Most of the sand went up in Los Angeles county proper. It was diverted near the end of imports. The Newport Beach area has a ton too, but down here in South Orange County the beaches were not as supplemented and have already gone back to their rocky nature.
This area is actually one of the few deep water upwelling regions on the planet. The reason why is the combination of wind direction and shore angle but also because just off of the coast the water is quite deep. Just a few hundred feet offshore the water can easily hit 100+ feet deep in many areas and there are valleys descending underwater. Like there is a dive park on Catalina Island over near the Casino. At around 50 feet from the shore the depth is already at the recreational dive limits, there is a ship at 106 feet down IIRC from two decades ago.
Any sand gets washed down hill and into the valleys. That is why certain beaches were built to massive depths of sand like in Santa Monica and Newport. Eventually it will all wash away. There is no shallow coral reef structure or anything like that around Los Angeles, the water is too deep and cold to support anything like that. During the summer, if it is calm for a few weeks the upper thermocline will be around 20 feet down but it only takes one solid wind event and it will be back up around 8 feet down. On Catalina there were 3 major thermoclines in the middle of summer and at 100 feet it was quite chilly.
But yeah, all that white sand is from Australia and stopped getting imported around 20 years ago IIRC. Natural beaches here are rocky with small spots of sedimentary sand.
without Australian sand imports California beaches are rocks and gravel
No way!! I’ve been to Santa Monica and I never would have guessed.
Most of the sand went up in Los Angeles county proper. It was diverted near the end of imports. The Newport Beach area has a ton too, but down here in South Orange County the beaches were not as supplemented and have already gone back to their rocky nature.
This area is actually one of the few deep water upwelling regions on the planet. The reason why is the combination of wind direction and shore angle but also because just off of the coast the water is quite deep. Just a few hundred feet offshore the water can easily hit 100+ feet deep in many areas and there are valleys descending underwater. Like there is a dive park on Catalina Island over near the Casino. At around 50 feet from the shore the depth is already at the recreational dive limits, there is a ship at 106 feet down IIRC from two decades ago.
Any sand gets washed down hill and into the valleys. That is why certain beaches were built to massive depths of sand like in Santa Monica and Newport. Eventually it will all wash away. There is no shallow coral reef structure or anything like that around Los Angeles, the water is too deep and cold to support anything like that. During the summer, if it is calm for a few weeks the upper thermocline will be around 20 feet down but it only takes one solid wind event and it will be back up around 8 feet down. On Catalina there were 3 major thermoclines in the middle of summer and at 100 feet it was quite chilly.
But yeah, all that white sand is from Australia and stopped getting imported around 20 years ago IIRC. Natural beaches here are rocky with small spots of sedimentary sand.
This is so fascinating from an ecological perspective. I had no idea this was a thing! Thanks for sharing!