Convection currents don't directly form underwater mountains. It's plate tectonics that's responsible for creating most underwater mountains. Here's how it works:

1. Convection Currents and Plate Tectonics:

* Convection currents within the Earth's mantle (the layer below the crust) are driven by heat from the Earth's core. Hotter, less dense material rises, while cooler, denser material sinks.

* This movement drags the tectonic plates (the Earth's outer shell) along with it.

2. Plate Boundaries and Mountain Formation:

* Convergent boundaries: Where tectonic plates collide, one plate can be forced beneath the other (subduction).

* Subduction zones often result in volcanic activity and the creation of:

* Volcanic island arcs: Chains of volcanic islands formed as magma rises through the overriding plate.

* Continental volcanic arcs: Volcanoes forming on the edge of continents due to subduction.

* Oceanic trenches: Deep depressions where the subducting plate bends.

3. Mid-Ocean Ridges:

* Divergent boundaries: Where tectonic plates move apart, magma rises from the mantle and creates new oceanic crust.

* Mid-ocean ridges are underwater mountain ranges formed by this process.

4. Other Mountain Formations:

* Fracture zones: Offset sections of mid-ocean ridges, creating mountains parallel to the ridge.

* Seamounts: Isolated underwater mountains that can be extinct volcanoes or formed by other tectonic processes.

In summary: Convection currents within the Earth's mantle drive plate tectonics, which in turn creates underwater mountains through processes like subduction, seafloor spreading, and other tectonic activity.