Porkchop Geyser, Norris Geyser Basin, YNP.

This pool is located at the southwest end of Norris’ Back Basin. It erupted as a geyser until 1989 when it erupted forcefully, hurling rock from its vent to form a 5-m-wide pool. The water is neutral-to-alkaline and rich in Cl. The temperature is measured ~20 cm beneath the pool surface, close to the pool’s edge.

Water temperature is measured beneath the pool surface. Temperature increases may reflect increased inflow of thermal water. Sudden decreases in temperature could be a result of a drop in water level beneath that of the temperature probe. This will usually result in large diurnal (24-hour) variations as the probe measures air temperature instead of water temperatures. Smaller diurnal variations are normal in pools.