Annotated record of the detailed examination of Mn deposits recovered during the COCOTOW expedition in the Southeastern Pacific ocean

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Main Author: Lonsdale, Peter
Format: Dataset Open Access
Language:en
Published: PANGAEA 1976
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_version_ 1867172336099131392
author Lonsdale, Peter
author_facet Lonsdale, Peter
collection Datos científicos de ciencias marinas y ambientales
contents The abyssal circulation of the Pacific Ocean east of the East Pacific Rise is deduced from hydrographic data, supported by a few direct current measurements. Two main flow paths are recognized: across the Chile Rise into the Chile Basin, and thence northward into the Peru Basin and Panama Basin; and eastward across the East Pacific Rise into the Guatemala Basin and into Bauer Basin. Transform fault troughs are important passages allowing flow across the rises, and the Peru-Chile Trench is the principal channel for inflow to the Peru and Panama basins. The deep water that flows across the East Pacific Rise near the equator has a similar temperature structure to that in the southern Chile Basin, but it is less saline and has lower oxygen concentrations. Along both flow paths the bottom waters become warmer, less saline, and less oxygenated as a result of vertical mixing (intensified near sills), geothermal heating (concentrated at active spreading centers) and in situ decay of organic matter (especially beneath productive surface waters). The regional pattern of abyssal circulation may partly control the distribution of metalliferous pelagic sediments (including both fine-grained precipitates and manganese nodules) and the rates of dissolution of calcareous sediments. Where the deep thermohaline flow is accelerated in narrow passages between basins it has deeply eroded the sea floor and transports sediment as bed load. Steady currents measured in one of these passages exceeded 30 cm/s.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_873180
institution PANGAEA
language en
publishDate 1976
publisher PANGAEA
record_format pangaea
spellingShingle Annotated record of the detailed examination of Mn deposits recovered during the COCOTOW expedition in the Southeastern Pacific ocean
Lonsdale, Peter
CCTW-03D; COCOTOW; Comment; Deposit type; DEPTH, sediment/rock; Description; Dredge; DRG; East Pacific Ocean; File name; Identification; Melville; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Position; Quantity of deposit; Sediment type; Size; Substrate type; Uniform resource locator/link to image; Visual description
The abyssal circulation of the Pacific Ocean east of the East Pacific Rise is deduced from hydrographic data, supported by a few direct current measurements. Two main flow paths are recognized: across the Chile Rise into the Chile Basin, and thence northward into the Peru Basin and Panama Basin; and eastward across the East Pacific Rise into the Guatemala Basin and into Bauer Basin. Transform fault troughs are important passages allowing flow across the rises, and the Peru-Chile Trench is the principal channel for inflow to the Peru and Panama basins. The deep water that flows across the East Pacific Rise near the equator has a similar temperature structure to that in the southern Chile Basin, but it is less saline and has lower oxygen concentrations. Along both flow paths the bottom waters become warmer, less saline, and less oxygenated as a result of vertical mixing (intensified near sills), geothermal heating (concentrated at active spreading centers) and in situ decay of organic matter (especially beneath productive surface waters). The regional pattern of abyssal circulation may partly control the distribution of metalliferous pelagic sediments (including both fine-grained precipitates and manganese nodules) and the rates of dissolution of calcareous sediments. Where the deep thermohaline flow is accelerated in narrow passages between basins it has deeply eroded the sea floor and transports sediment as bed load. Steady currents measured in one of these passages exceeded 30 cm/s.
title Annotated record of the detailed examination of Mn deposits recovered during the COCOTOW expedition in the Southeastern Pacific ocean
topic CCTW-03D; COCOTOW; Comment; Deposit type; DEPTH, sediment/rock; Description; Dredge; DRG; East Pacific Ocean; File name; Identification; Melville; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Position; Quantity of deposit; Sediment type; Size; Substrate type; Uniform resource locator/link to image; Visual description
url https://doi.org/10.1594/PANGAEA.873180