Ian's impacts: Gulf of Mexico discolouration

Hurricane Ian bought devastating winds, rain and storm surge to Florida, but has also affected the colour of the Gulf of Mexico.

In the wake of Hurricane Ian, water flowed from Charlotte Harbor and Gasparilla Sound into the Gulf of Mexico. The dark fresh water contrasts sharply with the water in the Gulf of Mexico, as seen from the satellite imagery above.

This was a result of freshwater flooding from all the rainfall produced by Ian, from rivers and canals that flow out into the Gulf of Mexico. The bright turquoise colour in the Gulf is also due to the vast amounts of sediment churned up from the hurricane.

In both Tampa Bay and Charlotte Harbor, a phenomenon known as a negative storm surge, or a blowout tide also occurred, which can be seen from the video below.

This happens when offshore hurricane winds actually pull water out from bodies such as rivers or canals, due to the rotation of the storm.

It can be dangerous as the water does then return quite quickly, and tends to happen in areas adjacent to those witnessing positive storm surge.

So, whilst a dramatic difference in appearance for the Gulf of Mexico, it is not especially rare and is only temporary. Hurricanes often churn up sediment and cause muddy outflows from storm surges and overflowing rivers.