Tales of Home [8]

Yep. That's me!

Ah, you edited as I was writing.  I didn't really buy the 15 most bizarre waterfalls thing.

Now with the pictures I can see that you have adopted the medieval defence against cannonballs: sloped walls.  Makes sense.

We've got a local family-run rock quarry about 18 miles away and a neighbor with a small construction company that has dump trucks and trailers, and a lot of people want to help, whether or not they give us any chance of success.  That's all you need for an experiment!

Edit: Except for permits. That's been an adventure in itself, but I'm becoming something of an expert in permitting projects that have never been done before. The secret is striking the right balance between sincere, charming, and obsessively insane. :

The pacific north west beautiful... landscape

Very cool! I can relate to the not liking to see/hear oneself talk but I appreciate you sharing the video, Dave.

I'd worry about the rocks sinking into the sand with time.

If the sand is able to start to re-extend the coastline would you have to add more rocks to protect that new bit, I guess?

Bluebottle wrote:I'll take your diagrams and pictures and raise you the need of an academic paper

OK Blue, I'll call your academic paper! Here's the seminal 1990 paper that started the discussion and that everybody still cites.

https://icce-ojs-tamu.tdl.org/icce/index.php/icce/article/viewArticle/4567

Testing Halfy's toolbar method:

Hey, I meant produce a new one. But that is interesting, sadly a bit to busy trying to finish up my own to give it a proper look though :/

Since it is from 1990, I am sure it could use an update treatment

halfwise wrote:I'd worry about the rocks sinking into the sand with time.

Nope! We're using the local basalt, what most of the sand is made of, so they're almost exactly the same density. There are however many cool self-sorting properties in various energy conditions. For example, under some conditions, sand will pass through the voids between the larger cobble like a sieve, while the mobile cobble rolls along the surface almost as if it were "floating" on top of the sand. In lower energy states, sand will accrete against the static cobble, burying it by up to several feet and giving the appearance of sinking, but in fact it's just sleeping and biding its time for the next storm that tries to take the sand away again. It's endlessly fascinating to watch, like an old lava lamp!

David H wrote:Testing Halfy's toolbar method:

Hmm...it needs to end up in an imgserver file. I think you did it wrong since it's linked to your desktop. Here's the steps:

1. click on the "host an image" icon
2. Drag your image to the box
3. push the blue upload button
4. a series of links will occur. Copy the first one, which is also the simplest.
5. click the "insert and image" icon
6. in the url space, paste the link you just copied

I think here it is quite usual to use round boulders to sure up a shoreline.



That is actually from Sweden though, seems we share the word "kampestein"

Wth, so big

David H wrote:

halfwise wrote:I'd worry about the rocks sinking into the sand with time.

Nope! We're using the local basalt, what most of the sand is made of, so they're almost exactly the same density. There are however many cool self-sorting properties in various energy conditions. For example, under some conditions, sand will pass through the voids between the larger cobble like a sieve, while the mobile cobble rolls along the surface almost as if it were "floating" on top of the sand. In lower energy states, sand will accrete against the static cobble, burying it by up to several feet and giving the appearance of sinking, but in fact it's just sleeping and biding its time for the next storm that tries to take the sand away again. It's endlessly fascinating to watch, like an old lava lamp!

I think that density is only part of the story. You also have the larger velocities of smaller objects under a forcing compared to larger objects. With wave action the sand will rattle around more, and eventually find itself on top as the slower moving stones settle downwards. I'm not entirely sure my picture is right: need to experiment shaking a can full of large and small marbles and see what the final result is.

Bluebottle wrote:Hey, I meant produce a new one. But that is interesting, sadly a bit to busy trying to finish up my own to give it a proper look though :/

Since it is from 1990, I am sure it could use an update treatment

That's been suggested, but I figure there are two kinds of researchers, those who figure things and those who write about them. I'd probably agree the the people who do the writing may actually have the greatest impact, but right now I'm too busy saving the world to be bothered writing about it  {{If only somebody would just assign me a good grad student who needs a thesis topic .... }}

Eldo or Norc might be available, perhaps offer them a semester abroad (kinda)

halfwise wrote:
I think that density is only part of the story.  You also have the larger velocities of smaller objects under a forcing compared to larger objects.  With wave action the sand will rattle around more, and eventually find itself on top as the slower moving stones settle downwards.  I'm not entirely sure my picture is right: need to experiment shaking a can full of large and small marbles and see what the final result is.

That's not been my experience. The kicker is that in the natural pocket beaches of the Olympic Peninsula which are subject to very similar wave conditions, there is a naturally occurring band of cobble that lays exposed against the upper shoreline above and sometimes on top of the sand. I'll see if I can find a pic since I don't seem to be able to post. The material I'm using is unsorted pit-run with a diversity of particle size from about pumpkin down to sand, with maybe 70% being in the 2"- 12" size range. The diversity of size gives a diversity of velocities that increase the number of collisions (like having bicycles on the same highway with small cars and large trucks). And the greater number of collisions, the more energy is dissipated while at the same time reducing material migration. Like I said, cool stuff!

Not the best picture, but here's ruby beach to the north. see how the cobble sits on top of the sand? You really need to watch it in action to understand it though.

If you look up I think you maybe can post, you're just copying the wrong link. Or maybe the upload times out on you or something.

halfwise wrote:

David H wrote:Testing Halfy's toolbar method:

Hmm...it needs to end up in an imgserver file.  I think you did it wrong since it's linked to your desktop.  Here's the steps:

1. click on the "host an image" icon
2. Drag your image to the box
3. push the blue upload button
4. a series of links will occur.  Copy the first one, which is also the simplest.
5. click the "insert and image" icon
6. in the url space, paste the link you just copied

I get no blue upload butten I'll mess around with it later. I gotta go take care of the new bog now. Bye all!

That's odd. Maybe it's because I'm registered with the default servimg site. It's free.

www.servimg.com

i'm flying home reaaaally early, and suddenly i realised i only would be able to sleep 4 hour because i am an idiot and started packing late, so now i am just up all night...

We look forward to hearing the increasingly loopy updates.

well, it's already 3 in the morning... taxi comes and picks me up in an hour and a half.. i am not taking a taxi all the way to the airport, because i cant fucking afford that, but i am taking it to where the airport-bus stops... because, i am an idiot, the regular bus obviously doesn't drive at four in the morning..