California Dreaming and Erosion “Crises”

guest post by Jim Steele

published in the Pacific Tribune July 24th

What’s Natural?

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California’s spectacular coastline attracts tourists from around the world. Headlands of granite or basalt resist erosion, defiantly jutting out into the sea. Pocket beaches form where focused wave energy bites into softer sandstones and uncemented stream sediments. Relentless waves undermine and steepen cliffs bordering 70% of California’s shoreline. Over hundreds and thousands of years, natural erosion sculpted our awe-inspiring undulating coast.

But beauty is in the eye of the beholder – likewise the magnitude of a “coastal crisis”. The Los Angeles Times recently published ‘California coast is disappearing under the rising sea. Our choices are grim. They inaccurately painted natural erosion as a recent crisis due to CO2 induced climate change. However, California’s erosion “crisis” must be understood within a greater timeframe.

Since the end of the last ice age, sea level has risen 400 feet. Over 18,000 years, San Francisco’s regional coastline marched 25 miles inland, advancing 7 feet a year – more than twice California’s average. My beautiful home town of Pacifica was featured in that Times’ article because it lost several homes unfortunately built on loosely cemented sand and gravel deposited 100,000 years ago when sea level was 20 feet higher. Although the ocean’s landward march has slowed over the past 5000 years, northern Pacifica’s fragile coastline still retreated by over 7 feet per year between 1929 and 1943. Despite a warming world, the average rate of cliff retreat then markedly declined since 1943.

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The ill-fated Ocean Shore Railway, initiated in 1905, foreshadowed California’s erosion problems. To give tourists awesome views, tracks were laid on a ledge dug into steep coastal cliffs. But landslides were common, and costly repairs forced the railway to close. Today, only 25% of the railway ledge built by 1928 still exists. Undeterred, designers of California’s scenic Pacific Coast Highway hoped to give automobile travelers similar breath-taking views. Again, landslides were common. Only 38% of the highway constructed by 1956 still remains. Geologists tell us such landslides constantly altered California’s modern coastline for hundreds of years.

There are few straight lines in nature. Our coastlines undulate. Likewise, our climate oscillates, and coasts erode episodically. Between 1976 and 1999 (the warm phase of the Pacific Decadal Oscillation), California experienced more frequent El Niños. Over 70% of California’s 20th century disappearing coastline eroded during El Niño events. El Niños bring more storms and more destructive waves. El Niños bring more rains that saturate soils and promote landslides. The Pacific Decadal Oscillation then switched to its cool phase. It brought more La Niñas and more drought, but fewer winter storms and less erosion. In 1949, also a time of less erosion, Pacifica’s government believed homes setback 65 feet from the edge of a bluff would be safe. They never suspected a single El Niño event would move the cliff edge 30 feet landward 50 years later.

There are some who see human structures as a blight on California’s natural coastline. In response to natural erosion, they suggest we abandon the coast. They argue California’s only choice is “managed retreat” versus “unmanaged retreat”. Although well engineered seawalls can protect homes and businesses, some environmentalists called seawalls a coastal “crisis”. California’s Coastal Commission recently pledged seawalls will “only be permitted if absolutely necessary”. But the Commission’s policy only fosters a mishmash of emergency fixes. Randomly armored properties deflect destructive waves downstream, accelerating erosion in a neighbor’s unprotected property. Coastal cities must construct well-engineered sea walls, without any gaps.

Because sea walls prevent erosion, the Commission ill-advisedly fears local beaches will be lost if denied locally eroded sand. The Times parroted that belief writing, ‘for every constructed seawall, a beach is sacrificed’. But is that true? San Francisco’s O’Shaughnessy sea wall built in 1929 prevents erosion of the fragile sand dunes supporting Golden Gate Park. Yet SF’s north ocean beach continues to grow. Without a seawall, San Francisco’s south ocean beach rapidly eroded, and threatened infrastructure now requires a sea wall.

