Ross Sea

An ocean that flows into Antarctica, located between 70 and 85 degrees south latitude and 165 degrees east longitude and 155 degrees west longitude. The Ross Ice Shelf covers the area south of 77 degrees south latitude. Most of the water is less than 1,000 meters deep, and the continental shelf is well developed. Pennell Bank, which is 300 meters deep, is located near the outer edge of the continental shelf. The water is 500 to 800 meters deep beneath the Ross Ice Shelf. The bottom is mostly glacial deposits, and the water temperature is 2°C to -2°C, and the salinity is 33.5 to 34.7. The water temperature is above 0°C offshore, but on the continental shelf it is almost -2°C, and there is little change in salinity. Near the edge of the ice shelf, there is a westward current of 1 to 3 knots, which weakens to 0.5 knots around 70 degrees south latitude. It was discovered and named by the British explorer James Ross in 1841. There is little sea ice in the western Ross Sea in the summer, and many explorers have been sailing there since ancient times. The Kainan Maru of Shirase's expedition also sailed east along the ice edge of the Ross Ice Shelf, discovering Kainan Bay and Ookuma Bay. Whaling in the Ross Sea has declined sharply, but the oil and gas resources on the continental shelf are attracting attention.

[Hiroshi Kusunoki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

南極の南緯70～85度、東経165度～西経155度の間にある南極大陸へ入り込む海。南緯77度以南はロス棚氷(たなごおり)に覆われている。水深は大部分が1000メートル以浅で、大陸棚が発達している。大陸棚の外縁付近に水深300メートルのペンネル堆(たい)Pennell Bankなどがある。ロス棚氷下の水深は500～800メートル。底質は氷河堆積(たいせき)物がほとんどで、水温は2℃～零下2℃、塩分濃度は33.5～34.7。沖合いでは水温が0℃以上になるが、大陸棚の上ではほぼ零下2℃で、塩分濃度の変化も少ない。棚氷の氷縁付近では1～3ノットの西向きの流れがあり、南緯70度付近では0.5ノットと弱まる。1841年イギリスのジェームズ・ロスが発見、命名した。ロス海西部は夏に海氷が少なく、昔から多くの探検船が進入した。白瀬隊の開南丸もロス棚氷の氷縁沿いに東航し、開南湾、大隈(おおくま)湾を発見した。ロス海での捕鯨は激減したが、大陸棚の石油やガス資源が注目されている。

［楠　宏］

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