Strong Aftershocks Research Articles

MUYAKAN-II EARTHQUAKE on MAY 23, 2014 with КР=14.3, Mw=5.5, I0=7–8 (Northern Baikal region)

We consider the May 23, 2014 Muyakan earthquake (Mw=5.5) occurred in the Muyakan Range at the north-east of the Baikal rift zone near the eastern tunnel portal of the Baikal-Amur Mainline. This event was followed by numerous aftershocks (КР=5.6–9.9) which number exceeded 2000 by the end of the year. Spatio-temporal analysis of the Muyakan seismic sequence shows that its epicentral field consists of two isolated clusters: eastern and western ones. All the main events including the foreshocks, main shock and the strongest aftershocks (Mw=4.4; 4.5) occurred in the eastern cluster while only small seismic events (КР<10.0) were recorded in the western one. Seismic moment tensor was calculated for the Muyakan earthquake from surface wave amplitude spectra. As a result, we obtained information about the rift type focal mechanism, scalar seismic moment (M0=1.9•1017 Nm), moment magnitude (Mw=5.5) and hypocentral depth (h=24 km). From regional data, hypocentral depths of the main shock and the major number of the following earthquakes (80 %) were distributed in the depth range h=3–11 km. Maximum intensity of the main shock (4–5 according to MSK-64) was felt in Severomuysk urban village (=29 km). The obtained results could be used for seismic hazard assessment of the crucial part of the Baikal-Amur Mainline.

Parametric and non-parametric estimation of extreme earthquake event: the joint tail inference for mainshocks and aftershocks

In an earthquake event, the combination of a strong mainshock and damaging aftershocks is often the cause of severe structural damages and/or high death tolls. The objective of this paper is to provide estimation for the probability of such extreme events where the mainshock and the largest aftershocks exceed certain thresholds. Two approaches are illustrated and compared – a parametric approach based on previously observed stochastic laws in earthquake data, and a non-parametric approach based on bivariate extreme value theory. We analyze the earthquake data from the North Anatolian Fault Zone (NAFZ) in Turkey during 1965–2018 and show that the two approaches provide unifying results.

Mainshock-Integrated Aftershock Vulnerability Assessment of Bridge Structures

Seismic fragility analysis is often conducted to quantify the vulnerability of civil structures under earthquake excitation. In recent years, besides mainshocks, strong aftershocks have been often witnessed to induce structural damage to engineered structures, including bridges. How to accurately and straightforwardly quantify the vulnerability of bridges due to sequential mainshocks and aftershocks is essential for an efficient assessment of bridge performance. While recognizing the limitation of existing methods, this paper proposes a mainshock integrated aftershock fragility function model, which empirically encodes the effects of mainshocks and retains the simple form of traditional fragility curves. A pile foundation-supported bridge system is modeled considering seismic soil-structure interaction to demonstrate the proposed fragility model. Numerical examples show that the resulting fragility curves incorporate the initial value for the probability of collapse of the bridge system due to a mainshock and the effects of the variable aftershocks conditional on the mainshock. Statistical analysis confirms that the proposed model fits the simulated vulnerability data (e.g., seismic intensities of aftershocks and the response demands conditional a select mainshock ground motion) both accurately and robustly.

Ongoing shortening in the Dinarides fold-and-thrust belt: A new structural model of the 1979 (Mw 7.1) Montenegro earthquake epicentral region

This study focuses on structure and kinematics of the 1979 Mw 7.1 Montenegro earthquake. Although this event represents the strongest instrumentally recorded event in the entire Dinarides-Hellenides fold-and-thrust belt, no tectonic model relating this event to any particular fault existed so far. We combined onshore geological information with well logs, seismic lines, bathymetric data, seismotectonic and seismological data as well as cross-section balancing techniques into a new structural model for the area. Our results suggest that main shock and strongest aftershock (Mw 6.2) occurred on the NE-dipping basal thrust of a largely Palaeogene-age nappe system involving Cretaceous neritic carbonates. Ongoing propagation of this thrust system is documented by the existence of elongated ridges located 15 km offshore. Reflection seismic and bathymetry data reveal that the ridges form crests of actively growing fault-related anticlines. Slip distribution models of the strongest events imply that the basal thrust below the ridges accommodated up to 2.7 m of coseismic displacement. Ongoing shortening along the basal thrust also induced surface uplift of structurally higher thrust imbricates, evidenced by dry valleys incising onshore anticline crests. Combining all evidence, we speculate that the observed structural and geomorphic features resulted from repeated seismogenic faulting events as in 1979.

