Comparisons of high‐frequency acoustic and shallow‐water ocean temperature fluctuations

2001 ◽  
Vol 109 (5) ◽  
pp. 2421-2421
Author(s):  
Roger W. Meredith ◽  
Steven J. Stanic ◽  
Ralph R. Goodman ◽  
Edgar T. Kennedy ◽  
Nickolas G. Pace
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Temperature Fluctuations ◽  
Ocean Temperature

Comparisons of High-Frequency Acoustic Fluctuations With Ocean-Temperature and Sea-Surface Fluctuations in Shallow Water

2004 ◽  
Vol 29 (2) ◽  
pp. 524-533
Author(s):  
R.W. Meredith ◽  
S.J. Stanic ◽  
R.R. Goodman ◽  
E.T. Kennedy ◽  
N.G. Pace
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Sea Surface ◽  
Ocean Temperature ◽  
Acoustic Fluctuations ◽  
Surface Fluctuations

Microbe-Worm Symbiosis Stabilizes Methane Hydrates in Deep Marine Environments

2021 ◽  
Author(s):  
Tianyi Hua ◽  
Maisha Ahmad ◽  
Tenzin Choezin ◽  
Ryan Hartman
Keyword(s):  
Methane Hydrate ◽  
Temperature Fluctuations ◽  
Methane Hydrates ◽  
Natural Ecosystem ◽  
Ocean Temperature ◽  
Marine Environments ◽  
Balance Equations ◽  
Temperature Records ◽  
Living Organisms ◽  
Hydrate Stability

Abstract Our Planet has a natural ecosystem comprised of living organisms and methane hydrates in deep marine environments. This ecosystem was constructed in the present work to examine the influence that subtle temperature fluctuations could have on the dynamic stability of the hydrate deposits. The coupled mass and energy balance equations that describe the microbial bioreactions, their consumption by feather duster worms, and methane hydrate dissociation confirm that the bioreaction kinetics are dominated by endothermic methanogenic metabolism that stabilizes methane hydrates with a fragile tolerance to 0.001K temperature increases. The feather duster worms also stabilize the hydrates via their selective consumption of methanotrophs that could otherwise overtake the system by their exothermic metabolism. Critical ocean temperature limits exist, beyond which hydrate dissociations would cause underwater eruptions of methane into the sea. Historical ocean temperature records and gas hydrate inventory estimates combined with our model suggests that hydrate deposits as deep as 560-meters below sea level could already be at risk, whereas the methane hydrate stability zone will retreat deeper as ocean temperatures rise. Slowing its retreat could avoid the massive release of greenhouse gas.

Polychaete palaeoecology in an early Late Ordovician marine astrobleme of Sweden

2010 ◽  
Vol 148 (2) ◽  
pp. 269-287 ◽  
Author(s):  
MATS E. ERIKSSON ◽  
ÅSA M. FRISK
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Relative Frequency ◽  
Late Ordovician ◽  
Crater Floor ◽  
Drill Core ◽  
Upper Ordovician ◽  
Composition Characteristic ◽  
Post Impact ◽  
Early Late

AbstractThe post-impact Dalby Limestone (Kukruse; Upper Ordovician) of the Tvären crater, southeastern Sweden, has been analysed with regards to polychaetes, as represented by scolecodonts. A palaeoecological succession is observed in the Tvären-2 drill core sequence, as the vacant ecospace was successively filled by a range of benthonic, nektonic and planktonic organisms. Scolecodonts belong to the first non-planktonic groups to appear and constitute one of the most abundant fossil elements. The polychaete assemblage recorded has an overall composition characteristic of that of the Upper Ordovician of Baltoscandia. Oenonites, Vistulella, Mochtyella and the enigmatic ‘Xanioprion’ represent the most common genera, whereas Pteropelta, Protarabellites?, Atraktoprion and Xanioprion are considerably more rare. The assemblage differs from coeval ones particularly in its poorly represented ramphoprionid fauna and the relatively high frequency of ‘Xanioprion’. A taxonomic succession and changes in abundance and relative frequency of different taxa is observed from the deepest part of the crater and upwards towards more shallow water environments. The initial post-impact assemblage does not, however, necessarily represent a benthonic colonization of the crater floor. Instead it seems to be a taphocoenosis, as indicated by its taxonomic correspondence to the rim facies fauna recovered from Dalby Limestone erratics of the Ringsön island. The Tvären succession has yielded considerably richer scolecodont assemblages than hitherto recorded from the approximately coeval Lockne crater, possibly as a consequence of shallower water settings in the former area.

Measurements of high-frequency shallow-water acoustic phase fluctuations

2000 ◽  
Vol 25 (4) ◽  
pp. 507-515 ◽  
Author(s):  
S.J. Stanic ◽  
R.R. Goodman ◽  
R.W. Meredith ◽  
E. Kennedy
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Phase Fluctuations ◽  
Acoustic Phase

Shallow water sediment properties derived from high-frequency shear and interface waves

1992 ◽  
Vol 97 (B4) ◽  
pp. 4739 ◽  
Author(s):  
John Ewing ◽  
Jerry A. Carter ◽  
George H. Sutton ◽  
Noel Barstow
Keyword(s):  
Shallow Water ◽  
High Frequency ◽  
Sediment Properties ◽  
Interface Waves ◽  
Shallow Water Sediment
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