Thursday, 29 November 2012

6. Limnic Eruptions and Exploding Lakes


Part of the plotline of “The Blue Angels” concerns itself with natural disasters, so I set myself the task of researching different types. We can all name some: earthquakes and tsunamis, volcanic eruptions, tornadoes and other types of storm, forest fires, landslips… the list goes on. The chances are that most of you will remember seeing reports of many of these on television, or in the newspapers, even if the exact date or location eludes you. Most of the world’s population lives in the shadow of at least one type of natural disaster and with climate change tightening its grip, that proportion is increasing all the time.

Of all the ways in which Mother Earth can kill, however, the phenomenon of the limnic eruption is one of the rarest - there have only been two in recorded history. What might be surprising then, is that both of these were within living memory, and both occurred within a short distance of each other. In a limnic eruption, vast volumes of gas are suddenly released from a body of water, suffocating surrounding animals and people. In 1984, Lake Monoun in Cameroon erupted, which killed 37 people. In 1986, neighbouring Lake Nyos erupted too, killing between 1700 and 1800 people. The second of these eruptions is known to have produced 80 million cubic metres of carbon dioxide. So, what is it about these two lakes that makes them so dangerous? Could the same thing happen at Windermere, Huron, Como, Baikal or Victoria?


What Makes a Lake “Explode”?

For a limnic eruption to occur, the lake must be saturated with dissolved gas. In Lakes Monoun and Nyos the gas in question was carbon dioxide, but at Lake Kivu (a limnically active lake that lies on the border between Rwanda and the DRC), methane is also a worry. The dissolved gas may come from volcanic sources under the lake bed, or from the decomposition of organic material, or it may be dissolved in the lake’s inflow. While the lake is building up to this point, it behaves like an unopened soda bottle: gas under higher pressure dissolves much more readily than gas at lower pressure. This is why bubbles in a soda can only form once the can is opened, as the release of pressure forces excess gas out of solution. In a lake, pressure increases steadily with depth, reaching a maximum at the lake bed. Gases such as carbon dioxide also dissolve more readily in cooler water, which is typically found at the lake bottom. Hence, a large deep lake can dissolved huge quantities of gas.

Once the lake is saturated with gas, it becomes unstable, only requiring a suitable trigger event to set off an eruption. In the case of Lake Nyos in 1986, landslides are suspected but a volcanic eruption, an earthquake or even wind and rain could trigger similar events in susceptible bodies of water. The trigger event displaces some of the gas-saturated water upwards, lowering its pressure and forcing it to release some of its dissolved gas as bubbles. These bubbles rise, pushing more water ahead of them, which in turn is forced to surrender some of its gas and so on. In this way, a column of rising gas quickly forms that pulls water and sediment from the bottom of the lake by suction, causing a runaway process. The released gas and sediment-rich water erupts onto the lake’s surface, giving it a boiling, dirty appearance. If the released gas is heavier than air (as is the case with carbon dioxide) then it cannot rise further and instead begins to spread out over the lake’s surface and ultimately onto surrounding land.

Fortunately, this type of eruption is rare. Firstly, there must be a source of gas, predisposing regions with volcanic activity. Secondly, lakes in the world’s temperate regions undergo regular “turn over” in response to seasonal surface temperature changes. These changes encourage water from different depths to mix, causing gases to be released much more gradually and preventing saturation. Finally, the lake must be deep in order to offer the high pressure, low temperature conditions that are favourable to limnic activity. Together, these factors imply that limnic eruptions are only possible in deep, stable, tropical volcanic lakes.


What are the Consequences of a Limnic Eruption?

As the released gas flows across the lake’s surface and onto neighbouring land, it pushes breathable air upwards. Carbon dioxide acidified body fluids and is toxic even at relatively low concentrations. Unlike other tasteless, colourless gases such as nitrogen, high levels in the blood causes the respiratory system to gasp, in an attempt to secure the required oxygen, thus speeding up its toxic effects.

At Lake Nyos, the gas cloud descended from the lake into a nearby village where it settled, killing nearly everyone. Fatalities were recorded as far as 16 miles from the lake. Some of the bodies exhibited a change in skin color, leading scientists to believe that the gas cloud may also have contained a dissolved acid, but this is uncertain. Many victims were found with blistered skin. This is believed to have been caused by low blood oxygen. At the lake’s edge, vegetation was damaged or destroyed by a five metre tsunami. Vegetation further away was largely unaffected, as would be expected from a temporary glut of carbon dioxide.

