what we're going to be looking at is pretty much why the beach looks the way that it does what factors control that and then figure out what's going on exactly with our beaches and how our system has really been interrupted from really human activity so just to give you an example of what we're talking about um right here on the left-hand side of your screen this is this is swami's okay so this is uh encinitas city beach um go down hang out swami's it's it's one of these places i grew up surfing right and it's just uh it it's dear to my heart i love it down there and what you're seeing on the beach here the waves are off to the left of your screen but um what you're seeing here is these flat pieces of rock okay this is what the wave actually breaks on is these flat pieces it's the del mar formation that's millions of years old it's mostly shale so very small particles right smaller than sand and it's consolidated meaning it's become lithified or become rock and you can find old oyster beds within it things like that so kind of showing you an idea of what the beach or maybe lagoon might have looked like you know millions of years ago um so there are times believe it or not when these right here you can't even see them they're they're buried under sand these as well here and then out over here all this gets buried with sand sometimes and other times you can see even more of these because the sand level is fluctuating on the beach is it seasonal is it because of el nino is it because of wave activity that's some of the stuff we're gonna talk about in this lecture um notice these rocks here this is all just man-made rocks all right so these are brought in from another location and they're brought into to stabilize the cliff because the the waves will come in at high tide hit these rocks and dissipate the energy rather than hitting up against the cliff because it's going to erode away the cliff and then everything's going to fall in right now that'll be the second lecture we talk about with regard to who owns the properties around here and why is it that we have things like this along the beach um another example is of this similar uh topic is here this is uh in scripps uh uh so just north of scripps pier in la jolla um you're looking north along the beach we're just north of the pier and what you see is this this formation here this is whale rock they call it whale rock because kind of looks like whale vertebrae i suppose like a backbone of a whale um and this believe it or not is sometimes buried under sand four five six feet so there's times when the level of the water or the level of the sand i should say is uh different depending on the time of the year that you're gonna be there okay um we're gonna talk about all those factors so two examples swami's scripts and let's get into what makes a beach a beach and and uh why our pacific coast looks the way that it does okay so okay another shot of the pacific coast here we have um up north a little bit this is in big sur and what you're gonna see here are these big rocks that are sticking way out into the ocean you know what where did those come from is my question um you might think they might have rolled off the cliff and out here but these are giant giant rocks and what i'm going to tell you is that this here this is all actually it was once part of the cliff side and that all of this has been eroded away so a lot of material has been eroded away and this is what's left behind this is called a c stack same thing with these here this one this one in particular looks like it could have come from a rock fall and landed in the ocean but maybe not it might have just been part of the cliff so if we look um the pacific coast it's dominated by erosional processes okay meaning we're going to be continuously eroding away material from our beaches all right why is that it's because we live in a tectonically active location and because of the faulting we're always being uplifted that's not always the case everywhere in the world where you have faults but here in california especially in the san diego region we are slowly but surely rising out of the ocean locally um that's what i mean land rises relative to sea level we're slowly making our way up what this leads to is our beaches are open to uh high energy waves from the north pacific storms some from the south pacific but mostly from the north pacific right so the to keep this thought in mind is the land where we live is always slowly but surely rising up uh in most locations and the water is fluctuating depending on whether or not we have a ice age or not so if it's an ice age then relative or global sea level would actually be going down because all their water would be locked up in ice but then when the ice melts then our sea level rises up that's going to be the constant fluctuation of sea level and then there's a constant slow uplift of the land and if you can kind of get those two in your mind you'll understand everything and why it looks the way that it does so here's the faulting i'm talking about so every single one of these little black lines those are faults these are all faults throughout this whole situation okay so here's san diego um the closest fault we have is this rose canyon inglewood fault this makes landfall right at la jolla cove so that's the spot la jolla cove