Question: When did the body of water next to Breaksea Islands come into existence?

full_context: Document 1: Breaksea Islands (Tasmania): The Breaksea Islands Group is a group of six islands, located in the Southern Ocean, off the south western coast of Tasmania, Australia.
Document 2: Antarctica: Positioned asymmetrically around the South Pole and largely south of the Antarctic Circle, Antarctica is the southernmost continent and is surrounded by the Southern Ocean; alternatively, it may be considered to be surrounded by the southern Pacific, Atlantic, and Indian Oceans, or by the southern waters of the World Ocean. It covers more than 14,000,000 km2 (5,400,000 sq mi), making it the fifth-largest continent, about 1.3 times as large as Europe. The coastline measures 17,968 km (11,165 mi) and is mostly characterized by ice formations, as the following table shows:
Document 3: Tasman Island: The Tasman Island, part of the Tasman Island Group, is an oval island with an area of , lying close to the south-eastern coast of Tasmania, Australia. The island is located in the Tasman Sea, situated off the Tasman Peninsula and is contained within the Tasman National Park.
Document 4: Sidmouth Rock: The Sidmouth Rock is a rock islet or small island, located in the Southern Ocean, off the southern coast of Tasmania, Australia. The island is situated approximately south-east of South East Cape and is contained within the Southwest National Park, part of the Tasmanian Wilderness World Heritage Site. An erosional remnant of the Tasmanian mainland with a diameter of , the island is estimated to have separated from the Tasmanian mainland at least 15,000 years ago.
Document 5: Twin Islets: The Twin Islets form a close pair of small, steep-sided, granite islands, with a combined area of 5.61 ha, in south-eastern Australia. They are part of Tasmania’s Hogan Group, lying in northern Bass Strait between the Furneaux Group and Wilsons Promontory in Victoria.
Document 6: Antarctic Plate: The Antarctic Plate is a tectonic plate containing the continent of Antarctica, the Kerguelen Plateau and extending outward under the surrounding oceans. After breakup from Gondwana (the southern part of the supercontinent Pangea), the Antarctic plate began moving the continent of Antarctica south to its present isolated location causing the continent to develop a much colder climate. The Antarctic Plate is bounded almost entirely by extensional mid-ocean ridge systems. The adjoining plates are the Nazca Plate, the South American Plate, the African Plate, the Somali Plate, the Indo-Australian Plate, the Pacific Plate, and, across a transform boundary, the Scotia Plate.
Document 7: Southern Ocean: By way of his voyages in the 1770s, Captain James Cook proved that waters encompassed the southern latitudes of the globe. Since then, geographers have disagreed on the Southern Ocean's northern boundary or even existence, considering the waters as various parts of the Pacific, Atlantic, and Indian Oceans, instead. However, according to Commodore John Leech of the International Hydrographic Organization (IHO), this situation has no scientific sense since it has different ecosystem and life from the three oceans mentioned before and is located on a southern portion of Earth, hence the name of an ocean. This remains the current official policy of the IHO, since a 2000 revision of its definitions including the Southern Ocean as the waters south of the 60th parallel has not yet been adopted. Others regard the seasonally - fluctuating Antarctic Convergence as the natural boundary.
Document 8: Hogan Group: The Hogan Group is a collection of six (to eight) islands and islets located in the Bass Strait that define part of the border between mainland Australia and the island state of Tasmania. Within the jurisdiction of Tasmania, the Hogan Group forms a land border between the states of Tasmania and Victoria. The island group is officially designated unallocated Crown land, within the Flinders Municipality in Tasmania and the South Gippsland Shire in Victoria.
Document 9: Pedra Branca (Tasmania): Pedra Branca is a rock islet or small island, located in the Southern Ocean, off the southern coast of Tasmania, Australia. The island is situated approximately south southeast of South East Cape and is contained within the Southwest National Park, part of the Tasmanian Wilderness World Heritage Site. An erosional remnant of the Tasmanian mainland, the island is approximately long, wide, with an elevation of above sea level. The island is estimated to have separated from the Tasmanian mainland at least 15,000 years ago.
