by InTrieste
A rare visual phenomenon appeared this week in the Gulf of Trieste, where sediment-rich freshwater from the Isonzo River formed a distinct pale plume as it entered the darker waters of the Adriatic Sea.
Observers along the coast noticed a clear color division: one side of the gulf remained deep blue, while the other turned a milky turquoise. The natural effect, scientists say, is caused by the meeting of fresh and salt water following intense rainfall in the river’s watershed.
Because freshwater is less dense than seawater, the river’s outflow spreads on the surface before gradually mixing with the marine environment. The phenomenon is short-lived and typically occurs during periods of strong river discharge, particularly in spring and autumn.
