TY - CHAP

T1 - Physical Processes and Seamount Productivity

AU - White, Martin

AU - Bashmachnikov, Igor

AU - Arístegui, Javier

AU - Martins, Ana

PY - 2008/4/15

Y1 - 2008/4/15

N2 - A brief review is given of the physical dynamics that occur at seamounts and the implications of these dynamics for seamount productivity highlighted. Several physical seamount characteristics, stratification and oceanic flow conditions interact to provide a number of different local dynamic responses at a seamount. These include Taylor Columns or Cones, doming of density surfaces, enclosed circulation cells and enhanced vertical mixing. Due to oceanic background flow variability, it is likely that the localised seamount dynamics, and resultant bio-physical interaction processes; will also be variable. This makes quantification of an 'idealised' response of a particular seamount to the impinging flow regime difficult. It has been widely accepted that dynamics at seamounts generate conditions such as increased vertical nutrient fluxes and material retention, to promote productivity that fuels higher trophic levels. To date, however, there has been little consistent concrete evidence for this in observations. This is likely due to the non-steady background oceanic forcing which may disrupt the 'idealised' response, such as Taylor Cones and circulation cells generated at the seamount. In addition, the seamount may shed passive tracers such as chlorophyll downstream, providing a source of oceanic bio-physical patchiness in the surrounding ocean. Such variability provides a challenge for the environmental management of seamounts.

AB - A brief review is given of the physical dynamics that occur at seamounts and the implications of these dynamics for seamount productivity highlighted. Several physical seamount characteristics, stratification and oceanic flow conditions interact to provide a number of different local dynamic responses at a seamount. These include Taylor Columns or Cones, doming of density surfaces, enclosed circulation cells and enhanced vertical mixing. Due to oceanic background flow variability, it is likely that the localised seamount dynamics, and resultant bio-physical interaction processes; will also be variable. This makes quantification of an 'idealised' response of a particular seamount to the impinging flow regime difficult. It has been widely accepted that dynamics at seamounts generate conditions such as increased vertical nutrient fluxes and material retention, to promote productivity that fuels higher trophic levels. To date, however, there has been little consistent concrete evidence for this in observations. This is likely due to the non-steady background oceanic forcing which may disrupt the 'idealised' response, such as Taylor Cones and circulation cells generated at the seamount. In addition, the seamount may shed passive tracers such as chlorophyll downstream, providing a source of oceanic bio-physical patchiness in the surrounding ocean. Such variability provides a challenge for the environmental management of seamounts.

KW - Anti-cyclonic vortex

KW - Earth's rotation

KW - Non-periodic impinging current

KW - Seamount productivity

KW - Taylor columns

UR - http://www.scopus.com/inward/record.url?scp=84948740610&partnerID=8YFLogxK

U2 - 10.1002/9780470691953.ch4

DO - 10.1002/9780470691953.ch4

M3 - Chapter

AN - SCOPUS:84948740610

SN - 9781405133432

SP - 62

EP - 84

BT - Seamounts: Ecology, Fisheries & Conservation

PB - Wiley-Blackwell

ER -