Deluge Sediments and Canyons on the Continental Shelves, a Synopsis

2021 ◽  
pp. 402-403
Author(s):  
Benjamin Franklin Allen
Keyword(s):  
Author(s):  
Andrew Clarke

The extreme meteorological surface air temperatures recorded to date are –89.2 oC in Antarctica, and 56.7 oC in Death Valley, California. Ground temperatures can be higher or lower than these air temperatures. The bulk of oceanic water is cold (< 4 oC) and thermally stable. Whilst data on limits to survival attract considerable attention, the thermal limits to completion of the life cycle (which define the limits to life) are much less well known. Currently identified upper thermal limits for growth are 122 oC for archaeans, 100 oC for bacteria and ~60 oC for unicellular eukaryotes. No unicells appear to grow below –20 oC, a limit that is probably set by dehydration-linked vitrification of the cell interior. The lower thermal limits for survival in multicellular organisms in the natural world extend to at least –70 oC. However in all cases known to date, completion of the life cycle requires summer warmth and the lowest temperature for completion of a multicellular eukaryote life cycle appears to be ~0 oC for invertebrates in glacial meltwater and ~–2 oC for marine invertebrates and fish living on the continental shelves around Antarctica.


2012 ◽  
Vol 27 (8) ◽  
pp. 800-806 ◽  
Author(s):  
Andy Ridgwell ◽  
Mark Maslin ◽  
Jed O. Kaplan
Keyword(s):  

2021 ◽  
Vol 168 (3) ◽  
Author(s):  
Carlos F. Rodríguez-Gómez ◽  
Gabriela Vázquez ◽  
Carlos A. Maya-Lastra ◽  
José A. Aké-Castillo ◽  
Christine J. Band-Schmidt ◽  
...  

2011 ◽  
Vol 26 (3) ◽  
pp. 355-383 ◽  
Author(s):  
Andrew Serdy

AbstractCreated by the United Nations Convention on the Law of the Sea to apply the rules in Article 76 on the outer limits of the continental shelf beyond 200 nautical miles from States’ territorial sea baselines, the Commission on the Limits of the Continental Shelf has on several occasions introduced new requirements for States not supported by Article 76, or impermissibly qualifying the rights Article 76 accords them. This article focuses on several such instances, one to the coastal State’s advantage (though temporally rather than spatially), another neutral (though requiring unnecessary work of States), but the remainder all tending to reduce the area of continental shelves. The net effect has been to deprive States of areas of legal continental shelf to which a reasonable interpretation of Article 76 entitles them, and in one case even of their right to have their submissions examined on their merits, even though, paradoxically, the well-meaning intention behind at least some of the Commission’s pronouncements was to avoid other controversies.


2021 ◽  
Vol 432 ◽  
pp. 106402
Author(s):  
Lucas Porz ◽  
Wenyan Zhang ◽  
Till J.J. Hanebuth ◽  
Corinna Schrum

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thomas J. Browning ◽  
Eric P. Achterberg ◽  
Anja Engel ◽  
Edward Mawji

AbstractResidual macronutrients in the surface Southern Ocean result from restricted biological utilization, caused by low wintertime irradiance, cold temperatures, and insufficient micronutrients. Variability in utilization alters oceanic CO2 sequestration at glacial-interglacial timescales. The role for insufficient iron has been examined in detail, but manganese also has an essential function in photosynthesis and dissolved concentrations in the Southern Ocean can be strongly depleted. However, clear evidence for or against manganese limitation in this system is lacking. Here we present results from ten experiments distributed across Drake Passage. We found manganese (co-)limited phytoplankton growth and macronutrient consumption in central Drake Passage, whilst iron limitation was widespread nearer the South American and Antarctic continental shelves. Spatial patterns were reconciled with the different rates and timescales for removal of each element from seawater. Our results suggest an important role for manganese in modelling Southern Ocean productivity and understanding major nutrient drawdown in glacial periods.


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