Answer:
The fan-shaped feature extending out from the shore where the Selenga River enters Lake Baikal is most likely a river delta.
A river delta is a landform created by the deposition of sediment carried by a river as it enters a larger body of water, such as a lake or an ocean. When a river flows into a standing body of water, the velocity of the river decreases, causing it to deposit sediment it has been carrying. Over time, this sediment builds up and forms a delta.
Deltas often have a fan-shaped appearance, with multiple channels branching out from the main river channel. These channels distribute the sediment and water across the delta, allowing it to build and expand over time.
The sediment deposited by the Selenga River in Lake Baikal forms the fan-shaped feature marked by "X" in the satellite image. This delta is an important ecological and geological feature, as it provides a unique habitat for various species and helps to stabilize the shoreline.
Step-by-step explanation:
In summary, the fan-shaped feature at the mouth of the Selenga River in Lake Baikal is most likely a river delta. It is formed by the deposition of sediment carried by the river as it enters the lake.