OIL IN THE LAKE OF WORLD HERITAGE

Abstract

Lake Baikal is the oldest and deepest lake in the world. It contains approximately 20% (23 · 103 km3) of the world’s surface reserves. Since the community of diverse endemic organisms of the lake has not suffered from human impact at its recent stage of development, it is included into the UNESCO world heritage list. Unique features of Lake Baikal include natural oil seeps in its shelf zone, which have been known since the 18th century. At oil shows in the middle and south sections of Lake Baikal, oil occurs as bitumen in shore cliffs or rises from the lake bottom as floating spherules of viscous hydrocarbons that make up spills (up to 1.5 m across) in an area of approximately 1 km2 in summer. In winter, the floating oil is accumulated under ice as bituminous films and inclusions in narrow fissures. The oil composition corresponds to the biodegraded type. Its origin and age were debatable until recently.