The seismic observations in the Carpathian region in 2013, which were conducted, as before, by two organizations from two states: in Ukraine, by the seismicity department of the Carpathian region of the Institute of Geophysics of the National Academy of Sciences of Ukraine, and in Moldova by the seismology laboratory of the Institute of Geology and Seismology of the Academy of Sciences of Moldova are described. There were 19 digital stations with a processing center in Lviv, Ukraine, and 6 stations with a center in Chisinau, Moldova. Various programs, local hodographs, and magnitudes were used. The consolidated catalog of earthquakes is created in Lviv. The map of epicenters and the table of the distribution of earthquakes of differ-ent classes by regions are given. The total number of earthquakes in 2013 was N=98 in the range of КР=5.7–14.1 and the depth interval of hypocenters h=1–150 km with total seismic energy Е=1.331014 J. Of these, 19 earthquakes with depths h=80–160 km is located in the Vrancea zone. Two maximum earth-quakes with КР=14.1 and КР=12.3 were recorded on October 6 and 15 in the Vrancea mountains with h=139.8 and 140.9 km. In Forecarpathians and Transcarpathia all earthquakes are weaker. The most significant event in Transcarpathia was the earthquake on April 4, 2013, with КР=8.4 in the area of «Nizhnее Selishche» seismic station. The earthquake source is located in the earth's crust at a depth of h=1.7 km. The earthquake was felt by the population of the Village Nizhnее Selishche with an intensity I=3–4. In general, in all seismic active zones of the Carpathians in 2013, there was a slight increase in the level of seismicity compared with that in 2012.
All earthquakes felt in 2014 on the territory of Moldova occurred outside its borders, in the Vrancea and Pre-Carpathian regions (Romania). In 2014, the population of Moldova felt 13 earthquakes. The article discusses in detail the most powerful events, occurred on March 29, September 6, and November 22. The March 29 earthquake, Mw=4.7, hрР=136 km was felt in the eastern and southern counties of Romania (in 41 settlements), in the Odessa region of Ukraine, and also in the central and southern regions of the Republic of Moldova (22 points). The epicenter was situated in a bend of the Vrancea mountains. The earthquake on Sep-tember 10, Mw=4.5, hрР=108 km was felt in the eastern and southern counties of Romania (in 27 settlements), in the central and southern parts of Moldova (22 points), in the north of Bulgaria and in the Odessa region of Ukraine. Both earthquakes, March 29 and September 10, occurred under the action of prevailing near-horizontal compressive stress. The November 22 earthquake, Mw=5.8, hрР=37 km occurred in the southwestern part of Romania and turned out to be the most significant crust event for the instrumental observation period. Movement in the source occurred under the action of tensile stresses. Earthquakes in this zone continued until January 19, 2015. The largest aftershock was on December 7 with МwMED=4.4. Foci are associated with the activation of the Peceneaga-Camena fault. The main shock was felt in Romania (in 66 settlements) and neighboring countries: Bulgaria, Moldova (23 settlements), Ukraine (18 settlements). The isoseismal maps were constructed for all three earthquakes considered in detail in this work. The intensity at the epicenter of the November 22 earthquake reached I0=6, for other two events I0=5.
