## Monday, 25 April 2016

### Comments from Sharky! (The Sand)

Hello!

So you have already gathered and analysed the data referring to the sand!
Let's have a look... (updated 17th May)

Happy to see that all your coordinates are so accurate!

Let's have a look at your data. This is very interesting, you have very colourful beaches!
Now, by looking at the table try to finish the sentence:
(1) The coarser the sand is the .............. (steeper/flatter) is the slope of the beach face.
(2) Can you tell why?

And you can send your data if you haven't done it yet! The Sand >>

Sharky

1. Maybe the inclination of the slope at the beach face has relation with the granulometry because we can see that the slope is bigger when the size of the sand is big too.
Except the Calamosca datas those we don't know how to explain. Maybe the composition of the sand is important too.
And we remember: when there is storm the slope of the beach is steeper.

2. Hello we are INS Antoni Ballester,
As we can see with the INS Serrallonga data, the bigger the grains of sand are, the bigger the slope face inclination is. We think in this way beacause there is a better compactation when the sand is thinner. Taking this into account, we guess that the data of the heaps aren't correct. But, we agree with INS Serrallong about the influence of the composition (grains shape and texture).

3. Hello we are INS Luís Domènech i Montaner.
The thiner the sand is the flatter is the slope of the beach face.
Our sand is thiner and our beach flatter than beaches with coarse grains.

4. Hello we are students of INS Lluís Domènech i Montaner.
We are sorry. Our coordinates were wrong. These are the correct ones: 41° 35' 10.2" N 2° 34' 59.8" E.

1. Check the table. The S'Agulla Team have updated you coordinates. THANK YOU!

5. EXCELLENT CONCLUSIONS!!! Coarser sand tends to make higher and narrower heaps of sand, but it will also depend on the shape of the grains. In places where there is more wind, the grains become more rounded making heaps not as high. Also depending on the composition they will be more easily eroded and become more rounded.
The size of the grains also makes it react differently when facing the waves. Coarser sand drains part of the water of the waves, so not all the sand that moves up goes down again. Therefore the slope is steeper. Finer sand is less permeable, so all the sand that goes up the beach goes down again, becoming flatter.
But as you have also noticed depending strength and direction of the wind, the type of waves and the tides the profile of the beach is never the same!
WELL DONE!!!

6. Hello, we are the students of INS SERRALLARGA
We are sorry. We went to the beach of Cala Sant Francesc not Santa Cristina.

1. No problem! The S'Agulla Team have already been informed. Thanks for the update!

7. Hi Ins Sant Pol! Thank you for sending your data. It is very interesting that you have done two heaps of sand of different size of grains. Nice to see that you confirm the conclusions that the rest of participating schools have found out by comparing each others results! WELL DONE!