The group issued a report this month noting that most Antarctic wildlife, including penguins, whales and seals, depend either directly or indirectly on the small shrimp-like creatures for food.
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The cruise, which had been advertised at less than $4,000 per person, is remarkably cheaper than most Antarctic expeditions, which often charge guests at least three times that amount for the privilege of visiting one of the wildest parts of the planet.
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One of the factors that has was underestimated in the U.N. reports, which envisage most Antarctic ice remaining frozen, is a process known as "hydro fracturing" whereby pools of meltwater on ice shelves seep deep into the ice, refreeze and force vast chunks of ice to crack off.
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Most Antarctic predators are found in the polar waters, including the orca and the leopard seal.
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The winter population is around 45, and the summer population averages 150. Most Antarctic Program personnel and cargo reach the South Pole from McMurdo Station via LC-130 ski-equipped aircraft, whereas most fuel IS transported via surface traverse from McMurdo Station. The short austral summer, when most activity occurs, is from late October through mid-February. The station is isolated for the rest of the year.
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A family of yellow-eyed penguin at the Penguin Place Lodge at Otago Peninsula, Dunedin, New Zealand Whether yellow-eyed penguins are colonial nesters has been an ongoing issue with zoologists in New Zealand. Most Antarctic penguin species nest in large high density aggregations of birds. For an example see the photo of nesting emperor penguin. In contrast yellow-eyed penguins do not nest within visual sight of each other.
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Jeffryes' meticulous records of wireless reception quality during the second year of the Australasian Antarctic Expedition were correlated by himself, and by other expeditioners, with other observations of variables such as magnetic readings, auroral intensity, and St Elmo's Fire. These identified, perhaps for the first time, the impacts of Antarctic conditions upon low frequency radio wave propagation. The expedition's head and designated spokesman, Douglas Mawson, had little to say in his published histories about Jeffryes' active service in Antarctica. For almost 100 years, the unfortunate wireless operator's name was suppressed from most Antarctic records.
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Severe cracks in an ice pier in use for four seasons at McMurdo Station slowed cargo operations in 1983 and proved a safety hazard. Major operational ports include: Rothera Station, Palmer Station, Villa Las Estrellas, Esperanza Base, Mawson Station, McMurdo Station, and offshore anchorages in Antarctica. Few ports or harbors exist on the southern (Antarctic) coast of the Southern Ocean, since ice conditions limit use of most shores to short periods in midsummer; even then some require icebreaker escort for access. Most Antarctic ports are operated by government research stations and, except in an emergency, remain closed to commercial or private vessels; vessels in any port south of 60 degrees south are subject to inspection by Antarctic Treaty observers.
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Traditionally, most extinct species of penguins, giant or small, had been placed in the paraphyletic subfamily called Palaeeudyptinae. More recently, with new taxa being discovered and placed in the phylogeny if possible, it is becoming accepted that there were at least two major extinct lineages. One or two closely related ones occurred in Patagonia, and at least one other—which is or includes the paleeudyptines as recognized today – occurred on most Antarctic and Subantarctic coasts. But size plasticity seems to have been great at this initial stage of penguin radiation: on Seymour Island, Antarctica, for example, around 10 known species of penguins ranging in size from medium to huge apparently coexisted some 35 mya during the Priabonian (Late Eocene).
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The Antarctic sea ice cover is highly seasonal, with very little ice in the austral summer, expanding to an area roughly equal to that of Antarctica in winter. It peaks (~18 × 10^6 km^2) during September, which marks the end of austral winter, and retreats to a minimum (~3 × 10^6 km^2) in February. Consequently, most Antarctic sea ice is first year ice, a few meters thick, but the exact thickness is not known. The area of 18 million km^2 of ice is 18 trillion square meters, so for each meter of thickness, given that the density of ice is about 0.88 teratonnes/million km^3, the mass of the top meter of Antarctic sea ice is roughly 16 teratonnes (trillion metric tons) in late winter.
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The effects of Soviet whaling were felt differently by different whale stocks, though all southern ocean baleen whales were negatively affected by it. Blue, humpback and right whales were affected most: Antarctic blue whales in the southern ocean were reduced to about 350, or less than 0.15 percent of their original numbers, due to Soviet whaling (though “legal” whaling by previous nations had already placed them in a precarious position); they are slowly recovering today. The effects of whaling on the more abundant pygmy blue whales is less known, but they are no doubt depleted and are recovering slowly. Humpback whales from the New Zealand-Oceania stock were depleted to perhaps 150 whales due to illegal Soviet whaling; even today, they number only about 20% of their original numbers and are increasing slower than other humpback populations.
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Poorly soluble hydrous ferric oxides are deposited at the surface of ice after the ferrous ions present in the unfrozen saltwater are oxidized in contact with atmospheric oxygen. The more soluble ferrous ions initially are dissolved in old seawater trapped in an ancient pocket remaining from the Antarctic Ocean when a fjord was isolated by the glacier in its progression during the Miocene period, some 5 million years ago when the sea level was higher than today. Unlike most Antarctic glaciers, the Taylor glacier is not frozen to the bedrock, probably because of the presence of salts concentrated by the crystallization of the ancient seawater imprisoned below it. Salt cryo- concentration occurred in the deep relict seawater when pure ice crystallised and expelled its dissolved salts as it cooled down because of the heat exchange of the captive liquid seawater with the enormous ice mass of the glacier.
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