Sources of beach sand fluctuate, and simplistic sea wall analyses are very misleading. Sand is stored and transported to beaches in many ways. Streams and rivers supply the most sand needed to nourish a beach, but mining SF bay’s sand has deprived nearby coastal beaches. Furthermore, ocean oscillations shift winds and the direction of currents that transport sand. Beaches grow for decades then suddenly shrink. Although some argue our beaches face a rising sea level “crisis”, archaeologist determined that despite more rapidly rising sea levels 5000 years ago, many California beaches grew when supplied with adequate sand.

Lastly, it’s interesting to note scientists suggested Pacific islands also face an erosion crisis due to rising sea levels. But the latest scientific surveys determined 43% of those islands remained stable while land extent of another 43% has grown. Only 14% of the islands lost land. So, I fear exaggerated crises only erode our trust in science.

Jim Steele is director emeritus of the Sierra Nevada Field Campus, SFSU

and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

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56 thoughts on “California Dreaming and Erosion “Crises”

  1. And who will tell us that Californian beaches are immune from tsunamis? Talk about sea level rise on steroids … and all totally unrelated to carbon dioxide.

  2. Across the Pacific at Fort Denison in Sydney Harbour an Oceanographer advises that the mean sea level of 2019 is more than 2 inches [6cms] LOWER than it was in 1914.

    Houses that were in danger of being washed out to sea in the ’60s and ’70s are now changing hands at tens of millions of dollars.

    Beaches along the east coast have never looked healthier.

    And king tides at our old sea wall are now 6 inches lower than they were in 1946.

    • While this doesn’t apply to the Sydney area, there is a good reason why beaches along the east coast of Australia have never looked better. That is the cessation of beach mineral sand mining. http://willkemp.net.au/enviroscience/land-degradation-and-rehabilitation-in-coastal-sand-mining/.

      I haven’t heard any explanation of why the records of mean sea level at Fort Denison are 2 inches (6 cms ) lower than in 1914. Is there any evidence of global sea level dropping that much, or sea level around Australia? Has sea level also fallen just outside Sydney Harbour as well as at Fort Denison? What other records are there for Sydney Harbour or Parramatta River, its main tributary? If measurement inconsistencies can be ruled out, then presumably this a local phenomenon. One possibility is a decrease of stream discharge into the Harbour, given that upstream it’s now suburbia for 50km (35 miles) inland, and run-off presumably goes into storm-water drains before discharging into the sea. Some is recycled for parks and gardens. https://www.smh.com.au/environment/where-does-all-the-stormwater-go-after-the-sydney-weather-clears-20150430-1mx4ep.html.

      Of course there’s always the possibility that For Denison, built on a small sandstone island, has subsided a bit.

      • One of our subsidiary companies used to be a major beach sand miner. The vast bulk of its extraction/return of sand was inland from the ocean beach, on historic dunes hundreds to thousands of metres from the sea. No plausible effect on sea level change, big effect on supply of titanium and zirconium as used in modern aircraft that give us all more comfortable, safer air journeys.
        I have had a neck full of green propaganda. Often it is simply lies told with an unrelenting negative, whinging tone denigrating anyone else bar the author and friends, who are so blameless that immaculate conception is an expectation for all of their fabricated 118 variations of gender.
        Sheesh! Geoff S

        • Yes, the more recent large scale mining was focused on the sand dunes behind the beaches. But if you reread the linked article on rehabilitation, you’ll see that there was also extensive mining of the beach itself, for gold at Ballina, and for building sand. This would have been fairly localised. I remember seeing some of the mineral sand mining areas in the 60s, and there was a lot of impact on the beach areas as well, even though they weren’t mining there. I am more familiar with the current mineral sand mining (over the last 20 years of so) of the late Tertiary coastal dunes in the Murray-Darling Basin. For those unfamiliar with Australia, large areas of inland south Australia were covered by a shallow marine sea from about 15 – 3 million years ago. As the sea retreated it left a series of coastal beaches and dune systems; the older ones were covered with later lacustrine sediments and aeolian dunes, and mining is subsurface. the younger ones are linear landscape features with the old coastal dunes silicified. https://www.researchgate.net/publication/295507426_Mineral_Sands_Occurrences_in_the_Murray_Basin_SoutheasternAustralia

          • What impacted ocean beaches on the east coast of Aus were the incredible number of cyclones we used to get south of the Tropic of Capricorn over 40 years ago which just stopped happening in 1976 with the Pacific climate shift.

