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.

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 A decade of seismicity in metropolitan France (2010-2019): the CEA/LDG methodologies and observations

2021 ◽  
Author(s):  
Clara Duverger ◽  
Gilles Mazet-Roux ◽  
Laurent Bollinger ◽  
Aurélie Guilhem Trilla ◽  
Amaury Vallage ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Activity ◽  
Atomic Energy Commission ◽  
Temporal Structure ◽  
Seismic Hazard Assessment ◽  
Moderate Earthquake ◽  
Seismicity Rates ◽  
Epicentral Intensity ◽  
Natural Earthquakes

We summarize ten years of the French seismicity recorded by the Geophysical and Detection Laboratory (LDG) of the French Alternative Energies and Atomic Energy Commission (CEA) network from 2010 to 2019. During this period, 25,279 natural earthquakes were detected by the LDG and located within metropolitan France and its immediate vicinity. This seismicity contributes to more than 47% of the natural earthquakes instrumentally recorded since 1962 (mainly due to the improvement of network capacity), and includes about 28% of the most significant earthquakes with a magnitude ML ≥ 4.0. Recent seismic events therefore significantly expand the available national catalogues. The spatial distribution of 2010-2019 earthquakes is broadly similar to the previous instrumental pattern of the seismicity, with most of the seismic activity concentrated in the French Alps, the Pyrenees, the Brittany, the upper Rhine Graben and the Central Massif. A large part of the seismic activity is related to the occurrence of individual events. The largest earthquakes of the last ten years include the November 11, 2019 Le Teil earthquake with ML 5.4 and maximal epicentral intensities VII to VIII, which occurred in the Rhone valley; the April 28, 2016 La Rochelle earthquake with ML 5.2 and epicentral intensity V, which occurred at the southernmost extremity of the Armorican Massif in the vicinity of the Oléron island; and the April 7, 2014 Barcelonnette earthquake with ML 5.1 and epicentral intensity VII, which occurred in the Ubaye valley in the Alps. In 2019, two other moderate earthquakes of ML 5.1 and ML 4.9 stroke the western part of France, in Charente-Maritime and Maine-et-Loire department, respectively. The recent moderate earthquake occurrences and the large number of small earthquakes recorded give both the potential to revise some regional historical events and to determine more robust frequency-magnitude distributions, which are critical for seismic hazard assessment but complex due to low seismicity rates in France. The LDG seismic network installed since the early 1960s also allows a better characterization of the temporal structure of seismicity, partly diffused and in the form of mainshock-aftershocks sequences or transient swarms. These aspects are important in order to lower the uncertainties associated to seismogenic sources and improve the models in seismic hazard assessment for metropolitan France.

A New State‐of‐the‐Art Platform for Probabilistic and Deterministic Seismic Hazard Assessment

2019 ◽  
Vol 90 (6) ◽  
pp. 2262-2275 ◽  
Author(s):  
Gabriel Candia ◽  
Jorge Macedo ◽  
Miguel A. Jaimes ◽  
Carolina Magna‐Verdugo
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
State Of The Art ◽  
Ground Motions ◽  
Tectonic Setting ◽  
Source Parameters ◽  
Seismic Hazard Assessment ◽  
Hazard Evaluation ◽  
Benchmark Solutions

ABSTRACT A new computational platform for seismic hazard assessment is presented. The platform, named SeismicHazard, allows characterizing the intensity, uncertainty, and likelihood of ground motions from subduction‐zone (shallow interface and intraslab) and crustal‐zone earthquakes, considering site‐specific as well as regional‐based assessments. The platform is developed as an object‐oriented MATLAB graphical user interface, and it features several state‐of‐the‐art capabilities for probabilistic and deterministic (scenario‐based) seismic hazard assessment. The platform integrates the latest developments in performance‐based earthquake engineering for seismic hazard assessment, including seismic zonation models, ground‐motion models (GMMs), ground‐motion correlation structures, and the estimation of design spectra (uniform hazard spectra, classical conditional mean spectrum (CMS) for a unique tectonic setting). In addition to these standard capabilities, the platform supports advanced features, not commonly found in existing seismic hazard codes, such as (a) computation of source parameters from earthquake catalogs, (b) vector‐probabilistic seismic hazard assessment, (c) hazard evaluation based on conditional GMMs and user‐defined GMMs, (d) uncertainty treatment in the median ground motions through continuous GMM distributions, (e) regional shaking fields, and (f) estimation of CMS considering multiple GMMs and multiple tectonic settings. The results from the platform have been validated against accepted and well‐documented benchmark solutions.

A seismological study of two Attica, New York earthquakes

1978 ◽  
Vol 68 (3) ◽  
pp. 641-651 ◽  
Author(s):  
Robert B. Herrmann
Keyword(s):  
New York ◽  
Source Parameters ◽  
Focal Depth ◽  
Strike Slip ◽  
Focal Mechanisms ◽  
The Other ◽  
Nodal Plane ◽  
Reverse Faulting ◽  
Epicentral Intensity ◽  
East West

abstract The Attica, New York earthquakes of January 1, 1966 and June 12, 1967 are studied in detail to obtain their focal mechanisms, depths and seismic moments. Both events have similar source parameters with one nodal plane striking about 120° and dipping 60°S and the other nodal plane striking about 20° and dipping 70°E. The fault motion on the NNE nodal plane has a component of right lateral strike slip and one of reverse faulting. Though this nodal plane parallels the Clarendon-Linden structure, the possibility of associating the other nodal plane with a diffuse east-west seismicity trend cannot be excluded. The shallow focal depth of 2 to 3 km for these two events can be used as an explanation of the relatively high epicentral intensity VIII of the Attica event of 1929.