Vulnerability assessment of a high‐rise building subjected to mainshock–aftershock sequences

SummaryStrong aftershocks have the potential to further aggravate the damage state of structures, and much less attention has been given to the seismic vulnerability of high‐rise buildings than that of low‐ to medium‐rise buildings. This study assesses the seismic vulnerability of a 32‐storey frame–core tube building by performing the incremental dynamic analysis on the material‐based three‐dimensional numerical model. A storey damage model based on the material damage is developed using the weighted average method. Eighteen recorded mainshock–aftershock sequences, whose mainshock records match the target spectrum, are selected. The results indicate that the developed stroey damage model can effectively reflect the additional damage induced by aftershocks. Strong aftershocks have high potential to change the location of weak storeys. Notably, shifts of weak storeys are observed in more than 30% of aftershocks with relative spectral acceleration of 0.8. As the mainshock‐induced damage state becomes more severe, the mainshock‐damaged building becomes increasingly fragile to the aftershock excitation and more sensitive to aftershock intensities. The probability of exceeding severe damage state increases from 35.3% to 62.1% due to the effects of strong aftershocks. The results in this study can provide supports to the seismic resilience assessment of this high‐rise building.

Time-Varying Seismic Fragility Analysis of Offshore Bridges with Continuous Rigid-Frame Girder under Main Aftershock Sequences

Durability damage of reinforced concrete bridges in an offshore environment often occurs in varying degrees with the extension of service life. Meanwhile, statistical data on earthquake damage show that most of the main earthquakes are accompanied by strong aftershocks, and the seismic response of bridges under the main shock and main aftershock is different. To analyze the effects of the main aftershock sequence and durability damage on the seismic performance of concrete bridges, this study establishes a nonlinear dynamic analysis model of an offshore bridge with a continuous rigid-frame girder based on the OpenSEES platform. Moreover, this work constructs the main aftershock sequence considering the degradation of the mechanical properties of materials after durability damage repair under normal maintenance conditions and the time-varying seismic effect of shortening the subsequent service period, and investigates the time-varying seismic fragility of offshore bridges under the main aftershock sequence. Results show that the seismic response of bridge structures considering the main aftershock sequence is significantly larger than that considering the main shock only. Material deterioration will lead to the increase in the seismic response of bridge components under earthquake. The seismic time-varying fragility of offshore bridges considering material deterioration and seismic time-varying effects is analyzed based on time-varying seismic action in the entire life cycle. The influences of the two factors should be considered comprehensively when evaluating the seismic performance of bridges throughout their entire life.

Analysis of the Impact of Removal of Aftershocks from Catalogs on the Effectiveness of Systematic Earthquake Prediction

Abstract—The effectiveness of earthquake prediction using the method of the minimum area of alarm when aftershocks are removed from the earthquake catalogs is evaluated. Testing was performed using the catalogs of earthquakes in Japan and the Mediterranean over the 1988–2019 period. The results of prediction of target earthquakes with aftershock sequences and the prediction of only main shocks obtained by the grid fields that were calculated from the full catalogs and the catalogs with the aftershocks removed are compared. This testing shows that the removal of aftershocks from the catalog of target earthquakes decreases the prediction quality. This may occur due to the decreasing number of training examples. Removal of aftershocks from the earthquake catalog to calculate the fields of prediction features makes sense if there is strong aftershock activity in the region.

Damage-based yield point spectra for sequence-type ground motions

Structural damage caused by mainshock can further be aggravated by aftershocks, which can lead to structural collapse. The current practices on the seismic design of structures generally only consider mainshock effects. This manuscript therefore presents the investigation on damage-based yield point spectra (YPS) of a single-degree-of-freedom (SDOF) system under sequential earthquakes. The collected sequence-type ground motions are recorded from 16 earthquake events and classified to four classes. The aftershocks in sequence are scaled according to different relative intensity levels. The modified Park-Ang model, which consists of maximum displacement and hysteretic energy dissipation, is employed to calculate YPS. The effects of period, ductility factor, damage index, site category, aftershock intensity, and structural damping are statistically studied. The results prove that the strong aftershock ground motion has more distinct influences on the YPS. In particular, the yield strength coefficient demand under seismic sequence increases by 10%–50%. The yield strength coefficient demand determined by the damage-based YPS is greater than that determined by the ductility-based YPS—the former is 10%–40% higher than the latter. Finally, the empirical expression of damage-based YPS is established by statistical mean method and regression analysis.

