I want you to imagine, that you and your friend went out on a certain day, to chill out close to a lake. In the beginning everything seems alright, the sun wasn't too much, the wind was perfect, blowing at just the right speed. The day seems so perfect. Then all of a sudden you start perceiving a very bad odour, like the smell of rotten eggs, and the temperature becomes unnecessarily warmer. And within minutes it feels as if all the oxygen in the world have disappeared and there is none, not even a drop left for you to breathe.
You struggle for air, hoping to find it, but you can't. Instead you observe that you are feeling as if you are going to blow up. You start to panic, wondering why you can't breathe. Then, with all the strength you got, you manage to turn your head to look at your friend to know if he is observing what is happening to you only to see his eyes trying to pop out of his eyes, and him asking you what is going on, and also pleading with you, with signs to come and save him.
Source:- Picture by Wikicommon CC BY-SA 3.0
At that point, you can't even get the strength to stand up, you can't even run to your car. Then you start feeling dizzy, very dizzy, now, you are hallucinating, hallucinating. Then your eye lids closes, then black out.
This little imagination you just had now is exactly how most people feel, and how they die from suffocation as a result of a Limnic eruption. In this article, I will be writing on Limnic eruption, and I will be telling us how a Limnic eruption occurs, what causes it and what to do during a Limnic eruption. It's going to be quite an interesting section.
LIMNIC ERUPTION
Limnic Eruption is one of the most unusual natural disasters. It has only been recorded to have occurred twice in human history, and it was quite disastrous. Also called "lake overturn" because of its mode of occurence, Limnic eruption is the type of natural disasters in which there is a sudden eruption of carbon dioxide that are dissolved in Lake waters. This erupted CO2 forms a gas cloud around the area of occurrence and goes on a mission of suffocating every single human and animal living in that region. This CO2 erupts with so much force up to the extent that it causes an overturn, displacing enough water with force which results to the formation of tsunami.
Even though that Limnic eruptions are related to volcanic eruptions, they are two separate natural disasters. Limnic eruptions have been known to be prompted by explosions, volcanic eruptions, earthquakes and other activities that shakes the earth to its core. For a lake to be susceptible to Limnic eruptions it must possess these qualities.
The lake must be very close to areas where volcanic activities occur.
Even though it's close to volcanic areas it must not have a direct interaction with volcanoes, and it should have a cool lake bottom.
The water that flows into the lake must be saturated with CO2.
Lastly, it's should have two thermal layers, the upper and lower layer whose level of CO2 saturation differs.
WHAT CAUSES LIMNIC ERUPTIONS
As stated early, the first prerequisite for the occurrence of Limnic eruption is that the lake must be saturated with CO2. It is also believed that the lake should also have a high concentration of methane gas (CH4).
The CO2 in these lakes are mainly supplied by decomposing organic matters in the lake and also by volcanoes. To better understand how CO2 is dissolved in water, and how erupts, I will be making an illustration using a bottled coke drink. You already know that Coke, Pepsi and some other soft drinks contain CO2 which is dissolved in them at high pressure to act as preservatives. Normally, Before you open a coke bottle, it look so calm and innocent as if it has no potential of spoiling your outfit. The reason why the CO2 doesn't explode in the bottle and spoil your outfit even when it is shaken vigorously can be explained by Henry's law.
Henry's law states that at constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.
From what Henry postulated, gases, like CO2 dissolved readily in liquid at high pressure, the bottle in which the carbonated coke drink is placed in provides and retains high pressure, invariably the CO2 remains dissolved in the drink. But immediately the bottle cap is removed, there is a pressure drop. At low pressure, CO2 doesn't remains dissolved in the liquid, thus it gets released and leaves the solution. In unshaken cokes and other carbonated drinks, this release is noticed as bubbles.
Now, it is observed that If the bottle was shaken vigorously before its open, a "carbonated drink eruption" occurs, unlike what is observed when the bottle was opened without being shaken.
