Beaches and Shores, Part 1
Virginia’s beaches and shores are complex systems. Topics covered in this section are:
2. environments
Sea Level Changes
Sea level does not always stay the same. The major processes that control sea level along Virginia’s coastline are:geologic processes; tides; storm surges; wind-wave action; and longshore and rip currents.
Geologic Processes
• Geologic processes, such as continental uplift or polar ice cap changes, can affect sea level.
lifting up; continents can rise
as a result of plate tectonics
• About 18,000 years ago, at the peak of the most recent glaciation, sea level was roughly 300 feet lower than today.
a time period when extensive glaciers developed, advanced,
and retreated; the Pleistocene Ice Age is an example of glaciation
• About 125,000 years ago, when ice caps were at a minimum, sea level was a few feet higher than now.
• Sea level can change because water rises or falls, or because the earth’s crust subsides or is uplifted.
• When water levels around the world rise and fall due to growth or melting of polar ice caps, sea level changes affect the whole world.
• When parts of the earth’s crust rise and fall due to tectonic forces, sea level changes are local.