This included the Tiber, which prompted officials in Rome to put the capital on flood alert as waters ran at least 15 feet (4.5 metres) above normal.

The rain was part of a variety of severe wintry conditions in southern Europe that also left tens of thousands of homes without power due to heavy snowfall.

But the precipitation fell mainly as rain in Sicily, causing that Italian island's rivers to swell as well.

When the European Space Agency’s Envisat satellite passed overhead late in the morning on December 12, it captured the dramatic runoff of sediment flowing out of several Sicilian rivers.

The sediments can be seen along most of the coastline, with the most prominent outflow clearly visible on the eastern coast near Catania.

The tongue of bright tan extending well into the Ionian Sea came, in part, from runoff down the slopes of Mount Etna’s fertile western slopes, carried to the sea by the Semeto River.

Swirls of aquamarine were blooms of algae, which are a common feature in many parts of the world's oceans. Maritime algae expands in coverage as it feeds on nutrients, mainly phosphates, that wash off the land into the sea.

As the skies were clearing when the satellite image was captured, a fresh blanket of snow could be seen among some lingering clouds over the higher elevations of Mount Etna.

Envisat data courtesy of European Space Agency