Leslie Massey
The East Australian Current (EAC) is a large-scale flow of water that runs south along the east coast of Australia. It is the largest ocean current close to the shores of Australia. The EAC is responsible for moving large volumes of water, heat, and other substances from the tropics to the temperate latitudes, influencing the weather, ocean environment, and ecosystems along the entire east coast of Australia. The EAC is driven by winds over the South Pacific and is strongest in the summer, with a total flow of around 36.3 Sv. It is famously portrayed in the animated film Finding Nemo as a superhighway for fish and turtles travelling south along the Australian coast.
| Characteristics | Values |
|---|---|
| Direction | North to South |
| Starting Point | Great Barrier Reef |
| Ending Point | Southern reaches of Tasmania |
| Width | 15-100 kilometres |
| Depth | 200-500 metres |
| Flow Speed | Up to 4 knots or 7 kilometres per hour |
| Flow Volume | 30-40 million cubic metres per second |
| Flow Velocity | Up to 90 cm/s |
| Impact | Transports marine species, warms the eastern coastline, influences weather patterns, and shapes marine ecosystems |
| Seasonal Variation | Strongest in summer, weakest in winter |
Explore related products
What You'll Learn
The East Australian Current (EAC) is a large-scale flow of water
The EAC plays a crucial role in the climate and ecosystems of eastern Australia. It transports warm tropical water from the Equator southward, interacting with the cooler waters of the Tasman Sea. This process contributes to the conditions that allow the Great Barrier Reef to thrive, maintaining a year-round temperature of around 18 °C. The EAC also acts as a transport system for tropical marine fauna, carrying them to habitats in subtropical regions.
The EAC is driven by winds over the South Pacific, which control its behaviour throughout the year. It begins on the western edge of the South Pacific Gyre, collecting warm, nutrient-poor water. As it moves along the Australian coast, it creates eddies—swirling pools of water that rotate clockwise or anticlockwise within the main flow. These eddies increase vertical mixing in the Tasman Sea, bringing nutrients up to the surface and influencing circulation patterns.
The strength and position of the EAC vary seasonally and over time. It tends to be strongest during the summer, with a total flow of around 36.3 Sv, and weakest in winter, flowing at approximately 27.4 Sv. Over the past six decades, the EAC has been steadily intensifying and moving southward, with the Tasman Sea region becoming warmer and saltier. This has resulted in a southward advance of the EAC Extension of about 350 kilometres.
Seafood Extenders: What's in Australia's Fake Fish?
You may want to see also
Explore related products
The EAC is an underwater superhighway for fish and turtles
The East Australian Current (EAC) is a warm southward current that flows along the east coast of Australia. It is the largest ocean current close to the shores of Australia. The EAC is formed from the South Equatorial Current (SEC) crossing the Coral Sea and reaching the eastern coast of Australia. It carries a large amount of warm tropical water from the Equator southward, contributing to the conditions that allow the Great Barrier Reef to thrive. The EAC is driven by winds over the South Pacific, which control its behaviour at different times of the year.
The EAC is indeed like an underwater superhighway for fish and turtles, as famously depicted in the animated film Finding Nemo. In the film, Marlin and Dory hitch a ride on the back of a turtle, surfing the EAC all the way to Sydney. This portrayal is not far from the truth, as the EAC does provide a pathway for marine species to travel southward along the Australian coast. The current transports tropical marine fauna to habitats in subtropical regions, impacting the composition and functioning of marine ecosystems.
Humpback whales, for example, use the EAC to migrate from breeding grounds on the Great Barrier Reef to cooler feeding grounds in the Southern Ocean. The EAC also carries larvae of many tropical species, larger fishes, and even sea snakes southward. However, some of these species can get carried too far south, ending up in the colder Southern Ocean waters where they may perish. The EAC's ability to transport marine life makes it a crucial factor in shaping the marine ecosystems along Australia's east coast.
The EAC is characterised by its high velocity and strength, with speeds reaching up to 7 kilometres per hour. It can transport an impressive 30 million cubic metres of water per second, equivalent to 16,000 Olympic swimming pools every second. The current is also quite wide, spanning up to 100 kilometres, and it can reach depths of more than 500 metres. As the EAC flows along the coast, it creates eddies or swirling pools of water that rotate clockwise or anti-clockwise within the main flow. These eddies play a significant role in bringing nutrients to the surface, influencing circulation patterns, and increasing mixing in the Tasman Sea.
French Beans in Australia: A Guide to Growing Success
You may want to see also
Explore related products
The EAC impacts the weather and ocean environment
The East Australian Current (EAC) is a warm, southward, western boundary current that flows along the east coast of Australia. As the strongest ocean current in the region, the EAC influences the weather and ocean environment in several ways.
Firstly, it transports vast amounts of warm tropical water from the equator southward, warming the eastern coastline of Australia. This helps to maintain the year-round temperature of around 18 °C along the east coast, preventing it from dropping to 12 °C in the winter. The EAC achieves this by producing warm core eddies, which contribute to the biodiversity of the Tasman Sea.
Secondly, the EAC causes upwelling along the coastline, increasing vertical mixing within the Tasman Sea. The associated turbulent eddies of the EAC influence circulation patterns and enhance mixing, bringing nutrients to the surface. This process of vertical mixing involves the thermocline layer mixing with the surface layer, providing essential nutrients for the marine ecosystem.
