Lake Euramoo

Lake Euramoo Ngimun
view from road site viewing platform
Location	Far North Queensland
Coordinates	17°09′33″S 145°37′44″E / 17.1591°S 145.629°ECoordinates: 17°09′33″S 145°37′44″E / 17.1591°S 145.629°E
Type	late Pleistocene maar: ovate double explosion crater
Primary inflows	no inflow channels
Primary outflows	no outflow channels
Catchment area	4.4 ha
Basin countries	Australia
Average depth	20 m (northern basin), 16 m (southern basin)
Surface elevation	718 m

Lake Euramoo (a.k.a. Ngimun & Nuta) is a shallow dumbbell-shaped volcanic crater lake (a maar) in North Queensland, Australia, formed about 10,000 years ago by two massive explosions from groundwater superheating.

The crater lake is known to Yidinji, within their oral history and mythology as Ngimun,^[1] and known to neighbouring Ngdjon-jii as Nuta;^[1] though formally gazetted on the Queensland government's placenames list as 'Lake Euramoo'^[2](possibly an anglicized version of Ngimun).

The lake (Ngimun) falls within the current Danbulla National Park and State Forest,^[3] on the Tertiary uplifted highlands of the Atherton Tableland, within the Wet Tropics of Queensland World Heritage Area, Australia.

Origins

Yidinji and Ngadjon-jii mythology explaining the origin of Ngimun plus two other companion crater lakes, Yidyam (Lake Eacham) and Barany (Lake Barrine), has been described as a plausible and surprisingly accurate oral account of volcanic eruptions or explosions in the area around 10,000 years ago.

It is said that two newly-initiated men broke a taboo and angered the rainbow serpent Yamany, major spirit of the area ... As a result 'the camping-place began to change, the earth under the camp roaring like thunder. The wind started to blow down, as if a cyclone were coming. The camping-place began to twist and crack. While this was happening there was in the sky a red cloud, of a hue never seen before. The people tried to run from side to side but were swallowed by a crack which opened in the ground'....

.. After telling the myth, in 1964, the storyteller remarked that when this happened the country round the lakes was 'not jungle - just open scrub'. In 1968, a dated pollen diagram from the organic sediments of Lake Euramoo [Ngimun] by Peter Kershaw (1970) showed, rather surprisingly, that the rain forest in that area is only about 7,600 years old.^[1]

Vegetation

The vegetation surrounding Lake Euramoo (Ngimun) is a remnant of moist submontane rainforest, surrounded by previously cleared land that, within the last 50 years, has been planted with endemic Hoop Pine (Araucaria cunninghamii) and exotic conifers, or recolonised by the remnant rainforest species.^[4]

Typical moist submontane rainforest species found near Lake Euramoo (Ngimun), within 100 m, include:^[4]

• Araliaceae (e.g. Polyscias australiana, Schefflera actinophylla)
• Araucariaceae (e.g. Agathis robusta)
• Moraceae (e.g. Ficus sp.),
• Elaeocarpaceae (e.g. Elaeocarpus grandis)
• Euphorbiaceae (e.g. Aleurites moluccana, Macaranga spp.)
• Myrtaceae (e.g. Austromyrtus spp., Eugenia cormiflora) and
• Rubiaceae (e.g. Flindersia brayleyana,Euodia bonwickii )

Around the margin of Ngimun are identifiable 'zones' of aquatic plants which fluctuate with water depth and the seasons:^[4]

• at Lake Euramoo (Ngimun)'s edge, rainforest lianas (e.g. Parsonsia spp.) intertwine with tall swamp grasses (Phragmites australis);
• away from the canopy's shade and the liana growth, up to 1 m water depth, the Hibiscus spp. and Ludwigia spp. become more common.
• further out there are rooted aquatic plants, floating vegetation mats, and, finally, up to 30 m from the edge are the floating aquatic plants (mainly Nymphoides spp.)

External links

• Ngadjonji - Earthwatch web page. Accessed 5 November 2007
• Queensland National Parks & Wildlife Service Accessed 6 November 2007.
• Recording of Striped Marsh frogs at the lake at Freesound

References

1. Dixon, Robert M. W . 1972. The Dyirbal language of North Queensland. Cambridge University. Cambridge. Page 28
2. Queensland Government Place Names Database. Accessed 6 November 2007.
3. Queensland National Parks & Wildlife Service Accessed 6 November 2007.
4. HABERLE, Simon G; TIBBY, John; DIMITRIADIS, Sophie; & HEIJNIS, Henk (2006) The impact of European occupation on terrestrial and aquatic ecosystem dynamics in an Australian tropical rain forest. Journal of Ecology. Volume 96. Pages 987- 1002.