Macroseismic Survey Research Articles

Earthquake on January 24, 2024 near Krasnodar city, Mw=4.1, I0=5

The article presents instrumental and macroseismic data on the earthquake on January 24, 2024 at 11:19 (UTC), Mw=4.1, h=8 km. The earthquake parameters were determined using instrumental data from the network of regional seismic stations in the North Caucasus of the GS RAS. The earthquake parameters were determined from instrumental data from the network of regional seismic stations in the North Caucasus of the GS RAS. The source spectra of three regional seismic stations (GOYR, MRNR and GUZR) were calculated, from which the seismic moment М0, the stress drop Δσ and the source radius R were determined. The solution of the focal mechanism was obtained from the polarization in P-waves at 71 seismic stations and the type of source fault with a right-lateral strike-slip component. The epicentral zone of the earthquake on 24.01.2024 is located within the high-magnitude Akhtyrka zone of potential earthquake source zones (ESZ) with Mmax=6.5-6.8 and represents the boundary between the Northwestern part of the structures of the Greater Caucasus and the West Kuban trough. According to macroseismic survey in the regions, 300 respondents were interviewed in 20 settlements. The maximum observed intensity was I=V MSK-64.

FELT EARTHQUAKE of JULY 4, 2017 with ML=3.7, I0=5–6 to NORTHWEST of the 1988 SPITAK EARTHQUAKE SOURCE ZONE

The instrumental data and results of macroseismic survey of the July 4, 2017 earthquake with ML=3.7, I0=5–6, occurred in the source zone of the devastating Spitak earthquake of 1988 with I0=10, are given. The earthquake was accompanied by a sound like an explosion. According to the focal mechanism parameters, a reverse faulting occurred along the NP1 plane of northwest strike and northeast dipping, or a thrust along the near-meridional NP2 plane dipping west. The migration of aftershocks to the north and east in October-December 2017 testifies in favor of choosing the NP1 nodal plane as the main one. An isoseismal map of the earthquake is constructed, according to which the isoseists are oriented to the northeast. The discrepancy between their orientation and the strike of the nodal planes is explained by the predominant influence on the macroseismic field of northeast oriented Akhourian fault, in the zone of which most of the surveyed settlements are located.

Detailed Macroseismic Survey and Rational Approach to Seismic Intensity Assessment within the Territory of a Large City: Case Study of the Consequences of the September 21, 2020 Bystraya Earthquake in Irkutsk

Detailed Macroseismic Survey and Rational Approach to Seismic Intensity Assessment within the Territory of a Large City: Case Study of the Consequences of the September 21, 2020 Bystraya Earthquake in Irkutsk

The damaging character of shallow 20th century earthquakes in the Hainaut coal area (Belgium)

Abstract. The present study analyses the impact and damage of shallow seismic activity that occurred from the end of the 19th century until the late 20th century in the coal area of the Hainaut province in Belgium. This seismicity is the second-largest source of seismic hazard in north-western Europe after the Lower Rhine Embayment. During this period, five earthquakes with moment magnitudes (Mw) around 4.0 locally caused moderate damage to buildings corresponding to maximum intensity VII on the European Macroseismic Scale 1998 (EMS-98). Reviewing intensity data from the official macroseismic surveys held by the Royal Observatory of Belgium (ROB), press reports and contemporary scientific studies resulted in a comprehensive macroseismic intensity dataset. Using this dataset, we created macroseismic maps for 28 earthquakes, established a new Hainaut intensity attenuation model and a relationship linking magnitude, epicentral intensity and focal depth. Using these relationships, we estimated the location and magnitude of pre-1985 earthquakes that occurred prior to deployment of the modern digital Belgian seismic network. This resulted in a new updated earthquake catalogue for the Hainaut area for the 1887–1985 period, including 124 events. A comparison with other areas worldwide where currently similar shallow earthquake activity occurs suggests that intensity attenuation is strong in Hainaut. This high attenuation and our analysis of the cumulative effect of the Hainaut seismicity indicate that current hazard maps overestimate ground motions in the Hainaut area. This reveals the need to use more appropriate ground motion models in hazard issues. Another strong implication for earthquake hazard comes from the reliability of the computed focal depths that helps clarifying the hypotheses about the origin of this seismicity. Some events were very shallow and occurred near the surface up to a depth not exceeding 1 km, suggesting a close link to mining activities. Many events, including the largest shallow events in the coal area before 1970, occurred at depths greater than 2 km, which would exclude a direct relationship with mining, but still might imply a triggering causality. A similar causality can also be questioned for other events that occurred just outside of the coal area since the end of the mining works.

