Sea level the warmer water expands. For at least the last 100 years, sea level has been rising at an average rate of about per year. Most of this rise can be attributed to the increase in temperature of the sea and the resulting slight thermal expansion of the upper of sea water. Additional contributions, as much as one-quarter of the total, come from water sources on land, such as melting snow and glaciers and extraction of groundwater for irrigation and other agricultural and human uses. Pilots can estimate height above sea level with an altimeter set to a defined barometric pressure.
Hampton-on-Sea dropped at Long Rock by an alternate normal east-west flow tide. When there are exceptional conditions on top of these tidal streams, for example a low pressure system causing higher water level coinciding with strong north-westerly winds, coastal flooding can occur. Hampton Brook, now Westbrook, reached the sea through a stone culvert but seaweed often blocked it, making it overflow and become stagnant. The land between the houses and the often-foetid Hampton Brook was low-lying enough to be subject to flood during a combination of spring tide, prolonged rainfall and onshore wind. Either the digging or the filling-in of the