Regionalne spremembe morske gladine: podatki, vplivni dejavniki in posledice

Abstract

V članku predstavljamo podatke o meritvah dviganja morske gladine, od globalne ravni, prek Sredozemskega in Jadranskega morja do Tržaškega zaliva. Svetovno morje se je v 20. stoletju dvignilo za 0,2 m. V Sredozemskem morju je dviganje regionalno zelo različno, v Jadranskem morju se gladina dviga s hitrostjo približno 1,7mm/leto, v Egejskem morju pa kar 5mm/leto. V Tržaškem zalivu je dviganje gladine dokumentirano že od rimske dobe, v zadnjih desetletjih je povprečno 1,7mm/leto. Obravnavamo dejavnike, ki vplivajo na višino morske gladine, kot so dvig temperature in posledično raztezanje oceanov, taljenje ledu, tektonika in ciklični pojavi, kot je severnoatlantska oscilacija, zaradi katerih je stopnja dviga morske gladine regionalno različna. Poplave morja so v zadnjem času 1,5-krat pogostejše kot pred desetletji, zato bo za obalna mesta bolj kot prilagajanje na višjo morsko gladino pomembno prilagajanje na večjo pogostost visokih plim, nevihtnih valov in morskih poplav. Regional sea level rise: data, drivers and effects In this article we present data on measurements of sea level rise, from the global level across the Mediterranean and Adriatic Sea to the Gulf of Trieste. Global sea level has risen by 0.2 m in the 20th century. In the Mediterranean, the rise varies from region to region, with the Adriatic Sea rising at a rate of around 1.7mm/year and the Aegean even at 5mm/year. In the Gulf of Trieste, sea level rise has been documented since Roman times and has averaged 1.7mm/year in recent decades. We consider the factors that influence sea level rise, such as temperature rise, the resulting expansion of the ocean, ice melt, tectonics and cyclical phenomena such as the North Atlantic Oscillation, which cause the rate of sea level rise to vary regionally. Sea flooding has recently become 1.5 times more frequent than decades ago. Adapting to the increasing frequency of high tides, storm surges and flooding will therefore be more important for coastal cities than adapting to higher sea levels.