Do you think that your area is representative of national mortality and fertility rates?

Every modern, economically developed nation has experienced the demographic transition from high to low levels of fertility and mortality. America is no exception. In the early nineteenth century, the typical American woman had between seven and eight live births in her lifetime and people probably lived fewer than forty years on average. But America was also distinctive. First, its fertility transition began in the late eighteenth or early nineteenth century at the latest. Other Western nations began their sustained fertility declines in the late nineteenth or early twentieth century, with the exception of France, whose decline also began eearly. Second, the fertility rate in America commenced its sustained decline long before that of mortality. This contrasts with the more typical demographic transition in which mortality decline precedes or occurs simultaneously with fertility decline. American mortality did not experience a sustained and irreversible decline until about the 1870s. Third, both these processes were influenced by America’s very high level of net in-migration and also by the significant population redistribution to frontier areas and later to cities, towns, and suburbs.

places of higher salinity. there are parts of the ocean where hardly any rain falls but warm dry winds cause lots of evaporation. this evaporation removes water – when water vapour rises into the atmosphere, it leaves the salt behind, so the salinity of the seawater increases. this causes the seawater to become denser.