Strange 'Ring' of Water in Michigan Seen From Space

Satellite imagery picked up a strange ring of warm water identified in southern Lake Michigan on Thursday afternoon.

The phenomenon attracted the attention of National Oceanic and Atmospheric Administration scientists at the University of Wisconsin-Madison, who shared thermal imagery of the ring on social media and then studied the warm water, revealing the cause in a blog on its website.

"A curious ring of warm water was revealed in southern Lake Michigan Thursday afternoon via #NOAA20 VIIRS derived Lake Surface Temperatures. Can you guess what caused it?" NOAA's Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison posted on X, formerly Twitter, on Friday morning.

The image shows warmer water along the coastlines, where water temperature is around 50 degrees. The lake gets progressively cooler closer to its center, nearing 40 degrees, but suddenly, a strange ring of warm water appears away from the shore that measured around 50 degrees.

Newsweek reached out to the CIMSS by online contact form for comment.

Clear skies on Thursday permitted the CIMSS researchers to evaluate lake surface temperatures at the five Great Lakes, which revealed a ring of warm water in southern Lake Michigan.

"Relatively cool waters persist in eastern Lake Erie, Lake Superior is uniformly cold (37 to 38^oF), and a curious warm ring has developed over southern Lake Michigan, 10^oF warmer at its center than the surrounding lake waters!" the blog said.

At times, warm water patches can be observed because of solar radiation reflection, but that wasn't the case for this occurrence.

"In this case you don't see glint in the True Color, and the I04 imagery doesn't show spectacular warmth," the blog said. "The GOES-16 Land Surface Temperature does show a warm eddy moving westward across the Lake however, at fairly high speed! That earns this post the, "What the heck is this?" tag!"

Eventually, researchers revealed that the phenomenon has occurred in Lake Michigan before.

"Such isolated warm water features are associated with areas of very light winds—usually beneath the center of high pressure at the surface—that allowed the water surface to warm more rapidly," the blog said.

Winds were identified as the source for the ring of warm water.

Some social media users had responded to the post with their own theories—which ranged from the presence of cicadas or a large school of fish swimming through the area to jokes that the Loch Ness Monster was residing in Lake Michigan.