In one final twist, many victims were also found with what appeared to be frost bite: the gas released from the lake bottom would have been very cold. Victims would have experienced a sudden and prolonged wind of bitter cold “air”. Some survivors reported a smell of rotten eggs and feeling warm before passing out. This can be explained by the fact that, at high concentrations, carbon dioxide acts as a sensory hallucinogenic.


What Can Be Done?



In 1990, a team of French scientists began to experiment with a controlled degassing of Lakes Monoun and Nyos. Under this scheme, a long tube is inserted vertically into the lake, with its upper end standing clear of the lake’s surface. A small amount of gas-saturated water is then pumped upwards, causing it to give up its gas. The gas then rises as bubbles, pushing water ahead of it as before. In open water, this effect spreads outwards as well as vertically, to create the runaway reaction described above. Inside the pipe, however, this outward spread is not possible, and so fresh water is drawn into the bottom of the pipe to create a kind of siphon. Gas and water emerge from the top of the pipe and gas concentrations in the lake are slowly lowered, reducing the risk of a further eruption.

Degassing Lake Nyos

Sunday, 18 November 2012

5. The Blue Spruce Routes

The plot of “The Blue Angels” demands that two reluctant characters be smuggled into the US from the UK using small business jets. I had an idea that these tiny craft might lack the range for a direct crossing and wondered how it might be done. After all, as David Lloyd George once remarked, “there is nothing more dangerous than to leap a chasm in two jumps.” It was time for more research. First, I had to decide which type of plane Joshua Hayle, the novel’s “villain”, might own, or be able to dragoon into service at short notice. Hayle is a man of means and connections, and is not someone to whom compromise comes easily. It seemed to me that the iconic Lear Jet, beloved accessory of rock and movie stars, would be the obvious choice. After some research into this area, I decided on the Lear Jet 85, a new member of the Lear Jet line. I did not intend to name the plane in the novel, but it was vital that I had sufficient reference material to enable realistic descriptions of it and its interior, and to calculate likely flight times. I downloaded brochures and technical specs from the Bombardier Aerospace web site and discovered that the plane’s maximum range was 3,455 NM, give or take. This sounded sufficient but, given the number of provisos attached to this figure, I had doubts. I consulted a number of on-line forums to see if it was possible and, in doing so, “discovered” the eponymous “Blue Spruce” routes. These transatlantic routes, which pass over vast stretches of boreal forest and which land in a number of unfamiliar destinations en-route, felt perfect for a clandestine operation. I picked one and researched it so that I could describe what a passenger travelling one of these routes might see from his window.

The route I chose begins in Prestwick in southern Scotland. This airport’s main claim to fame is as the only patch of the United Kingdom upon which Elvis Presley set foot. Rumours persist of a day in London in 1958, guided by Tommy Steele, but Prestwick can boast photographic evidence from 1960 when Elvis’ army transport plane touched down to refuel on its way home. From Prestwick, my chosen route lands in several exotic locations.

Reykjavik, Iceland

 Iceland is firmly on the tourist map these days and its colourful houses are readily recognisable.
Iceland's Colourful Houses
Reykjavik Aiport from the Air
The airport is still an impressive sight from the air however.


From Iceland, and its relative familiarity, the route continues to Greenland, a vast, apparently empty landmass that has captured my imagination since I was a child. 

Kangerlussuaq, Greenland

One of the most surprising things about Greenland is the fact that is owned by Denmark. I don’t know the history; that’s something for another day. Another surprise is that Greenland is home to a permanent civilian population, numbered in the tens of thousands. If you look at a map of it in any reasonable world atlas, you will see several settlements indicated around its south coast, many of which bear names that are redolent of Inuit culture. I was vaguely aware of these facts already, but I had no idea that Greenland also hosts a number of international airports, one of which is at Kangerlussuaq. I found a travelogue that was posted by a group of friends who had made the journey eastward. In one picture, one member of the group is seen sitting in a tee-shirt, in a comfortable and modern-looking departure lounge, about to tuck into a huge burger, just like any traveller in any airport in the developed world. The difference here was that the burger was of musk-ox meat.

