<P> There are various methods for the direct dating of marine terraces and their related materials including C radiocarbon dating, which is the most common one . E.g. this method has been used on the North Island of New Zealand to date several marine terraces . It utilizes terrestrial biogenic materials in coastal sediments such as mollusc shells analyzing the C isotope . In some cases dating based on the Th / U ratio was applied though in case of detrital contamination or low uranium concentrations a high resolution dating was found to be difficult . In a study in southern Italy paleomagnetism was used to carry out paleomagnetic datings and luminescence dating (OSL) was used in different studies on the San Andreas Fault and on the Quaternary Eupcheon Fault in South Korea . In the last decennia, the dating of marine terraces has been enhanced since the arrival of terrestrial cosmogenic nuclides method, and particularly through the use of Be and Al cosmogenic isotopes produced in - situ . These isotopes record the duration of surface exposure to cosmic rays. and this exposure age reflects the age of abandonment of a marine terrace by the sea . </P> <P> In order to calculate the eustatic sea level for each dated terrace it is assumed that the eustatic sea - level position corresponding to at least one marine terrace is known and that the uplift rate has remained essentially constant in each section . </P> <P> Marine terraces play an important role in the research on tectonics and earthquakes . They may show patterns and rates of tectonic uplift and thus may be used to estimate the tectonic activity in a certain region . In some cases the exposed secondary landforms can be correlated with known seismic events such as the 1855 Wairarapa earthquake on the Wairarapa Fault near Wellington, New Zealand which produced a 2.7 m uplift . This figure can be estimated from the vertical offset between raised shorelines in the area . </P> <P> Furthermore, with the knowledge of eustatic sea level fluctuations the speed of isostatic uplift can be estimated and eventually the change of relative sea levels for certain regions can be reconstructed . Thus marine terraces also provide information for the research on climate change and trends in future sea level changes . </P>

A coast that is straight and has marine terraces is a