ANTARCTICA · 2015-11-30 · Antarctica began to move towards the South Pole and experienced more...
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Cape Denison Casey Station Mawson Station Davis Station Geoscience Australia’s Earth monitoring activities consist of four major elements: a geodetic program that maintains and develops positioning infrastructure in Antarctica; a geomagnetic program that monitors geomagnetic field changes in the auroral zone; a seismological program that monitors global earthquake activity; and a nuclear test monitoring program. There are permanent observatories operating across the major Antarctic bases of Casey, Davis, Macquarie Island and Mawson. The Antarctic Geoscience project provides advice to the Australian Government for the environmental management of vulnerable and threatened onshore and marine ecosystems and non-living features within the Australian Antarctic Territory. Activities include geoscience map production, seabed habitat and ecosystem assessment, identification and protection of sites of rare geological and geomorphological value, and sub glacial geothermal heat flow studies to better understand ice sheet behaviour in the context of global climate change. All of these activities contribute toward a greater understanding of the Antarctic continent and its relationship to the Earth around us. www.ga.gov.au 3 6 0 M a 2 8 0 M a 1 6 0 M a 7 0 M a 4 5 M a Throughout geological time large-scale forces acting upon the Earth’s outer crust have repeatedly reconfigured the arrangement of the continents. This rearrangement is cyclic with continents colliding to form supercontinents and then rifting apart into smaller continents again. This process (referred to as the supercontinent cycle) has had major effects on global ocean circulation and climate, and has resulted in the arrangement of continents and oceans that we are familiar with today. More than 470 Ma (million years ago) all of the continents that we know today were part of a single ancient supercontinent. At this time Antarctica was near the equator and experienced tropical climatic conditions. Around 360 Ma this supercontinent split in two, with a large southern hemisphere continent comprising of Antarctica, Australia, South America, Africa and India and a large northern hemisphere continent comprising the Eurasian and North American continents. Antarctica began to move towards the South Pole and experienced more temperate climates. Less than 100 million years later, at about 280 Ma, the landmasses again united as a single supercontinent that is referred to as Pangea. During this time Antarctica drifted over the South Pole and was covered by an ice cap, like modern day Antarctica. About 160Ma, Pangea began to split apart forming two large continents Laurasia and Gondwana. Laurasia was comprised of the North American and Eurasian continents, and Gondwana was comprised of Antarctica, Australia, India, Africa and South America. Antarctica again moved away from the South Pole and the ice cap melted. By 130 Ma, Gondwana began to break up, dividing the landmass into a western half, made up of Africa and South America and an eastern half including Antarctica, India and Australia. India then broke away and began its northward journey through the early Indian Ocean. New Zealand and New Caledonia also rifted away from Australia and Antarctica began to move back towards the South Pole. The split between Antarctica and Australia was the last event in the Gondwanan breakup beginning about 80 Ma when a deep rift valley formed along the southern edge of Australia. By 70 Ma Antarctica continued moving towards the South Pole and the Indian Ocean began to take its present day shape. About 45 Ma, Australia moved northwards as Antarctica moved into a polar position and became covered by a polar ice cap. Antarctica has remained in its present position for approximately the last 25 million years. GEOSCIENCE AUSTRALIA CONDUCTS EARTH MONITORING ACTIVITIES AND APPLIED GEOSCIENCE RESEARCH WITHIN THE AUSTRALIAN ANTARCTIC TERRITORY AND SUB-ANTARCTIC TERRITORIES. GEOSCIENCE ANTARCTIC PROGRAMS A KEY PIECE OF GONDWANA 4 7 0 M a 1 1 . 5 8 6 7 -2 Commonwealth of Australia (Geoscience Australia) 2012 GA11-5150 Source: http://en.wikipedia.org/wiki/File:Emperor_Penguin_ Leap.jpg#filelinks ANTARCTICA
Transcript of ANTARCTICA · 2015-11-30 · Antarctica began to move towards the South Pole and experienced more...
ANTARCTICA
Cape Denison
Casey Station
Mawson Station
Davis Station
11-5867-1
Geoscience Australia’s Earth monitoring activities consist of four major elements: a geodetic program that maintains and develops positioning infrastructure in Antarctica; a geomagnetic program that monitors geomagnetic field changes in the auroral zone; a seismological program that monitors global earthquake activity; and a nuclear test monitoring program.
There are permanent observatories operating across the major Antarctic bases of Casey, Davis, Macquarie Island and Mawson.
The Antarctic Geoscience project provides advice to the Australian Government for the environmental management of vulnerable and threatened onshore and marine ecosystems and non-living features within the Australian Antarctic Territory. Activities include geoscience map production, seabed habitat and ecosystem assessment, identification and protection of sites of rare geological and geomorphological value, and sub glacial geothermal heat flow studies to better understand ice sheet behaviour in the context of global climate change.
All of these activities contribute toward a greater understanding of the Antarctic continent and its relationship to the Earth around us. www.ga.gov.au
360 Ma
280 Ma
160 Ma
70 Ma
45 Ma
Throughout geological time large-scale forces acting upon the Earth’s outer crust have repeatedly reconfigured the arrangement of the continents. This rearrangement is cyclic with continents colliding to form supercontinents and then rifting apart into smaller continents again.
This process (referred to as the supercontinent cycle) has had major effects on global ocean circulation and climate, and has resulted in the arrangement of continents and oceans that we are familiar with today.
More than 470 Ma (million years ago) all of the continents that we know today were part of a single ancient supercontinent. At this time Antarctica was near the equator and experienced tropical climatic conditions.
Around 360 Ma this supercontinent split in two, with a large southern hemisphere continent comprising of Antarctica, Australia, South America, Africa and India and a large northern hemisphere continent comprising the Eurasian and North American continents. Antarctica began to move towards the South Pole and experienced more temperate climates.
Less than 100 million years later, at about 280 Ma, the landmasses again united as a single supercontinent that is referred to as Pangea. During this time Antarctica drifted over the South Pole and was covered by an ice cap, like modern day Antarctica.
About 160Ma, Pangea began to split apart forming two large continents Laurasia and Gondwana. Laurasia was comprised of the North American and Eurasian continents, and Gondwana was comprised of Antarctica, Australia, India, Africa and South America. Antarctica again moved away from the South Pole and the ice cap melted.
By 130 Ma, Gondwana began to break up, dividing the landmass into a western half, made up of Africa and South America and an eastern half including Antarctica, India and Australia. India then broke away and began its northward journey through the early Indian Ocean. New Zealand and New Caledonia also rifted away from Australia and Antarctica began to move back towards the South Pole.
The split between Antarctica and Australia was the last event in the Gondwanan breakup beginning about 80 Ma when a deep rift valley formed along the southern edge of Australia. By 70 Ma Antarctica continued moving towards the South Pole and the Indian Ocean began to take its present day shape.
About 45 Ma, Australia moved northwards as Antarctica moved into a polar position and became covered by a polar ice cap. Antarctica has remained in its present position for approximately the last 25 million years.
GEOSCIENCE AUSTRALIA CONDUCTS EARTH MONITORING ACTIVITIES AND APPLIED GEOSCIENCE RESEARCH WITHIN THE AUSTRALIAN ANTARCTIC TERRITORY AND SUB-ANTARCTIC TERRITORIES.GEOSCIENCE ANTARCTIC PROGRAMS
A KEY PIECE OF GONDWANA
470 Ma
11.5867-2
Commonwealth of Australia (Geoscience Australia) 2012 GA11-5150
Source: http://en.wikipedia.org/wiki/File:Emperor_Penguin_Leap.jpg#filelinks
ANTARCTICA
