Geoscience Reference
In-Depth Information
Texas, on 8 September 1900, killing 6000-8000 people.
A rapidly rising storm surge trapped inhabitants, who
then either drowned as waves swept through the city or
were killed by the 170 km hr
-1
winds. Apathy and igno-
rance exacerbated the death toll. There have been at
least four cyclones in recorded history that, as single
events, killed over 300 000 people - all but one
occurred over the Indian subcontinent. The most
destructive cyclone in the twentieth century was the
one that struck Bangladesh - formerly East Pakistan -
in November 1970, killing over 500 000 people. It is
memorable for two reasons. Firstly, most people were
killed by the storm surge rather than strong winds or
floodwaters. Secondly, although viewed by inhabitants
as a rare event, the disaster was repeated in May 1985
and on 29 April 1991, resulting in another 100 000 and
140 000 deaths, respectively. The press also graphically
documented the 1970 disaster. The ensuing ineffectual
rescue and reconstruction effort by the Pakistan
government led to political upheaval and indepen-
dence for Bangladesh. Ironically, while Bangladesh
obtained its independence because of a cyclone,
ultimately it became the poorest country in the world,
mainly because it never recovered economically from
the disaster.
Historically, cyclones account for the greatest
number of deaths resulting from any short-term
natural hazard. Flooding over swathes of 400-500 km
along the cyclone track causes most of this death toll.
The most horrific cyclone-induced flooding occurred
in China along the Chang River between 1851 and
1866. During this period, 40-50 million people
drowned on the Chang River floodplain because of
tropical cyclone-related rainfall. Another 1.5 million
died along the Chang River in 1887 and, in 1931,
3-4 million Chinese drowned on the Hwang Ho River
floodplain because of cyclone flooding.
Tropical cyclones have even changed the course of
history in the Far East. In 1281 AD, Kublai Khan
invaded Japan, and after seven weeks of fierce fighting
was on the verge of breaking through Samurai defenses
- until a typhoon swept through the battlefield. The
storm destroyed most of the 1000 invading ships and
trapped 100 000 attacking soldiers on the beaches,
where they either drowned in the storm surge or were
slaughtered by the Japanese. The Japanese sub-
sequently believed their homeland was invincible,
protected by the Kamikaze (or Divine Wind) that
had saved them from this invasion.
Tropical cyclones can even affect non-tropical areas.
As mentioned above, Hurricane Hazel swept through
southern Ontario, Canada, in October 1954. This
storm occurred during a period of remarkable super-
storms that afflicted Japan and North America
between 1953 and 1957. Hazel drifted northward
along the eastern coast of the United States, where it
killed 95 people, raised a storm surge of 5 m, and
produced the strongest winds ever recorded at Wash-
ington and New York. It then turned inland over the
Appalachians and headed across the Great Lakes to
Toronto, 600 km from the nearest ocean. Here 78
people lost their lives in the worst storm in 200 years.
In Australia, on 4-5 March 1899, Cyclone Mahina
(or the Bathurst Bay Cyclone) crossed the northern
Great Barrier Reef and killed 407 people. The storm
surge reached 4 m, which is high for Australia. Small
cyclones, with eyes less than 20 km in diameter, are
called 'howling terrors' or 'kooinar' by the Aborigines
and appear the most destructive. For instance, the
Queensland town of Mackay, with 1000 inhabitants, was
destroyed in 1918 by one of these small cyclones.
Cyclone Ada in 1970 was so small that it slipped unno-
ticed through the meteorological observation network,
and then surprised and wrecked holiday resorts along
the Queensland coast. The Yongala Cyclone of 1911,
when it reached landfall south of Cape Bowling Green,
cleanly mowed down mature trees 2 m above the
ground in a 30-kilometre swathe. In recent times,
Cyclone Tracy has been the most notable cyclone.
Tracy, with an eye diameter of 12 km, obliterated
Darwin on Christmas Day 1974 (Figure 3.6), killing
over 60 people and reaching wind speeds over
217 km hr
-1
. In world terms, its wind speeds were small
and the loss of life meager. There was also no surge
damage because the tidal range in Darwin is about 7 m
and the cyclone occurred at low tide, with a storm surge
of 4 m. Tracy is one of the best-documented Australian
cyclones, with its graphic evidence of wind damage
forming a benchmark for engineering research into
the effects of strong winds. It also resulted in one of
the largest non-military air evacuations in history, as the
majority of the population of 25 000 was airlifted south
to gain shelter and avoid the outbreak of disease.
Hurricane Andrew, 24 August 1992
(Gore, 1993; Santana, 2002)
In recent times, two events are noteworthy: Hurricane
Andrew in the United States in 1992 and Hurricane