Cumulative Damage of Structures under the Mainshock-aftershock Sequences in the Near-fault Region

ABSTRACT This manuscript quantifies the effects of aftershocks with pulse characteristics on the cumulative damage of structures. The revised randomization method is developed to generate the artificial mainshock-aftershock (MSAS) ground motions showing pulse characteristics. The efficiency of period normalization is discussed from the point of view of dispersion, and the effects of the aftershocks are quantitatively studied. It is found that strong aftershock can contaminate the efficiency of period normalization, and the effects of strong aftershocks in the near-fault region on cumulative damage can exceed 20% and reach 40%. The equations are proposed for the prediction of damage induced by pulse-like MSAS sequences.

Forecasting strong aftershocks in earthquake clusters from northeastern Italy and western Slovenia

In this study, we propose an analysis of the earthquake clusters that occurred in North-Eastern Italy and western Slovenia from 1977 to today. Given a mainshock generating alarm in the population, we are interested in forecasting if a similar magnitude earthquake will follow. We classify the earthquake clusters associated with mainshocks of magnitude Mm into two classes: if the strongest aftershock has a magnitude ≥Mm-1 (swarms or large aftershock seismic sequences) as type A, otherwise (smaller aftershocks seismic sequences) as type B. A large aftershock following a main shock can cause significant damages to already weakened buildings and infrastructures, so a timely advisory information to the civil protection is of great interest for effective decision-making. For the first time, we applied to a new catalogue a pattern recognition algorithm for cluster type forecasting that we developed for all Italy (Gentili and Di Giovambattista, 2017). Thanks to the lower completeness magnitude of the local OGS catalogue, compared to the national one, and to a new version of the algorithm, we were able to lower the threshold of the clusters mainshocks magnitude from 4.5 to 3.7. The method has been validated by rigorous statistical tests. We tested the algorithm on the 1976 highly destructive earthquake cluster (mainshock magnitude 6.5 – the strongest in the last 80 years in the region) and we retrospectively forecasted it as an A cluster. Successful results were obtained also on other three smaller earthquake clusters in 2019.

Experimental evaluation of self-centering hybrid coupled wall subassemblies with friction dampers

Post-tensioned hybrid coupled wall system has desirable seismic characteristics including self-centering capability and tolerance for large nonlinear displacements with limited damage. In this study, the behavior of concrete coupled wall subassemblies with post-tensioned steel coupling beam was experimentally evaluated. In this system, the coupling beam is not embedded into the walls, and the coupling of the concrete walls is accomplished by post-tensioning the steel coupling beam to the walls using unbonded post-tensioning strands. Steel angles and friction dampers were used at the beam-to-wall connection region for energy dissipation. In the first series of tests, a friction damper with different values of the clamping force was tested under two different loading frequencies. In the second series, seven quasi-static cyclic tests were conducted on 2/3-scale subassemblies of the post-tensioned hybrid coupled wall system. The test specimens included a control specimen without energy dissipation device, a specimen with steel angles and four specimens with friction dampers. In addition, one of the tested specimens with dampers was re-tested to investigate the structural behavior and residual capacity of the system during a strong aftershock. The test parameters included the type of energy dissipation device, the initial stress of post-tensioning strands and the amount of damper normal force. The test results show that the subassemblies equipped with friction dampers exhibit excellent lateral stiffness, strength, ductility and energy dissipation and are capable of withstanding large nonlinear cyclic deformations up to the drift of 8%, without residual displacements and without significant damage to the system. Whereas the subassembly equipped with steel angles provide lower energy dissipation capacity and because of the low-cycle fatigue fracture of angles, energy dissipation and load carrying capacities of the specimen decrease significantly.

