Sea level at Troy in Finland

Stuart Harris BS, MS, MBA

Essential to understand Troy in Finland is knowledge of relative sea level versus time.

During the last ice age, an ice cap over Finland sank much of the country below sea levle, especially in the south. As the ice cap melted, islands emerged from the sea. The rate of uplift generally exceeded the rising sea, so that once land emerged, it remained dry. To facilitate transportation, Finns tended to build new homes as close to the sea as possible, but no closer than three fathoms (18 feet) above sea level to avoid damage from occasional tsunamis.

This rule of thumb provides a means to estimate the age of a building. First determine its elevation at the lowest point, subtract three fathoms, then look up the date from a curve of relative sea level versus time. Thus by merely examining a building on a topographic map, its age can be estimated. This paper describes how relative sea level at Troy was obtained by combining sparse local data with detailed Florida data.