Sunday, October 04, 2015
Sulphur Works, Lassen Volcanic National Park
Geothermal Action at Sulphur Works
Unlike Bumpass Hell which can only be seen after a good work-out (hiking), Sulphur Works on the other hand is one of the geothermal feature in Lassen Volcanic National Park that can be seen by visitors right from the road. However, compared to Bumpass Hell, Sulphur Works is very small in area. Though small in area, but it features fumaroles, mudpots, hot steam, boiling water, stinky hydrogen sulfide gas and other geothermal features.
Notice the bright colored soil around, it is the result of the action of sulfurous acid and sulfuric acid on andesite rocks, which is the primary composition of the surface. The acid breaks down hard, gray-green andesite lavas into red, yellow and buff clays. When the water diminishes, mudpots arises, and the dry vents exist as fumaroles.
Fumarole and Multi Colored Surface
A fumarole is an opening in Earth's crust, which emits steam and gases such as carbon dioxide, sulfurous gases, hydrochloric acid and hydrogen sulfide. This geothermal feature in the park is right by Hwy 89. We actually saw this geothermal feature first since we passed this area on our way to Bumpass Hell trailhead coming from the South Entrance of the park.
This is actually 4 miles or less from the Bumpass Hell trailhead, but what a different sight. Here, the wildflowers are already in their beautiful display, whereas 4 miles up the road, Bumpass Hell trailhead and the trail itself was still fully covered with snow. Though only 4 miles apart, but the 1000 ft difference in elevation made the big difference.