Additionally, the EAC acts as a transport mechanism for tropical marine fauna, carrying them to subtropical habitats along the southeast Australian coast. This transport of fauna, including larvae of tropical species, larger fishes, and sea snakes, can sometimes result in them being carried further south than intended and becoming stranded in the colder Southern Ocean waters.
The EAC is driven by winds over the South Pacific, which control its behaviour at different times of the year. It is influenced by the South Pacific Gyre, where it collects warm, nutrient-poor water. The EAC's strength and flow patterns have been impacted by human actions and climate change, with a recorded temperature rise of more than 2 degrees Celsius in the Tasman Sea over the last 40 years.
Flipping Houses: An Australian Guide to Success
You may want to see also
Explore related products
The EAC is the strongest ocean current in the region
The East Australian Current (EAC) is a large-scale flow of water that runs south along the east coast of Australia. It is a warm, southward, western boundary current formed from the South Equatorial Current (SEC) crossing the Coral Sea and reaching the eastern coast of Australia. The EAC is the largest ocean current close to the shores of Australia, moving approximately 30 million cubic metres of water per second. The current is almost 100 kilometres wide and over 500 metres deep, flowing at speeds of up to 7 kilometres per hour.
The EAC plays a crucial role in the region's climate and ecosystems. It contributes to the conditions that allow the Great Barrier Reef to thrive by keeping the east coast around 18°C year-round. The current is low in nutrients but remains essential for the marine ecosystem. It transports tropical marine fauna to habitats in subtropical regions along the southeast Australian coast. Additionally, the EAC influences the weather above water, warming the air and adding moisture, affecting a large portion of the Australian population and economy.
The EAC is characterised by the formation of eddies, swirling pools of water that rotate clockwise or anticlockwise within the main flow. These eddies increase vertical mixing in the Tasman Sea, bringing nutrients up to the surface. The strength and behaviour of the EAC vary seasonally, with the current reaching its maximum velocity during the summer months. The EAC's path and characteristics are influenced by wind patterns, the spin of the Earth, and interactions with the coastline.
The EAC has gained popularity through its portrayal in the animated film "Finding Nemo," where it is depicted as a superhighway for fish and turtles travelling south along the east coast of Australia. This depiction, while imaginative, highlights the significant role the EAC plays in marine life movements and the region's overall climate and ecosystems.
Witchetty Grubs: Australia's Tasty Treats and Their Habitat
You may want to see also
Explore related products
![National Geographic Road Atlas 2026: Adventure Edition [United States, Canada, Mexico]](https://m.media-amazon.com/images/I/81rRihqWqgL._AC_UL320_.jpg)
The EAC is formed from the South Equatorial Current
The East Australian Current (EAC) is formed from the South Equatorial Current (SEC). The EAC is a warm, southward, western boundary current that is driven by winds over the South Pacific. The EAC is the largest ocean current close to the shores of Australia, moving as much as 30 million cubic meters of water per second. It can be up to 100 kilometres wide and over 500 meters deep, flowing at speeds of up to 7 kilometres per hour.
The SEC crosses the Coral Sea and reaches the eastern coast of Australia. Near the Australian coast, around 15° S, the SEC divides, forming the southward flow of the EAC. The EAC flows along the east coast of Australia, sweeping warm tropical waters from the Coral Sea southwards and interacting with the cool, temperate waters of the Tasman Sea. The EAC is responsible for transporting vast amounts of water, heat, and other properties southward from the tropics to the temperate latitudes, impacting the weather, ocean environment, and marine ecosystems along the east coast of Australia.
The EAC plays a crucial role in the climate and ecosystems of eastern Australia. It contributes to the conditions that allow the Great Barrier Reef to thrive by keeping the east coast around 18 °C year-round instead of dropping to 12 °C in the winter. The current is low in nutrients but remains important for the marine ecosystem. It produces warm core eddies, which increase vertical mixing within the Tasman Sea and contribute to the region's biodiversity.
The EAC also acts as a transport mechanism for tropical marine fauna, carrying them to habitats in subtropical regions along the southeast Australian coast. Humpback whales, for example, use the EAC to migrate from breeding grounds on the Great Barrier Reef to cooler feeding grounds in the Southern Ocean. The EAC's strength and temperature have increased over the last 40 years due to human actions and climate change, impacting the Tasman Sea along which it flows.
Creating Playdough: An Australian Guide
You may want to see also
Frequently asked questions
The EAC is a large-scale flow of water that runs south along the east coast of Australia. It is like a massive underwater conveyor belt, transporting 30-40 million cubic metres of water per second. The EAC is around 100 kilometres wide and more than 1.5 kilometres deep.
The EAC can flow at speeds of up to 4 knots, or 7 kilometres per hour. It reaches its maximum velocity of 90 cm/s at 30° S.
The EAC transports warm tropical water from the Equator southward, warming up the eastern coastline of Australia. It also transports marine species southward, and contributes to the conditions that allow the Great Barrier Reef to thrive.
![National Geographic Road Atlas 2026: Scenic Drives Edition [United States, Canada, Mexico]](https://m.media-amazon.com/images/I/814R4OsGtCL._AC_UL320_.jpg)