            It was claimed that beach erosion prior to that was due to sand mining but with all those heavy minerals that were removed, beaches are more stable when they should be less stable. Nothing to do with mining. Just better weather.

      • “Is there any evidence of global sea level dropping that much, or sea level around Australia?”
        Nope-
        “One of the oldest tide gauge benchmarks in the world is at Port Arthur in south-east Tasmania. When combined with historical tide gauge data (found in the London and Australian archives) and recent sea level observations, it shows that relative sea level has risen by 13.5 cm from 1841 to 2000”.
        https://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html

        That’s an average annual SLR of 0.85mm a year for over a century and a half but there’s a much older one in the geology of Hallett Cove in South Australia. That can show an average annual SLR of 16.25mm for EIGHT THOUSAND years beginning around 15,000 years ago. No doubt Nick, Griff, et al will be along shortly to explain it all to us with their plant food data and how to fix the current dooming.

        • Observa,
          You should have stated that BOM/CSIRO reported on the original John Daley research on this important tide mark. The Daly studies showed tiny level change. The BOM report claimed that the tide mark referred to a different tide state. So a higher level could be claimed. It depends on which interpretation is made about some ambiguous words in the original reporting.
          The net effect, when this is not explained, is that what seems like an unlikely scenario, that is, most plausibly wrong, becomes entrenched as correct only because it was created by the latter day authorities.
          Geoff S

          • Spot on Geoff. Lempriere, who made that original mark could easily see the tide range marked on the rock cliff and simply put the MSL mark half way up.

            And guess what? It’s still half way up.

            Here are the MSLs from Fort Denison:

            1914 – 1.11 metres

            1924 – 0.98 metres

            1934 – 0.98 metres

            1944 – 0.97 metres

            1954 – 1.00 metres

            1964 – 1.09 metres

            1974 – 1.09 metres

            1984 – 1.02 metres

            1994 – 1.04 metres

            2004 – 1.08 metres

            2014 – 1.12 metres

            2019 – 1.05 metres

            And Fort Denison is actually sinking slightly from GPS info so that makes any SLR recorded there somewhat less likely.

          • I meant to include this comment from the Oceanographer who supplied that data:

            The seas and oceans to the east of Australia forms the largest body of water on Earth. This broadly connected vast body of water presents a genuine sea level. The Sydney Fort Denison Recording Station provides stable, accurate and genuine mean sea level data.

          • I wasn’t aware of that-
            https://john-daly.com/deadisle/hobart-msl.htm
            Seems his historical assessment of Port Arthur matches more closely the one at Fort Denison in this ancient weathered continent but the telling one is still Hallett Cove. My arithmetic is good when I read about that 130M rise in sea level on the geology signboard there that they’ve subsequently removed and now replaced with a wishy washy camouflaged reference. No matter as I have a copy of the original comprehensive Govt pamphlet about it all.

            Even with the CSIRO’s current 1.6mm global estimate and NOOA’s 1.7mm they can’t explain away 16.25mm a year average rise for eight millenia with aboriginal cooking fires and traditional burnoffs to flush out game anymore than this glimpse of the past-
            https://www.msn.com/en-au/news/world/storm-hannah-unearths-sunken-forest-from-more-than-4500-years-ago/ar-AABVEuD
            Their perpetual 12 year Great Leap Forward rolls on but like all those before them that attempt ultimate control and stamping out dissent their Lysenko prescriptions will bring their wall down. They’re going to change the climate remember?

      • CommieBob. You are quite right, but it’s actually because globe is always shown the wrong way up. We Australians are the right way up, the rest of youse are upside down.

        The ‘north’ pole should be at the bottom, and the ‘south pole’ at the top. This explains why most of the continents cluster at one side of the equator – they are heavier than water and they have slid to the bottom. Now, the water is slipping away too, so the sea level around Australia (up the top) is dropping. QED.

        • Tom,

          In Oz the moon rises upside down, the sun dials run counter clockwise and y’all drive on the wrong side of the street. You probably eat dinner holding the fork in the wrong hand too.