EMS98 intensities distribution of the “Le Teil” earthquake, France, 11 November 2019 (Mw 4.9) based on macroseismic surveys and field investigations

EMS98 intensities distribution of the “Le Teil” earthquake, France, 11 November 2019 (Mw 4.9) based on macroseismic surveys and field investigations

SEISMICITY of the RUSSIAN PART of EAST EUROPEAN PLATFORM and ADJACENT TERRITORIES in 2015

It is reported that 41 stationary seismic stations, 2 arrays, and 7 temporary seismic stations, located in the area of Novovoronezh and Kursk nuclear stations, monitored seismicity of the Russian territory of the East European Platform (EEP) in 2015. The registration capabilities of the seismic network at the EEP as a whole were estimated based on the average station noise level and the equation for the energy decay of seismic phases. Zones with the best capabilities have been allocated. A feature of seismicity in 2015 is the manifestation of earthquakes of moderate magnitudes (ML=2.7–3.9) in the peripheral regions (in the southwest, west, and northwest) and in zones associated with paleorift structures: in the southwest – with the Dnieper Donetsk and in the northeast – with the Kirov-Kazhim and Soligalich (Central Russian) aulacogenes. The results of the macroseismic survey are given for the earthquake in Poltava on February 2, 2015, with M=3.7; focal mechanisms of two earthquakes (03.02.2015 and 12.06.2015) are constructed. According to the data of the Latvian Center, an earthquake was recorded in the region of Lithuania bordering the Kaliningrad region. Weaker natural seismicity with ML≤2.5 was recorded in Karelia and the regions bordering with Finland, near the Kandalaksha Bay, near the Khibiny, and Lovozersky massifs on the Kola Peninsula, and on the territory of the Voronezh crystalline massif.

Macroseismic survey of the 6 February 2016 KwaZulu-Natal, South Africa earthquake

AbstractOn the 6th of February 2016 at 11:00 hours local time (0900 UTC), KwaZulu-Natal was struck by an earthquake of local magnitude ML=3.8. The epicentre of the earthquake was located offshore in the Durban Basin. The earthquake shaking was widely felt within the province as well as in East London in the Eastern Cape province and was reported by various national media outlets. Minor structural damage was reported. A macroseismic survey using questionnaires was conducted by the Council for Geoscience (CGS) in collaboration with the University of KwaZulu-Natal (UKZN) which yielded 41 intensity data points. Additional intensity data points were obtained from the United States Geological Survey (USGS) Did You Feel It? programme. An attempt was made to define a local intensity attenuation model. Generally, the earthquake was more strongly felt in low-cost housing neighbourhoods than in more affluent suburbs.

Macroseismic intensity attenuation equations for Central Asia earthquakes

Based on macroseismic survey data for strong earthquakes in Central Asia, the coefficients of attenuation of seismic intensities with distance in the Blake-Shebalin- and Kovesligethy -type equations were refined. A new generalized dependence of macroseismic intensity attenuation on distance, taking into account the depth of the earthquake hypocentre, were obtained. Relations between the minor and major axes of the ellipse approximating real isoseists depending on the shaking strength, source depth and earthquake magnitude were found. With the example of the territory of eastern Uzbekistan, the influence of the choice of the law of seismic intensity attenuation with distance on the obtained seismic hazard assessments is investigated.

Землетрясение 12 декабря 2020 г. в Анапской зоне с Mw=3.8, I0=4–5 баллов

The article presents instrumental and macroseismic data on the earthquake on 12.12.2020 at 14:54 with Mw=3.8, h=30 km. The epicenter and parameters of the earthquake were deter-mined using instrumental data from the network of regional seismic stations in the western zone of the North Caucasus of the EGS RAS. This earthquake occurred in the shelf zone of the Eastern Black Sea coast near the resort town of Anapa, in the Anapa seismically active area. This area tectonically is the conjunction of the northern side of the Tuapse trough and the thrust front of the Greater Caucasus. The focal mechanism for the earthquake was calcu-lated. The solution of the focal mechanism was obtained from the polarization in P-waves at 29 seismic stations. From the focal follows the type of source up thrust-thrust movement. The GS RAS organized a macroseismic survey in the Anapa and Novorossiysk regions on the “VKontakte” social network a day after the earthquake. According to the results of the study, 144 respondents in 15 settlements in 7 days were interviewing. The maximum observed in-tensity was I=4-5 points in Su-Psekh and Varvarovka according to the results of the macro-seismic survey, a map of the distribution of intensity points was create. The SEISAN software package calculated the spectral parameters of the source: seismic moment, corner frequency, spectral density level and spectral magnitude Mw.