right and believe it or not mount soledad is a mountain it's popped up because of this right lateral fault making a left hand turn into the land and therefore causing compression they call that a flower structure um and anyway it's lifted up uh mount soledad and then it creates the bay behind when it makes its next turn so rose canyon angle would fall that's our closest fault um you got the san andreas in this dark darker thicker bolder black line right um san andreas fault running all the way through through the salton sea out um just throughout the desert right uh and then you've got all these other faults all these faults are causing us to slowly but surely lift up so there you go like i said because of the land rising we end up with a lot of erosional land forms okay so these are all things that i want you to know um if you look we've got here's our here's a wave cut bench okay so in essence this wave cut bench is happening you can see where the slope is right here's our slope this is a nice flat spot okay and it's where the bottom of the wave so the wave base starts interacting with the sea floor and it causes a very flat slightly sloped but very flat surface that is a wave cut bench okay if you look up here on top of the cliff you'll see it's an uplifted marine terrace what i'm telling you is the land is always rising so what you see is that this uplifted marine terrace used to be down here and was a wave cut bench but with time it's risen up out of the ocean and become a bench in my mind what i like to think of is for a giant so a giant comes in and goes hey you know i've had a long time walking i need to sit down on the cliffs there it is there's that giant bench and if they get really hot which you know it's been pretty hot lately they could go sit in the water on the wave cut bench and this one day will be another marine terrace okay a couple other things you see here are sea arches so this is from you know waves pounding at the cliff and they end up causing a nice little sea arch um you can also have sea caves so this sea arch started as a sea cave and then slowly but surely popped through and became a sea arch they call these headlands just anything that sticks out okay and coves anything that is um pushed inland so this is where you end up hanging out on the beach right setting up your umbrella make sure you don't get too close to the cliff i'm always going to tell you that don't do it don't sit up there set up out here okay away from the cliff um this headland used to be connected believe it or not to this this spot and it would have been a sea arch but the sea arch collapsed so that's what can happen with sea arches that's why it's a little bit sketchy to go through them i know it's tempting but be careful and then that leads to a c stack so when this collapses this will be a c stack all right so you can see these throughout the world um we've got in greece look at those sea caves right we've got in new zealand look at all these sea stacks imagine there was a day when all these could have been sea arches and just absolutely amazing maze but um a lot of uh sea stacks like you can see here we also have archways in australia one of the coolest videos i ever saw of rock climbing was this guy actually climbing up in this arch and making his way as far as he could but he couldn't quite make one spot and then he would fall and it would be right into the ocean and i thought to myself that's where i want to rock climb because you know i'd rather fall into some nice ocean then into uh some hard rock um but yeah that's beside the point sorry to uh diverge from our point oh diverge nice tectonics yes all this is tectonic related right without tectonics we don't have an ocean without an ocean we don't have waves so therefore tectonics equals waves that's why it's my favorite um so this is why the beach looks the way that this because does anyone know of any spot all right we talked about this wave cut bench in this uplift marine terrace but does anyone know of any spot that looks like this that has all of these um features nearby anyone i know i'm asking questions to all of you individually and maybe in the darkness or in the light wherever you are outside you know in your house uh what do you what do you think anywhere around that you've ever seen hopefully someone may have said sunset cliffs let's take a look at what sunset cliffs looks like check it out look at this you have all of the features we talked about so this would be a sea cave and you could make your way in and then this actually used to be a small blow hole in which high tide would come in and shoot water up out of it but it got so big from erosion that now it's just really this this view into the sky now this area is you know fenced off and you're not supposed to go in here and i'm not saying you should at all definitely don't but it does exist here it's sunset cliffs here's a nice archway you know at sunset cliffs this whole crowd here is because they're all jumping off at high tide doing tricks and flips and stuff like that maybe some of you have done that um definitely not condoning it not saying do it at all i want to be clear on that but it does occur here at sunset cliffs so now we've got our sea cave our archway and guess what else sea stacks right this would have been an arch now it's a c stack