The reason for this, is that for an unshaken soft drink, the CO2 the gets released gradually, this is noted by observing the bubbles. But for the shaken one, all the CO2 in the bottle tries to leave at once causing the drink to spill on your clothe instead.
Comparing this with what happens in Limnic eruption, the first thing we need to know is that these CO2 that gets dissolved in these lakes are generated at the bottom of the lake from the decomposing of organic materials and volcanic activities. From Pascal's work on pressure, pressure of a column of liquid is known to increase with depth, thus the pressure is highest at the bottom of the lake and the deeper the lake, the higher the pressure.
Water bodies like lakes are quite large, this insinuates that a very high amount of CO2 can be dissolved in large, deep lakes. The rate by which CO2 dissolves is also proportional to the temperature of the water. Thus the cooler the water, the higher the amount of CO2 dissolved. Since CO2 dissolves more as the temperature reduces, it is not surprising that an increase in the temperature can cause the release of CO2.
Calm down, Calm down. I know you are about to ask me why limnic eruptions do not happen everytime since an increase in temperature results to the release of CO2, and lakes get heated up by the sun everyday. Don't worry, relax, I will soon explain that.
Alright, let's continue.
As observed from the "coke bottle experiment", for the unshaken bottle, when the bottle cap was removed the gas gets released, but gradually. The same occurs in the lake. Some of these dissolved gases get released as the temperature of the lake increases, but gradually since there is no real disturbance of the lake. But if the lake is disturbed, what happens when the shaken bottle of coke was opened, would be observed.
Thus, it's worth noting that two conditions have to be satisfied for Limnic eruption to occur. They are;
The lake has to be saturated with CO2.
The eruption needs to be triggered by an event.
The saturation of the lake by CO2 makes it very unstable, thus, what is just needed for the occurrence of a Limnic eruption is just an event to act as a trigger mechanisms. These events may include earthquake, volcanic eruption, landslide, wind and rain storm, and other phenomenons known to shake the earth to its core. What the trigger does is to push a part of the saturated water to a higher point in the lake, to a point where the water pressure is not high enough to keep the dissolve CO2 in the solution.
Pixabay.com: A volcanic eruption is a major trigger of Limnic eruption
When this occurs, immediately bubbles starts to form in that areas, and due to the buoyancy of the bubble, the saturated water is lifted to a higher point in the lake where the pressure is even lesser than the former, thus, a larger amount of CO2 is released out of the solution. This process forms a column of CO2 gas. At the same time this occurs, the other part of the saturated water at the bottom of this column formed is pulled up by suctions, and this movement results to the release of CO2 also. The CO2 released pours in to the air, and due to the upliftment of the water body, there is high likelihood of a tsunami occurrence.
The reason this type of eruption rarely occur is due to the fact that most lakes are not located close to the source of CO2 like volcanoes, and also, not so many lakes are quite deep enough to dissolve a very large volume of CO2. Another reason is based on the fact that most lake are mainly holomictic, i.e their layers mix regularly. This mixing prevents the building up of the dissolved gas unlike what happens in meromictic lakes in which the water layers do not mix. Limnic eruption occur mainly in meromictic lakes and the number of meromictic lake is the world is not that much. The ratio of the number of meromictic lakes to that of holomictic lakes is 1 : 1000. Thus, it is hard to find a meromictic lake, talkless of one close to a CO2 source.
THE EFFECT OF LIMNIC ERUPTION
Every time a Limnic eruption occurs, the CO2 formed forms a cloud above the Lake, gases are known to diffuse, thus some of it diffuses to the surrounding region. Now, remember that CO2 gas is heavier than the atmospheric air, therefore it has more tendency to sink to the ground.
Being more closer to the ground, it pushes the air humans and animals can breathe upwards, starving every livestock and humans in that region of oxygen. This action, which last for hours causes all living thing within the reach of the CO2 cloud to suffocate and die.
