In:
Geophysical Research Letters, American Geophysical Union (AGU), Vol. 44, No. 13 ( 2017-07-16), p. 6914-6925
Abstract:
Australia is the most arid habitable continent on earth, however its climate is capable of dramatic change with seasonal monsoon rains in the otherwise arid northwest. We analyzed natural gamma radiation in a recently drilled borehole (IODP Expedition 356 Site U1463) off NW Australia to examine long‐term climate changes over the last 6 million years. Based on variations in potassium, thorium and uranium, as well as common clay minerals, we show that the NW continent was more humid during the Pliocene period, between ~5.5 and 3.3 million years ago (Humid Interval), and became arid by the early Pleistocene, ~2.4 million years ago (Arid Interval). We attribute the Humid Interval to an expansion of warm surface waters in the western Pacific, supplying warm and moist air to the continent. As Australia moved north, the Maritime Continent (islands to the north) emerged, restricting the flow of warm surface currents from the Pacific (Indonesian Throughflow), resulting in drier conditions on land. The Arid Interval ushered in a modern‐like Australian climate, with seasonal rainfall and dust storms, and a more modern Indian Ocean circulation. Our results show that the Maritime Continent is an important control on both Australian climate and Indian Ocean circulation.
Type of Medium:
Online Resource
ISSN:
0094-8276
,
1944-8007
DOI:
10.1002/2017GL072977
Language:
English
Publisher:
American Geophysical Union (AGU)
Publication Date:
2017
detail.hit.zdb_id:
2021599-X
detail.hit.zdb_id:
7403-2
SSG:
16,13
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