Document 10: Opening of the North Atlantic Ocean: Rocks from the North Atlantic Igneous Province have been found in Greenland, the Irminger Basin, Faroe Islands, Vøring Plateau (off Norway), Faroe - Shetland Basin, Hebrides, Outer Moray Firth and Denmark. The supercontinent known as Pangea existed during the late Paleozoic and early Mesozoic eras and began to rift around 200 million years ago. Pangea had three major phases of breakup. The first major phase began in the Early - Middle Jurassic, taking place between North America and Africa. The second major phase of breakup began in the Early Cretaceous. The South Atlantic Ocean opened around 140 million years ago as Africa separated from South America, and about the same time, India separated from Antarctica and Australia, forming the central Indian Ocean. The final major phase of breakup occurred in the early Cenozoic, as Laurentia separated from Eurasia. As the two plates broke free from each other, the Atlantic Ocean continued to expand.
Document 11: Broken Group: The Broken Group is a group of small islands and islets in the middle of Barkley Sound on the West Coast of Vancouver Island, British Columbia, Canada. The group is protected as the Broken Islands Group Unit of the Pacific Rim National Park Reserve, which includes Long Beach, between Ucluelet and Tofino to Barkley Sound's northwest, and the West Coast Trail between Port Renfrew and Bamfield, which is to the southeast. The group lies between Imperial Eagle and Loudon Channels and includes Brabant Islands, Hand Island, but not Pinkerton Islands. The southernmost of the group is Cree Island, the easternmost is Reeks Island. Benson Island, on the northwest corner of the Broken Group, is an important cultural site for the Tseshaht First Nation.
Document 12: Geological history of Earth: Antarctica continued to become more isolated and finally developed a permanent ice cap. Mountain building in western North America continued, and the Alps started to rise in Europe as the African plate continued to push north into the Eurasian plate, isolating the remnants of Tethys Sea. A brief marine incursion marks the early Oligocene in Europe. There appears to have been a land bridge in the early Oligocene between North America and Europe since the faunas of the two regions are very similar. During the Oligocene, South America was finally detached from Antarctica and drifted north toward North America. It also allowed the Antarctic Circumpolar Current to flow, rapidly cooling the continent.
Document 13: Geological history of Earth: During the Eocene (56 million years ago - 33.9 million years ago), the continents continued to drift toward their present positions. At the beginning of the period, Australia and Antarctica remained connected, and warm equatorial currents mixed with colder Antarctic waters, distributing the heat around the world and keeping global temperatures high. But when Australia split from the southern continent around 45 Ma, the warm equatorial currents were deflected away from Antarctica, and an isolated cold water channel developed between the two continents. The Antarctic region cooled down, and the ocean surrounding Antarctica began to freeze, sending cold water and ice floes north, reinforcing the cooling. The present pattern of ice ages began about 40 million years ago.[citation needed]
Document 14: Antarctica: Antarctica (US English i/æntˈɑːrktɪkə/, UK English /ænˈtɑːktɪkə/ or /ænˈtɑːtɪkə/ or /ænˈɑːtɪkə/)[Note 1] is Earth's southernmost continent, containing the geographic South Pole. It is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At 14,000,000 square kilometres (5,400,000 square miles), it is the fifth-largest continent in area after Asia, Africa, North America, and South America. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages 1.9 km (1.2 mi; 6,200 ft) in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula.
Document 15: Southern Ocean: The Southern Ocean, geologically the youngest of the oceans, was formed when Antarctica and South America moved apart, opening the Drake Passage, roughly 30 million years ago. The separation of the continents allowed the formation of the Antarctic Circumpolar Current.
ground_truth: roughly 30 million years ago
sub_queries: Breaksea Islands >> located in or next to body of water Answer: Southern Ocean
when did Southern Ocean come into existence Answer: roughly 30 million years ago