TheBanyanTree: Escape from New York

[Peter Macinnis]

On 8/01/2013 03:42, Theta Brentnall wrote:
> What I am wondering about is Roger Pye and Robin-Tenant Woods, who are
> living in an area where the fire danger is labeled "catastrophic."  Even
> in California, a state given to burning itself up on a regular basis, I
> have never seen a threat level of catastrophic.  We all need to send
> them fire-proof mojo!

Right now, the air is still, here on the coast near Sydney.  That is 
ominous, because it is nearly 8 am here, and the sea breeze, a 
nor-easter should be stirring.  Out west, a body of hot dry air will 
soon start forcing through.  There will be winds up to 80 kph (50 mph) 
with single-digit humidity.

We are safe here, so I have time to provide a bit of background.  In 
1967, the original five-point scale was being developed near Canberra, 
and each afternoon, the fire research people would round up all the 
holiday students working at the Forestry Research Institute and truck us 
out to a selected site near Canberra, either west of Black Mountain or 
on what is now Belconnen.

We went mob-handed, about 40 of us, with two tankers, Macleod tools 
(also called rake-hoes), knapsack sprays, sampling equipment, 
anemometer, you name it, we had it.

Then we would light a bushfire.  This is the background to my occasional 
overly-dramatic claim to have "lit a bushfire each afternoon". In fact 
it was only on the safer ones.

The reason?  Studying the first hour or two of a fire was almost impossible.

We spear carriers (I had an entomologist's hat at the time), stood 
around the edges of the fire, and each two minutes, on command, we 
dropped a numbered marker on the fire's edge.  In between, I was free to 
gather up as much insect material that was flushed out by the fire as I 
could, so I would start with 100 empty specimen tubes in my left patch 
pocket, and end up with 100 full ones on the other side.  Back at the 
lab, these were pickled and stored in case they were needed later for 
population studies.

When we finished, we cleared the edges, burned up to them, and then we 
spear carriers were set to work spraying everything down under the 
watchful eyes of experienced fireys.

Next day, the core team would go out and map the site in 2-minute 
contours, and correlate the growth pattern with fuel dryness (from 
samples), temperature,  wind speed and direction (and maybe one or two 
other things: I was just a spear carrier).

We kept the radios on in the tankers and listened for the watch towers 
on high points about 15 miles off (we hadn't gone fully metric back 
then) to call in the fire when they saw the smoke.  They gave range, 
bearing and estimated vegetation at the site, based on the smoke, and 
were amazing reliable.  And quick.  With cross-bearings, the locations 
were close enough to get a team in fast, had it been a real fire.  The 
spotters would suspect we were out, the timing (we were public servants 
and started right after lunch) would suggest it was one of ours--and 
their bosses knew where we would be and our boss called in as soon as he 
had checked the specified location by placing their bearings on the map.

All of this gave rise to the McArthur scale, created by our boss, Alan 
McArthur and his crew.  I have just discovered at 
<http://adb.anu.edu.au/biography/mcarthur-alan-grant-10889> that he was 
born close to where I am standing right now.  The scale extrapolated up 
to the most extreme conditions known and on that, there was a sensible 
scale of five categories.

Using the available data, the McArthur index is calculated for each area 
each day, and this is converted into words: low, moderate, high, very 
high and extreme.  People know those and understand them.

Then a few years back, there came a day, a bit like this, when the index 
went to 200.  We were WAY off-scale, in "perfect storm" category, and 
nobody was ready for it.  Using the wisdom of hindsight, such a high 
score is now called "catastrophic".

That word gets your attention.  So does the fire danger map you can see 
here: <http://www.rfs.nsw.gov.au/dsp_content.cfm?cat_id=1109>.

Back when the internet was young, I sent off some posts about the fires 
attacking the area around Sydney in 1993, and later, combined them into 
one of my first web pages.  It's still there at 
<http://members.ozemail.com.au/~macinnis/fireweek.htm> and is a useful 
background to bushfires 101.

I have yet to tell the tale of how, in 1970, I attended a fire which 
entailed chasing it up a cliff.  I was in the company of drunks and 
idiots, so for once I felt quite competent, but I damn near fell off 
that cliff, dodged several dislodged rocks and at one point, had to 
seize a burning stump to steady myself.

The scar on my hand lasted for years, but we caught the fire at the 
cliff top and knocked it out before it could spread far enough in from 
the edge to take off.  It's simple physics, really, but not a barrel of 
laughs.  Since then, I have restricted my interests to more distant 
observation, teaching kids the signs to look out for, and what to do if 
threatened.

They also serve who only stand and babble.  Or type.

The trees are stirring outside, so now the trial begins.  It will be 43C 
here today (107F), so it's time to go around, and close the windows, 
because lucky us, all we need do is stay cool and hydrated.  Hopefully, 
without using electricity, because others will need it desperately.

Good luck, Robin and Roger!

peter

-- 
Peter Macinnis            petermacinnis at ozemail.com.au
Cross-cultural watercraft maker, polymorphic monohulls
and Delphic coracles a specialty, also Tribo-economics
http://oldblockwriter.blogspot.com/