A recent satellite photograph from NASA’s Earth Observatory highlights a massive geological formation in central Brazil that serves as the hidden engine behind the area’s renowned thermal baths. Captured by the Landsat 9 satellite on May 19, 2025, the image reveals the Caldas Novas dome, also known as Serra de Caldas, a towering monolith in Goiás state that functions as a critical water reservoir for the region.
The oval-shaped structure spans approximately 12 miles (20 kilometers) in length and 7 miles (12 kilometers) in width, rising up to 1,000 feet (300 meters) above the surrounding terrain. According to NASA, an optical phenomenon known as relief inversion can sometimes mislead viewers into perceiving the elevated landmass as a bowl-like depression. The feature is named after the nearby town of Caldas Novas, which sits between the dome and Lake Corumbá, an artificial reservoir formed by a hydroelectric dam. While the town is home to roughly 100,000 residents, it attracts hundreds of thousands of tourists annually, many drawn specifically by the local hot springs.
The dome’s ability to sustain these springs relies heavily on the Cerrado biome, a tropical savanna that blankets the structure. Often referred to as Brazil’s
Does anyone know if the groundwater levels are dropping? The tourism numbers seem to be outpacing the recharge rate.
This is exactly why preserving the Cerrado matters. If the sponge dries up, the springs disappear.
Relief inversion is fascinating. I definitely looked at the image and saw a crater instead of a dome!
I always thought hot springs were volcanic. Who knew the Cerrado biome was doing all that heavy lifting?