Question

Describe the surface and deep ocean circulation of Panthalassa. Consider radiative imbalance, Coriolis, and the way the placement of continents on the current earth impact atmospheric and oceanic circulation.

Answer 1

Panthalassa was a hemisphere-sized ocean, much larger than the modern Pacific. It could be expected that the large size would result in relatively simple ocean current circulation patterns, such as a single gyre in each hemisphere, and a mostly stagnant and stratified ocean. Modelling studies, however, suggest that an east-west sea surface temperature (SST) gradient was present in which the coldest water was brought to the surface by upwelling in the east while the warmest water extended west into the Tethys Ocean. Subtropical gyres dominated the circulation pattern. The two hemispherical belts were separated by the undulating Intertropical Convergence Zone (ITCZ).

In northern Panthalassa there was mid-latitude westerlies north of 60°N with easterlies between 60°N and the Equator. Atmospheric circulation north of 30°N is associated with the North Panthalassa High which created Ekman convergence between 15°N and 50°N and Ekman divergence between 5°N and 10°N. A pattern which resulted in northward Sverdrup transport in divergence regions and southward in convergence regions. Western boundary currents resulted in an anti-cyclonic subtropical North Panthalassa gyre at mid-latitudes and a meridional anti-cyclonic circulation centred on 20°N.

In tropical northern Panthalassa trade winds created westward flows while equatorward flows were created by westerlies at higher latitudes. Consequently, trade winds moved water away from Gondwana towards Laurasia in the northern Panthalassa Equatorial Current. When the western margins of Panthalassa were reached intense western boundary currents would form the Eastern Laurasia Current. At mid-latitudes the North Panthalassa Current would bring the water back east where a weak Northwestern Gondwana Current would finally close the gyre. The accumulation of water along the western margin coupled with the Coriolis effect would have created a Panthalassa Equatorial Counter Current.

Pangea was surrounded by a global ocean called Panthalassa, and it was fully assembled by the Early Permian Epoch (some 299 million to 273 million years ago). The supercontinent began to break apart about 200 million years ago, during the Early Jurassic Epoch (201 million to 174 million years ago), eventually forming the modern continents and the Atlantic and Indian oceans. Pangea’s existence was first proposed in 1912 by German meteorologist Alfred Wegener as a part of his theory of continental drift. Its name is derived from the Greek pangaia, meaning “all the Earth.”

During the Early Permian, the northwestern coastline of the ancient continent Gondwana (a paleocontinent that would eventually fragment to become South America, India, Africa, Australia, and Antarctica) collided with and joined the southern part of Euramerica (a paleocontinent made up of North America and southern Europe). With the fusion of the Angaran craton (the stable interior portion of a continent) of Siberia to that combined landmass during the middle of the Early Permian, the assembly of Pangea was complete. Cathaysia, a landmass comprising the former tectonic plates of North and South China, was not incorporated into Pangea. Rather, it formed a separate, much smaller, continent within the global ocean Panthalassa.

The mechanism for the breakup of Pangea is now explained in terms of plate tectonics rather than Wegener’s outmoded concept of continental drift, which simply stated that Earth’s continents were once joined together into the supercontinent Pangea that lasted for most of geologic time. Plate tectonics states that Earth’s outer shell, or lithosphere, consists of large rigid plates that move apart at oceanic ridges, come together at subduction zones, or slip past one another along fault lines. The pattern of seafloor spreading indicates that Pangea did not break apart all at once but rather fragmented in distinct stages. Plate tectonics also postulates that the continents joined with one another and broke apart several times in Earth’s geologic history.

Panthalassa, existed on Earth. Currents in this ocean would have been simple and slow, and Earth’s climate was, in all likelihood, warmer than today. The Tethys seaway formed as Pangea broke into Gondwana and Laurasia. In the narrow ocean basins of the central North Atlantic and a huge ocean basin, Panthalassa, with its branch, the Tethys Sea (a large indentation in the tropical eastern side of Pangea).e

The globe was covered by Panthalassa, an enormous world ocean that stretched from pole to pole and extended to about twice the width of the present-day Pacific Ocean at the Equator. Scattered across Panthalassa within 30° of the Triassic Equator were islands, seamounts, and volcanic archipelagoes, some associated with deposit.

Pangea, also spelled Pangaea, in early geologic time, a supercontinent that incorporated almost all the landmasses on Earth.

The land on Earth is constantly moving. Over millions of years, the continents broke apart from a single landmass called Pangea and moved to their present positions.

The land and seas on Earth are constantly moving. Over the course of millions of years, the continents broke apart from a single landmass called Pangea and moved to their present positions.

