Molloy Deep

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

Molloy Deep is located in Arctic
Molloy Deep
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[]

  1. ^ "Fram Strait Bathymetry". Alfred Wegener Institute for Polar- and Marine Research. Archived from the original on 14 May 2013. Retrieved 2 October 2012.
  2. ^ IHO-IOC GEBCO Gazetteer of Undersea Feature Names (2018-06-25), available online at http://www.ngdc.noaa.gov/gazetteer/
  3. ^ Thiede, Jörn; Pfirman, Stephanie; Schenke, Hans-Werner; Reil, Wolfgang (1990). "Bathymetry of Molloy Deep: Fram Strait between Svalbard and Greenland". Marine Geophysical Researches. Springer. 12 (3): 197–214. Bibcode:1990MarGR..12..197T. doi:10.1007/BF02266713. S2CID 129241736.
  4. ^ Klenke, Martin; Schenke, Hans Werner (2002-07-01). "A new bathymetric model for the central Fram Strait". Marine Geophysical Researches. 23 (4): 367–378. Bibcode:2002MarGR..23..367K. doi:10.1023/A:1025764206736. S2CID 128515547.
  5. ^ Bourke, Robert; Tunnicliffe, Mark; Newton, John; Paquette, Robert; Manley, Tom (1987-06-30). "Eddy near the Molloy Deep revisited". Journal of Geophysical Research. 92: 6773–6776. doi:10.1029/JC092iC07p06773.
  6. ^ Thiede, Jörn; Pfirman, Stephanie; Schenke, Hans Werner; Reil, Wolfgang (1990-08-01). "Bathymetry of Molloy Deep: Fram Strait between Svalbard and Greenland". Mar. Geophys. Res. 12 (3): 197–214. Bibcode:1990MarGR..12..197T. doi:10.1007/BF02266713. S2CID 129241736.
  7. ^ Freire, Francis; Gyllencreutz, Richard; Jafri, Rooh; Jakobsson, Martin (2014-03-31). "Acoustic evidence of a submarine slide in the deepest part of the Arctic, the Molloy Hole". Geo-Marine Letters. 34 (4): 315–325. doi:10.1007/s00367-014-0371-5. S2CID 130008727.
  8. ^ a b "Five Deeps Expedition is complete after historic dive to the bottom of the Arctic Ocean" (PDF).
  9. ^ Freire, F.; Gyllencrentz, R.; Jafri, R.U.; Jakobsson, M. (2014). "Acoustic evidence of a submarine slide in the deepest part of the Arctic, the Molloy Hole". Geo-Marine Letters. 34 (4): 315–325. doi:10.1007/s00367-014-0371-5. S2CID 130008727.
  10. ^ Jakobsson; et al. (2012). "The International Bathymetric Chart of the Arctic Ocean (IBCAO) Version 3.0". Geophys Res Lett. 39 (12): 1–6. doi:10.1029/2012GL052219. hdl:2445/175672.
  11. ^ Laderach, C., et al. (2011). Seismicity and active tectonic processes in the ultra-slow spreading Lena Trough, Arctic Ocean. Geophysical Journal International, v.184, pp. 1354–1370. doi.org/10.1111/j.1365-246X.2010.04926
  12. ^ Baturin, D.G. (1990). "Structure and Geodynamics of the Molloy Transform Fracture Zones in the Mid-Ridge System of the Norway–Greenland Oceanic Basin". Okeanologiya. 30 (3): 436–443.
  13. ^ JThiede, J.; et al. (1990). "Bathymetry of Molloy Deep: Fram Strait Between Svalbard and Greenland". Marine Geophysical Researches. 12 (3): 197–214. Bibcode:1990MarGR..12..197T. doi:10.1007/bf02266713. S2CID 129241736.
  14. ^ a b Chamov, N. P.; Sokolov, S. Yu.; Kostyleva, V. V.; Efimov, V. N.; Peive, A. A.; Aleksandrova, G. N.; Bylinskaya, M. E.; Radionova, E. P.; Stupin, S. I. (2010). "Structure and composition of the sedimentary cover in the Knipovich Rift valley and Molloy Deep (Norwegian-Greenland basin)". Lithology and Mineral Resources. 45 (6): 532–554. doi:10.1134/S0024490210060039. S2CID 56258200.
  15. ^ "Do You Know the Different Types of Faults?".
  16. ^ Cochran, J.R.; et al. (2003). "The Gakkel Ridge: Bathymetry, gravity anomalies, and crustal accretion at extremely slow spreading rates". Journal of Geophysical Research. 108 (B2): 2116. doi:10.1029/2002JB001830.
  17. ^ Nikishin, A.M.; et al. (2018). "Eurasia Basin and Gakkel Ridge, Arctic Ocean: Crustal asymmetry, ultra-slow spreading and continental rifting revealed by new seismic data". Tectonophysics. 746: 64–82. doi:10.1016/j.tecto.2017.09.006. hdl:10852/72327.
  18. ^ Gakkel Ridge
  19. ^ Burton G. Hurdle (ed.), The Nordic Seas: Springer-Verlag, 1986; pp.227-28.
  20. ^ Amos, Jonathan (2019-09-09). "US adventurer reaches deepest points in all oceans" (in British English). Retrieved 2019-09-10.
  21. ^ "Full Ocean Depth Submersible LIMITING FACTOR". fivedeeps.com. Retrieved 2019-10-10.
  22. ^ Five Deeps Expedition (2019-09-09). "Five Deeps Expedition is complete after historic dive to the bottom of the Arctic Ocean" (PDF) (in American English). Retrieved 2019-10-10.
  23. ^ Bongiovanni, Cassandra; Stewart, Heather A.; Jamieson, Alan J. (2021-05-05). "High‐resolution multibeam sonar bathymetry of the deepest place in each ocean". Geoscience Data Journal. Royal Meteorological Society. n/a (n/a). doi:10.1002/gdj3.122. Retrieved 2021-05-16.
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