Am telling you, Mehn!, It takes an act of God for someone to survive from a Limnic eruption. The humans brain can manage to survive without oxygen for only 6 minutes after which it starts dying.
Just try to hold your breathe and see if you can last up to 6 minutes. I just remembered one of my teachers in primary school. Apart from the fact that she gives me poor grades, in three of my terms in her class, for some other reasons I don't really like her. In one of her classes, she ended her teaching by saying.
"Class, remember, obedience is better than sacrifice, now, I will like us to do a bit of an exercise, in test of that..
'Breath In... Out.. Breath In... Out...
Breath In..., Wait, I will be right back!'.
And with that she left the class. Nnahh!, As good pupils we tried, God! we tried. I couldn't even hold my breath past 30 seconds. Then I thought, to hell with being obedient, I better stay alive and pay the sacrifice. I don't need to tell you anymore an incident in my life where being disobedient saved me, in case you plan on asking me, because this is one. It took her more than 20 minutes to come back to the class, and then she said yelled "Breath Out". Mehn, I don't just like her.
That's by the way, now let's get back to our discussion.
Apart from the fact that the CO2 released, deprives all all living things that breath in oxygen, the oxygen they need, it also causes CO2 poisoning. This is because CO2 in its excess makes the humans bodily fluids to become very acidic. You can't do without breathing, and the body is not selective of what it breathes in at that moment it suffocates. As the victim of Limnic eruption gasps for air, they can't help but to breathe in the CO2 gas close to the ground. Breathing in of carbon dioxide causes the victim more harm than good.
Due to the increasing level of CO2 and low level of oxygen in the blood of the victim, within minutes the victim develops pressure ulcers. This pressure ulcer can be observed by the blisters on the skin of the victim which develops within minutes of the incident. Also changes in the color of the skin is also observed.
Another effect caused by this release of CO2 is the reduction in temperature, this is because the carbon dioxide which is released from the lake is at a lower temperature when compared to the to the temperature of the surrounding air. The drop in temperature causes frostbite. Frostbite on itself is terrible, now try to imagine what happens when it occurs alongside Limnic eruption.
PREVENTION AND SOLUTION TO LIMNIC ERUPTION
After the 1984 and the 1986 Limnic eruptions, man have been very careful to prevent any future CO2 build up in lakes, and have kept on doing his best to see that limnic eruption is prevented from occurring. Man have achieved this feat by discovering a way to remove the gas from the lakes by the use of siphons (also known as pipe).
The process
The pipe is inserted into the lake with the upper end of the siphon above the water surface. Due to this action, the water which is saturated with CO2 enters the siphon from the bottom, climbs up the pipe and then, it flows out of the pipe from the top.
As I said earlier, dissolved CO2 comes out of a solution at lower pressure, thus as the CO2 flows out of the top of the pipe it is released due to the reduction in pressure. This process is done gradually and slowly, and as the CO2 leaves the water it is observed as bubbles.
The water climbs up the pipe due to the pressure difference between the two entrances of the pipe, and with the help of the natural buoyancy which is a property of the bubbles, the water is drawn up through the pipe at high speed. This causes a large fountain to be developed on the surface of the water.
This is a continuous and self sustained process since the water which is been degassified acts as a pump, therefore, it keeps drawing out more and more water out of the lake up the pipe. This just the same as what happens during the natural eruption, but this procedure removes the gas gradually without causing harm. Quite a large number of pipe is required to render the lake safe. This is because each pipe used has a definite pumping ability and can't pump more than at a giving rate, which invariably means only a little portion of the lake is degassified.
Inadequacies of this method
Even though this process seems like a very good idea, it still haves it's defects and cost. For one, the pipes and other electronics that are needed for this extraction needs to be serviced always due to the corrosion that occurs on them as a result of the acidic nature of the water. Remember that CO2 is an acidic oxide. This requires a lot of money. Another problem with this process is that it still involves the release of CO2. The CO2 released forms a layer of unbreathable air on the surface of the lake, which might affect the wildlife there.
