Pat Morrison: Palos Verdes landslide can illuminate Los Angeles’ past

Oh, thousands of years ago, the Palos Verdes Peninsula rose from the sea like Aphrodite, beautiful and wet.

Okay, so this didn’t happen. Exactly That way. An unstoppable wonder of geology—a nod to Poseidon, the god of earthquakes and seas—created the stunning headland that juts from Los Angeles County into the Pacific Ocean.

Geology also plays a role in recent landslide dangers. (Poseidon: Mortal, don’t blame me!)

When the winter rains finally arrive wherever they are in the summer, the Peninsula can tally up its casualty list over the past eight to nine months.

Most importantly, and most recently, the luminous Wayfarers Chapel, a National Historic Landmark, Lloyd Wright’s wood-and-glass marvel in Rancho Palos Verdes, It always seems to be hovering above the sea.Now it has tilted miserably towards it: it has closed, and may andMay reopen in the same location Later.

Homes in Rancho Palos Verdes were red-tagged a few months ago.this Portugal Bend landslide system It keeps accelerating. As Rancho Palos Verdes Mayor John Cruikshank ruefully described, the land “used to move a few inches a year; now it moves once a year. Last year, Rolling Hills Estates’ 10 houses catastrophically fell into the canyon.

There is no part of Los Angeles County’s more than 4,000 square miles of majestic scenery, deserts, mountains, oceanfronts, hills and basins, that has not been affected by what I call “late flooding,” but high up on the PV Peninsula, it’s dramatic and expensive.

What looked like an eternal fortress, turned out to be feet of clay—and I mean that literally, as you’ll see.

The peninsula’s human history is truncated compared to its geology. Native Americans established their villages on this promontory, and Malaga Bay has been a settlement for at least seven thousand years. On October 8, 1542, four days and 50 years after Columbus landed in the New World, the PV Peninsula was discovered by Portuguese explorer Juan Rodriguez Cabrillo, whose name is translated as Spanish. Perhaps he deserves the title “Father of Smoke” because he called the place “Smoke Bay,” possibly from the signal fires built by Native Americans on the headland.

Some centuries later, the peninsula became part of spanish land grant, and the territory of Manuel Dominguez as his Rancho San Pedro. Later, in California, Mexico, another prominent family, the Sepulvedas, became owners of the land, now known as Rancho Palos Verdes.

A whaling station briefly operated here, and by the 20th century the cattle that once grazed on the cape had long since disappeared, but people kept coming.

1

2

1. A vintage postcard from the collection of Patt Morrison shows the rolling green hills of Palos Verdes Estates, where development later brought thousands of homes to the peninsula. 2. Another postcard shows the terracotta roof tiles typical of Palos Verdes Estates. It also shows the dangers of homes to which some roof tiles are attached.

During World War I, an influential financier named Frank Vanderlip He visited the place and was struck by its beauty, and began a plan to acquire and develop the peninsula, a sort of Newport on the Pacific, a California version of the Rhode Island community where the rich and powerful of the Gilded Age lived. Beachfront “cabins” made of marble and marble were built. Vanderlip built his own magnificent estate, Villa Narcissa, in the 1920s. A few years ago I was invited by a British friend to have lunch there. Vanderlip’s noble daughter-in-law Irene.

In the 1930s, locals held fox hunts, ball hunts and other fashionable gatherings, but it wasn’t until the end of the next world war that the peninsula really filled up with people, with more modest houses appearing amid the spectacular surroundings. Of course, these houses are still very crude compared to the old ones. Hypermetabolic mansion Beverly Hills and West Los Angeles, but now the prices are just as amazing as the views.Supporting characters over the years have gone to Ocean World (now closed), aggressive territory surf gang, wild peacockand the inevitable golf course, One of them is Donald Trump’s.

A vintage postcard from Patt Morrison’s collection directed drivers to the La Venta Inn, which still serves as a wedding venue and shows the outline of the peninsula’s coast. Don’t miss a turn.

This is a short Twitter summary of human history.

I consulted Kevin Coffey, a lecturer in Earth, planetary and space sciences at UCLA, about the geographic genealogy that created today’s unruly Palos Verdes Peninsula.

Coffey lives on the peninsula and is excited to have real-life science on his doorstep: “The geology of the Palos Verdes Peninsula is unique in many ways. In other ways, it’s what we do on the peninsula. The same geology that most of Los Angeles has, but what’s unique about it is the way it’s uplifted, and how we see it all.

