877 articles
Litke Deep
Litke Deep, a depression in the Eurasian Basin of the Arctic Ocean about 350 km north of Svalbard, long cited as the Arctic's deepest point at 5,449 m; modern analysis finds about 4,000 m, with the Molloy Deep deeper. Named for Fyodor Litke.
Littoral zone
Littoral zone, also called intertidal zone, is the shore band between land and sea, from the spray zone through the tide-covered intertidal to shallow subtidal water; subdivided by tide level and wave exposure, it also names lake and river shores.
Lombok Strait
The Lombok Strait is a deep channel between the Indonesian islands of Bali and Lombok connecting the Bali Sea to the Indian Ocean, and the deepest route for ships too large for the Strait of Malacca.
Lomonosov Ridge
Lomonosov Ridge: an about 1,800 km band of continental crust crossing the central Arctic Ocean, separating the Amerasian and Eurasian Basins, and claimed by Russia, Canada, and Denmark under UNCLOS Article 76.
Long Island Sound
Long Island Sound is a major urban estuary between Connecticut and Long Island, New York, connected to the ocean via the East River and three eastern passes. About 185 km long, it supports 1,200+ invertebrate species, a $9.4 billion economy, and ongoing hypoxia-restoration efforts.
Lord Howe Rise
Lord Howe Rise: submerged continental plateau of Zealandia, ~2,000 km long east of Australia, 20–23 km thick crust, rifted from Australia during Tasman Sea opening (~83–85 Ma), Cretaceous rhyolites, frontier petroleum region.
Lord Howe Seamount Chain
The Lord Howe Seamount Chain (LHSC) is an age-progressive ~1,000 km north-south line of at least 19 guyots, reefs, and banks on the Lord Howe Rise in the Tasman Sea, formed 28-7 Ma as the Australian plate moved north over a hotspot; Lord Howe Island and Ball's Pyramid are its only islands.
Lulworth Cove
Lulworth Cove, Dorset, England: an almost circular bay on the Jurassic Coast World Heritage Site, cut where the sea breached hard Portland limestone and eroded softer Purbeck, Wealden, and Greensand rocks behind the Purbeck Monocline.
Lystad Bay
Lystad Bay: bay 2.5 mi wide on the west side of Horseshoe Island, NE Marguerite Bay, Antarctica; named for Capt. Isak Lystad, first surveyed 1936-37 by the BGLE, site of the Turkish Science Base.
M'Clure Strait
M'Clure Strait, an arm of the Beaufort Sea in Canada's Northwest Territories, is the western leg of Parry Channel in the Northwest Passage, named for explorer Robert McClure; about 270 km long, first transited by icebreakers in 1954.
Mackenzie Bay
Mackenzie Bay, the Arctic bay off the Mackenzie River mouth in the Canadian Beaufort Sea (Yukon/NWT), brackish, sediment-rich, a beluga management zone; also an Antarctic bay on the Amery Ice Shelf.
Macquarie Ridge
The Macquarie Ridge is a submarine ridge in the Southern Ocean, running about 1,600 km from the Puysegur Trench south of New Zealand along the Australian-Pacific plate boundary.
Madeira Abyssal Plain
Madeira Abyssal Plain: flat 68,000 km² deep-sea plain in the Canary Basin, NE Atlantic, over 5400 m deep, built of turbidites from NW Africa, the Canaries, and nearby seamounts; studied for ODP Leg 157 and radioactive waste disposal.
Maho Beach
Maho Beach is a beach on the Dutch side of Sint Maarten at the end of Princess Juliana International Airport's runway, famous for planes passing low overhead.
Majan Ridges
Majan Ridges, an Arabian Sea undersea feature classified as a ridge in the Marine Regions and GEBCO gazetteers, listed near the Murray Ridge, Kurma Ridge, Khanjar Ridge, Oman Basin, and Oman Abyssal Plain.
