Comments problem - apologies and bits of sand news

Thanks to a fortuitous correspondence with Suvrat on the issues of dams, I discovered that comments to this blog over the last ten days or so may have encountered problems and never appeared (I received no notifications - possibly as a result of a blizzard of spam, that I hadn't picked up on, clogging things up). I've now deleted all the spam and added a "captcha" requirement and it seems to be working again.

However, if anyone tried to leave a comment and found that it was never posted, I sincerely apologise - and would be delighted if you would re-post it!

Meanwhile, sand in the news:

1. Sand theft turns Mexican beach into a crime scene

http://www.google.com/hostednews/ap/article/ALeqM5jgHmDqLU_femenG_nkw722vLPzlAD99P68DO0

2. Massive sand engineering project in Grand Isle, Louisiana

http://www.geoprac.net/geonews-mainmenu-63/64-project-related/544-video-sand-filled-geotextile-tubes-to-protect-grand-isle-louisiana

3. Not directly to do with sand, but dramatic - a new sinkhole in Texas (is this where the comments ended up?)

http://www.kcbd.com/Global/story.asp?s=10810490

[sand alphabet courtesy of Umbrella Corporation

Comments

[F]

Well, I'll take the opportunity to submit my first comment, then.

Mostly, I'd just like to say that I've been following your blog for a while, and I think it is fantastic. Truly fascinating are the subjects on which yo write here.

Also, I thought I'd mention that I've just seen the National Geographic Channel's "America's Wild Spaces: Death Valley", which among other things, demonstrates the singing/booming sand dune effect. I've read about it before, but, what a sound! Complete with cross-section diagram of how the sound waves travel through the top layer of dry sand. Very cool.

http://channel.nationalgeographic.com/episode/death-valley-4296/Overview#tab-Videos/06912_00

Not sure how recent this production is, but if I've seen it before, I missed this part.

Cheers!

[Sandglass]

Glad you took the opportunity! And thanks for the link - I hadn't seen that video before. The initial sounds seem more like a didgeridoo than anything. It's a while since I've checked on the status of research into dune sounds, but it certainly used to be quite a controversial topic, with different groups of researchers arguing vociferously in favour of their particular models. Time for a bit of update research, I think!

Cheers

M