Аннотация. В статье приведены инструментальные и макросейсмические данные о землетрясениях Карпатского региона в 2013 г., ощущавшихся на территории Республики Молдовы. Три землетрясения с промежуточной глубиной очага произошли в зоне Вранча: 11 августа с h=93 км, К Р =11.8; 6 октября с h=140 км, К Р =14.1; 15 октября с h=144 км, К Р =12.3. Кроме того, в 2013 г. был зафиксирован рой мелких землетрясений вблизи г. Галаца (Румыния) и г. Джурджулешты (Молдова). Рой возник 23 сентября, толчки регистрировались в течение двух месяцев. Произошло более 370 сейсмических событий, из которых три имели К Р 11 (29 и 30 сентября, 4 октября с К Р =11.2, 10.9, 10.6). Интенсивность сотрясений в эпицентре достигала 5 баллов. Для землетрясений 29, 30 сентября и 4 октября получены региональные решения механизма очага из каталога А.О. Мострюкова и В.А. Петрова (ГО «Борок» ИФЗ РАН). Событие 11 августа 2013 г. с К Р =11.8, произошедшее на глубине 93 км на северо-восточной окраине очаговой зоны Вранча, ощущалось в эпицентре с интенсивностью I=4 балла. В Кишинёве слабые толчки почувствовали лишь отдельные люди (I=2 балла). Два самых крупных землетрясения 2013 г. произошли 6 октября в 01 h 37 m (К Р =14.2, m b =5.3, I 0 =6) и 15 октября в 19 h 33 m (К Р =12.3, m b =4.8), в центральной части фокальной зоны Вранча. Между этими событиями отмечено еще три землетрясения с ML=3-3,5. Однако наиболее обширные макросейсмические проявления возникли от главного толчка-6 октября, вызвавшего сотрясения на территории четырех государств-в Румынии, на севере Болгарии, на юго-западе Украины и в Молдове. Причина столь значительного распространения колебаний кроется в большой глубине очага, равной 140 км. Но по этой же причине интенсивность макросейсмического воздействия не превысила 5 баллов в Румынии и 4-5 баллов в Молдове и на Украине. Как результат дается карта распределения интенсивности землетрясения 6 октября, построенная на основе обработки данных в 104 населенных пунктах. Представлены различные решения механизмов очага промежуточных землетрясений 2013 года. Последовательное проявление роя коровых землетрясений и целого ряда землетрясений промежуточной глубины подтверждает единство тектонических процессов в Карпатском регионе. Накопленные сейсмические напряжения предварительно реализовались в виде коровых толчков, затем произошла мощная разрядка в области Вранча, которая прервала серию событий, приуроченных к разломам Сфынтул-Георге и Печеняга-Камена. Ключевые слова: параметры землетрясения, макросейсмические данные, интенсивность сотрясений, карта изосейст, механизм очага.
All earthquakes felt in 2015 on the territory of Moldova occurred outside its borders, in the Vrancea and Pre-Carpathian regions (Romania). In 2015, the population of Moldova felt 4 earthquakes: on January 19 and 24, on March 16 and 29. The article discusses in detail the three most powerful of them – January 24, March 16, and 29 with epicenters in the Vrancea mountain range. The January 24 earthquake with Mw=4.3 and hрР=89 km was felt in Romania and the Republic of Moldova, where it was observed with the intensity I=3 in Cahul and I=2 in Chisinau. The March 16 earthquake with Mw=4.3 and hрР=121 km was felt in the eastern and southern counties of Romania (8 settlements). It was observed on the territory of the Republic of Moldova with the intensity I=3 in Cahul and I=2–3 in Chisinau. The intensity in the epicenter did not exceed I=4. The March 29 earthquake with Mw=4.5 and hрР=144 km was felt in the eastern and southern counties of Romania (8 settlements). It was observed on the territory of the Republic of Moldova with intensity I=3–4 in Cahul and I=2–3 in Chisinau. Solutions of the focal mechanism based on data from various agencies are presented. All three earthquakes occurred under the influence of the prevailing near-horizontal compression stress. The study is carried out within the framework of the State program, Geoseism project, registration number 36/21.10.19А.
The article describes seismic observations in the Carpathian region in 2015, which were carried out, as before, by two organizations from two states: in Ukraine – the Seismicity department of the Carpathian region of the Institute of Geophysics of the NAS of Ukraine, in Moldova – the Seismology laboratory of the Institute of Geology and Seismology of the Academy of Sciences of Moldova. 20 stationary digital stations with a processing center in L'viv and six stations with a center in Chisinau operated in Ukraine and Moldova respectively. Different programs, local hodographs and magnitudes were used. The consolidated catalogue of earthquakes was created in L'viv. The total number of earthquakes in 2015 was NΣ=164 in the ranges: KR=4.7–12.2, h=1–160 km. The total seismic energy ΣE=5.381012 J. 23 earthquakes with depths h=50–160 km were located in the Vrancea zone. The maximum earthquake with KR=12.2 was registered on January 24 in the Vrancha mountains with hрР=89 km. In the Precarpathian region, nine events with energy classes KR=4.7–8.9 were registered, the total seismic energy of which is ΣЕ=1.25109 J. Increased seismic activity was observed in Transcarpathia. A series of tangible earthquakes with aftershocks was recorded in the Tyachiv area. Their total number was NΣ=77. The strongest tangible earthquake occurred in the area of Okrugla village on July 19 with KR=11.1. The earthquake source is located in the Earth's crust at a depth of h=7.7 km. The earthquake was felt by the population in the epicentral area with an intensity of I=6. In addition, this earthquake, like 5 others, was felt in the territory of northern Romania. In general, a decrease in the seismicity level in the Carpathians in 2015 was observed compared to that in 2013 and 2014.
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