          • Na, Aussies still eat with their finger, not a knife and fork. They have to keep one hand free for a stubby. 😉

          • Steve case

            But we in the UK and Australia drive on the ‘right’ side of our vehicles.

            Just so our buggy whips don’t get caught in the hedgerows.

            And when we’re all forced back to using said buggies, we’ll once again have the whip hand. 🙂

          • Us Americans also drove on the ‘right’ side of our vehicles during the horse drawn buggy, wagon and stagecoach days.

            I figured it was a carry-over from European “righthanded” driving which began because it required a strong “right arm” for pulling the manual “braking” lever.

            I don’t know why Americans switched to “left hand” drive with the advent of automobiles …… unless it was because of the steering “wheel”, …. Gearbox …. and “shifting” lever location.

            With “4-on-the-floor”, … “speed” shifting gears “left handed” by a right-handed driver might be kinda tricky.

          • It’s rather surprising that Americans have left-hand drive. This puts your right hand in the centre of the car. Surely right hand drive would be more appropriate for American culture- so you can shoot your gun out the window with your right hand?

            By the way, Samuel, when you learn to drive on a right-hand manual “4-on-the-floor” (I’ve got 5), it’s not tricky, it just becomes second nature.

          • But, but, but, …… Americans were shooting their guns while riding horseback a hundert years for automobiles were invented. Yup, they had ta learn ta shoot backward and forward, but hardly ever ta never, sideways. Yup, ya could be ”chasin n’ shootin” at Indians and stage coach robbers, ….. or they could be ”chasin n’ shootin” at you.

            By the way, Tom, shifting “left handed” is akin to eating with fork in left hand, right. Nurtured habits persevere for a lifetime.

            In my younger days I purchased a new 66’ XKE. I think it would have been a challenge for me to “squeal-the-tires” in all 4 gears iffen I had to be shifting with my left hand.

        • Tom,
          American cars work best with a separate driver and gunner – a person in the right front seat is said to be “riding shotgun”.

      • commie Bob
        …it is clear that it’s because Australians are upside down compared with the rest of us.

        Not so mate! Since water likes to run downhill its not surprising that most of the world’s water is in the Southern Hemisphere. On the other hand if they changed the datum for Sea Level, say to the top of mount Everest, we could prove conclusively that sea level is falling… All those frightened folk in Miami and the Marshall Islands could sleep in peace without fear of waking up drowned!
        Cheers
        Mike

    • Lil Fella from OZ, On the outer Barcoo, spangled drongo. Geez, I wonder where you blokes are from.

      • You need to look up how anagrams work, Loydo is not an anagram of Griff.

        • The three I named know exactly what I meant, aparently you do not. No I am not Griff, if that is what you’re implying. A mod can verify that.

  3. This week on the Dutch RTL4 news reporter Eric Mouthaan confused coastal erosion in Wahington state (North Cove, Wilapa Bay)with climate change. This report shows that is bas been going on for centuries.

    Assessment of Coastal Erosion and Future Projections for North Cove, Pacific County
    Authors: Bobbak Talebi, George M. Kaminsky, Peter Ruggiero,
    Michael Levkowitz, Jessica McGrath, Katy Serafin, Diana McCandless
    Washington Department of Ecology. June 2017 Publication no. 17-06-010
    https://fortress.wa.gov/ecy/publications/documents/1706010.pdf

    • North Cove and Willapa Bay have been disappearing for years. Shortly before America entered WWII, the old Willapa Bay Lighthouse near North Cove collapsed after the cliff on which it stood eroded away, as did a good portion of the North Cove area. The local cemetery was saved after swift action was taken to relocate the graves: caskets, headstones and all, to a safer location before they could be affected.

      Islands and headlands disappearing is not a new phenomenon. Many islands and coastal land forms in the U.S. alone have disappeared over the course of the 19th and 20th centuries even….