Makarov Basin
Makarov Basin, wedge-shaped deep Arctic Ocean basin between the Lomonosov Ridge and Alpha-Mendeleev Ridge, discovered 1962 by ARLIS II; over 500 km wide, up to 3,940 m deep, largely filled with Eurasian Basin water.
Makassar Strait
Makassar Strait (Selat Makassar), sea passage between Borneo and Sulawesi, Indonesia, linking the Celebes and Java Seas; carries ~77% of the Indonesian Throughflow (~12–13 Sv) and is an active tectonic and shipping corridor.
Manawatū River mouth and estuary
Manawatū River mouth and estuary (Manawatū Estuary), a 200-plus-hectare bar-built estuary at Foxton Beach, New Zealand; Ramsar site no. 1491 (2005), famed for 95 bird species, migratory bar-tailed godwits, and wrybills.
Manihiki Plateau
The Manihiki Plateau is a large oceanic plateau in the central Pacific Ocean east of the Ontong Java Plateau, formed by massive Early Cretaceous volcanism about 120 million years ago.
Manila Bay
Manila Bay (Look at the bay, Look at Manila) is a semi-enclosed estuary and natural harbor on Luzon, Philippines, site of Dewey's 1898 defeat of the Spanish fleet, 1944 fighting, and modern reclamation and rehabilitation programs.
Manus Basin
Manus Basin: actively spreading back-arc basin in the eastern Bismarck Sea, Papua New Guinea, between fossil Manus Trench and active New Britain Trench; opens ~10 cm/yr, hosts Pacmanus, Vienna Woods, Solwara 1 hydrothermal sulfide deposits.
Marajó Bay
Marajó Bay (Baía de Marajó), a roughly 4,500 km2 tide-dominated estuary in Pará, Brazil, southwest of Marajó Island near Belém, fed mainly by the Pará and Tocantins rivers, muddy year-round, shallow, and a key artisanal fishing ground.
Mare Nostrum
Mare Nostrum, Latin for 'our sea', was the Roman name for the Mediterranean Sea, revived by Fascist Italy as imperial rhetoric and reused for Italy's 2013-2014 migrant search-and-rescue naval operation.
Marguerite Bay (landform)
Marguerite Bay, a large bay on the western Antarctic Peninsula at 68°30′S 68°30′W, discovered and named by Charcot in January 1909; known for raised beaches, a 1,600 m deep trough, Rothera Research Station, and the Wordie Ice Shelf.
Marine Atlantic
Marine Atlantic Inc. (Marine Atlantique), Canadian federal Crown corporation since 1986 (formerly CN Marine) operating the constitutionally required North Sydney–Port aux Basques ferry and seasonal Argentia route with four ice-class vessels.
Marine channel
Marine channel: a waterway deep enough for navigation through otherwise shallow or obstructed water, either a natural sea passage like the English Channel or a dredged lane such as the Ambrose and Savannah shipping channels; also submarine channels carved by turbidity currents.
Marine life of the Indian Ocean
The marine life of the Indian Ocean is the fish, corals, mammals, and other fauna of the 70 million km² basin between Africa, Asia, and Australia.
Marine life of the Mediterranean Sea
The marine life of the Mediterranean Sea comprises about 17,000 recorded species, with the small, nutrient-poor sea supporting 4–18% of the world's marine biodiversity, including bluefin tuna spawning grounds and the threatened Mediterranean monk seal.
Maritime chokepoint
A maritime chokepoint is a narrow sea channel critical to international trade and energy security, such as Hormuz and Malacca, whose closure forces ships onto much longer, costlier detours.
Marlborough Sounds
Marlborough Sounds, New Zealand drowned river valley network (rias) at the top of the South Island, including Queen Charlotte Sound/Tōtaranui and Pelorus/Te Hoiere; about 4,000 km², one tenth of NZ's coastline, formed by Miocene incision, subsidence, and sea-level rise.