Pangea was surrounded by a global ocean called Panthalassa, and it was fully assembled by the Early Permian Epoch (some 299 million to 273 million years ago). The supercontinent began to break apart about 200 million years ago, during the Early Jurassic Epoch (201 million to 174 million years ago), eventually forming the modern continents and the Atlantic and Indian oceans. Pangea’s existence was first proposed in 1912 by German meteorologist Alfred Wegener as a part of his theory of continental drift. Its name is derived from the Greek pangaia, meaning “all the Earth.”

During the Early Permian, the northwestern coastline of the ancient continent Gondwana (a paleocontinent that would eventually fragment to become South America, India, Africa, Australia, and Antarctica) collided with and joined the southern part of Euramerica (a paleocontinent made up of North America and southern Europe). With the fusion of the Angaran craton (the stable interior portion of a continent) of Siberia to that combined landmass during the middle of the Early Permian, the assembly of Pangea was complete. Cathaysia, a landmass comprising the former tectonic plates of North and South China, was not incorporated into Pangea. Rather, it formed a separate, much smaller, continent within the global ocean Panthalassa.

Infographic showing evidence of submerged continents that formed and broke up during Earth's geologic history.

The mechanism for the breakup of Pangea is now explained in terms of plate tectonics rather than Wegener’s outmoded concept of continental drift, which simply stated that Earth’s continents were once joined together into the supercontinent Pangea that lasted for most of geologic time. Plate tectonics states that Earth’s outer shell, or lithosphere, consists of large rigid plates that move apart at oceanic ridges, come together at subduction zones, or slip past one another along fault lines. The pattern of seafloor spreading indicates that Pangea did not break apart all at once but rather fragmented in distinct stages. Plate tectonics also postulates that the continents joined with one another and broke apart several times in Earth’s geologic history.

Paleogeography and paleoceanography of Early Triassic time. The present-day coastlines and tectonic boundaries of the configured continents are shown in the inset at the lower right.
Adapted from: C.R. Scotese, The University of Texas at Arlington.

The first oceans formed from the breakup, some 180 million years ago, were the central Atlantic Ocean between northwestern Africa and North America and the southwestern Indian Ocean between Africa and Antarctica. The South Atlantic Ocean opened about 140 million years ago as Africa separated from South America. About the same time, India separated from Antarctica and Australia, forming the central Indian Ocean. Finally, about 80 million years ago, North America separated from Europe, Australia began to rift away from Antarctica, and India broke away from Madagascar. India eventually collided with Eurasia approximately 50 million years ago, forming the Himalayas.

BRITANNICA

Panthalassa
ANCIENT OCEAN
Alternative Title: Panthalassic Ocean

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paleoceanography
In paleoceanography
…of Pangea, one enormous ocean, Panthalassa, existed on Earth. Currents in this ocean would have been simple and slow, and Earth’s climate was, in all likelihood, warmer than today. The Tethys seaway formed as Pangea broke into Gondwana and Laurasia. In the narrow ocean basins of the central North Atlantic,…

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paleogeography
Permian Period
Permian paleogeography
In Permian Period: The Permian environment
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…and a huge ocean basin, Panthalassa, with its branch, the Tethys Sea (a large indentation in the tropical eastern side of Pangea).

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Triassic Period
Triassic paleogeography
In Triassic Period: Paleogeography
…the globe was covered by Panthalassa, an enormous world ocean that stretched from pole to pole and extended to about twice the width of the present-day Pacific Ocean at the Equator. Scattered across Panthalassa within 30° of the Triassic Equator were islands, seamounts, and volcanic archipelagoes, some associated with deposits

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Pangea
ANCIENT SUPERCONTINENT
WRITTEN BY: The Editors of Encyclopaedia Britannica
See Article History
Alternative Title: Pangaea
Pangea, also spelled Pangaea, in early geologic time, a supercontinent that incorporated almost all the landmasses on Earth.