      Watts Island (Virginia) Eroded away by winter storms 1944
      Billingsgate Island (Massachusetts) Eroded away due to unstable soil 1915
      A portion of Cape Henlopen (Delaware) Erosion of unstable sand deposits 1926
      Frank’s Island (Louisiana) Swallowed up by the almost bottomless Mississippi mud circa 1950’s
      Dog Island (Florida) Eroded away by numerous hurricanes 1875
      Tucker’s Island (New Jersey) Eroded away by nor’easters 1927
      A portion of Hog Island (Virginia) Eroded away due to unstable soil 1948
      Morris Island (South Carolina) washed away by a 1935 hurricane
      Most of the islands in the Ocracoke Inlet/Cape Fear River areas in North Carolina have disappeared in the early 20th century

      Horn Island (Mississippi) washed away by a 1906 hurricane.
      Sand Island (Alabama) washed away by a 1906 hurricane
      Bodkin Island (Maryland) unstable soil erosion 1914
      North Manitou Island (Michigan) unstable soil erosion circa 1940s.

      More recent examples can include…..

      Round Island (Mississippi) washed away by Hurricane Georges in 1998
      Chandeleur Island (Louisiana) washed away by Hurricane Katrina in 2005 (The storm everyone blames climate change for)

      Tangier Island in Virginia is slowly disappearing since the 1850s. Excessive missile testing on the island during the Cold War has accelerated the erosion.

      One strange example is Troubridge Island in South Australia, where the island appears to be “moving”, as the sand shifts from area to the next, which it has apparently done for years.

      Then, in Dungeness, Kent, UK, the beach seems to be growing rather than disappearing.

      • Dungeness is at the western end of Romney Marsh, which in Roman times was a lagoon, now extremely fertile farmland. There are the remains of a Roman port on the South Downs at Lymnpe some 2 miles inland from today’s coastline. The soil at the foot of the Downs is full of large fossil mussel shells, 6” or more in length, mute witnesses of the higher temperatures of the Roman Warm Period. The lagoon of Roman times was filled in by natural causes by about 1000 AD and drained for agriculture in medieval times.

        • Dungeness is a strange place. I’ve read a couple of stories about how the sea continues to recede from the shore. Most of the ground is shingle.

      • While these are not the best places to build or hang around too long, Chandeleur, Dog and Horn Islands are still there. The former has been steadily eroding, some of the southern part turned to shoals over the last century, northern part eventually lost its century old lighthouse. Hurricanes cause numerous cuts through low spots, temporarily healed by remaining sand from alongshore currents. Historical images in Google Earth show this.

        Exceptionally low Louisiana sea levels were associated with a La Niña event in 1988, some marshes went uncovered. [Childers, D. L., J. W. Day and R. A. Muller. 1990. Relating climatological forcing to coastal water level in Louisiana estuaries and the potential importance of El Niño-Southern Oscillation events. Climate Research. 1:31-42.] Predicting sea level there difficult.

        • You’re right. Most of these islands are just shoals now. Billingsgate and Watts Islands are just small semi-submerged shoals, as are most of the islands around the Ocracoke Inlet/ Cape Fear River areas. Recently a team of researchers in Florida discovered the remains of a lighthouse and other structures on the shoal that was formerly Dog Island. The remains of the century old lighthouse at Chandeleur Island has surprisingly not been found despite having collapsed in shallow water. Another small island I forgot to mention was Frazer Isand in Western Australia (Not the larger and more famous Frazer Island in Australia’s Queensland region) which was washed away by a storm in the 1970’s, the wreckage of the flimsy lighthouse that sat on the island can be found on the ocean floor.

          Hurricane Sandy (Another storm blamed on climate change) didn’t wash away any islands if my memory serves correctly. Hurricane Irma, which everyone cried was the “apocalyptic climate change induced hurricane that would be the end game”, didn’t wash away any islands either, (none that I heard of anyways) and the Caribbean islands it ravaged are still there too.

          I’m surprised that they haven’t began making alarmist claims that New York’s many islands are being washed away by rising sea levels yet. Maybe they’re still getting to that.

  4. While I generally agree with the article, there seem to be some contradictions:

    “Although the ocean’s landward march has slowed over the past 5000 years, northern Pacifica’s fragile coastline still retreated by over 7 feet per year between 1929 and 1943. Despite a warming world, the average rate of cliff retreat then markedly declined since 1943.” and

    “In 1949, also a time of less erosion, Pacifica’s government believed homes setback 65 feet from the edge of a bluff would be safe. They never suspected a single El Niño event would move the cliff edge 30 feet landward 50 years later.”

