СКОРОСТИ МЕДЛЕННЫХ МИГРАЦИЙ СЕЙСМИЧЕСКОЙ АКТИВНОСТИ В ПРИБАЙКАЛЬЕ

Three-dimensional space-time diagrams of «logarithm of total energy released by earthquakes» parameter, lgEsum are constructed for regions with stable concentrations of earthquake epicenters in Cis-Baikal region for a period from 1964 to 2002. Based on analyses of such diagrams, areas of slow migration of seismic activity are defined. Estimated are distances, time and velocities of slow migration in the range of the first kilometers – first dozen of kilometers per year.Procedures of seismic data projection and construction of 3D diagrams are described in brief. A general scheme including contours of projection areas is proposed for the Pribaikalie (Fig. 1).Three space-time diagrams are presented as examples of application of the above mentioned procedures. They are constructed for the Middle and Southern Baikal basins and the western part of the NE flank of the Baikal rift system (Fig. 2). Integrated analytical results are presented for all the diagrams which record earthquake migration within the Baikal rift system.We also present a scheme of the zone of slow migrations ranked by dominating velocities (Fig. 3) and a diagram of the migration velocity range. We consider possible causes of slow migration of seismic activity at variable velocities: (1) slow deformation waves spreading in the crust, and (2) independent propagation of the deformation front along active faults.Regulations of migration of strong earthquakes can be useful for definition of timelines and locations of future strong seismic events.На базе анализа трехмерных пространственно-временных диаграмм параметра «логарифм суммарной выделившейся при землетрясениях энергии» (lgEsum), построенных для районов стабильных концентраций эпицентров землетрясений за период 1964–2002 гг., на территории Прибайкалья выделены области, которым свойственны медленные миграции сейсмической активности. Определены расстояния, время и скорости медленных миграций, измеряемые первыми километрами – первыми десятками километров в год.Кратко описана методика проецирования сейсмических данных и построения трехмерных диаграмм, приведена иллюстрационная схема Прибайкалья, содержащая контуры областей проецирования (рис. 1).Представлены примеры пространственно временных диаграмм трех областей: Среднебайкальской впадины, Южно-Байкальской впадины, а также западной части северо-восточного фланга Байкальской рифтовой системы (рис. 2). Приведены обобщенные результаты анализа всех диаграмм, на которых зафиксированы миграции землетрясений в пределах Байкальской рифтовой системы, схема зон медленных миграций, ранжированных по преобладающим скоростям, и диаграмма спектра скоростей миграций (рис. 3).Рассматриваются возможные причины, вызывающие медленные миграции сейсмической активности с различной скоростью: (1) медленные деформационные волны, распространяющиеся в земной коре, (2) самостоятельное продвижение фронта деформаций вдоль активных разломов.Закономерности миграций землетрясений в сейсмоактивных областях могут быть использованы для определения времени и места будущих сейсмических событий

ПРОБЛЕМЫ СОВРЕМЕННОЙ ГЕОДИНАМИКИ (ВСЕРОССИЙСКОЕ СОВЕЩАНИЕ И МОЛОДЕЖНАЯ ШКОЛА В ИЗК СО РАН)

The article provides review of presentations of the All-Russia Conference with participation of invited foreign scientists «Contemporary Geodynamics of Central Asia and Hazardous Natural Processes: Quantitative Research Results» and the All-Russia Young Scientists Workshop on issues of contemporary geodynamics, which were held on 23–29 September 2012 at the Institute of the Earth's Crust SB RAS in Irkutsk, Russia.В статье приведен обзор докладов и материалов Всероссийского совещания «Современная геодинамика Центральной Азии и опасные природные процессы: результаты исследований на количественной основе» и Всероссийской молодежной школы по современной геодинамике, состоявшихся 23–29 сентября 2012 г. в Институте земной коры СО РАН (г. Иркутск)