Features of the earthquakes’ manifestation intensity formation in mountainous areas

Analysis of the destructive earthquakes‘ consequences engineering macro-seismic survey data shows that the earthquakes manifestation degree is in close correlation with the peculiarities of geomorphological conditions. Moreover, this dependence is not of a simple character: there is a clearly expressed multifactorial nature of correlations. The work shows that the earthquakes intensity is determined not only by the relief slope magnitude, but also by the specific location of the site in the mountain range hierarchy. The results of the experimental studies analysis (field and laboratory experiments) are presented. It is noted that from a physical point of view, the relief has a certain potential energy. To estimate the indicated energy, a phenomenological indicator was introduced in the form of the so-called “relief factor”, which is the product of the relief inclination angle by the corresponding height. It is noted that upon reaching the value R=650 (degrees m) the intensity increment is one point. The use of a new relief parameter, which makes it possible to fully take into account the specific conditions of the location of the investigated area, increases the establishment validity of the mechanisms for the earthquake intensity formation in mountainous regions.

Analysis of susceptible disaster region based on the peak ground acceleration and earthquake intensity in Mamasa 2018

This study aims to know the susceptible disaster region based on peak ground acceleration and earthquake intensity on earthquake study cases in Mamasa 2018. Data that is used in this research is data on earthquake cases in Mamasa 2018 that is gained from the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) district IV Makassar, it included data of the time when the earthquake happened, latitude, longitudinal (, depth (< 60 km) and magnitude (≥ 5) SR. The calculation of on peak ground acceleration was conducted by using Donovan and Mc.Guirre methods, whereas to calculate the value of intensity, it is using the Wald method (1999). The result from the calculation of on peak ground acceleration by Donovan is 95.903 gal to 377.094 gals with the intensity VI to VIII MMI. Whereas the calculation result of on peak ground acceleration by Mc.Guirre method is 58.981 gal to 227.39 gals with the intensity V to VII MMI. MMI intensity of the Wald method is obtained by using the PGA value conversation Mc.Guirre method that is closer to the intensity of the result of the macroseismic survey in Mamasa District and relates with the damage that happened on location. The mapping of earthquake intensity based on PGA Mc.Guirre method shows that 3 (three) sub-districts that have an intensity of VII MMI, namely Tawalian Sub-district, Mamasa Sub-district, and Sesean Padang Sub-district. The area is the most vulnerable. Mamasa has low-risk level from the earthquake, although sometimes an earthquake happened until now. This result is supported by a geological map in the Mamasa regions that showed source rock in that area is a type of hard rock that consis of granitic materials.

KAJI-SAIEARTHQUAKEonNovember 14, 2014 withКР=13.7, Mw=5.4, I0=7 (Kyrgyzstan, SouthernIssyk-Kul’)

Information on the earthquake with Mw=5.4 that occurred on the southern coast of the Issyk-Kul lake on the southwestern slope of the Tegerek mountains (Kyrgyzstan) on November 14, 2014 is given. The epicenter is located in the Jumgalo-Terskey zone, identified as the Tonsky block, in which felt earthquakes with intensity up to 7 have occurred repeatedly. 231 aftershocks were recorded in the first day, in the second day – 13 aftershocks, then seismic activity decreased. Most of the aftershocks are localized in the depth range of 17–21 km, close to the depth of the main shock (h=20 km). The earthquake had the reverse fault type. Macroseismic survey was fulfilled only in the epicentral zone due to the complex weather conditions (late autumn, highlands). The theoretical isoseismal map was created for receiving the more complete picture of the earthquake impact outside of its epicentral zone.

SPITAK-V EARTHQUAKE on July 6, 2014 with МL=4.0, I0=5–6 (Armenia)

The work presents the results of macroseismic survey of the Spitak-V earthquake which occurred on July 6, 2014 with МL=4.0, I0=5–6 in the focal zone of the destructive Spitak earthquake 1988 with I0=10. The isoseismal map of the July 6, 2014 earthquake was made and the focal mechanism parameters were determined. According to the focal mechanism decision, the movement in the source was a strike-slip with minor uplift components.