Kangerlussuaq Airport, Greenland
That traveller’s tee-shirt got me thinking about temperatures. He may have been travelling in the height of summer, but “The Blue Angels” is set in October. He was also prepared for his journey; my characters are not. A further search revealed that average daily temperatures at this airport for that month range between -2C and -10C. That’s cold - especially for someone who is dressed only in thin clothing. I imagined how such a passenger might abandon a spur of the moment escape bid to a distant terminal in favour of the warmth of a second plane should a changeover be required in such temperatures.

Iqaluit, Nunavut, Canada

The final exotic location on my chosen route is Iqaluit, with its bright canary yellow airport terminal.
Iqualuit Airport, Nunavut, Canada
Nunavut is Canada’s newest province and is known as “the homeland of the Inuit people”. The daily average temperature here in October is a cool -5C.

The Onward Journey

From Iqaluit, westbound planes may take individual routes, as the Atlantic is now behind them, and landing and refuelling sites are much easier to find.

Conclusion

I had never given any real thought to the problem of crossing the Atlantic in anything other than an Ocean liner or a huge passenger plane. I had also assumed that Greenland and the northern reaches of eastern Canada were untamed wilderness. Now, thanks to the research that I have undertaken for “The Blue Angels” I know different. I also have an idea for a very different holiday.

One day.

Perhaps.

Wednesday, 7 November 2012

4. Keeping Track of Progress

So, let’s suppose that you followed some or all the tips in my earlier “Getting Started” post, or that you worked things out for yourself, and that you’re now writing. How do you keep track of progress? How do you keep track of all the questions that crop up while you’re writing? No matter how thorough your research, there will always - I suspect - be questions that crop up that will require an answer but do you really want to break your stride to answer them now? If not, you’ll need somewhere to keep them all so that you can go back to them later.
When I first started to write "The Marguerite Effect" I had no real plan and, as it was going to be a short story, it was all in one document, so I could easily get a word count. If I found that I needed to answer a question, then I could simply include the question in the text: (e.g. “It was <<the date of the night before the battle of Quatre-Bras>>”) and carry on, to revisit the question later. This was fine until I had reached 25,000 words and realised that I had a lot more to say. “Marguerite” was becoming a novel. At first, I didn’t really know what I needed to know, but I had a few ideas. I’d need to know: how many words were in each chapter and how many scene-breaks, for example. I’d also like somewhere to go for a simple, broad-brush prĂ©cis of the chapter, to help me find it again quickly should I need to go back to fill in the answer to a question. A word count for the whole novel is a valuable thing to know, as is the average length of a chapter. With these questions in mind, I began to develop the Excel workbook that I continue to use for “The Blue Angels”. For simplicity, I keep the workbook in the same folder as the novel itself, or close by (in a parent folder, for example).

My Writing Workbook

I’ll attach a copy of the workbook at the end of this post for anyone who’s interested. If you do download it and use it, I’d be interested to hear of any enhancements you make.
In my workbook, there are a minimum of two worksheets, one showing each chapter in a separate row, and the other, the “To Do” sheet, that shows my questions and thoughts. I should mention at this point that the “thoughts” in the second worksheet are quick things that have a bearing perhaps on this and/or later chapters. They aren’t detailed research results: I keep these in OneNote.

