Visualization of macroseismic parameters during examination of epicentral zones of strong earthquakes

The article discusses the fragile destruction of building materials during strong earthquakes, the features of the macroseismic effect of cracking expressed in the protective coatings of buildings; it is recommended to optimize the composition based on polymer by composition that increases the crack resistance of plaster solutions. In particular, the visualization of macroseismic parameters is given on the example of the survey of the epicentral zones of the Tashkent (2008), Cannes (2011) and Marzhanbulak (2013) strong earthquakes that occurred in Kyrgyzstan and Uzbekistan. Possible directions of crack development and density of their distribution over the macroseismic area are analyzed. It was revealed that the vulnerability to micro-destruction of types of protective materials is proportional to the seismic intensity and is mainly due to the intensity of seismic vibrations.

SAKHALIN

A review of the Sakhalin seismicity in 2014 based on the data of regional network is given. The network included four stationary and ten temporary digital seismic stations. This network was supported by ten stations of local network operating in the south of Sakhalin. Parameters of 450 seismic events, including 25 explosions, and focal mechanisms for 4 events are determined. 22 earthquakes had a macroseismic effect. The map of earthquake completeness and the map of epicenters are given. The distribution of crust and deep earthquakes on magnitude and their summarized energy for seven seismoactive areas in comparison with average parameters for 2001–2013 are presented. For each area and the region as a whole, an analysis of the seismic regime parameters in 2014 in comparison with long-term parameters is given, tangible and strong earthquakes are described. The seismicity of the Sakhalin region in 2014 can be characterized as a moderate one. Somewhat increased seismic activity was recorded in the East Sakhalin and Southeastern areas.

ARMENIA

The article describes changes in the composition and equipment of the network of seismic stations in Armenia, which ensured a representative level of earthquake registration in Armenia in 2014 with K3min=8.0. The analysis of seismicity on the territory of Armenia and neighboring regions is carried out, focal mechanisms of 17 earthquakes are determined using the signs of P-wave first arrivals at the seismic stations of Armenia and neighboring countries. Within the Republic, the highest level of seismic activity in 2014 was in the North, in the focal zone of Spitak earthquake 07.12.1988 with MLH=6.8, I0=10. The macroseismic effect of earthquakes felt in Armenia is described.

EARTHQUAKE MAY 20, 2014, ML=2.8, I0=4–5 IN THE CENTRAL PART OF THE REPUBLIC OF BASHKORTOSTAN

The article provides macroseismic data on the earthquake 20.05.2014 18h26mUTC ML=2.8, that had a local but relatively strong macroseismic effect (I0=4–5) in the Chishminsky district of the Republic of Bashkortostan. After the event, macroseismic data were collected in 27 settlements in the epicentral zone. This data allowed to determine the macroseismic epicenter, which is close to the instrumental one. The events in the same area during the historical period were considered in detail and modern seismic records were revised. The data allowed to identify a series of similar seismic events with less magnitudes in 2014. The classification of these activities into two groups has been justified there. There are tectonic and natural events induced by Alkinskoye oil deposit exploration.

SAKHALIN

The review of seismicity for Sakhalin in 2013 based on the data of four seismic stationary stations and 10 temporary digital seismic stations "DAT", working in the south of Sakhalin, is given. The main parameters of 688 earthquakes and focal mechanisms of five of them are determined. 42 earthquakes showed a macroseismic effect. The maps of the representativeness of earthquakes and of epicenters are given, the distribution of crust and deep earthquakes on the magnitude and their summarized energy for seven seismoactive districts are presented. For each area, seismic conditions are described. The seismicity of the Sakhalin region in 2013 can be characterized as moderate. Somewhat increased seismic activity was recorded in the East Sakhalin region, against the background seismicity in previous years. Somewhat increased activity was also recorded in the West Sakhalin region, where a moderately strong earthquake occurred with MLH=5.1.

AZERBAIJAN

In 2013, four digital stations («Horadiz», «Agdam», «Beylagan», «Yardimli») were opened. The complete network consisted of 35 digital stations. The network of analog stations continued to operate unchanged. In 2013, the set of parameters for estimating the earthquake size decreased – determining the magnitudes MPVA and the energy classes КР was stopped. Only the local magnitude ML Азр is measured and then recalculated into energy class КР. The seismicity of the territory of Azerbaijan is analyzed. Maps of epicenters of earth-quakes are given. The total number of earthquakes in 2013 was 5248 with ML Азр>0.1, of which only 165 with ML Азр3.0 are published in the Yearbook. A decrease in the seismic activity of the studied territory was noted. Powerful seismic activity, observed in 2012, was replaced in 2013 by a decrease in seismicity to the background level. The most significant seismic event on the territory of the Republic was the April 18 earth-quake with ML Азр=5.3 with macroseismic effect I0=4.

OKHOTSK-III EARTHQUAKE 24.05.2013 with Mwreg=8.3, I0=6 (Sea of Okhotsk)

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.

SOME SPECIAL FEATURES OF THE EARTHQUAKES MACROSEISMIC EFFECT OF DAGHESTAN AND ADJACENT TERRITORIE

Рассматриваются некоторые временные и пространственные закономерности макросейсмических проявлений землетрясений Дагестана и прилегающих территорий. Построены кумулятивные графики на- копления макросейсмических событий и выявлены средние периодичности сотрясений разной интенсив- ности. Показано, что разные очаговые зоны характеризуются различными коэффициентами в формулах типа Блейка-Шебалина. Приводятся корреляционные соотношения для расчета большего и меньшего радиусов изосейст и большего и меньшего гипоцентральных расстояний в зависимости от магнитуды и балльности изосейсты Some time and three-dimensional laws governing the macroseismic effects of the Daghestan earthquakes and adjacent territories are examined. The cumulative graphs of the accumulation of macroseismic events are built and the average periodicities of the shake-ups of different intensity are revealed. It is shown that the different focus zones are characterized by different coefficients in the formulas of Blake-Shebalin type. The correlation relationships for the calculation of isoseists greater and less radii and larger and less than hypocentral distances depending on magnitude and intensity of isoseist are given