АКАДЕМИК Н.А. ЛОГАЧЕВ И ЕГО НАУЧНАЯ ШКОЛА: ВКЛАД В ИЗУЧЕНИЕ КАЙНОЗОЙСКОГО КОНТИНЕНТАЛЬНОГО РИФТОГЕНЕЗА

N.A. Florensov and N.A. Logatchev pioneered development of fundamental concepts of the structure and evolution of the Baikal system of rift basins. At the turn to the 21st century, in view of the wide availability of scientific research data on the Cenozoic continental rift zones located in Eurasia, Africa and North America, and taking into account the application of new research methods and options to process and analyze huge amounts of geological and geophysical data, a priority was comprehensive modeling of rifting from its origin to the current period of time. This scientific challenge was addressed by the research team under the leadership of N.A. Logachev.Фундаментальные представления о строении и развитии Байкальской системы рифтовых впадин были заложены в трудах Н.А. Флоренсова и Н.А. Логачева. Высокая степень изученности кайнозойских континентальных рифтовых зон Евразии, Африки и Северной Америки, а также новые методики и возможности обработки и анализа больших массивов геологической и геофизической информации выдвинули на рубеже XX и XXI столетий в качестве приоритетной задачи создание комплексной модели развития рифтогенеза с его зарождения до современности. Решение поставленной задачи осуществлялось в рамках работ научной школы под руководством Н.А. Логачева

PROBLEMS OF CONTEMPORARY GEODYNAMICS (THE ALLRUSSIA CONFERENCE AND YOUNG SCIENTISTS WORKSHOP IN THE INSTITUTE OF THE EARTH’S CRUST, SB RAS)

The article provides review of presentations of the All-Russia Conference with participation of invited foreign scientists «Contemporary Geodynamics of Central Asia and Hazardous Natural Processes: Quantitative Research Results» and the All-Russia Young Scientists Workshop on issues of contemporary geodynamics, which were held on 23–29 September 2012 at the Institute of the Earth's Crust SB RAS in Irkutsk, Russia

VELOCITIES OF SLOW MIGRATION OF SEISMIC ACTIVITY IN CIS-BAIKAL REGION

Three-dimensional space-time diagrams of «logarithm of total energy released by earthquakes» parameter, lgEsum are constructed for regions with stable concentrations of earthquake epicenters in Cis-Baikal region for a period from 1964 to 2002. Based on analyses of such diagrams, areas of slow migration of seismic activity are defined. Estimated are distances, time and velocities of slow migration in the range of the first kilometers – first dozen of kilometers per year.Procedures of seismic data projection and construction of 3D diagrams are described in brief. A general scheme including contours of projection areas is proposed for the Pribaikalie (Fig. 1).Three space-time diagrams are presented as examples of application of the above mentioned procedures. They are constructed for the Middle and Southern Baikal basins and the western part of the NE flank of the Baikal rift system (Fig. 2). Integrated analytical results are presented for all the diagrams which record earthquake migration within the Baikal rift system.We also present a scheme of the zone of slow migrations ranked by dominating velocities (Fig. 3) and a diagram of the migration velocity range. We consider possible causes of slow migration of seismic activity at variable velocities: (1) slow deformation waves spreading in the crust, and (2) independent propagation of the deformation front along active faults.Regulations of migration of strong earthquakes can be useful for definition of timelines and locations of future strong seismic events

ACADEMICIAN N.A. LOGATCHEV AND HIS SCIENTIFIC SCHOOL: CONTRUBITION TO STUDIES OF THE CENOZOIC CONTINENTAL RIFTING

N.A. Florensov and N.A. Logatchev pioneered development of fundamental concepts of the structure and evolution of the Baikal system of rift basins. At the turn to the 21st century, in view of the wide availability of scientific research data on the Cenozoic continental rift zones located in Eurasia, Africa and North America, and taking into account the application of new research methods and options to process and analyze huge amounts of geological and geophysical data, a priority was comprehensive modeling of rifting from its origin to the current period of time. This scientific challenge was addressed by the research team under the leadership of N.A. Logachev