    The ‘average’ may have declined, but there can still be extreme events ‘never suspected’. Actually, they should be suspected and definitely expected. Cliff erosion and retreat continues and the degree will vary due to local geography, storms, tsunamis regardless of climate change (or not). Given this, I am surprised that people continue to built on cliff-top edges (or coastal dunes). Why not leave a zone clear of houses, with natural vegetation, gardens, walking tracks, sports fields, etc.? This has two benefits, it minimises houses falling or being damaged, and it provides public access and usage of these scenic areas.

    My favourite cliff top usage – Waverly Cemetery, south of Bondi, Sydney, Australia. http://www.waverleycemetery.com/

    • How wide of a setback should this bluff-top park create? How long will the park remain as wide as it originally was?
      I suspect these two questions were originally answered by the present construction situation and have shown to be a futile and only temporary answer.

      All human creations are temporary. Nature likes its clean slate. Get over it, and stay agile.

    • Tom,
      Why are you bothering to write here about possible ways in which authorities can control land use, when history shows that many folk prefer to make their own decisions about the land whose title they seek or have?
      What motivated you to pop up with a socialistic proposal when a free enterprise one is probably better. Are you pushing an agenda?
      Geoff S

  5. STOCKHOLM, Sweden — The United Nations Intergovernmental Panel on `Climate Change (UN IPCC) is misleading humanity about climate change and sea levels, a leading expert on sea levels who served on the UN IPCC told The New American. In fact, it is more likely that sea levels will decline, not rise, explained Dr. Nils-Axel Mörner, the retired head of the paleogeophysics and geodynamics at Stockholm University. A new solar-driven cooling period is not far off, he said. But when Mörner tried to warn the UN IPCC that it was publishing false information that would inevitably be discredited, they simply ignored him. And so, dismayed, he resigned in disgust and decided to blow the whistle.

  6. I recall seeing photos of a Island in about 1944 where the airstrip which was vast, was built from coral from the reef. It said that as the coral was laid and cruised it was sprayed with sea water to let it grow, thus it locked together.

    The Japanese surrender aircraft, the white ones, landed there.

    Now with so much damage done to the natural coral, it would be of interest to see if any research was done on a possible recovery of the coral.

    MJE VK5ELL

  7. “published in the Pacific Tribune July 24th”

    That should have read “Pacifica Tribune”

    Those cliffs are going to continue to erode naturally, else there wouldn’t be cliffs. Trying to stop that erosion is ultimately as futile as King Canute ordering the tide to stay out.

  8. The Pacific Plate is tilting, up in the west and down in the east. The convergent plate boundaries, and associated phenomena like the “ring of fire” raises the western part of the Pacific Plate. Coastlines are straight, sea cliffs are common, and earthquakes and volcanos keep it all going. The east coast is a passive plate boundary, and erosion wins here. Coastlines are irregular, sea cliffs are rare, and there are not any earthquakes or volcanos. If you build your house on a cliff-top on the west coast, with a magnificent sea-view, erosion may some day convert your house to a houseboat, just saying. The sea level going up and or down with glacial cycles exagerates the above. Never mind the local phenomena, this is the big picture.

  9. no one can tell me why my area is covered in whats basically greyish white beach sand over ironstone pebble rock with iron rich clay under that
    and not ONE single shell is found!
    and we have no limestone deposits at all
    it was very obviously a shallowish? inland sea area some distant time past

  10. Grew up there. Never felt sorry for those rich enough to buy on a cliff but stupid enough to do so.

  11. Thank you Jim Steele. You are a voice of reason. Reminiscent of Paul Harvey’s “the rest of the story”.
    Thank you Anthony Watts for this site.

  12. Don’t they teach basic geological science in grade school anymore? Coastlines are the most temporary features on the planet.

    Reminds me of years ago when I was in Yosemite Valley shortly after one of the sizable floods that occasionally occur. One “scientist” was going on about the “ecological damage” done by the very kind of natural event that created the place to begin with!

