Exam Qs Flashcards
Explain the difference between eustatic, isostatic and tectonic sea level change.
Eustatic change is a global change in sea level resulting from an actual rise or fall in sea level. Also produces submergent features like rias/fjords.
Isostatic change produces local change in sea level resulting from land rise or falling relative to the sea. This is seen in the Uk. Isostatic readjustment is causing south to fall relative to sea whereas north is rising. Also produces emerged features like raised beaches.
Isostatic change happen more slowly then eustatic change.
Tectonic activity produces local change but its as a result of ocean basing becoming larger or smaller through either spreading of ocean floors (constructive) or uplifting of mountain ranges (destructive). If the basin gets larger, despite the volume of water remaining the same it will lead to a eustatic fall in sea level. Conversely, is basin gets smaller volume of sea becomes more compact causing eustatic rise.