Fault-Plane Determination of the 4 January 2020 Offshore Pearl River Delta Earthquake and Its Implication for Seismic Hazard Assessment

2021 ◽  
Author(s):  
Han Chen ◽  
Xiaohui He ◽  
Hongfeng Yang ◽  
Jiangyang Zhang
Keyword(s):  
Seismic Hazard ◽  
Focal Depth ◽  
River Estuary ◽  
Correlation Method ◽  
Primary Source ◽  
Seismic Hazard Assessment ◽  
Earthquake Hazard ◽  
Fault System ◽  
Pearl River ◽  
Rupture Directivity

Abstract On 4 January 2020, an ML 3.5 earthquake occurred in the Pearl River Estuary (PRE) and was felt at a distance of more than 200 km. According to the China Earthquake Networks Center, this event has been the only M>3 earthquake within the PRE since 1900. The Guangdong–Hong Kong–Macau Bay Area (GHMBA) surrounding the PRE is one of China’s most critical financial circles, and coastal earthquake hazard has become an increasing concern. Investigating the source parameter and causative fault of this earthquake is helpful for seismic hazard estimation and mitigation in the GHMBA. In this study, we first determined the focal mechanism of the mainshock using the cut-and-paste method. We then used the sliding-window cross-correlation method to detect foreshocks and aftershocks before relocating the earthquakes. Finally, we conducted forward modeling to retrieve the rupture directivity of the mainshock, using waveforms of one aftershock as empirical Green’s functions. The results demonstrate that this earthquake was an Mw 3.7 strike-slip event, with a focal depth of 10 km. The rupture direction of the mainshock was 78°, consistent with the northeast-east-trending fault system in the region. The identified source fault confirmed a seismogenic segment of the northeast-east-trending fault system in the PRE, which is the primary source of seismic hazard in the area.

Within and Between-Events Variability of Strong-Velocity Pulses

2020 ◽  
Author(s):  
Ming-Hsuan Yen ◽  
Kuo-Fong Ma ◽  
Fabrice Cotton ◽  
Yen-Yu Lin ◽  
Ya-Ting Lee
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Structural Engineering ◽  
Ground Motions ◽  
Hanging Wall ◽  
Seismic Hazard Assessment ◽  
Foot Wall ◽  
Complete Understanding ◽  
Significant Damage ◽  
Rupture Direction

<p>Ground motions with strong pulses often bring significant damage to structures. The period and the amplitude of the strong-velocity pulses are critical for structural engineering and seismic hazard assessment. The scaling of pulses periods with magnitudes and the within-event variability of pulses is however poorly understood. In this study, we analyze two moderate earthquakes, namely 2016 Meinong earthquake and 2018 Hualien earthquake, using Shahi and Baker’s criteria (2014) to detect pulses. The observations in this study show that the amplitudes of the pulse decay with the distance from the source to the stations, and is also associated with the rupture direction from the asperity instead of the direction from the hypocenter. In addition, we further perform simulations using a simple FK method to clarify the causes of the variability of the pulse periods within and between events. We test the effect of faults dipping angles and the impacts of the asperity location and size. Through our simulations, we reveal that the amplitudes of the pulses in the shallow dipping fault are larger on the hanging wall than on the foot wall, and that the asperity properties has a large impact on the pulses periods and the amplitudes at the nearby stations. The results show that the asperity characteristics are critical for the occurrence of the strong-velocity pulses. The complete understanding of the kinematics of the rupture is then important for clarifying the effects of the strong-velocity pulses and improving ground-motions predictions.</p>

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.

Virginia's two largest earthquakes—December 22, 1875 and May 31, 1897

1971 ◽  
Vol 61 (4) ◽  
pp. 1033-1039 ◽  
Author(s):  
G. A. Bollinger ◽  
Margaret G. Hopper
Keyword(s):  
Focal Depth ◽  
Geological Structure ◽  
Maximum Intensity ◽  
Contributing Factors ◽  
Middle Atlantic ◽  
The North ◽  
Macroseismic Effects ◽  
Moderate Seismicity ◽  
Chesterfield County ◽  
Felt Area

abstract A study of the macroseismic effects associated with the two largest of Virginia's historic earthquakes, based primarily on journals and archival newspaper accounts, reveals that exceptionally large felt areas can be associated with moderate earthquakes in the middle Atlantic region. Occurring at opposite ends of the state, the two shocks exhibit similar effects to the north, which appear related to the surficial geology, but differing intensity distributions to the southwest, which may reflect the differences between the two areas that exist in the geological structure. Differences in focal depth and focal mechanism may also be contributing factors. The Giles County earthquake of May 31, 1897, in the folded Appalachian Province of western Virginia, is assigned a maximum intensity (MM) of VIII and a felt area of at least 280,000 square miles. The Chesterfield County earthquake of December 22, 1875, in the crystalline Piedmont Province near Richmond, had a maximum intensity (MM) of VII and a 50,000-square-mile felt region. In both cases the previously reported intensities and felt areas were found adequate. For the moderate seismicity of the Appalachians, an extremely long period, May 3 to June 6, of seismic and acoustic phenomena occurred in conjunction with the May 31, 1897 shock.

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