22°S 141°E Toolebuc – Queensland by Degrees

AT THE POINT

Degree Confluence 22°S 141°E, Google Earth

sit

n

Looking north

e

Looking east

s

Looking south

w

Looking west

Location: Degree Confluence 22°S 141°E is located on the working property, Toolebuc, after which the degree square is named. The site is in north-west Queensland, just to the south of the Selwyn Range, and while the confluence itself is unmarked, a GPS was used to find the exact location. Well-graded dirt tracks following the Cannington Mine powerlines came within 7 km of the point, and the last part of the journey was made on quad bikes, along with a final 375 m on foot. Aside from the locality associated with the nearby Cannington Mine, the closest settlement is Middleton, 70 km to the south-east of the point. The site was visited at mid afternoon by a party of RGSQ members travelling in four 4WD vehicles from Brisbane in June, 2009.

Landscape: The view from the degree confluence shows the gently undulating terrain of the Selwyn Range, which has an elevation of 300 m. The point is predominantley covered by spinifex, with a few eucalypts (height 5-6 m) scattered nearby. The grassland surrounding the confluence was largely green during the visit, due to recent rains.

While no animals were seen at the point, a both kites and pelicans were sighted nearby.

Red soil and stones are also present at the point, on top of a base of Lower Cretaceous Allaru mudstone and siltstone. This landscape is typical of much of the surrounding country.

The closest watercourse is located less than 1 km to the north-east, and is an outlying tributary of the Hamilton River, which continues to flow south at a slightly lower level of elevation. The Hamilton River and all other nearby drainage is part of the Eyre Basin. There are also a great number of bores in the general vicinity, some which are used for water in the Cannington Mine, which is 18 km to the north-west. Degree Confluence 22°S 141°E, surrounded by a number of tributaries of both the Hamilton (to the west) and Warburton (to the east) Rivers.

 

Point Photo Credits: Paul Feeney, Mary Comer

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

IN THE DEGREE SQUARE

loc

Climate: The closest representative weather station to the confluence is at the Boulia Airport, which is 151 km to the south-west of the degree confluence, and has an elevation of 162 m. The station has been recording data since 1886.

 

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: Despite the area's inland location, it is still subject to the impact of some cyclones. The database maintained by the Bureau of Meteorology shows that eleven cyclones have passed within 200 km of the confluence since 1906, one of which passed within 50 km (TC Brownyn in 1972). Even distant cyclones bring with them potentially destructive winds and intense rainfall. 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.

Cyclones tracked, BOM

Like most places in the Australian tropics, extreme heat is also a danger. Records show that the Boulia Station experiences 138 days annually with temperatures 35°C or warmer, 46 days of which reach over 40°C. Such extreme temperatures can cause heat stroke and death if appropriate measures are not taken such as avoiding strenuous physical effort, keeping as cool as possible and drinking lots of water. Heat waves kill more people in Australia than all other natural hazards combined.

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

 

Edited by:  Hayley Freemantle

REFERENCES

Information: Ken Granger

Geoscience Australia, NATMAP Raster

Geoscience Australia, Scanned 250 K Geology Maps