Earth Science

Volcanoes can form at 'hot spots' due to mantle plumes, which are upwellings of hot mantle material that melt through the crust to create volcanic activity independent of tectonic plate boundaries.

The South Atlantic Ocean rarely experiences tropical cyclones due to unfavorable conditions such as cooler sea surface temperatures and stronger vertical wind shear, unlike the Western Pacific, North Atlantic, and Indian Ocean where tropical cyclones are common.

Approximately 97% of the Earth's water is salt water, primarily found in oceans and seas. This makes option C the correct answer.

The Earth completes a full 360° rotation in 24 hours. Dividing 360° by 24 hours gives 15° per hour, which is the degree of rotation of the Earth each hour.

Earthquakes are primarily caused by the movement of tectonic plates, which create stress and release energy in the Earth's crust. While landslides and volcanic eruptions can be associated with earthquakes, they are not the main cause of earthquakes themselves.

During a volcanic eruption, the volcano emits solid materials (like ash and rocks), liquid lava, and gases (such as sulfur dioxide and carbon dioxide). Therefore, the material includes solid, liquid, and gaseous forms.

Atmospheric temperature increases at higher altitudes due to a temperature inversion, where a layer of warmer air lies above cooler air, reversing the normal temperature decrease with altitude. This phenomenon is called 'inversion,' not convection.

Marble and slate are both metamorphic rocks formed from the transformation of limestone and shale, respectively, under heat and pressure. This process changes their mineral structure without melting them, classifying them as metamorphic rocks.

The Moon's gravitational pull is the primary force that causes tides in Earth's oceans. While the Sun also affects tides, its influence is less than that of the Moon. Galaxies and meteorites do not have a significant effect on ocean tides.

The coldest point in the atmosphere is the mesopause, which is the boundary between the mesosphere and the thermosphere. Temperatures there can drop to around -90°C, colder than at the tropopause or exopause.