scholarly journals HISTORICAL EARTHQUAKES IN THE REGION OF LEFKADA ISLAND , IONIAN SEA - ESTIMATION OF MAGNITUDES FROM EPICENTRAL INTENSITIES

2004 ◽  
Vol 36 (3) ◽  
pp. 1389 ◽  
Author(s):  
A. Fokaefs ◽  
G. A. Papadopoulos
Keyword(s):  
Seismic Hazard ◽  
Seismic Hazard Assessment ◽  
Historical Earthquakes ◽  
Maximum Intensity ◽  
16Th Century ◽  
Time Interval ◽  
Ionian Sea ◽  
The Past ◽  
Documentary Sources ◽  
Lefkada Island

Historical documentation of strong shocks for Lefkada Island, Ionian Sea, exists since the 16th century A.D. In this paper we establish a relation between magnitude and maximum intensity from twenty-nine instrumental events that hit the area in the past. Then, on the basis of historical documentary sources we reevaluate the intensities of strong historical earthquakes, their maximum intensity being observed on Lefkada in the time interval from AD1577 to 1911, recalculate their magnitudes on the basis of the magnitude/intensity relation and, finally, compile a new catalogue of historical earthquakes. The results obtained are of importance for the seismicity studies and seismic hazard assessment in the area.

scholarly journals Tectonic Geomorphology and Paleoseismology of the Sharkhai fault: a new source of seismic hazard for Ulaanbaatar (Mongolia)

2021 ◽  
Author(s):  
Abeer Al-Ashkar ◽  
Antoine Schlupp ◽  
Matthieu Ferry ◽  
Ulziibat Munkhuu
Keyword(s):  
Seismic Hazard ◽  
Scaling Laws ◽  
Active Faults ◽  
Seismic Hazard Assessment ◽  
Capital City ◽  
Tectonic Geomorphology ◽  
Time Interval ◽  
Coseismic Slip ◽  
Slip Rates ◽  
Large Earthquakes

Abstract. We present new constraints from tectonic geomorphology and paleoseismology along the newly discovered Sharkhai fault near the capital city of Mongolia. Detailed observations from high resolution Pleiades satellite images and field investigations allowed us to map the fault in detail, describe its geometry and segmentation, characterize its kinematics, and document its recent activity and seismic behavior (cumulative displacements and paleoseismicity). The Sharkhai fault displays a surface length of ~40 km with a slightly arcuate geometry, and a strike ranging from N42° E to N72° E. It affects numerous drainages that show left-lateral cumulative displacements reaching 57 m. Paleoseismic investigations document the faulting and deposition record for the last ~3000 yr and reveal that the penultimate earthquake (PE) occurred between 1515 ± 90 BC and 945 ± 110 BC and the most recent event (MRE) occurred after 860 ± 85 AD. The resulting time interval of 2080 ± 470 years is the first constraint on the Sharkhai fault for large earthquakes. On the basis of our mapping of the surface rupture and the resulting segmentation analysis, we propose two possible scenarios for large earthquakes with likely magnitudes between 6.4 ± 0.2 and 7.1 ± 0.2. Furthermore, we apply scaling laws to infer coseismic slip values and derive preliminary estimates of long-term slip rates between 0.2 ± 0.2 and 1.0 ± 0.5 mm/y. Finally, we propose that these original observations and results from a newly discovered fault should be taken into account for the seismic hazard assessment for the city of Ulaanbaatar and help build a comprehensive model of active faults in that region.

scholarly journals Seismic hazard assessment of Iran

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.

The analysis of historical seismograms: an important tool for seismic hazard assessment. Case histories from French and Italian earthquakes

2011 ◽  
Vol 182 (4) ◽  
pp. 367-379 ◽  
Author(s):  
Nicola Alessandro Pino
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Southern Italy ◽  
Source Parameters ◽  
Seismic Hazard Assessment ◽  
Historical Earthquakes ◽  
Waveform Analysis ◽  
Source Characteristics ◽  
Seismic Waveform ◽  
Earthquake Source Parameters