Where Los Angeles is now, there is only the ocean.Natural History Museum of Los Angeles County Los Angeles Underwater Exhibition Let’s go back to life under water in Los Angeles 90 million years ago.

Even after the peninsula shook off those long immersions about a million years ago (roughly a few centuries ago), it remained an island for a long time, like its nearby relative Santa Catalina. A line of water separates it from the mainland. It wasn’t until 75,000 or 100,000 years ago that the waterway silted up and filled in, and voila, the cape merged with the mainland.

What Coffey likes about PVP is that it is made up of all three types of rock: sedimentary, metamorphic, and igneous.

If you cut it like a cake, you’ll find:

There is shale mud on top, the Altamira Shale, which is like the icing on the cake, the sedimentary legacy of thousands of years under the sea. The layers have mouth-watering names that sound like expensive paint colors or delicate pastries: Valmont diatomaceous earth, San Onofre breccia and the photovoltaic specialty Malaga mudstone. Combined, Coffey said, it’s “hundreds of feet deep,” which sounds big to us, but geologically speaking, it’s about as thick as fingernail polish and is basically dirt that accumulated in ancient times. The seafloor was compacted and formed.

The base layer of the PV cake is Catalina schist. We All Live on Catalina Schist is a great name for the band. It’s the solid metamorphic rock beneath the Los Angeles Basin, “the bedrock of the entire region,” Coffey said.It’s right there, beneath us garden and highwayThe only place on the mainland where you can see a newborn baby naked is in Palos Verdes, where there is a nature preserve and canyon called George F. (Who was George F. so immortal? No one knows for sure— Daily breeze recommended It is either a mistranscription of the name of early land baron George S. Bixby, or it is named after San Pedro rancher George F. Vickery).

But lurking in the sediment like a nest of snakes are slippery zones that are responsible for most of what is shed: ash.

The view is beautiful (on a vintage postcard from Pat Morrison’s collection) – if you can afford it.

Now, if you woke up in high school science class, you would think, igneous rocks: volcanic lava.something solid, so solid that Icelandic architects have been suggesting Use lava as a building material. A volcano some distance away left behind some solid volcanic rock, but also left traces of ash that floated underwater before the PV peninsula returned to its original state.

Volcanic ash is very different from lava, so light ash can be blown away. Underfoot and underground, it is fluid. When it’s wet, it turns into what Coffey calls “gooey clay” that can become as smooth as a water slide. In Palos Verdes, Coffey said, it works like this: As water seeps through the shale’s frost layer, which Coffey calls a “sedimentary veneer” that’s been underwater for eons, it then hits With these ash deposits, the veneer can start to slip like Buster Keaton on a banana peel, taking whatever is on it with it.

Oh, and then there was an earthquake.

Much of Southern California lies near the rugged intersection of the North American and Pacific plates, a boundary we know as the San Andreas Fault.

This is a strike-slip fault, which creates earthquakes when these plates slide past each other. But when the fault itself bends, severe plate contact occurs, the kind of earthquakes that drove the formation of the San Gabriel and San Bernardino Mountains (I think of uplift as the geological push-up bra).

The San Andreas Peninsula is a long way from the San Andreas, but Los Angeles is still dotted with a series of smaller, related faults—some of them as jagged and dramatic as the outlines of a lightning strike. These are the people who helped shape the peninsulasqueezing the land into sinuous bends, folds and dips.

By contrast, Coffey said, “If you go to Torrance in Carson, you’re standing underneath the same rocks on the Palos Verdes Peninsula — they’re still there because nothing happened to push them up. “

Landslides have been happening since the peninsula became land, so last year’s danger was nothing new. Coffey noted that the Portuguese Bay area “has a long history and has experienced multiple ice ages.” These cycles cause the Earth to slide when it’s wet, then stop or slow down when the land dries out. What’s new in the recipe is what we humans add: the weight of homes and roads, and the water that PV Peninsula cities pump into the ground for landscape irrigation and septic systems.

But at this point, late spring weather forecasts show temperatures and precipitation in the region that will be very similar to those on the peninsula itself: hot and dry.

Explaining Los Angeles with Pat Morrison

Los Angeles is a complicated place. In this weekly feature, Pat Morrison explains its workings, history and culture.