Example of places where this procedure have been tried out is on Lake Nyos and Lake Monoun, each currently degassified with the use of three pipes with very large diameter. But all that this pipes have managed to achieve is to remove an equivalent amount of the CO2 gas that gets dissolved in the lake yearly, (since dissolving of CO2 in lakes is unavoidable).
IMPENDING DOOM
The matter that is currently a source of worry for the whole world is the "time bomb" lake Kivu. I bet you are wondering, right now, why it is a cause to be worried uabout. Don't worry, let me tell you. Lake Kivu alone is 2,000 times larger than Lake Nyos, with a depth that is more than that of Lake Nyos. More than 5 gallons of CO2 dissolves in every gallon of water. Now Imagine the amount of CO2 that would be released if a Limnic eruption occurs.
Picture by Steve Evans - Wikicommons CC BY-SA
Lake Kivu
The terrible thing about this is that the lake is located in a very populated area with more than 2 million people living along its shore. Even though that it is not yet completely saturated, it is already heavily saturated, and it can reach saturation point anytime soon, which is the more reason why we should be concerned about it the more. The indication of the increment of CO2 and the likelihood of Limnic eruption occurring is the increment in the surface temperature of that region (up to 0.12•C increment every 10 years) and also the high rates of methane dissociation.
Another reason to be concerned is the fact that it is located close to an active volcano, Mount Nyiragongo, and other active volcanoes. Volcanic eruptions triggers volcanic eruptions. The last time Mount Nyiragongo erupted was in January 2002.
I know that right now you will be asking why this lake have not been degassed in the same way that these other lakes (Lake Nyos and Lake Monoun) are currently undergoing degassification. Well, the reason is because of the size of the lake. It is 2,000 times more than Lake Nyos which is barely degassed by 3 very large pipes. Now to degassify Lake Kivu, large amount of money is needed, allegedly, hundreds of millions of dollars. Looking at it in another light, maybe the reason why nothing have been done yet is because our charity organizations don't have that kind of money yet to take up the project themselves, or that the whole world can't afford to make that kind of expenses right now. I really don't know. But, I quite agree with you that whatever the expense is, we should always having it in the back of our minds that we are talking about 2 million lives here.
MAN AND LIMNIC ERUPTION
Based on my own opinion, I don't think that there is any other worst way of dying than death due to suffocation, with every single part of your body yearning for it's number one need. Limnic eruption have only happened twice in human history, in 1984 and in 1986, killing quite a lot of people in the most terrible way the human mind can imagine. In this section, I will be telling us how those two events happened.
It happened on August 15, 1984. At first, after it occurred, the whole world thought it was a terrorist attack that killed the unfortunate victims of the eruption. It was only till the second Limnic eruption occurred two years later that we got to know what really happened. When it started, the survivors said they heard loud noises, and everywhere smelled of rotten eggs, then they felt as if as someone was trying to suffocate them. 37 people died in the first eruption, which occurred in Lake Monoun.
The victims of the eruption were observed to have suffered skin damages like discoloration. All the vegetation in that area was leveled down by the tsunami which developed as a result of the eruption. Only few people survived, of which includes two passenger of a truck carrying twelve people. It so happened that the passengers of the truck were quite unfortunate and their engine decides to stop working while they flee. When the engine stopped to work, the passengers of the truck came out of the truck and they got suffocated. The two people that survived, survived due to the fact that they were sitting on top of the truck, and their position allowed them to breathe in a little oxygen.
On the 21 of August, 1986, the second Limnic eruption occurred. No one knows what really triggered the eruption, but what ever it is that caused it, the result of the eruption was catastrophic. It began when the lake exploded, pushing a fountain of water that is as high as 300 feet up into the air.
This caused a sudden release of thousands of tons of carbon dioxide traveling at the speed of 60 mph for more than 15 miles. Within few minutes, 1,746 people and more than 3,500 livestock were suffocated and killed by the carbon dioxide. Out of the 800 people that resides in Nyos, only 6 people survived.
