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2.1.6 Climate of the past several centuries
Instrumental records of weather for Queensland are of a
high quality due to the foresight and tenacity of the first Government Meteorologist,
Clement Wragge, working in the late 19th century. These records extend
back little more than a century which is a relatively short time to assess the
long-term natural variability of climate. To examine variations of climate before
the mid-19th century proxy climate records are required eg tree rings,
ice cores. For shallow-water tropical ocean regions a wealth of proxy climate
and environmental information is locked away in the annual bands of certain
massive coral skeletons which can live to be 700-800 years old (Barnes &
Lough, 1996). A reconstruction of Burdekin River runoff from luminescent bands
in corals from Havannah and Pandora Reefs (see Isdale et al. 1998) shows
much greater variations of river flow than have been experienced in the 20th
century (Figure 6). A reconstruction of sea-surface temperature from the calcification
rates of corals along the GBR (Lough & Barnes, 1997) also shows larger excursions
of temperature than experienced in the 20th century (Figure 7). These
proxy records contain many sources of error and more records are required to
refine the climate histories they suggest.

Figure 2.6
Reconstructed Burdekin River runoff, 1644-1980, from luminescence in coral skeletons.
Thick line is 30-year gaussian filter to emphasize multi-decadal variability
(from Isdale et al. 1998).

Figure 2.7
Reconstructed sea surface temperature anomalies for the Great Barrier Reef from
calcification rates in 10 corals. Thick blue line is 30-year gaussian filter
to emphasise multi-decadal variability (from Lough & Barnes, 1997).
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