TRACES OF HIGH SEISMIC ACTIVITY IN THE UPPERMOST SEDIMENTS OF LAKE BAIKAL, SIBERIA

Sedimentation in Lake Baikal is significantly affected by continuous seismic activity in the Baikal Rift Zone. Our study shows that historical earthquakes, as well as recent seismic events, considerably influenced sedimentation in this deep tectonic basin. Here we present some of the results of extensive international research activities during the period of 1996–2019. To identify traces of seismic events in the uppermost sediments (<1.5 m), short cores were recovered from many coring stations throughout the entire lake. Based on lithological descriptions, measurements of magnetic susceptibility, and concentration of inorganic and organic components, we identified earthquake indicators in the sediment cores. Impacts of historical earthquakes were traced within South Baikal (near the Sharyzhalgai Station and the Station 106-km of the Circum-Baikal railway, hereafter CBR) and Proval Bay (near the Selenga River delta)

СЛЕДЫ ВЫСОКОЙ СЕЙСМИЧЕСКОЙ АКТИВНОСТИ В ПОВЕРХНОСТНЫХ ОТЛОЖЕНИЯХ ОЗЕРА БАЙКАЛ, СИБИРЬ

Sedimentation in Lake Baikal is significantly affected by continuous seismic activity in the Baikal Rift Zone. Our study shows that historical earthquakes, as well as recent seismic events, considerably influenced sedimentation in this deep tectonic basin. Here we present some of the results of extensive international research activities during the period of 1996–2019. To identify traces of seismic events in the uppermost sediments (<1.5 m), short cores were recovered from many coring stations throughout the entire lake. Based on lithological descriptions, measurements of magnetic susceptibility, and concentration of inorganic and organic components, we identified earthquake indicators in the sediment cores. Impacts of historical earthquakes were traced within South Baikal (near the Sharyzhalgai Station and the Station 106-km of the Circum-Baikal railway, hereafter CBR) and Proval Bay (near the Selenga River delta).Осадконакопление в озере Байкал происходит на фоне постоянной сейсмической активности Байкальской рифтовой зоны. Современные и исторические землетрясения оказывают значительное влияние на формирование донных отложений в этом глубоком тектоническом бассейне. В статье представлены результаты международных исследований за период 1996–2019 гг. Для обнаружения следов сейсмических событий в самых верхних слоях отложений (<1.5 м) были отобраны короткие керны по всему озеру. Приведены карты с точками отбора кернов и сейсмичностью озера. Литологический состав, данные измерения магнитной восприимчивости, оценка органических и неорганических компонентов осадков позволяют определить индикаторы землетрясений в донных отложениях озера. Следы исторических землетрясений были обнаружены в пределах Южной котловины Байкала (районы станций Шарыжалгай и 106-й км Кругобайкальской железной дороги) и в заливе Провал рядом с дельтой р. Селенги