thumb|300px|Map of the geothermal areas

thumb|Lassen hydrothermal system

The geothermal areas in Lassen Volcanic National Park include several groups of hot springs and fumaroles, as remnants of former volcanic activity, exist in Lassen Volcanic National Park in northeastern California. Most of these lie in or are closely adjacent to Mount Tehama's caldera. Bumpass Hell is the most spectacular of these, but others of importance are Sulphur Works, Little Hot Springs Valley, Boiling Springs Lake and Devil's Kitchen. In each thermal area, the highest temperature of water generally is close to the boiling temperature at the altitude of the particular spring or fumarole — at Bumpass Hell and on the northwest flanks of Lassen Peak. Temperatures as high as have been recorded in the park.

Spring activity varies with water supply. Abundant water results in clear springs during early summer, but as the season progresses and the water supply decreases, springs change successively to turbid, warm pools, spattering mudpots, and finally steaming fumaroles. There are no true geysers within Lassen Volcanic National Park.

Gases from hot springs are composed mostly of steam and carbon dioxide, with minor amounts of other gases. These react with the rocks around the springs to ultimately form opal if temperature and acidity are high, or kaolin if they are low. Deposits of sulfur, pyrite, quartz and other substances are also found around the springs and in their runoff channels.

Solfataric alteration within the caldera of Mount Tehama covers about , The area was named in his honor.

Devils Kitchen

About southeast of Lassen Peak is Devils Kitchen. In this geothermal area the hot springs are so acidic that they have eaten pits and holes in the bedrock.

Terminal Geyser

thumb|Terminal Geyser

Located in the southeast corner of the park, Terminal Geyser is not actually a geyser, but rather a cold stream flowing over a steam vent. This is about 100 feet (30 m) from the site of a geothermal boring operation that took place in 1962 and 1978. The 4,008-foot (1,222 m) well is now plugged and abandoned.

Boiling Springs Lake

thumb|Boiling Springs Lake is acidic and very hot. The first hybrid virus was discovered here in 2012. Genetic hybrids are called "[[chimera (mythology)|chimera", after mythological creatures like the Griffin or winged horse.]]

Just northwest of Terminal Geyser, large, warm-water Boiling Springs Lake has many hot springs, mudpots, and fumaroles along its west shore. Unlike the more heavily visited areas of the park, this area is not developed with boardwalks or signs and offers a chance to view thermal features in a more natural setting.

In 2012, scientists studying the viruses in Boiling Springs Lake found the first known case of a natural hybrid or "chimera" virus, apparently made of two very different groups of viruses that recombined into a single organism. They named this "mythological beast of a virus" the "Boiling Springs Lake RNA−DNA Hybrid Virus" or "BSL−RDHV". The study showed there is still much to learn about how viruses can evolve. Other types of viral hybrids have since been found elsewhere, and are called the CHIV group ("chimeric viruses").

See also

  • Geology of the Lassen volcanic area
  • Geothermal areas of Yellowstone
  • Lassen Peak
  • Lassen Volcanic National Park
  • Volcanic Legacy Scenic Byway

References

  • Kendall Van Hook Bumpass
  • Geology of National Parks: Fifth Edition, Ann G. Harris, Esther Tuttle, Sherwood D., Tuttle (Iowa, Kendall/Hunt Publishing; 1997)
  • National Park Service: Lassen Volcanic National Park, Nature & science, Volcanoes / Lava Flows (adapted public domain text; accessed 22 September 2006)
  • Volcano Hazards of the Lassen Volcanic National Park Area, California, U.S. Geological Survey Fact Sheet 022-00, Online version 1.0 (adapted public domain text; accessed 25 September 2006)
  • “Hot Water” in Lassen Volcanic National Park— Fumaroles, Steaming Ground, and Boiling Mudpots, USGS fact sheet on Lassen Volcanic National Park
  • NPS page about the plugging of the well at Terminal Geyser