About Rob Grafton Expertise I can offer help up to UK degree level and have access to the national oceanographic library in Southampton. My speciality areas are marine biology ecology and physiology although I have a good understanding of chemical oceanography and physical Oceanography.
Experience I studied and am continuing my studies of M MarBiol at the university of Southampton
Organizations University of Southampton (uk)
National Oceanography Centre Southampton (uk)
JMBUK member
Expert: Rob Grafton Date: 11/12/2007 Subject: sea level
Question Is it true that sea level at the Eastern shores of Asia is higher than those in the US because of the rotation of the Earth?
Answer Sea level is dependant upon many factors, sun and moon position (although when surveying and map making an average for the area is taken, they usually use the lowest astronomical tide (lowest possible tide level)), sea bed topography, weather conditions and yes the rotation of the earth does have some effect but is the same for everywhere at the same latitudes, Most of the shores of asia are at similar levels to those of the us so experience the same amount of centripetal force (the actual force behind the mistaken centrifugal force, look it up on the internet if you want more information). This should not create any difference in sea height.
Currents flowing over topographic features on the sea bed, such as trenches and hills (the major shapes on the sea bed, 1000s of km long) will alter the height of the sea. (imagine motorbikes going over jumps, the bikes representing a moving watermass. Most currents are created by differences in water temperature, AND the rotation of the earth through an effect called the CORIOLIS effect. So it is quite possible that indirectly the rotation of the earth causes a difference in sea level, although comparing relative sea levels accross areas a large as 2 continents is difficult due to the fact that the earth is not a perfect sphere and the way that water sits on the earth is very irregular. All maps stating hight above sea level use their own reference point( the lowest astronomical tide) from a specific place and everywhere is compared to there. This point is called the chart datum.
