Jakarta –
The strip of ocean sandwiched between the islands of Florida and the Bahamas is one of the world’s most studied marine environments and an enduring center of geological mystery.
Since at least the 1930s, scientists in the region have noticed strange white billowing clouds rising from the surface of seemingly serene turquoise water.
This strange phenomenon is called a whiting event, and scientists still don’t understand why it occurs in the Bahamas. This is a mystery that researchers at the University of South Florida (USF) are trying to solve.
Bright patches of disconcertingly colored oceans are sometimes seen in other seas and lakes around the world. But in the Bahamas, these patches appear more frequently than usual.
Direct sampling of the turbid water showed that this environment contained high concentrations of carbonate-rich particles.
Most of the Bahamas are located on submerged carbonate platforms known as the Bahama Banks. Does this mean sediment is rising to the surface? Or could the flowering of phytoplankton actually produce suspended matter?
No one knows the answer to that question, but scientists at USF are determined to find out. They’ve used satellite images from NASA to show how whiting events ebb and flow in the Bahamas.
The research team didn’t know whether the trend they identified occurred naturally or was caused by humans. But what they did know, from 2003 to 2020, the size of these whiting events seemed to correlate with the seasons.
|
The whiting event in the Bahamas. Photo: NASA Earth Observatory/USGS
|
The biggest ‘patches’ occur from March to May and October to December. On average, the white patches are about 2.4 square kilometers in size. On a clear day, satellite imagery usually captures about 24 of them, covering an area of 32 square kilometers.
However, between 2011 and 2015, the patch suddenly swelled in size, covering more than 200 square kilometers of ocean at its peak. However, in 2019, the patch shrunk again, though never as small as before.
The findings suggest that the 10-year cycle may play a role in this. But what cycle exactly? It is still a mystery.
“I wish I could tell you why we’re seeing that peak of activity, but we’re not there yet,” said USF oceanographer Chuanmin Hu.
“We did see some interesting relationships between environmental conditions, such as pH, water salinity, and the behavior of winds and currents, but we can’t say yet what mechanical, biological or chemical processes are responsible for these peaks in activity,” he said.
More hands-on field experiments are needed, and not just in the Bahamas. Comparing whiting events in other regions can help scientists find out what features they have in common.
USF researchers tested their model on whiting events in the Great Lakes and had moderate success. But now, this research needs to support that pattern in land, or more precisely, in water.
Several studies, for example, show that whiting occurs more frequently in places with muddy sediments.
In addition, it could be that some ocean conditions favor the suspension of sediment and calcium carbonate in the water column. As previously noted, recent satellite data shows white spotting over the Bahamas is more common in the spring and winter, and this is when the north-to-south Florida Current switches. Without further proof, all of these theories will remain as they are.
Watch Video “A Closer Look at Malakit, the World Cup Trophy Stone“
[Gambas:Video 20detik]
(rns/rns)
