How a Poisonous Lake Reveals an Ancient Catastrophe
In How a Poisonous Lake Reveals an Ancient Catastrophe, geologist Iain Stewart highlights scientists exploring a toxic mystery behind the Permian mass extinction. While the surface teems with life, the lake’s bottom holds deadly hydrogen sulfide, turning the water pink with millions of purple bacteria. These bacteria are key to understanding how, 250 million years ago, this toxic gas escaped into the air, devastating life on Earth. This video is excerpted from BBC’s Earth: The Power of the Planet, a documentary series in which Dr. Iain Stewart discovers how Earth's forces can shape nature, species, and even the climate.
Lesson Express
Q: What risks do scientists take when diving into Green Lake, and why is it important for their research?
A: When scientists dive into the lower layers of Green Lake, they risk being exposed to toxic hydrogen sulfide, which can get through their wetsuits and make them sick. Even though it’s dangerous, they dive to collect information about the bacteria and chemicals that may have caused the ancient extinction, helping them understand Earth’s history.
Q: How could hydrogen sulfide gas have caused the mass extinction during the Permian period?
A: When hydrogen sulfide gas escaped into the air 250 million years ago, it poisoned the land, killed plants, and harmed animals. It created an environment where most life couldn’t survive, which is why it’s believed to be a big cause of the mass extinction.
Q: Why is it helpful for scientists to study places like Green Lake today?
A: By studying Green Lake, scientists can learn how dangerous gases build up in still, oxygen-free waters. This helps them understand how modern environmental problems, like pollution or ocean changes, could harm life on Earth in the future.