Sailing over an eruption and Friday’s NtV Riddle

Image by NASA showing the eruption of a new island. The image is from seventh of January 2012, 8 days before the eruption ended.

In 1997 I spent a couple of weeks in an old rust bucket of a merchant ship in the company of navy people trying their best to look like Philippine merchant mariners. Just seeing them hurting over not being allowed to make the ship look ship shape and Bristol ready was a hoot, they were visibly in pain over being ordered to look like slobs.

We were patrolling the waters just south of Iceland waiting for the ultra shy American Boomer fish, renowned back then for never having been caught on a passive hydrophone. When we looked for the fish we heard a lot of odd sounds growling deep down in the ocean. The noise was the MAR spreading, black smokers gushing hydrothermal water and somewhere south of Iceland, a volcanic eruption took place.

A few years later I had the joy of sailing from Jakarta to Papua New Guinea passing by Krakatau and sailing along the south shore of the main Island. As we came to the strait leading to New Guinea I was brutally woken up by someone banging on the cabin roof. When I came out we had sailed into a large orange sheet of pumice.

Since that day I have been thinking on and off how dangerous it would be to sail over an erupting volcano, after all 70 percent of the worlds active volcanoes are below the surface of the ocean. So, how dangerous would it be? And what would kill you if your luck ran out?

Image from Wikimedia Commons. Surtseys northern tip in 2009.

Being blown to pieces would of course be a sure way of dying when sailing across a volcanic eruption. But, unless you are sailing over something like Surtsey being born, that will not happen and it sure would be akin to committing suicide since you would see the large detonations as they happened from afar. This type of eruption is what people associate with submarine eruptions, but they are actually quite uncommon and only happen if the volcano is close to the surface, or as a volcanic edifice has grown close to the surface.

Over the years I have heard a lot of gibbity gook about the gas emanating from a volcano could sink the boat. It is one of the most persistant myths of the ocean that gas bubbles can sink a ship. The thought behind the myth is that the gas would lower the waters ability to buoy up the ship due to the loss of density. In reality a rising gas bubble will rise with the same amount of energy as it lowers the density, and as it hits the ship that force will lift the ship in equal measure to the water the gas displaced to begin with. There is a Mythbusters episode where they tried to sink Adam Savage with air bubbles, go watch that before starting an argument with me on the matter.

Most of us watched the eruption south of El Hierro that lofted fairly large glowing rocks that stayed on the surface for quite some time. Perhaps one of those rocks would sink the boat and kill you? Actually not, a modern sailing boat is sturdy enough to survive hitting one of those stones. And the heat would not be a problem either due to the ability of the plastics used to withstand heat. Your boat would probably be scratched and a bit bubbly in the topcoat, but otherwise it would be fully operational. And, you would anyhow probably do your best to avoid hitting them.

Above a volcano there can be tremendous currents and water upwelling. As long as it is not explosive like at the Zubayr Islands eruption in 2011 you would be able to survive it, you would though not be able to control the boat efficiently, but the current would actually push you away from the center until you hit calmer waters.

Rare historical picture of the rebirt of Krakatau. Here we can see when the new volcano, Anak Krakatau, comes out of the water. Not the best place to sail over.

Now we come to the thing most likely to kill you, and that would be breathing in poisonous gases from the volcano. So, if you really are going to go sailing across an erupting volcano you should wear a scuba tank. A gas mask won’t cut it.

Now the multimillion dollar question, would I like to sail over a volcanic eruption willfully? No, only an idiot would do that. The reason is that there is always a possibility that something unexpected would happen. Let us say for instance that we have a large effusive eruption that is fairly harmless to sail over, and when you are halfway across the magma chamber roof collapses and we have a caldera forming detonation right under the keel. Also, there are a lot of things that could go wrong. But, in the end you would most likely actually survive sailing over an erupting volcano. In retrospect there was never a phase of the El Hierro eruption that would have killed you as long as you had your scuba tank with you.

Did we catch the Boomer? Well… that is classified.

CARL

NtV RIDDLE (3)

Hints added!

2 points per volcano … 

No 1 – Location of the USA’s Project Sanitary deception … (4↑ & 9↓). SOLVED Cu Lao Re (4 Islands above the water and 9 below)

No 2 – Its highest peak would make an ace vantage point. SOLVED Christmas Island (Murray Hill is the highest peak here)

No 3 – Fantasy bunny’s repeated lamment. SOLVED Late Island (White Rabbit’s song in Alice in Wonderland … I’m late, I’m late etc)

No 4 – Enterprising request for a free ride. SOLVED Vulcan’s Thumb

No 5 – Temptress set in bleak isolation. SOLVED Eve Cone (Set in the Desolation Lava Field)

No 6 – There’s no mountainside ingredients in the vegan’s stir fry. SOLVED Svartsengi (Thanks for the help Carl … its got no mountain on top and is an anagram of  ‘vegan’s stir)

No 7 – Southern hooker’s post Civil War Texas stamping ground . SOLVED Hell’s Half Acre ( Popular Texan term for a red light district following the Civil War)

No 8 – Massive North Americanwith a paradox. SOLVED Level Mountain

CURRENT POINTS TABLE:

Alison 10

Kelda 6

Frances 4

Diana Barnes 2 inannamoon667 1 Random Joe 1 KarenZ 1 mdatc 1

KILGHARRAH