    It’s literally as though the eco-left has a snapshot of the planet from 1820 and honestly believes that that is how the planet always was and always should be.

    • John the Econ
      July 31, 2019 at 6:47 am

      Yes, the eco left doesn’t have a clue.
      My question for them is when was the world perfect…what is the ideal temperature, sea level, CO2 level, etc. that they so desire. Was it in 1900, 2000, when Al Gore/Hansen/Leonardo/Greta were born…when?

      They can never answer that one.

      Here in NZ they all love the scenery but don’t realise that it is there only thanks to the glaciers/earthquakes/volcanoes/coastal erosion that we have had and will have again. They seem to think the world should remain static since they were born.

  13. My wristwatch shows an unstoppably increasing time. Scientists don’t have a clue how to counter it. Our choices are grim.

  14. Jim Steele ==> I grew up on the beaches of the Los Angeles, CA, surfing from the Venture County Line south to Torrance Cliffs [ key the ♫ Beach Boys…].

    I have witnessed the formation and disappearance of beaches in the Caribbean — in in particular that could appear and disappear again in a single day, gaining and losing six vertical feet of sand – exposing and hiding caves in the volcanic rocky shoreline.

    To protect Pacifica will be a near impossible job requiring heroic engineering. It is a problem common to human endeavers — building homes/cities in the wrong place. If I recall correctly, the cliffs at Pacifica are sand[stone] and are doomed even on a time-scale of centuries.

    The error is literally Biblical — Matthew 7:24-27 and the results known from hard experience over thousands of years.

  15. The CA coastline isn’t made of granite, most of it’s just a soft sedimentary rock. There is a WWII era bunker in Pacifica that was buried in the hillside 50 years ago, at least 100 feet above sea level, and its now a cement box sitting at the summit of a barren hill because all of the earth it was buried in has eroded away. So what did sea level and climate change have to do with that?

    https://www.google.com/search?client=safari&channel=iphone_bm&source=hp&ei=cLdBXcV2x7j6BPK7orAE&q=devils+slide+bunker&oq=devils+slide+bunker&gs_l=mobile-gws-wiz-hp.3..0j0i22i30j33i299.3267.22530..23545…0.0..0.211.3037.0j18j1……0….1…….8..41j0i131j46j46i131j0i10j46i275j46i10j33i160.FuLXo4QQPUA

    Not surprising to the locals though as this is right next to a section of the coast highway called Devil’s Slide, so named because in my lifetime the road has been closed by landslides at least a dozen times. So much so they finally built a bypass tunnel to this stretch 10 years ago. And just 2 years ago about a half mile of hillside slid into the sea just about 10 miles south of the bridge pictured at the top of this article.

    It has nothing to do with climate. It’s called erosion.

  16. California’s Monterey and Point Reyes Peninsulas, with some of the state’s most scenic beaches, have been moving north towards Alaska at the rate of 2.5 inches per year for at least a million years.

    I blame it on global warming.

    • Everything west of the the San Andreas is moving northwest, (LA, San Diego, Santa Barbara). Not to Alaska, but to a triple junction around Eureka. North of there, a tiny remnant plate pushes under Oregon and Washington along the Cascadia fault. This will “soon” produce a 9.0 quake like the Japan tsunami. (last 9.0 on Cascadia was in 1700).

      Re: Pacifica, this is where the San Andreas goes to sea, so everything west of the fault is shoved into the ocean. The Sacramento River (that discharges just north through the Golden Gate), and winter Ocean storms erode everything, creating the cliffs along Pacifica.

  17. Since the end of the last ice age –> since the begin of the interstadial in the current ice age.

  18. Thousands of years of Erosion and silt from all flood waters that end up in the seas and oceans must effect sea levels add to that sand and dust blown out to sea from all the deserts .Just as most country’s with a coastline practice land reclamation also adds to sea levels in a small way so can anyone answer by how much .If you half fill a bucket with water then add sand level will rise. Wave action on beaches will erode and replace sand .A dust storm from Australia was blamed for turning snow fields in New Zealand reddish all the dust that landed in the Tasman sea wont end up on a beach somewhere

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