Which of the following is an example of an Earth event that can occur rapidly?

Earthquakes or explosions are examples of Earth events that can occur rapidly due to the sudden release of energy in the Earth's crust. This release leads to a rapid shaking of the ground and can happen without warning, typically within seconds to minutes. The dynamics involved in tectonic plate movements, which often cause earthquakes, can accumulate stress over time that culminates in a sudden event.

In contrast, rock erosion is a gradual process influenced by weathering and environmental factors, including wind and water, over long periods. Plate tectonics movement, while it can lead to rapid events like earthquakes, occurs on a much slower scale, often observed through gradual shifts over millions of years. Glacial melting, influenced by climate and temperature changes, also happens over extended periods, rather than in a rapid manner. This highlights how the nature and speed of these processes differ significantly, making earthquakes or explosions the clear example of a rapid Earth event.