Seismology of the 2017 Hojedk earthquakes (MN 6.0–6.1), Kerman province, SE Iran

Three moderate earthquakes on 1 and 12 December 2017 with MN magnitudes of 6.0–6.1 (MS1, MS2 and MS3) occurred in the SE Iran. They happened in the area between Nayband and Kuh Banan fault systems, NE of the Kerman metropolice. We combined satellite imagery, seismicity, focal mechanism solutions, strong motions, and Coulomb stress to investigate the earthquakes. These events were located near the southeastern splay of the N-S Lakar Kuh right-lateral strike-slip fault. Active tectonics of the Lakar Kuh fault as well as the earthquake deformations were confirmed by satellite imagery and field photographs, respectively. Hypocenters of the three Mw ~6.0 earthquakes and their aftershocks indicated a migration of faulting from the SE towards the NW. According to high resolution satellite imagery, the third earthquake produced ~6 km of coseismic surface rupture in the alluvial fan deposits (east of Mian Kuh) with maximum deformation in the middle part. The focal mechanisms of both the mainshocks and the strongest aftershocks (MN > 4.6) determined from P wave first motions indicated ~NW-SE fault strikes for the 3 events (dipping SW for MS3), with dominant reverse slip and minor strike-slip components. General northwestward migration of mainshocks as well as strong motions recorded at accelerometers nearby showed evidence for northwestward rupture directivity in all three earthquakes. It was in accordance with the rupture geometry, hypocenter and centroid depth of MS3. The Coulomb stress investigation also revealed that the aftershocks of the 3 events partially covered the increasing areas of Coulomb stress.

A probabilistic framework for the economic loss estimation of structures considering multiple aftershocks

The strong aftershocks have the potential to induce the additional economic loss of structures. This manuscript proposes a framework to estimate the additional economic loss induced by multiple aftershocks, and meanwhile to determine the necessary number of aftershocks that should be considered in the economic loss estimation. Four analysis models (hazard model, structural model, damage model, and loss model) are contained in the proposed framework, which is applied to a 4-story reinforced concrete structure. The result indicates that the additional economic loss induced by a given aftershock is lower when more aftershocks occur before this one. From the perspective of probability, at least two aftershocks should be considered in the loss estimation for M6.0 mainshock, while this number increases to 10 and 28 for M7.0 and M8.0 mainshocks respectively. For low-rise reinforced concrete frame structure, the impact of aftershocks on the economic loss increases with the increase of mainshock magnitude, and it can exceed 40% for strong mainshock from the perspective of probability. The proposed framework and results in this study would be helpful for the decision making in the pre- and post-earthquake environment.

Landslide development within 3 years after the 2015 Mw 7.8 Gorkha earthquake, Nepal

The Araniko and Pasang Lhamu highways are two critical trading routes connecting Nepal and China that are experiencing and are threatened by landsliding. The April 25 Mw 7.8 Gorkha earthquake and its May 12 Mw 7.3 aftershock in 2015 significantly increased landsliding along these highways. Multi-temporal remote sensing images (pre-seismic to December 2017) on Google Earth, aerial photography acquired in 2018 using an unmanned aerial vehicle (UAV), and field investigations and surveys in June 2015, November–December 2017, and April–May 2018 quantify the development of selected landslides after the earthquake along the two highways. These include detailed studies of 39 and 30 landslide locations in 2017 and 2018, respectively, with 14 locations common to both the 2017 and 2018 studies. Only the landslides in five locations showed a slight decrease in activity after the earthquake, and most landslides continued to move and enlarge. More than five new landslides were triggered by monsoon rainfalls in the summers of 2017 and 2018. All the landslides pose significant challenges for infrastructure reconstruction and hazard reduction in the area affected by the Gorkha earthquake, especially along the Araniko and Pasang Lhamu highways. Comparison of landslide debris volume, pre- and post- earthquake rainfalls, and earthquakes that occurred before and after the 2015 Gorkha earthquake with the 1999 Chi-Chi, 2005 Kashmir, and 2008 Wenchuan earthquakes show that continuing rainfall after earthquakes and strong aftershock shaking are key factors affecting continued landsliding in these earthquake-effected areas.