The Columns of the Word Count Worksheet

A.    Part: The Blue Angels is arranged in parts (all within the one book/ebook). This indicates which part contains the chapter.
B.     Chapter: This contains a hyperlink to the document that contains the chapter in question. Hyperlinks are easy to create in Excel.
C.     This hidden column is used to calculate column D. The formula in this column searches the “To Do” worksheet for unresolved items:
(for row 27) =MATCH(G27,'To Do'!A:A,0)
D.    See the "To Do" Worksheet: This column interprets the result of the calculation in column C and, if it indicates the presence of unresolved “To Do” items for the chapter, displays a hyperlink to the first of them. This gives a ready visual check of those chapters that require a little more research and makes it easy to locate pertinent questions.
E.     Draft: You will visit and revisit your work. This is the revision number of your chapter. It’s up to you how big a change constitutes a new draft: you may decide that any edit requires a new draft number, or you may decide that a substantial re-work is required. I tend toward the latter: any change that feels big enough to require a fresh proof-read gets a new draft number.
F.     Read By: I use this to tell me who has proof read this chapter. I use X to indicate that no-one has read it and <WIP> to indicate that I am currently working on this chapter. Otherwise, I simply add an initial. You may wonder why I use the <WIP> convention - after all, we’re always working on the last chapter aren’t we? This might be true during the first draft but when you’re re-drafting, it almost invariably won’t be. Placing <WIP> in this column is a useful habit as it clears it of proof-reads before a rework and reminds you where you were when you last finished work.           
Hint: I write on the train and so am often forced to stop writing at inopportune moments. If this is the case, I quickly write <HERE!!> into the document at the current location. This makes it easy to find out where I was even if I have to shut down the computer until the next day. This is a little risky, as I might leave one behind, but I find it very useful and worth the risk.
G.    Ch. #: (The chapter number). This is required to work out the average chapter length and to search the “To Do” list.
H.    Start Date & Time (Local): This column is used in the fight again continuity errors that I alluded to in an earlier post. This marks the date and time when the action described in the chapter begins. For me, the year is immaterial, so I just pick one and stick to it. I also opt not to display the year here. You must do what suits you.
I.       End Date & Time (Local): This column marks the date and time when the action described in the chapter ends.
J.       GMT Offset (Hours): “The Blue Angels” is set in England, Texas and (unless plans change) Italy. I am physically located in England, so GMT is my natural time zone. This column helps me track of the novel’s timeline in absolute GMT terms.
K.    Location: This describes where action described in the chapter actually takes place.
L.     Scenes: How many scenes are there in this chapter? I tend to use a centre-aligned *** to mark a scene break, but there are other conventions.
M.    Words: How many words are in this chapter? Microsoft word gives you this free and it’s a valuable piece of information: not only can you track the length of your novel; you can check if the chapters all conform to the novel’s “rhythm”.
Hint: It’s broadly accepted that a novel’s chapters should be of similar length. This isn’t a hard and fast rule, but it is something of which you should be aware.
N.     Pages: This is the number of pages that this chapter occupies and will always be an “approximation” as there is no single correct value: it depends on the format and font size of your printed book, or the settings of the ebook reader. Kindle appears to use a figure of around 300 words per page in its ebook listings. I simply use what Word gives me. It’s up to you.
O.    Running Word Count: How many words have you written up to and including the end of this chapter?
P.     Running Page Count: How may pages have you written up to an including the end of this chapter?
Q.    Novel Progress: How far into the novel are you? This the percentage of the novel, in terms of word count, that you have written so far, including this chapter. To give this figure meaning early on, I assume that the novel will be at least 85,000 words on completion, hence the formula (for row 2, e.g.): =I2/(MAX(F$1,85000))
R.    Avg. Chapter Length: How many words are there in an average chapter up to the end of this chapter? This helps you gauge how well you’re keeping to your novel’s “rhythm”.
S.      Chapter Summary: This column gives a very brief description of what happens in the chapter, to help you to find a particular one more quickly when reworking.

The Columns of the “To Do” worksheet.

A.    Chapter: This is the number of the chapter to which the “To Do” item is linked.
B.     To Do / Question: This is the question or “To Do” item itself. It describes the query/issue.
C.     Resolved? This is a simple “Y”/”N” field: “Y” implies that the item is resolved and need not appear as a hyperlink in the main worksheet. “N” implies that the item is still open.           
Hint: I have chosen to show the number of unresolved items in the header of this column, as a ready reckoner. The value of header cell is given by the formula:
=CONCATENATE("Resolved? (", COUNTIF(D2:D2001,"N"), ")")
D.    Resolution / Answer: This is the resolution to the issue raised, or the answer to the question, as appropriate.

How To Use the Workbook

It’s easy to use the workbook described above. Simply open it in Excel. When you start a new chapter, copy a row of the main worksheet into the clipboard, paste it in (usually at the bottom) and edit the values to suit. Copying and pasting is used to preserve the formulae. Similarly, to raise a new “To Do” item, copy and paste an existing row and tailor it. If I want to raise an issue that is more general (i.e. that applies to the whole novel and not just a single chapter) then I simply specify chapter number zero in the appropriate column. When you have an answer to the “To Do” item, write appropriate text into the resolution column and set the resolved column to “Y”. It’s as simple as that.
I find that it’s best to open the workbook first and then to use the hyperlinks to open the actual Word documents. This makes it more natural to update the word counts etc. once I finish work on a chapter.

I hope this little glimpse into my working methods is helpful to you. Please download the Excel Workbook (from which all spoilers have been removed!) and see what you think. I'm new to Google Docs etc. so please bear with me if the link doesn't work.