armenian, Syriac, Greek, Arab, Persian and Georgian. A comparison of the local sources with those belonging to other cultures enab]es the historical and seismological I"adition of the Mediterl'anean to be "linked" with that of the Iranian p]ateau, traditionally considered as two separate areas. We analyzed historical events listed in the most recent catalogues of earthquakes in the Armenian area compiled by Kondorskaya and Shebalin (1982) and Karapetian (1991). Important and valuable though these catalogues are, they are in need of revision. We found evidence for six hitherto unrecorded seismic events. Numerous errors of dating and location have been corrected, and several new localities and seismic effects have been evidenced. Each modification of the previous catalogues has been documented on the hasis of the historiographical and literary sources and the data from the written sources have been linked with those concerning the history of Armenian cities and architecture (monasteries, churches, episcopal complexes). On the whole. the revised earthquakes seem underestimated in the previous catalogues. The aim of this catalogue is to make a contribution to the knowledge of historical seismicity in Armenia, and at the same time to underline the specific nature of the Armenian case, thus avoiding a procedure which has generally tended to place this area in a marginal position, within the wider field of other research on historical earthquakes.

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Seismic hazard assessment of Iran

Annals of Geophysics ◽

10.4401/ag-3781 ◽

1999 ◽

Vol 42 (6) ◽

Author(s):

B. Tavakoli ◽

M. Ghafory-Ashtiany

Keyword(s):

Seismic Hazard ◽

Peak Ground Acceleration ◽

Grid Point ◽

Seismic Hazard Assessment ◽

Earthquake Hazard ◽

Seismic Source ◽

Historical Earthquakes ◽

Earthquake Insurance ◽

Ground Acceleration ◽

Seismic Source Models

The development of the new seismic hazard map of Iran is based on probabilistic seismic hazard computation using the historical earthquakes data, geology, tectonics, fault activity and seismic source models in Iran. These maps have been prepared to indicate the earthquake hazard of Iran in the form of iso-acceleration contour lines, and seismic hazard zoning, by using current probabilistic procedures. They display the probabilistic estimates of Peak Ground Acceleration (PGA) for the return periods of 75 and 475 years. The maps have been divided into intervals of 0.25 degrees in both latitudinal and longitudinal directions to calculate the peak ground acceleration values at each grid point and draw the seismic hazard curves. The results presented in this study will provide the basis for the preparation of seismic risk maps, the estimation of earthquake insurance premiums, and the preliminary site evaluation of critical facilities.

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Empirical Relationship for Assessing the Near-Field Horizontal Coseismic Displacement Using GPS Seismology Data

Geofísica Internacional ◽

10.22201/igeof.00167169p.2021.60.1.2025 ◽

2021 ◽

Vol 60 (1) ◽

pp. 31-50

Author(s):

Ryad Darawcheh ◽

Riad Al Ghazzi ◽

Mohamad Khir Abdul-wahed

Keyword(s):

Near Field ◽

Empirical Relationship ◽

Active Faults ◽

Historical Earthquakes ◽

Dead Sea ◽

Fault System ◽

Coseismic Displacement ◽

Data Set ◽

Earthquake Parameters ◽

Gps Station

In this research, a data set of horizontal GPS coseismic displacement in the near-field has been assembled around the world in order to investigate a potential relationship between the displacement and the earthquake parameters. Regression analyses have been applied to the data of 120 interplate earthquakes having the magnitude (Mw 4.8-9.2). An empirical relationship for prediction near-field horizontal GPS coseismic displacement as a function of moment magnitude and the distance between hypocenter and near field GPS station has been established using the multi regression analysis. The obtained relationship allows assessing the coseismic displacements associated with some large historical earthquakes occurred along the Dead Sea fault system. Such a fair relationship could be useful for assessing the coseismic displacement at any point around the active faults.

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Historical Earthquake Scenarios for the Middle Strand of the North Anatolian Fault Deduced from Archeo-Damage Inventory and Building Deformation Modeling

Seismological Research Letters ◽

10.1785/0220200278 ◽

2020 ◽

Vol 92 (1) ◽

pp. 583-598

Author(s):

Yacine Benjelloun ◽

Julia de Sigoyer ◽

Hélène Dessales ◽

Laurent Baillet ◽

Philippe Guéguen ◽

...

Keyword(s):

Historical Earthquakes ◽

Historical Seismicity ◽

North Anatolian Fault ◽

First Century ◽

Building Vulnerability ◽

Earthquake Scenarios ◽

The North ◽

Seismicity Catalog ◽

Quality Ranking ◽

The City

Abstract The city of İznik (ancient Nicaea), located on the middle strand of the North Anatolian fault zone (MNAF), presents outstanding archeological monuments preserved from the Roman and Ottoman periods (first to fifteenth centuries A.D.), bearing deformations that can be linked to past seismic shaking. To constrain the date and intensity of these historical earthquakes, a systematic survey of earthquake archeological effects (EAEs) is carried out on the city’s damaged buildings. Each of the 235 EAEs found is given a quality ranking, and the corresponding damage is classified according to the European Macroseismic Scale 1998 (EMS-98). We show that the walls oriented north–south were preferentially damaged, and that most deformations are perpendicular to the walls’ axes. The date of postseismic repairs is constrained with available archeological data and new C14 dating of mortar charcoals. Three damage episodes are evidenced: (1) between the sixth and late eighth centuries, (2) between the nineth and late eleventh centuries A.D., and (3) after the late fourteenth century A.D. The repartition of damage as a function of building vulnerability points toward a global intensity VIII on the EMS-98. The 3D modeling of a deformed Roman obelisk shows that only earthquakes rupturing the MNAF can account for this deformation. Their magnitude can be bracketed between Mw 6 and 7. Our archeoseismological study complements the historical seismicity catalog and confirms paleoseismological data, suggesting several destructive earthquakes along the MNAF, since the first century A.D. We suggest the fault might still have accumulated enough stress to generate an Mw 7+ rupture.

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