A Method for Controlling Seismic Damage of RC Bridge Piers Subjected to Strong Aftershocks

A Method for Controlling Seismic Damage of RC Bridge Piers Subjected to Strong Aftershocks

Regional seismic-damage prediction of buildings under mainshock—aftershock sequence

Strong aftershocks generally occur following a significant earthquake. Aftershocks further damage buildings weakened by mainshocks. Thus, the accurate and efficient prediction of aftershock-induced damage to buildings on a regional scale is crucial for decision making for post-earthquake rescue and emergency response. A framework to predict regional seismic damage of buildings under a mainshock-aftershock (MS-AS) sequence is proposed in this study based on city-scale nonlinear time-history analysis (THA). Specifically, an MS-AS sequence-generation method is proposed to generate a potential MS-AS sequence that can account for the amplification, spectrum, duration, magnitude, and site condition of a target area. Moreover, city-scale nonlinear THA is adopted to predict building seismic damage subjected to MS-AS sequences. The accuracy and reliability of city-scale nonlinear THA for an MS-AS sequence are validated by as-recorded seismic responses of buildings and simulation results in published literature. The town of Longtoushan, which was damaged during the Ludian earthquake, is used as a case study to illustrate the detailed procedure and advantages of the proposed framework. The primary conclusions are as follows. (1) Regional seismic damage of buildings under an MS-AS sequence can be predicted reasonably and accurately by city-scale nonlinear THA. (2) An MS-AS sequence can be generated reasonably by the proposed MS-AS sequence-generation method. (3) Regional seismic damage of buildings under different MS-AS scenarios can be provided efficiently by the proposed framework, which in turn can provide a useful reference for earthquake emergency response and scientific decision making for earthquake disaster relief.

EXPERIMENTAL STUDY ON THE DAMAGE CLASSIFICATION METHOD WITH THE PERFORMANCE CURVES OF R/C STRUCTURES DERIVED FROM RECORDED ACCELERATIONS

Once a catastrophic earthquake occurs, many buildings may be affected. Some buildings are severely damaged and may collapse during a following strong aftershock. It is needed to conduct a rapid inspection to evaluate the buildings in the affected area. “Manual for post-earthquake rehabilitation techniques for buildings (draft)” was developed in 1986 to evaluate the damage class of the buildings based on the visual observation. Recent earthquakes revealed that it becomes quite difficult to conduct visual inspection because structural members are covered by the finishings and many highrise buildings were constructed. The author has been conducting a series of research to develop a new method to evaluate the damage class with instrumented sensors based on the capacity spectrum method. The capacity curve is derived from the measured accelerations and displacements calculated from accelerations with double integral. The proposed system can predict the possible damage level during the maximum aftershock. However, the damage class according to the proposed system and to the guidelines based on the visual observation has not been compared. The earthquake insurance also conducts the visual investigation and evaluate the damage class to estimate the earthquake insurance premium. The damage class according to the earthquake insurance is also compared.

ЗЕМЛЕТРЯСЕНИЕ 28 февраля 2013 г. с Mw(GCMT)=6.8, I0=5–6 (Юго-восточное побережье Камчатки)

The February 28, 2013 earthquake (MwGCMT=6.8), which occurred on the southeast coast of Kamchatka, is discussed. The instrumental hypocenter location reported by the KB GS RAS is φ=50.67N, λ=157.77E, h=61 km. Three magnitudes were obtained: local magnitude ML=6.9, code-wave magnitude Mc=6.6, mo-ment magnitude Mw=6.7. The focal mechanisms of the February 28, 2013 earthquake and its aftershocks with ML≥6 correspond to the tectonic conditions of subhorizontal compression in the NW–SE direction. For most of these mechanisms, the shallow plane falls under Kamchatka, which corresponds to the geometry of the subduction zone. The small-focus aftershocks cloud of the February 28, 2013 earthquake has the 5828 km size and is extended in the north-east – south-west direction. The aftershock process has the three-phase character and can be considered as a stream of seismic events decreasing in time with three successive stages with different attenuation modes. The change in attenuation modes is associated with strong after-shocks. The duration of the decaying aftershock process is ~ 100 days. The February 28, 2013 earthquake was felt with intensity ranged from 2 to 5–6 on the MSK-64 scale in 33 localities (Δ=81–493 km). The mac-roseismic impact area was about 56∙103 km2. The mainshock and its four strong aftershocks have a similar picture of macroseismic manifestations: the macroseismic effect is larger on the east coast of Kamchatka; the strongest shakes has been observed in Severo-Kurilsk (Paramushir Island). The elongation of the isoseist along the Kamchatka eastern coast has been observed, which is typical for Kamchatka earthquakes. The strong ground motions from the February 28, 2008 earthquake has been recorded using the Kamchatka net-work of digital accelerographs. The level of peak amplitudes for this earthquake is consistent with average trends in the Kamchatka region. Attenuation parameters are typical for Kamchatka. The shallow layer of the seismic focal zone of the Kuriles and South Kamchatka, in which the February 28, 2013 earthquake was recorded, is one of the most active seismic areas in the North-West Pacific. Earthquakes with M>8 were re-peatedly occurred here, causing a tsunami and intensity of shakes up to 9 on the MSK-64 scale in the south of Kamchatka.

