Molloy Deep

Coordinates: 79°8′12″N 2°49′0″E / 79.13667°N 2.81667°E / 79.13667; 2.81667

Molloy Deep

Location of Molloy Deep

The Molloy Deep (also known as the Molloy Hole) is a bathymetric feature in the Fram Strait, within the Greenland Sea^[1] east of Greenland and about 160 km west of Svalbard. It is the location of the deepest point in the Arctic Ocean.^{[2][3][4][5][6][7][8]}

The outer rim of the trench is at a depth of 2,700 m (8,900 ft) and contains about 600 km² inside the rim, descending to approximately 5,550 m (18,210 ft) at its greatest depth. The basin floor measures about 220 km², and is the deepest point in the Arctic Ocean.^[9][10] The first and only person to have reached the bottom of the Molloy Deep is American explorer Victor Vescovo, as part of his Five Deeps Expedition.

Geology[]

The Molloy Deep is a roughly rectangular, seismically active,^[11] extensional,^[12] sea-floor basin, that lies between the northwestern tip of the Molloy Fracture Zone,^[13] (a right-lateral,^[14] strike-slip fault^[14]), and the Spitsbergen Fracture Zone (also a right-lateral, strike-slip fault). These two fracture zones connect the Knipovich Ridge (the actively spreading northern segment of the Mid-Atlantic Ocean ridge system), with the Lena Trough, an actively spreading mid-ocean ridge region north of the Spitsbergen Fracture Zone. The Lena Trough joins the southwestern end of the Arctic Ocean's Gakkel Ridge^[15] which is the slowest spreading mid-ocean ridge on Earth,^[16][17] and which stretches across the entire Arctic Oceans’ Eurasian Basin.^{[18][circular reference]}

History[]

DSSV Pressure Drop and DSV Limiting Factor at its stern

The Molloy Deep was discovered in September 1972 by the USNS Hayes (T-AGOR-16), the first of a new class of catamaran-hulled oceanographic research vessels. The Molloy Deep, Molloy Hole, Molloy Fracture Zone, and Molloy Ridge were named after Arthur E. Molloy, a U.S. Navy research scientist who worked in the North Atlantic, North Pacific and Arctic Oceans in the 1950s-1970s.^[19]

Crewed descent[]

The first, and so far only, person to reach the bottom of the Molloy Deep is Victor Vescovo on 24 August 2019.^[8][20] The Five Deeps Expedition leader and chief submersible pilot, Vescovo, descended into the Molloy Deep in the Deep-Submergence Vehicle DSV Limiting Factor (a Triton 36000/2 model submersible) from the support ship, the Deep Submersible Support Vessel DSSV Pressure Drop.^[21] The Five Deeps Expedition established the depth of the Molloy Deep as 5,550 m (18,210 ft) ±14 m (46 ft) by direct CTD pressure measurements.^[22] This is shallower than previous estimations using earlier technology with less precise bathymetric methods.^[23]

References[]