23°S 141°E Brighton Downs – Queensland by Degrees

AT THE POINT

Degree Confluence 23°S 141°E (Google Earth Image)

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Looking north

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Looking east

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Looking south

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Looking weat

Location: Degree Confluence 23°S 141°E is deep in western Queensland, on the working cattle property, 'Brighton Downs', after which the degree square is named. The homestead of the property itself is located some 70 km to the south-east, and the closest settlement is Middleton, approximately 92 km to the north-east. While the confluence itself is unmarked, a GPS was used to find the exact location (accurate to within a few metres). A well-graded property track came to within 600 m of the point, and the remaining distance was travelled by 4WD across country. The site was visited in the early afternoon by a party of RGSQ members travelling in four vehicles from Brisbane in June, 2009.

Landscape: The view from the degree confluence shows a largely flat terrain, with an elevation of 165 m. The few hills visible on the western horizon rise approximately 70 m above the surrounding country. Surface material at the point is comprised totally of grass, and there are scattered trees (height to 5 m) and shrubs along nearby drainage gullies. Although 'Brighton Downs' is a working property, very few cattle were seen during the visit.

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Nearby hill with weathered top

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A typical view of the surrounding countryside

The geology of much of the surrounding country is Mesozoic Lower Cretaceous siltstone and claystone, except along nearby creeks, which are characterised by Cainozoic alluvium. The closest of these creeks to the confluence is less than 500 m to the west, and all drainage in the area occurs at slightly lower levels of elevation. Many nearby watercourses flow south to join the Diamantina River, which is part of the Eyre Basin. Numerous bores are also found in the surrounding countryside

Point Photos By: Paul Feeney, Mary Comer

Point Information By: Paul Feeney, Jo Grant, Mary Nowill

IN THE DEGREE SQUARE

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Climate: The closest weather station to the confluence is at the Boulia Airport, which is 112 km to the west-north-west of the degree confluence, and has an elevation of 162m.

 

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Year

Mean max
(ºC)

38.5

37.4

35.4

31.4

26.7

23.3

22.9

25.7

30.2

34.2

36.9

38.6

31.8

Mean min
(ºC)

24.5

24.0

21.8

17.1

12.5

8.9

7.7

9.5

13.6

17.9

21.3

23.4

16.9

Mean rain
(mm)

48.6

50.7

35.7

14.0

13.1

10.5

9.4

6.4

6.9

14.9

21.3

31.5

262.5

The highest temperature recorded was 48.3°C in February 1915, and the lowest was -1.4°C in August 1906. The greatest rainfall recorded in a year was 798.6 mm in 1950, and the least was 24.1 mm in 1905. These and other climate statistics for Boulia can be found at: Australian Bureau of Meteorology, http://www.bom.gov.au/climate/averages/tables/cw_038003_All.shtml.

Extremes of Nature: The area experiences extreme heat throughout much of the year, with Boulia having an average of 138 days annually that have maximum temperatures equal to or over 35°C. The hottest months are November to March, all of which experience on average approximately 20 days or more with temperatures equal to or over 35°C. With a low average rainfall and only 30 days a year with any rain, very dry conditions also prevail in the area.

Despite the area's relatively inland location, since 1906 one cyclone has passed within 50 km of the degree confluence (Brownyn in 1972), and a further six have passed within 200 km. Cyclone information for this area and all of Australia can be found at the Australian Bureau of Meteorology website, http://www.bom.gov.au/cgi-bin/silo/cyclones.cgi.

 

Cyclone map BOM

 

Today: The population of this degree square at the 2011 national Census was probably less than 50.

 

Information: Ken Granger

Climate information: Jo Grant

Edited By: Hayley Freemantle

REFERENCES

Geoscience Australia, NATMAP Raster

Geoscience Australia, Scanned 250 K Geology Maps