AbstractSeismic hazard assessment relies on the knowledge of the source characteristics of past earthquakes. Unfortunately, seismic waveform analysis, representing the most powerful tool for the investigation of earthquake source parameters, is only possible for events occurred in the last 100–120 years, i.e., since seismographs with known response function were developed. Nevertheless, during this time significant earthquakes have been recorded by such instruments and today, also thanks to technological progress, these data can be recovered and analysed by means of modern techniques.In this paper, aiming at giving a general sketch of possible analyses and attainable results in historical seismogram studies, I briefly describe the major difficulties in processing the original waveforms and present a review of the results that I obtained from previous seismogram analysis of selected significant historical earthquakes occurred during the first decades of the XXth century, including (A) the December 28, 1908, Messina straits (southern Italy), (B) the June 11, 1909, Lambesc (southern France) – both of which are the strongest ever recorded instrumentally in their respective countries –and (C) the July 13, 1930, Irpinia (southern Italy) events. For these earthquakes, the major achievements are represented by the assessment of the seismic moment (A, B, C), the geometry and kinematics of faulting (B, C), the fault length and an approximate slip distribution (A, C). The source characteristics of the studied events have also been interpreted in the frame of the tectonic environment active in the respective region of interest. In spite of the difficulties inherent to the investigation of old seismic data, these results demonstrate the invaluable and irreplaceable role of historical seismogram analysis in defining the local seismogenic potential and, ultimately, for assessing the seismic hazard. The retrieved information is crucial in areas where important civil engineering works are planned, as in the case of the single-span bridge to be built across the Messina straits and the ITER nuclear fusion power plant to be built in Cadarache, close to the location of the Lambesc event, and in regions characterized by high seismic risk, such as southern Apennines.

scholarly journals Tsunami threat versus development activities along the coast of Pakistan: A Geographic Assessment

2019 ◽  
Keyword(s):  
Risk Assessment ◽  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Hazards ◽  
Population Development ◽  
The West ◽  
Safety Measures ◽  
The Past ◽  
Growing Population

<p>Pakistan is located at the earthquake prone zone. The west coast of the country is in a zone of serious seismic hazards where a subduction zone is found. This area has been victimized by severe earth quakes and tsunamis in the past. Bathymetric and earthquake interpolated maps have been prepared for risk assessment. Growing population, development and planning along the coast of Makran, especially at Gawadar, could be a serious risk in future without seismic hazard assessment. Considering the safety measures against the probable tsunami, special attention must be paid in the prospect of planning and development along the coast. The article is an attempt to assess the magnitude of the risk on behalf of onshore and offshore morphologic configuration with their tectonic setup.</p>

scholarly journals On historical earthquakes in Switzerland: summary of compilations and investigations

2009 ◽  
Vol 47 (2-3) ◽  
Author(s):  
D. Mayer-Rosa ◽  
G. Schwarz-Zanetti
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Historical Earthquakes ◽  
Macroseismic Data ◽  
The Creation ◽  
Systematic Collection ◽  
Made In

Studies of historical earthquakes in Switzerland are contained in monographs, chronological collections of effects and parametric catalogues. The systematic collection of macroseismic material started with the creation of the Swiss Seismological Commission in 1878. All parametric catalogues since 1975 have been prepared for seismic hazard assessment. The most up-to-date investigation of macroseismic data and compilation into a catalogue (ECOS) was made in the 2002 in context of the re-assessment of seismic hazard for nuclear sites.

Historical Earthquake Damages to Domed Structures in Istanbul

2015 ◽  
pp. 649-673 ◽  
Author(s):  
İhsan E. Bal ◽  
F. Gülten Gülay ◽  
Meltem Vatan ◽  
Eleni Smyrou
Keyword(s):  
Spatial Distribution ◽  
Seismic Hazard ◽  
Historical Earthquakes ◽  
Seismic Events ◽  
Historical Earthquake ◽  
Historical Buildings ◽  
The Past ◽  
Ottoman Architecture ◽  
Hazard Level ◽  
Earthquake Damages

This chapter discusses the domed structures in Istanbul, which are reported damaged during strong historical earthquakes. The attention is focused mostly to their domes, the most important component of the Byzantine and the Ottoman architecture. The significant shakings, together with their estimated epicenters and magnitudes, have been defined and the spatial distribution of the reported damages in the domed structures has been examined. It is underlined once more that the Historical Peninsula, which is where once Constantinople was located, has several vulnerable structures and high seismic hazard level at the same time. Certain structures are quite vulnerable to strong shakings and received significant damages multiple times. The chapter discusses the possible effects of the future seismic events on the historical buildings in Istanbul, based on the recorded damages occurred during the past seismic events.

