Raised shorelines
Encyclopedia
A raised shoreline is an ancient shoreline exposed above current water level. These landforms are formed by a relative change in sea level due to global sea level rise, isostatic rebound, and/or tectonic uplift
. These surfaces are usually exposed above modern sea level when a heavily glaciated area experiences a glacial retreat, causing water levels to rise. This area will then experience post-glacial rebound
, effectively
raising the shoreline surface.
Examples of raised shorelines can be found along the coasts of formerly glaciated areas in Ireland and Scotland, as well as in North America. Raised shorelines are exposed at various locations around the Puget Sound
of Washington State.
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...
. These surfaces are usually exposed above modern sea level when a heavily glaciated area experiences a glacial retreat, causing water levels to rise. This area will then experience post-glacial rebound
Post-glacial rebound
Post-glacial rebound is the rise of land masses that were depressed by the huge weight of ice sheets during the last glacial period, through a process known as isostasy...
, effectively
raising the shoreline surface.
Examples of raised shorelines can be found along the coasts of formerly glaciated areas in Ireland and Scotland, as well as in North America. Raised shorelines are exposed at various locations around the Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...
of Washington State.
Related links
- IsostasyIsostasyIsostasy is a term used in geology to refer to the state of gravitational equilibrium between the earth's lithosphere and asthenosphere such that the tectonic plates "float" at an elevation which depends on their thickness and density. This concept is invoked to explain how different topographic...
- LandformLandformA landform or physical feature in the earth sciences and geology sub-fields, comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography...
- Machair
- Marine terraceMarine terraceA marine terrace, coastal terrace, raised beach or perched coastline is a relatively flat, horizontal or gently inclined surface of marine origin, mostly an old abrasion platform which has been lifted out of the sphere of wave activity . Thus it lies above or under the current sea level, depending...
- Parallel Roads of Glen RoyGlen RoyGlen Roy in the Lochaber area of the Highlands of Scotland is a National Nature Reserve and is noted for the geological puzzle of the three roads ....
- Raised beaches
- Terrace (geology)
- Terrace (geology)
- wave-cut platformWave-cut platformA wave-cut platform, or shore platform is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by the action of waves. Wave-cut platforms are often most obvious at low tide when they become visible as huge areas of flat rock...