Regional Eustasy Research Articles

Revolution in Cretaceous sea-level analysis

A thorough analysis of the geographical distribution of sea-level changes throughout Cretaceous time reveals that, besides normal tectono-eustasy, there were large-scale latitudinal eustatic sea-level changes. These represent south-to-north migrating geoidal-eustatic highs and lows, or gravitational “drop motions.” This is a novel factor in sea-level analyses. It implies that global eustasy is an illusion and that regional eustasy should be the new key phrase.

Eustatic changes during the last 8,000 years in view of radiocarbon calibration and new information from the Kattegatt region and other northwestern European coastal areas

In view of the calibration of the non-absolute radiocarbon chronology and the accumulation of new field data and radiocarbon dates, the calculated eustatic and isostatic factors responsible for the shore-level displacement in the Kattegatt region are revised for the period covering the last 8,000 sidereal years. The revision does not lead to any drastic changes: some levels are changed by some decimeters and the age of the transgression maximum PTM-7 is now regarded as younger than previously considered. The revised eustatic curve agrees (even in details) very well with all northwestern European relative sea-level records. The tidal effect in the Kattegatt is less than 1 dm. Possible meteorological influences cannot yet be accounted for. The Kattegatt record can be used to test local relative sea-level curves and supposed eustatic curves. Considering possible horizontal and vertical changes of the main geoid pattern, and other factors influencing the surface distribution of the ocean water, regional eustasy (like the present NW European curve) may not be globally valid in detail. The eustatic amplitude variations reflect the Earth's glacial history. The transgression/regression sequence reflects cyclic variations in the world climate of irregular frequency.