There are about 200 billion stars in our galaxy, with 40 billion of them like our sun, Marcy said. One of his co-authors put the number of sun-like stars closer to 50 billion, meaning there would be at least 11 billion planets like ours
Answer:
Russia
Only over 7% of the land is fertile
Answer:
Renewal of Wetlands. Floods contribute to the health of ecologically important wetland areas. ...
Returning Nutrients to Soil. Floods distribute and deposit river sediments over large areas of land. ...
Preventing Erosion and Maintaining Land Mass Elevation. ...
Recharge and Replenish Ground Water.
Answer:
Options (A), (B), (C), and (D)
Explanation:
The volcanic activity refers to the eruption of magma at the surface of the ocean floor and continental land areas, forming volcanoes.
Some of the tectonic settings that are associated with volcanic activity are as follows-
- Mantle plumes- These are the large uprising bodies of magma that are generated due to the formation of convection current in the mantle. These are localized body and are located away from the tectonic boundaries. For example, Hawaii is formed as the plates moved over the mantle plumes.
- Continental rifts- This refers to the eruption of magma at the surface of the continents, due to the divergent motion of two continental plates. It results in the formation of a rift, rift valley and then later forms an ocean.
- Island arcs- These are formed due to the collision of two oceanic plates, where the volcanoes are formed on the lighter oceanic plate due to the rising up of magma.
- Continental arcs- These are formed due to the collision between an oceanic and a continental plate, where the volcanoes are formed due to the uprising of magma in the lighter continental plates.
