Ocean Boulevard Landslides

Landslide definitions

Grabens A graben is a down-dropped block between two scarps. They often form within the bodies of rotational landslides.

The head scarp is at the top of a landslide. Structures and utilities that cross these structures may be deformed or broken by landslide movement.

Along Ocean Blvd, the landslide toe is constantly eroded by the ocean. The toe is the bottom of the landslide. It is often marked by a bulge or mound. Along Ocean Blvd, the landslide toe is constantly eroded by the ocean.

Utilities Utilities along Ocean Blvd include electrical, telephone, water, and sewer. The arrows show utility poles that are moving because they are in the body of a landslide.

Underground Utilities Movement on the head scarp has caused damage to local water and sewer lines, particularly east of the Distillery.

Evidence of Recent Movement scarp lines shown with tick-marks on down-dropped side

landslide locations are approximate, shown as head scarp only

Future Movement The landslides now affecting Ocean Boulevard will continue to move. The toes of these failures are continually being eaten away by the ocean, which means the slope cannot reach equilibrium.

Future Growth The landslides along Ocean Boulevard will probably continue to grow and change. The head scarps will migrate inland, and the bodies of the slides may expand laterally. The ocean bluff will continue to retreat, sometimes in the form of large slumps. Seismic ground shaking and/or the introduction of significant amounts of water into these landslides may accelerate these changes. cracks opening in Distillery’s upper parking lot old foundation eroding from below