18°S 142°E Croydon – Queensland by Degrees

AT THE POINT Degree confluence 18S 142 E (Google Earth image) Location: Degree Confluence 18S 142E is located in far north-west Queensland. The closest settlement is Croydon (after which the degree square is named), approximately 35 km to the south-east. The confluence itself has yet to be visited, but access to the general area can be gained via the Gulf Development Road that runs less than 5 km to the south. Private property tracks then travel closer to the point. Landscape: Elevation at the degree confluence is approximately 75 m, and the landscape is a predominately flat plain, broken by the courses of numerous creeks, which could make the terrain muddy and boggy during the tropical summer rains. Significant human features include the Development Road, and the train line between Croydon and Normanton that follows it. The Google Earth image also shows that the area surrounding the confluence is fairly densely vegetated. Aside from a great many waterholes, Green Creek is the closest watercourse to the point, and all creeks and rivers in the area drain into the Gulf of Carpentaria. The primary geological features at the site include Cainozoic Quaternary (less than 2.5 million years ago) sedimentaries such as quartzose sand and silt. Point Information: Jo Grant   IN THE DEGREE SQUARE The country: An interesting geological feature of the degree square is the Gregory Range to the south-east of the confluence. Numerous mines and quarries are found in this area of Middle Proterozoic geology (1 600-1 000 million years ago), which includes igneous formations of rhyolite, rhodacite and granites. Climate: The closest representative weather station to the confluence is at Croydon, which is 35 km to the south-east of the degree confluence, and has an elevation of 116 m. The station has been recording data since 1889. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year Mean max (ºC) 35.5 34.6 34.4 34.0 31.7 29.2 29.2 31.1 34.3 36.9 38.0 37.3 33.8 Mean min (ºC) 24.2 23.9 23.3 21.0 17.9 14.7 14.0 15.7 19.2 22.4 24.4 24.6 20.4 Mean rain (mm) 220.0 178.8 114.7 23.5 8.0 8.7 4.0 2.7 5.3 13.7 44.4 114.4 740.4 The highest temperature recorded was 43.9°C in November 1965, and the lowest was 2.6°C in July 1983. The greatest rainfall recorded in a year was 1 445.1 mm in 1974, and the least was 225.4 mm in 1952. These and other climate statistics for Croydon can be found at: Australian Bureau of Meteorology, http://www.bom.gov.au/climate/averages/tables/cw_029012.shtml. Extremes of Nature: The area is subject to the impact of tropical cyclones. The database maintained by the Bureau of Meteorology shows that 41 cyclones have passed within 200 km of the confluence since 1906, seven of which passed within 50 km (1911, 1927, 1948, 1951, 1956, 1964, and 1996). These and 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. Cyclone tracks within 200 km of point 1906 to 2006 (Bureau of Meteorology web site) Like most places in the Australian tropics, extreme heat is also a danger. Records show that the Croydon Station experiences 143 days annually with temperatures 35°C or warmer, twelve days of which can 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.

Last updated 223 October 2009. For more information email admin@rgsq.org.au Return to home