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INTERVIEWER: And what about the workplace; you mentioned a vocational per
spective earlier?
PROFESSOR: That’s right. Some employees need to read information from
graphs and charts, or from tables. And it’s quite common to have
to record measurements and take readings at work.
[Q29]
Some people struggle to read instrument dials properly.
This could create a problem if you wanted
a job with the postal
service, for example, where you might need to weigh items on a
scale or balance.
INTERVIEWER: ... And I guess there are many other jobs and careers where
numeracy skills are vital.
PROFESSOR: So much so, that many employers insist on testing numeracy
[Q30]
skills as a means of screeningout unsuitable candidates.
INTERVIEWER: ... I see. Yes, as part of shortlisting. Well thank you once again,
Professor. There’s plenty for our listeners to think about.
AUDIOSCRIPTS FOR THE LISTENING TESTS
139
Section
4
Hi! I’m Dr Scott Stormwell and I’m going to talk briefly
about hurricanes and
tornadoes. I’ll be covering how and where they form, then I’ll move on to describe
the hurricane naming system; by that I mean the use of male and female first names
like Hurricane Calvin or Hurricane Julia.
And whilst we’re on the subject of names I’ll also be explaining the differences
between names like cyclone, hurricane, typhoon, tornado and twister. Some of these
names are used interchangeably to refer to the same phenomena, which
[Q31]
can lead to confusion, but I’ll be keeping to the strict meteorological
definitions.
OK, a twister is the
informal name for a tornado; so that’s easy. A tornado is
a relatively small column of violently rotating air formed over land during a severe
thunderstorm. The majority of tornadoes are less than 200 metres in diameter,
and they spin with high wind speeds, typically up to 200
miles per hour; that’s
[Q32]
300 kilometres per hour, which makes them very destructive. The tornado,
or twister, forms inside thick storm clouds when warm air, rising from the ground,
is forced to spin as it hits cold, fastmoving air from above. If the tornado forms over
water, for example a lake or the sea, it becomes a waterspout.
Tornadoes can form in any part of the world but they occur most frequently over
flat areas in America; typically in the central and southern states,
[Q33]
reducing in number towards the eastern seaboard.
The western half of
America is rarely affected. So the worstaffected states tend to be Kansas, Missouri,
Iowa and Kentucky, down to Texas, Mississippi and Louisiana, but not exclusively
these places.
Right, let’s move on to cyclones. These are massive; several hundred miles in
[Q34]
diameter, sometimes over 1,000 kilometres. Cyclones form over warm seas,
typically above 25 degrees C. As the warm, moist air from the ocean evaporates,
it rises to create an area of low pressure beneath. This depression drags in the
[Q35]
surrounding air which then swirls in the same direction as the earth rotates.
Speeds are usually lower than those in a tornado but they can still build to 150 miles
per hour or 240 kilometres, sufficient to wreak tremendous damage when the cyclone
reaches land, where it eventually dies out. The centre of the storm contains a calm
region, the eye of the cyclone, which can be tens of kilometres wide.
So what about hurricanes and typhoons? Well this is straightforward. Cyclones,
hurricanes and typhoons describe the same type of cyclonic storm. However, the
HOW TO MASTER THE IELTS
140
word cyclone tends to be used with storms that form below the equator of the
earth, whereas hurricanes and typhoons are cyclones that form above the equator.
[Q36]
Typhoon is the favoured term in Asia and Hurricane in America.
– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
Right, I mentioned at the beginning of the talk that I’d be looking into the hurricane
naming system, so that’s what I’d like to do now…. You’ve pro bably all heard names
like Hurricane Katrina and Hurricane Andrew because these hurricanes were two of
America’s largest natural disasters. But how did the naming system originate and
how were the names chosen? Before I go into this I need to make a distinction
between a tropical
storm and a tropical cyclone, or hurricane. A tropical storm is
referred to as a hurricane when the storm achieves a sustained wind speed in excess
of 40 miles per hour, that’s
[Q37]
65 kilometres per hour. It’s the tropical storm that’s given a name first. So,
for example, tropical storm William becomes Hurricane William if its speed exceeds
40 miles per hour. There’s no Hurricane William if the tropical storm dissipates before
it reaches 40 miles per hour.
Now, in the early days of weather forecasting, by that I mean pre1940, hurricanes
[Q38]
weren’t usually named; forecasts simply referred to the storm in terms of its
position, ie latitude and longitude. However, this became problematic as a means of
tracking individual hurricanes so the most severe hurricanes were given names,
though not in any systematic way. Initially, names were chosen at random, or they
might reflect the name of a place in the vicinity of the storm.
The current official
naming system originated in America in 1945, and was first applied to storms within
the Western Pacific Ocean. Only female names were chosen until 1979, similar to the
[Q39]
naming of boats and ships, after which time male and female names were
alternated.
Today, there are official lists of names for most of the world’s oceans, in most
cases at least 20 names per ocean, per year, are made available. The names are
placed in alphabetical order, so the first tropical storm of the season will start with the
letter A, and the next storm will have a name starting with the letter B, and so on.
[Q40]
Complete sets of names are drawn up to cover several years of storms, after
which time the names can be recycled.
One final thing; the names Hurricane Katrina and Hurricane Andrew will never
appear again; the name of any destructive hurricane is always retired from the lists of
names.
