California experienced an extraordinary snowfall that captivated residents and visitors alike. Mother Nature bestowed the state with an abundance of snow, transforming the California landscape into a winter wonderland. From the Sierra Nevada mountains to the peaks of the San Gabriel and San Bernardino ranges, a thick blanket of snow covered the terrain, creating breathtaking scenes and opportunities for winter recreation.
Beyond the thrill of winter sports, the snowfall also had ecological benefits for the state. California’s water supply greatly depends on the snowpack in the mountains, which acts as a natural reservoir. The ample snow accumulation promised relief for the parched land, replenishing rivers, lakes, and reservoirs and mitigating the impacts of drought.
More than just snow needs to be removed from State Route 120 W to Yosemite before it can reopen to the public. Rockslides fell onto the highway and shoulder over the winter season. Once the snow removal is complete, maintenance crews will shift to clearing debris from the road. pic.twitter.com/kMpEEvlMx3
— Caltrans District 9 (@Caltrans9) May 18, 2023
Caltrans District 9 posted this video of boulders that had landed on State Route 120 W to Yosemite National Park.
“More than just snow needs to be removed from State Route 120 W to Yosemite before it can reopen to the public. Rockslides fell onto the highway and shoulder over the winter season. Once the snow removal is complete, maintenance crews will shift to clearing debris from the road.”
However, significant snowfalls can have both positive and negative effects on landslides and rockfalls in California.
On the positive side, heavy snowfall can act as a stabilizing factor for slopes. The snow cover adds weight to the terrain, increasing the overall stability and reducing the likelihood of landslides and rockfalls. The accumulated snow can provide a protective layer that helps to hold the underlying soil and rocks in place.
However, there are also potential negative impacts. Rapid snowmelt, which can occur during periods of warm weather or intense rainfall, can contribute to increased water infiltration into the ground. This excess water can saturate the soil, reducing its strength and cohesion, and potentially triggering landslides and rockfalls. The added weight from the water can also increase the pressure on slopes, further destabilizing them.
The freeze-thaw cycle can play a significant role in slope instability. In California’s higher elevations, where snowfall is common, temperatures fluctuate between freezing and thawing. Water seeps into cracks and crevices within rocks, and when it freezes, it expands, exerting pressure on the surrounding rock. Over time, this freeze-thaw action weakens the integrity of the rocks, making them more susceptible to fracturing and causing rockfalls.