East Pacific Rise: Hot Springs and Geophysical Experiments

来自 NCBI

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168

作者：

FN Spiess，KC Macdonald，T Atwater，R Ballard，A Carranza，D Cordoba，C Cox，VMD Garcia，J Francheteau，J Guerrero

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摘要：

Hydrothermal vents jetting out water at 380degplusmn30degC have been discovered on the axis of the East Pacific Rise. The hottest waters issue from mineralized chimneys and are blackened by sulfide precipitates. These hydrothermal springs are the sites of actively forming massive sulfide mineral deposits. Cooler springs are clear to milky and support exotic benthic communities of giant tube worms, clams, and crabs similar to those found at the Galapagos spreading center. Four prototype geophysical experiments were successfully conducted in and near the vent area: seismic refraction measurements with both source (thumper) and receivers on the sea floor, on-bottom gravity measurements, in-situ magnetic gradiometer measurements from the submersible Alvin over the sea-floor magnetic reversal boundary, and an active electrical sounding experiment. These high-resolution determinations of crustal properties along the spreading center were made to gain knowledge of the source of new oceanic crust and marine magnetic anomalies, the nature of the axial magma chamber, and the depth of hydrothermal circulation

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关键词：

Experimental/ biology geology geomagnetism gravity oceanic crust seawater sediments seismology tectonics terrestrial electricity terrestrial heat/ East Pacific Rise hot springs geophysical experiments hottest waters mineralized chimneys hydrothermal springs exotic benthic communities giant tube worms clams crabs prototype geophysical experiments seismic refraction measurements gravity measurements in-situ magnetic gradiometer measurements submersible Alvin active electrical sounding experiment crustal properties marine magnetic anomalies axial magma chamber sea floor magnetic reversal boundary ocean spreading centre thumper seismic source seafloor seismic receivers hydrothermal circulation depth new oceanic crust source massive sulphide mineral deposits ocean floor geology ocean floor biology sedimentation black smoker hydrothermal vents white smokers plate tectonics/ A9110Q Gravity fields of the Earth A9125J Geomagnetic spatial variations attributed to sea floor spre