July 29, 2005
This strange shot captures a bubble of hot mud popping atop a mud volcano near the Salton Sea in southern California. The bubble is about two inches (5 cm) across. As it pops, circular holes open up and expand until the bubble vanishes in a tiny explosion of droplets. The field of volcanoes and mud pots lie in the Salton Sea Geothermal Field and are associated with near surface magma in the tectonic spreading center at the north end of the Sea of Cortez. Carbon dioxide is generated by hydrolysis of limestone and other deposits washed down from the Colorado Plateau. The gas is forced upward and carries mud to the surface where it accumulates and forms mini volcanoes, a few feet (1 m) high with vents on the top and sides. Depending on the seasonal level of the water table, the mud emerging from the volcano may be runny, gooey or virtually nonexistent, with only hot carbon dioxide escaping.
Taking the picture was tricky. Since I was using a digital camera with the annoying delay between pressing the button and recording the image, I took a number of pictures -- about twenty in a couple of minutes. Until I returned home a few days later, I didn't realize I had captured this unusual photo.Related Links: