Understanding Landslides

When soil, rock, and debris decide to take the move downhill, we call it a landslide. While this might sound simple, however, landslides have many triggers, ranging from heavy precipitation to snowmelt, to seismic shaking, and come in many sizes – ranging from smaller, shallow slides to massive, deep-seated movements in rock. Here in Oregon, we regularly encounter various types, including shallow translational slides, deep-seated rotational slides, earthflows, and dramatic rockfalls.

What Triggers These Earth Movements?

Three main culprits typically set the stage for landslides:

• Water: Rain or snowmelt seeping into the ground can cause soil and rock to buoyant, weakening the strength of soil and rock.
• Erosion: Particularly active near rivers and coastlines, where water gradually undermines slope stability
• Earthquakes: A special concern in the Pacific Northwest, where the potential for a major Cascadia Subduction Zone earthquake could trigger widespread landsliding

Nature’s Warning Signs

While landslides can sometimes catch us off guard, they often leave clues:

• Deep cracks appearing in the ground (tension cracks)
• Unusual ground movement – sinking at the top of slopes and bulging at the bottom
• Trees taking a unexpected lean or showing curved trunks
• Changes in vegetation patterns, especially the appearance of water-loving plants
• Structural deficiencies, such as sticky doors or transverse cracks

Taking Action: How We Manage Landslide Risk

Understanding and managing landslide risk is at the core of our research. While some massive landslides can be challenging to control, many can be prevented or stabilized through smart engineering approaches. Our work focuses on developing innovative solutions, from advanced drainage systems to reinforcement techniques, helping communities build resilience against these natural hazards.

Want to dive deeper into landslide science? Explore our research projects!