МАРЖАНБУЛАКСКОЕЗЕМЛЕТРЯСЕНИЕ 26 мая 2013 г. сКР=15.0, MS=5.9, I0=8 (Узбекистан, Джизакскаяобласть)

The instrumental data and the results of the macroseismic survey of the Marjanbulak earthquake MwMOS=6.2 with an intensity of 8 on the MSK-64 scale, which occurred in Uzbekistan, are presented. The isoseismal map is given. Correspondence between the intensity of the earthquake manifestation and the regional macroseismic field equation is shown. Geological and geophysical, engineer-geological conditions in the epicentral zone are described. The seismicity of the observation area is reviewed.

Investigation of macroseismic intensity of the Mw5.9 September 10, 2016 Kagera earthquake: Implications for site effect amplification

The Kagera earthquake of magnitude Mw5.9 occurred on September 10, 2016 at 12:27 GMT, 15:27 local time, with an epicenter located northwest of Bukoba town, in Minziro village close to the border of Tanzania and Uganda. The earthquake resulted in the widespread damage within the Kagera region with an officially announced death toll of 17, many residential structures destroyed, and others damaged beyond repair. Following the earthquake, a macroseismic survey was conducted by interviewing various affected people using macroseismc questionnaires to delineate the distribution of seismic energy and establish the effects of ground shaking. The results of the macroseismic survey indicate variations of intensity values from IV-VIII on the MSK-64 scale with more frequently assigned values of intensity range from VI-VII. The orientation of the intensity pattern is elongated towards the southeast in accordance with the rupture directivity towards Bukoba town, which is in agreement with the orientation of the fault rupture from the focal mechanism and the distribution of aftershocks. The duration of shaking in many localities was observed to be over 20 s, resulting in resonance effects. Both findings of the observed variations of the intensity values and the duration of shaking indicate that site effects, which result in the amplification of the seismic signals, likely played a great role in the damage distribution. The maximum intensity of VIII, which corresponds to the instrumental magnitude of 6.2, differs from the instrumental result of magnitude 5.9 by a factor of 0.3; the difference is attributed to the amplification by site effects within the region. The observed site effects therefore emphasize the importance of reinforcing the buildings, and, in the future, adherence to seismic building codes and specifications in all regions within the East African Rift system (EARS). It is also hoped that the database of the intensity data points from macroseismic survey will be useful in the development of the seismic intensity prediction equation for the earthquakes within the region and for the assessment of the impact on regional seismic hazard and the entire EARS.

Minimum Isoseismal Distribution Based On Macroseismic Interpolation For Earthquake Disaster Mitigation in Palu City

Palu City is the city that suffered the most damage and many casualties, effect from event Palu-Donggala earthquake on September 28, 2018. This earthquake triggered a tsunami, liquifaction and landslides which caused difficulties in determining a closest safe location for the temporary evacuation site in location affected disaster. The aftershocks that occurred after the main earthquake caused unrest for refugees and village government officials, because it was feared that the location to be used as a temporary evacuation site would run into the impact of an earthquake similar to other severe locations. To determine a safe location around the impact area destructive earthquake, information about the map of the minimum isoseismal distribution is very important. This study aims to map Minimum Isoseismal Distribution as the place that has the smallest disaster risk in areas affected by the earthquake, tsunami, liquefaction and landslides. The research methodology that be done are plotting and interpolate data from macroseismic surveys then were verified using satellite citra data and photo documentation of survey. The results showed that a minimum isoseismal distribution was found in 8 areas, located in the village: Kabonena, Lere, Kamonji, Siranindi, between Boyaoge and Nunu, Tawanjuka, Palupi and Tinggede.

Revisiting The 2018 Kalibening Earthquake Sequence In Central Java: Call for the Revision of Earthquake Hazard