ИЛЬПЫРСКОЕ ЗЕМЛЕТРЯСЕНИЕ 13 марта 2013 г. с Mwрег=5.8, ML=6.2, КS=13.9, I0p=8 (Камчатский перешеек)

The strong (Mwreg=5.8, ML=6.2) near-surface seismic event (Ilpyrskoye earthquake) occurred at 03h12m on 13 March, in the Kamchatka Isthmus. It was the strongest earthquake between 1962 and 2013 for this area. The greatest macroseismic effect was observed at a distance of ~30 km, I=6–7 on the scale MSK-64. We used two independent methods for determining its regional focal mechanism: 1) regional moment tensor in-version using broadband waveforms; 2) solution based on polarities of the P waves. The results are similar: the focal mechanism of Ilpyrskoye earthquake is thrust faulting with strike-slip component; the compression axis is subhorizontal and is oriented in the north-east – south-west direction. The mechanisms for the two strongest aftershocks were also identified, as a result, a change in focal movements during the aftershock process was revealed.The analysis of the aftershock process which consists of two stages with different de-cay character was performed. The process lasted ~ 75 days. About 200 aftershocks ML=3.0–5.7 (КS=7.5–12.9) were recorded, hypocenter depth estimations vary from 0 to 10 km for about 80 % of them. The strongest aftershock was on May 6, 2013 with ML=5.7, Mwreg=4.8, at which the change in focal movements occurred. According to the results of near real time processing, aftershock cloud of Ilpyrskoye earthquake had a pronounced linearity and a great length, which was an artifact. The main cause of the artifact is the minimum number of stations involved in determining the hypocenters of most aftershocks and their quasi-linear disposition. The confidence areas within which solutions are equivalent are shown. We concluded that Ilpyrskoye earthquake is a serious argument that the area of compression between the Okhotsk and North American plates is extended further to the east and the border passes through the Kamchatka Isthmus

ОХОТОМОРСКОЕ-III ЗЕМЛЕТРЯСЕНИЕ 24 мая 2013 г. с Mwрег=8.3, I0=6 (Охотскоеморе)

The strongest deep earthquake on May 24, 2013 (Mwreg=8.3) is discussed. It occurred under the Sea of Okhotsk at a depth of about 630 km. The instrumental hypocenter location reported by the KB GS RAS is φ=54.75N, λ=153.78E, h=630 km. Three magnitudes were obtained: local magnitude ML=7.8, code-wave magnitude Mc=7.6, moment magnitude Mwreg=8.3. The Okhotsk earthquake hypocenter is located on the northern part of the ancient slab, practically at the lower end of the seismogenic region. The earthquake caused significant co-seismic displacements at most GNSS observation points. The earthquake focal mecha-nisms solutions have been obtained by three ways. The solutions are very similar. The submeridial hollow falling nodal plane seems more preferable. For the deep quake of May 24, 2013, a series of aftershocks were registered. The aftershock process had three consistent stages with different decay character. The cloud of deep-focus aftershocks has the 400200 km size, with the 450–700 km depth range and is extended in the North–South direction. The aftershock process has the three-phase character and can be considered as a stream of seismic events decreasing in time with three successive stages with different attenuation modes. The change in attenuation modes is associated with strong aftershocks. The duration of the decaying after-shock process is ~ 280 days. The anomalous distribution of impact was observed for the earthquake: 1) a large range of macroseismic effect – quake was felt throughout the World; 2) in the territory of Kamchatka, maximum shakes and ground motions were observed at the points located on the eastern coast of Kamchat-ka, and at comparable northern and western distances macroseismic and instrumental intensities were lower. Despite the globality of the macroseismic effect, in the nearest settlements (Kamchatka region), the earth-quake was felt with intensity up to 5–6 and caused no damage. The May 24, 2013 earthquake produced many strong motion records. The ground motion characteristics such as peak amplitudes of motion, spectral shape and response spectrum were received using the records of the earthquake from Kamchatka network of digital accelerographs.