A paleoshoreline is a shoreline which existed, in the geologic past; note paleo means old or ancient; see perched coastline, a fossil coastline currently above the present coastline.

Due to tides, the ocean advances and recedes, commonly twice per day. But sea level can advance and recede quite slowly, and finding paleoshorelines is more tricky. A lake may have a paleoshoreline.

Just of the coastline of North America, in the last 15,000 years sea level has varied from over 100 metres (330 ft) below, to as high as 10 metres (33 ft) above its present level. That entire time, humans have lived in North America.

Paleoshorelines have been inferred, on Mars; see Burgsvik Beds and Martian dichotomy.

Image of the Bering land bridge being inundated with rising sea level across time
Paleoshorelines illustrated: Beringia sea levels (blues) and land elevations (browns) measured in metres from 21,000 years ago to present

Why do paleoshorelines matter?

Paleoshorelines capture valuable records of environmental change and can tell us about modern shelf ecosystems. These structures can indicate distributions of seabed features that are habitat of marine life; they also may shed light on the location of coastal resources once used by humans, thus so are of archaeological significance.


See also

External links and references

Physical geography

Bodies of water

Uses material from the Wikipedia article Paleoshoreline, released under the CC BY-SA 3.0 license.