Bryce Canyon in Winter

March 01, 2010

Bryce canyon

Photographer: James Van Gundy
Summary Author: James Van Gundy

March 2010 Earth Science Picture of the Day Viewer's ChoiceWith a canyon rim elevation between 8,000 and 9,000 ft (2,438 - 2,743 m), Utah's Bryce Canyon National Park can be a cold and snowy place during winter. The average seasonal snowfall here is 95 in (240 cm) and, in fact, snow has been recorded in every month of the year. During the winter months, daytime temperatures average about 40 degrees F (4.4 C) and typically fall to 15 degrees F (-9.4 C) at night. The average minimum nighttime temperatures are above freezing only during the months of June through September. Because of the huge diurnal temperature variability, freeze-thaw cycles have played a major role in the creation of the Bryce Canyon landscape

Rather than being a single canyon, Bryce is more a series of narrow interconnected canyons separated by relatively thin partitions of rock. High gradient headwater streams have eaten headward into the soft multicolored limestone of the Wasatch Formation. The rock is so soft and the weathering conditions so extreme that the canyon rim recedes by about 3 ft (1 m) every 200 years -- a very rapid rate by geological standards. Two days before this picture was taken, on January 24, 2010, nearly 48 in (122 cm) of snow fell throughout the park. As this snow melts, it’ll saturate the canyon walls and provide the ice that will chip away at the rock by repeated freezing and thawing. Snowmelt runoff will then provide the water power to transport the products of weathering through the steep, narrow canyons to the Paria River.