Today’s Image of the Day is part of a series highlighting wintertime photographs of Earth shot by astronauts on the International Space Station. View the full collection here.
January is typically the coldest and snowiest month of the year for Yellowstone Lake, which is both the largest lake in Yellowstone National Park and the largest high-elevation lake in North America. Cold weather usually ices the lake over by December, with ice thickness varying from a few inches to a few feet.
In January, snow really starts to pile up. By the end of the month, an average of 30 inches (76 centimeters) of snow blankets the lake, according to data compiled by the Western Regional Climate Center. Subsequent months bring even more snow, with an average of 41 inches piled onto the lake ice by March.
When an astronaut aboard the International Space Station snapped this photograph on January 26, 2022, a thick layer of snow adorned the lake. But deep below it, much warmer conditions lurked in certain areas. An array of underwater hot springs, hydrothermal vents, steam explosion craters, and siliceous spires dot the lake floor. One of the hydrothermal vents, just east of Stevenson Island and 410 feet (125 meters) below the lake surface, releases water that’s a remarkable 174°C (345°F), making it the hottest spring in Yellowstone National Park.
“This is much hotter than any surface hot spring at Yellowstone because the weight from the overlying lake water acts like a pressure cooker lid and allows temperatures higher than boiling to be reached. These are the hottest hydrothermal vents measured in a lake anywhere in the world,” the U.S. Geological Survey explained in an article about the diversity of hot springs on the lake floor.
The concentration of hydrothermal features in Yellowstone Lake isn’t coincidental. They are the leftovers from a cataclysmic volcanic eruption some 640,000 years ago that created the Yellowstone Caldera, which the lake sits within. A smaller eruption about 130,000 years created the knob-shaped bay known as West Thumb.
Astronaut photograph ISS066-E-131711 was acquired on January 26, 2022, with a Nikon D5 digital camera using a focal length of 200 millimeters. It is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 66 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by Adam Voiland.