Photos: San Pedro Is Falling Into the Ocean
The Palos Verdes Peninsula is a geological wonder. The newest Paseo del Mar Landslide joins the company of the Sunken City two miles to the southeast and the still-active Portuguese Bend Landslide to the west.
Initially closed on Sept. 19 to motorists and Oct. 7 to pedestrians and cyclists after the roadway sank approximately six inches, the Paseo del Mar Landslide has gained velocity this month. According to the City of Los Angeles Bureau of Engineering, between Nov. 3 and Nov. 7 the landslide was moving approximately 0.5 inches per day. Between Nov. 7 and Nov. 14 the rate increased to four inches per day.
With that and the rains that poured on Sunday, a 600-square foot area including portions of Paseo del Mar fell approximately 100 feet into the ocean. It was clear after walking near the site this afternoon that more portions of the road and land also look to be heading down the cliff.
The area is not unfamiliar to shifts in the land in recent years. While under construction in 1999, a 16-acre area of the 18th hole of the Ocean Trails Golf Course slid into the ocean. In Dec. 2009 a little landslide occurred when a chunk of earth fell from a cliff on the 1800 block of West Paseo del Mar, less than a mile away from the current area. Also in July 2010, a chunk of the Sunken City cliff collapsed into the ocean.
While it might be easy to dismiss the landslide as a case of coastal erosion, it's a bit more complex than that.
It is still unknown as to what caused the Sunken City Landslide in 1929 on the 600 block of Paseo del Mar. The land continued to slip for as much as 11 inches a day well into the 1930's when it abruptly stopped. All but two houses were moved away from the area which eventually found a home at the bottom of the cliff.
As for the Portuguese Bend Landslide, that is a part of an ancient Altamira Landslide, an ice age feature more than 200,000 years old. The landslide lay dormant until August 1956 when an extension of Crenshaw Blvd. was in the beginning stages of construction with 160,000 cubic yards of road fill was placed at the head of the ancient landslide.
The Portuguese Bend Landslide moves between 0.1 to more than an inch a day depending on rainfall and hasn't stopped in the since the reactivation. One of the mitigating actions in Portuguese Bend was the installation of de-watering wells that reduced the groundwater levels that altered the chemistry of the rocks below the earth that helped propagate the slide.
Local reaction to the Paseo del Mar Landslide has been mixed. While no houses or structures are threatened, residents in the immediate area are wary of any slight cracks they see on the ground. Residents from outside the immediate area come by to gawk and relive their moments of the childhood. One lady who lives by the Harbor said that she couldn't wait to barbeque down the cliff referencing the Sunken City as a local hangout.
One thing of note that amused me. Right in the vicinity of the landslide area and in the White Point Nature Preserve is the former launch site of Nike missiles. Built in 1955, it was one of many sites around Southern California where the nuclear-capable missiles could be launched at any point. Decommissioned in 1974 it has been rusted from disuse, although it is perhaps the most intact site in Southern California.
Imagine if this landslide occurred 40 years ago.
Both the White Point Nature Preserve and White Point Beach remain open to the public for as long as it remains safe. In other words, you might want to giddy-up if you want to see the action for yourself. Updates of the landslide can be found at DPWCare.org and clicking "Paseo del Mar Incident".
Great photos of the landslide area can be seen at The Daily Breeze.