The Međimurje (Croatia) Earthquake of 1738

2020 ◽  
Vol 91 (2A) ◽  
pp. 1042-1056 ◽  
Author(s):  
Davorka Herak ◽  
Mladen Živčić ◽  
Iva Vrkić ◽  
Marijan Herak
Keyword(s):  
Seismic Hazard ◽  
Historical Data ◽  
Hanging Wall ◽  
Source Parameters ◽  
Focal Depth ◽  
Seismic Hazard Assessment ◽  
Maximum Intensity ◽  
Epicentral Intensity ◽  
Felt Area ◽  
The Town

Abstract The 30 March 1738 earthquake with an epicenter near Čakovec in Međimurje (Croatia) is the largest known earthquake in the low-seismicity area that includes northernmost Croatia, northeastern Slovenia, southeastern Austria, and southwestern Hungary. So far, it has attracted very little attention in the seismological communities of those countries. It is missing or has wrong source parameters in all of the relevant earthquake catalogs (including the Seismic Hazard Harmonization in Europe (SHARE) catalog, Stucchi et al., 2013), which may influence seismic hazard assessment in this part of Europe, most critically in the Međimurje region itself. We present contemporary historical data shedding some light on the effects that the earthquake had on settlements mostly in Međimurje, but also elsewhere in Croatia, Slovenia, and Hungary. We were able to assign intensities to 12 localities surrounding the epicenter and to resolve the confusion about its date of occurrence. The intensity points were inverted for the location of the macroseismic hypocenter and epicentral intensity (I0=7.9 MSK [Medvedev–Sponheuer–Karnik]). The epicenter is found to lie on the hanging wall of the reverse Čakovec fault, about 6 km from its surface trace, and 8 km north-northwest of the town of Čakovec. The rather small felt area for an earthquake of this maximum intensity implies a shallow macroseismic focal depth of 6 km. These values of intensity and depth correspond to a macroseismic magnitude of MLm 5.1.

Comparing Probabilistic Seismic Hazard Maps with ShakeMap Footprints for Indonesia

2020 ◽  
Vol 91 (2A) ◽  
pp. 847-858
Author(s):  
Adrien Pothon ◽  
Philippe Gueguen ◽  
Sylvain Buisine ◽  
Pierre-Yves Bard
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Selection Process ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Hazard Maps ◽  
Data Set ◽  
Seismic Hazard Maps ◽  
The Past

Abstract A number of probabilistic seismic hazard assessment (PSHA) maps have been released for Indonesia over the past few decades. This study proposes a method for testing PSHA maps using U.S. Geological Survey ShakeMap catalog considered as historical seismicity for Indonesia. It consists in counting the number of sites on rock soil for which the independent maximum peak ground acceleration (PGA) of the ShakeMap footprints between May 1968 and May 2018 exceeds the thresholds from the PSHA map studied and in comparing this number with the probability of exceedance given in the PSHA map. Although ShakeMap footprints are not as accurate and complete as continuous recorded ground motion, the spatially distributed ShakeMap covers 7,642,261 grid points, with a resolution of 1  km2, compensating the lack of instrumental data over this period. This data set is large enough for the statistical analysis of independent PGA values on rock sites only. To obtain the subdata set, we develop a new selection process and a new comparison method, considering the uncertainty of ShakeMap estimates. The method is applied to three PSHA maps (Global Seismic Hazard Assessment Program [GSHAP], Global Assessment Report [GAR], and Standar Nasional Indonesia [SNI2017]) for a selection of sites first located in Indonesia and next only in the western part of the country. The results show that SNI2017 provides the best fit with seismicity over the past 50 yr for both sets of rock sites (whole country and western part only). At the opposite, the GAR and GSHAP seismic hazard maps only fit the seismicity observed for the set of rock sites in western Indonesia. This result indicates that this method can only conclude on the spatial scale of the analysis and cannot be extrapolated to any other spatial resolution.

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