The Northern Hemisphere contains approximately two-thirds of the Earth's land surface. This includes the entirety of North America and Europe, as well as the majority of Asia and Africa, resulting in a significantly higher land-to-water ratio than the Southern Hemisphere.

Approximately 97% of the water on Earth is saline, found primarily in the oceans and seas. The remaining 3% is freshwater, most of which is trapped in glaciers, ice caps, and deep underground aquifers, leaving only a very small fraction available for human consumption and surface ecosystems.

The Mid-Atlantic Ridge is a divergent tectonic plate boundary located along the floor of the Atlantic Ocean. As tectonic plates pull apart, magma rises from the mantle to create new crust. In areas where this volcanic activity is particularly intense, the ridge builds up enough material to breach the ocean surface, resulting in the formation of volcanic islands, such as Iceland and the Azores, which are direct surface expressions of this underwater mountain range.

Mid-ocean ridges are continuous mountain ranges formed by plate tectonics and volcanic activity on the ocean floor. As tectonic plates diverge, magma rises from the mantle to fill the gap, cooling to form new oceanic crust. This process creates long, elevated ridges across the seafloor, which are significant features of the global ocean floor configuration.

The Mid-Atlantic Ridge is a divergent tectonic plate boundary located along the floor of the Atlantic Ocean. It is the longest mountain range in the world, stretching from the Arctic Ocean down through the Atlantic, passing between the Americas and Europe/Africa, and continuing toward the southern tip of Africa.

The mid-oceanic ridge system is the longest mountain range on Earth, spanning approximately 65,000 kilometers across the ocean floors. It is a continuous chain of volcanic mountains formed by plate tectonics at divergent plate boundaries, where new oceanic crust is constantly being created through seafloor spreading.

A knot is a unit of speed equal to one nautical mile per hour. Since one nautical mile is approximately 1.852 kilometers, 15 knots is calculated as 15 multiplied by 1.852, which equals approximately 27.78 km/h. Given the options provided, 26 km/h is the closest approximation.

The California Current is a cold Pacific Ocean current that moves southward along the western coast of North America. It originates from the North Pacific Current and plays a significant role in moderating coastal temperatures and influencing the climate of the region, often contributing to coastal fog and cooler summer temperatures.

The North Atlantic Drift is a powerful, warm western boundary current that extends the Gulf Stream northeastward. It plays a crucial role in moderating the climate of Western Europe by transporting warm tropical waters toward higher latitudes, significantly raising temperatures compared to other regions at similar latitudes.

Desalination is the industrial process of removing mineral components, specifically salts, from saline water. This is a critical technology for providing fresh water in arid regions where natural freshwater sources are scarce or depleted.