HOW TO SURVIVE A LIMNIC ERUPTION
Well, I would have suggested that you should never go close to lake or even live 15 miles close to it, but I know that is not possible since most people love fishing and swimming. Thus, that is not really an option.
Considering other alternatives, following these few rules will really help you to survive an eruption.
Always be observant of your environment. Pay attention to the news, so that you will be informed when a Limnic eruption occurs.
Before hand make plans with your family and decide amongst yourselves were you all are to meet, if natural disaster happens to separate you guys.
Once you notice a sudden feeling of.warmth or if the surroundings starts smelling like rotten eggs, just know that Limnic eruption and occurred and be aware that what you do from that very moment would determine if you will see the next day.
Hold your breath, don't breathe. Even though that all your body instinct tells you to breathe, don't. This is because the first thing Carbon dioxide does when it enters into your system is to cause you to hallucinate, and in that way, it over powers you, causing you to keep breathing it in into your system till it poisons and suffocates you. So, hold your breath.
The next thing to do is to get out of that area. I pray it happens when you are in a car or a motorcycle, because you can't run on foot. Have you ever tried running while holding your breath? It is almost impossible. And if you are in a car, wind up the windows of the car immediately.
Picture by Jack Lockwood - WikiCommons CC BY-SA 3.0
A cow suffocated as a result of Limnic eruption
Drive away very fast and get yourself as far as possible (more than 16 miles if possible) from the lake. Get to a higher ground. Remember that CO2 is denser than air, and it stays close to the surface of the earth and displaces breathable air upwards. Thus all you really need to do is to climb above the "CO2 cloud".
If during this period you are fortunate to have a source of oxygen on you, You can take a sip ( if it is an oxygen boost) or a breathe (if it is an oxygen supply) at intervals. It would increase your chances of surviving.
In all these, the first and the most important thing to do is to pray.
MY THOUGHTS
I don't really need to overemphasize on the fact that something needs to be done about Limnic eruption, and quite soon, even if not for anything but for the fact that we are currently threatened by the Lake Kivu, and more than 2 million lives is at stake here. We have already examined the current method of degassifying of lakes and we observed that even the small amount of gas that is released forms a cloud of CO2 at the surface of the water posing a threat to the lives of the animals living in that lake. Thus a better solution is needed.
Carbon dioxide is of great importance, it's uses are quite numerous. In chemistry we use it to control the temperature of reactors, we also use it in making of dry ice which is used in refrigeration. It is also used in waste water treatment and as a coolant in the environmental testing of electronic devices. It is also used as fire extinguishers since it doesn't support combustion. It is used in making of soft drinks, and when liquid carbon dioxide is vaporized, it is used for blasting of coal mines. Since CO2 have so many uses why don't we discover a way of exploiting Limnic eruption to our advantage, and find a way to make use of this great amount of CO2 produced?
Rwanda makes use of the methane which is trapped in lakes as a fuel source for the generation of electricity, which is quite an achievement since it degassifies the lake as it provides source for energy. Since we know that when degassification is done, the CO2 released forms a cloud close to the surface of the water, why don't we produce a machine that would suck up the whole CO2 formed into a reservoir and then use the CO2 for all these uses listed above instead of wasting time and resources producing CO2?
To achieve such a machine won't be that hard. Come to think of it, haven't we established already that the released CO2 pushes breathable air upwards while it remains close to the water surface. Thus, we can produce a machine like a vacuum pump which would suck up the gas as it is been produced at that ground level, and then use the CO2 produced for our benefit. Thus, there would be no CO2 to suffocate anyone. This idea can be applied in the Lake Kivu situation and help to safe the lives of 2 millions people. Man is a strong being. I believe we can achieve anything we desire once we out our minds to it. And if we can allow our minds to believe in this possibility even just for one minute, I bet you that Limnic eruption won't be something to worry about anymore.
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