Paleogeography and paleoceanography of (top) Early Permian and (bottom) early Late Permian times.
Paleogeography and paleoceanography of (top) Early Permian and (bottom) early Late Permian times.
Adapted from C.A. Ross and J.R.P. Ross, Cushman Foundation for Foraminiferal Research, Special Publication 24
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Pangea
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Alfred Wegener
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plate tectonics
Triassic Period
Permian Period
continental drift
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Scientists initially ridiculed Wegener's theories about continental movement as "delirious ravings".
continental drift
continental drift
The land on Earth is constantly moving. Over millions of years, the continents broke apart from a single landmass called Pangea and moved to their present positions.
Encyclopædia Britannica, Inc.
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continental drift
continental drift
The land and seas on Earth are constantly moving. Over the course of millions of years, the continents broke apart from a single landmass called Pangea and moved to their present positions.
Created and produced by QA International. © QA International, 2010. All rights reserved. www.qa-international.com
See all videos for this article
Pangea was surrounded by a global ocean called Panthalassa, and it was fully assembled by the Early Permian Epoch (some 299 million to 273 million years ago). The supercontinent began to break apart about 200 million years ago, during the Early Jurassic Epoch (201 million to 174 million years ago), eventually forming the modern continents and the Atlantic and Indian oceans. Pangea’s existence was first proposed in 1912 by German meteorologist Alfred Wegener as a part of his theory of continental drift. Its name is derived from the Greek pangaia, meaning “all the Earth.”

TOP QUESTIONS
How long ago did Pangea exist?
What is a supercontinent?
How did Pangea form?
How did Pangea’s formation affect life on Earth?
How did Pangea affect Earth's climate?
During the Early Permian, the northwestern coastline of the ancient continent Gondwana (a paleocontinent that would eventually fragment to become South America, India, Africa, Australia, and Antarctica) collided with and joined the southern part of Euramerica (a paleocontinent made up of North America and southern Europe). With the fusion of the Angaran craton (the stable interior portion of a continent) of Siberia to that combined landmass during the middle of the Early Permian, the assembly of Pangea was complete. Cathaysia, a landmass comprising the former tectonic plates of North and South China, was not incorporated into Pangea. Rather, it formed a separate, much smaller, continent within the global ocean Panthalassa.

paleocontinent
paleocontinent
Infographic showing evidence of submerged continents that formed and broke up during Earth's geologic history.
Encyclopædia Britannica, Inc./Kenny Chmielewski

The mechanism for the breakup of Pangea is now explained in terms of plate tectonics rather than Wegener’s outmoded concept of continental drift, which simply stated that Earth’s continents were once joined together into the supercontinent Pangea that lasted for most of geologic time. Plate tectonics states that Earth’s outer shell, or lithosphere, consists of large rigid plates that move apart at oceanic ridges, come together at subduction zones, or slip past one another along fault lines. The pattern of seafloor spreading indicates that Pangea did not break apart all at once but rather fragmented in distinct stages. Plate tectonics also postulates that the continents joined with one another and broke apart several times in Earth’s geologic history.

Pangea: Early Triassic Period
Pangea: Early Triassic Period
Paleogeography and paleoceanography of Early Triassic time. The present-day coastlines and tectonic boundaries of the configured continents are shown in the inset at the lower right.
Adapted from: C.R. Scotese, The University of Texas at Arlington
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The first oceans formed from the breakup, some 180 million years ago, were the central Atlantic Ocean between northwestern Africa and North America and the southwestern Indian Ocean between Africa and Antarctica. The South Atlantic Ocean opened about 140 million years ago as Africa separated from South America. About the same time, India separated from Antarctica and Australia, forming the central Indian Ocean. Finally, about 80 million years ago, North America separated from Europe, Australia began to rift away from Antarctica, and India broke away from Madagascar. India eventually collided with Eurasia approximately 50 million years ago, forming the Himalayas.

During Earth’s long history, there probably have been several Pangea-like supercontinents. The oldest of those supercontinents is called Rodinia and was formed during Precambrian time some one billion years ago. Another Pangea-like supercontinent, Pannotia, was assembled 600 million years ago, at the end of the Precambrian. Present-day plate motions are bringing the continents together once again. Africa has begun to collide with southern Europe, and the Australian Plate is now colliding with Southeast Asia. Within the next 250 million years, Africa and the Americas will merge with Eurasia to form a supercontinent that approaches Pangean proportions. The episodic assembly of the world’s landmasses has been called the supercontinent cycle or, in honour of Wegener, the Wegenerian cycle.

If the Earth did not rotate on its axis, the atmosphere would only circulate between the poles and the equator in a simple back-and-forth pattern. Because the Earth rotates on its axis, circulating air is deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. This deflection is called the Coriolis effect.

If the Earth did not rotate and remained stationary, the atmosphere would circulate between the poles (high pressure areas) and the equator (a low pressure area) in a simple back-and-forth pattern. But because the Earth rotates, circulating air is deflected. Instead of circulating in a straight pattern, the air deflects toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere, resulting in curved paths. This deflection is called the Coriolis effect. It is named after the French mathematician Gaspard Gustave de Coriolis (1792-1843), who studied the transfer of energy in rotating systems like waterwheels.