As moderate devastating earthquake that impacted the economic loss was about $ 1.68 million US, the 2018 Kalibening earthquake quite shocked where the faulting mechanism still unconfirmed. There was no reference indicating the existence of the faulting zone exactly on the earthquake sequence. We take a benefit from seismic temporary network with the density ±2 km, which deployed while a macroseismic survey in purposing to evaluate the 2018 Kalibening earthquake sequence. Earthquake relocation using double difference combined with cross-correlation and determining earthquake moment tensor inversion solution using near source seismograms were applied. We suggested the deformation scheme of this earthquake with a thrust faulting with 307.5 / 28.8 / 118.5 (Strike / Dip / Rake) as a result from mainshock and supported by aftershock moment tensor solutions. This parameter consistent to aftershocks relocation results which formed a lineation trending NW-SE appropriate with Strike = 307.5. The cross-section exhibits aftershocks pattern which elongated deeper and formed a slope from SW to NE approximately fit to Dip = 28.8. The results from investigating the background seismicity in Banjarnegara Region using combined catalog (ISC-USGS-BMKG) compared to BJI (single station) showed the sparse and the lacking of InaTEWS seismic network configurations. Finally impacted to losses in earthquake cataloging, leads the low area coverages around Banjarnegara region. Together with our results, we called for the revision of earthquake hazard assessment for Central Java province, especially in Banjarnegara region.

Investigation on damage progression during the 2016–2017 seismic sequence in Central Italy using the European Macroseismic Scale (EMS-98)

On 24th of August 2016 a strong earthquake (Ml 6.0; Mw 6.0) struck Central Italy, causing destruction and about 300 victims. The earthquake was the first in a long-lasting seismic sequence characterized by seven events of magnitude larger than 5.4, with the main event of Mw 6.5 occurring on 30th of October 2016. A macroseismic survey was carried out soon after each damaging shock. In some of the most damaged villages a building-to-building survey was carried out. Assessing the intensity during the campaign in the presence of increasing damage was one of the main problems to be dealt with. In this paper we present the data collected in Amatrice, Accumoli, Arquata del Tronto, and its expanded area called Borgo, after the 24th of August and the 30th of October earthquakes, in order to investigate the damage progression and its influence on the intensity assessment according to the European Macroseismic Scale (EMS-98). This work aims to document the evolution of the damage that was observed during the sequence in the above-mentioned areas, by analysing the behaviour of each vulnerability class, and to contribute to the discussion on the assessment of macroseismic intensity in presence of cumulative damage.

The 2016–2017 earthquake sequence in Central Italy: macroseismic survey and damage scenario through the EMS-98 intensity assessment

In this paper we describe the macroseismic effects produced by the long and destructive seismic sequence that hit Central Italy from 24 August 2016 to January 2017. Starting from the procedure adopted in the complex field survey, we discuss the characteristics of the building stock and its classification in terms of EMS-98 as well as the issues associated with the intensity assessment due to the evolution of damage caused by multiple shocks. As a result, macroseismic intensity for about 300 localities has been determined; however, most of the intensities assessed for the earthquakes following the first strong shock on 24 August 2016, represent the cumulative effect of damage during the sequence. The earthquake parameters computed from the macroseismic datasets are compared with the instrumental determinations in order to highlight critical issues related to the assessment of macroseismic parameters of strong earthquakes during a seismic sequence. The results also provide indications on how location and magnitude computation can be strongly biased when dealing with historical seismic sequences.

Fast characterization of sources of recent Italian earthquakes from macroseismic intensities

We analysed the intensity data collected immediately after three strong earthquakes (Mw ≥ 6) that occurred in Italy in the last decade to infer location, orientation and size of the relevant seismogenic faults using the Boxer method. We show that, starting from a few hours after the earthquake, such macroseismic method could have provided a characterization of the seismogenic source comparable to instrumental methods, some of which would have required much more time to provide stable results. Particularly for the 6 April 2009 earthquake, the analysis of macroseismic survey data could have been able to accurately constrain, starting already from the early afternoon of the day of the main shock, location, orientation and size of the area of maximum coseismic displacement, related to the activation of the Paganica-S. Demetrio fault system. For the 20 May 2012 Emilia and the 24 August 2016 Amatrice earthquakes, preliminary macroseismic surveys were carried out within a few days from the main shocks, but their data were made available publicly a month later. For the 20 May 2012 Emilia earthquake, the orientation of the fault could have been correctly determined even if the size would have been underestimated. For the 24 August 2016 Amatrice earthquake, both the orientation and the size could have been correctly assessed. We also compared such macroseismic determinations with those obtained for some historical earthquakes in the same areas. The analysis of the cumulate intensities observed after the shocks of 24 August, 26 and 30 October 2016 indicates an overall Mw 6.8 comparable to that (Mw 6.9) of the largest earthquake occurred in the same section of the Apennines (14 January 1703). Even if the inferred orientations of the 2016 and 1703 boxes are very similar, the epicentres differ of about 20 km indicating a probable distinct fault system for the two earthquakes.