Baikal Web World - Seismic Lake Baikal


Origin & Development
Legends & Fairy tales • Earth's Crust Thickness • Underwater Relief • Landscapes • History & Formation • Seismic Activity •
History of Lake Baikal
History of Explorations • Inhabitants & Settlers • First maps of Baikal • Archaeological Sites •
Lake Baikal Climate
Introduction • Fogs • Winds & Waves • Ice Conditions •
Fauna & Vegetation
Mammals • Baikal seal - Nerpa • Ichthyofauna • Invertebrates • Vegetation •
Water of Lake Baikal
Colour • Transparency • Temperature • Pressure • Depth • Currents • Budget • Chemical Composition • Pollution •
Recreational Areas
Circumbaikal Railway • Peschanaya Bays • Olkhon Island • Chivirkuysky Gulf • Wooden Irkutsk • Trans-Siberian Railway •
People of Lake Baikal
People of Siberia • Buryat nation in Baikal • Russians in Baikal •

Explanation of the local terms and geographical names at lake Baikal

Lake Baikal Seismic Activity

The Process of formation of the Baikal rift, the active stage of which stared 3-4 Ma ago, is also in progress now, as evidenced by numerous earthquakes which occur at the present time. Further development of the Baikal basin results from earthquakes, which are accompanied by considerable vertical displacements of the lake bottom, collapses and landslides in the coastal zone. Thus, during the 1862 earthquake the Tsagan steppe went below the water surface (up to 7-

8 m) and the Bay Proval with an area of more than 200 km2 formed. In the epicentral zone of Srednebaikalsk earthquake of 1959 a portion of lake bottom subsided by 15-20 m. Subsidence of the Upper Angara river delta by 2-2,5 m is associated with the 1931 earthquake.

Seismicity:
Annual number of earthquakes: >2000
Earthquakes' recurrence (Mg - magnitude):
Mg - 5: 1 - 2 years
Mg - 6: 5 - 10 years
Mg - 7: 50 - 100 years
Mg > 7: 150 - 200 years

The strongest earthquakes:
1. Tsaganskoe, 1862 - formation of Proval Bay: Mg > 6.5-7
2. Srednebaikalskoe, 1959: Mg > 6 (Baikal bottom subsidence in the epicenter was up to 15-20 m)
3. Chivirkuyskoye, 1981: Mg - 5.8
4. South Baikal, 1999: Mg - 5.8

Earthquakes' epicenter depth: 12 - 22 km
Maximum altitude of the mountain ridges around Baikal (the Barguzin mountain range): 2840 m
Maximum depth of Baikal: 1637 m
Maximum thickness of sediments in Baikal basin (geophysical data): 8500 m
Amplitude of the rift slit between the maximum altitude of the mountain ridge and the basement of Baikal basin: 12977 m

To compare:
Maximum ocean depth (Mariana Trench in the Pacific Ocean): 11022 m