What geological event lowers water levels and creates land bridges between islands?

Ice ages are significant geological events characterized by prolonged periods of colder temperatures on Earth, leading to the expansion of glaciers and large ice sheets. During these periods, substantial amounts of water are locked up in ice, resulting in lower sea levels. This drop in sea level can expose land that was previously submerged, creating land bridges between islands.

These land bridges play a crucial role in the movement and migration of species, allowing animals and plants to move between separated areas, which can lead to genetic exchange and increased biodiversity. The most notable example of this phenomenon is the Bering Land Bridge, which once connected Asia to North America during the last ice age, facilitating migration between the two continents.

While volcanic eruptions can create new land and earthquakes can reshape existing land, they do not primarily affect global sea levels in the way that ice ages do. Flood events are transitory and do not lead to lasting changes in sea level or the formation of persistent land bridges between islands.