Hakima:

It is important to know whether there are several holes like that in the area and whether sand is mixed with liquid/gaseous hydrocarbon? Does the hole expel sand at regular/irregular intervals? Also have a look at this link:

http://www.dailymail.co.uk/news/article-3576719/What-Workers-baffled-discovering-blowhole-desert-sends-sand-shooting-hundreds-feet-air-refuses-filled-in.html

Best

Syed

Hello,

complementing the answer of Syed:

https://en.wikipedia.org/wiki/Blowhole_%28geology%29

Dear Syed, jérôme,

So the Blowhole is formed as sea caves grow landwards and upwards into vertical shafts and expose themselves towards the surface?

Many time for your time, effort and interest.

All the best,

Hakima

Very interesting!

It reminds me of the Old Faithful geyser or any geyser. There must be some gas (air) or liquid under pressure, so that every time you throw down some sand it blocks the system and the sand plus gas or gases are expelled together.

If there was sulphur or methane in the system, people would smell it and report it. So, it is probably water or some other gas.

Worth investigating further! Make a proposal for further study / investigation. People would line up to help you and sponsor you!

See a geyser animation on youtube.

www.popsci.com/scitech/article/2002-01/old-faithful-how-it-works

Dear Michael,

Thank you so much for your response, it was very interesting and enthusiasming to start a study for understanding more this phenomenon.

Many thanks for the link.

Best regards,

Hakima

Hi Hakima,

Yes, I agree with the answer of Mr. Michael, there must be a gas in the hole.

Regards

Varoujan Sissakian

Iraq, Erbil

 Dear Hakima, 

My money is also on a gas driven system, which would be emanating a more or less continuous flow of e.g. CO2. I can imagine that throwing enough material in, will briefly reverse the flow leading to a rapid build up of pressure, resulting in a 'violent' and brief expulsion.

The pressure and flow need to be very substantial. I was looking for drilling rigs on the youtube footage, but can only see some pipeline (?) material. What I mean to say is that If this is a natural vent, then I suspect it is 'opened up' (or widened) 'relatively' recently, e.g. by drilling or digging. 

Characteristics would be: 

• Significant flow
• Unidirectional flow (outward)
• Clearly non-air dominated gas system
• If triggered: activity decreasing through time (may be years)

I'm not a specialist, but atmospheric (pressure) driven dry blowholes, as suggested earlier, would in my opinion not be able to generate the pressure needed to expel sand in this way. Anyway, in this case you would see: 

• Bidirectional flow (depending on atmospheric pressure)
• Air dominated gas system

I think we would need to be joined by someone with local experience or background info to more accurately point the finger.

But nevertheless intriguing enough. 

Kind regards, 

Kris

Hi Akima

The explanation proposed by Jérôme is only valid if the hole is very close to the shoreline. Probably not more than 100 -200m from the littoral. If not there has to be some gas escape structure (possibly methane) that builds up pressure to a value that allows it to blow out the sand.

I suggest that the hole is the top of an abandoned well originally drilled for oil and gas exploration, but finding a natural accumulation of N2 (nitrogen) that is left venting to the atmosphere.

Dear Varoujan, Kris, José & Roberto,

According to your answers, now it is very clear to me about the origin of the blow-hole and the nature of the exile gas in the hole.

Many thanks for your reactivity, time and interest to this question.

Best regards,

Hakima