Quiz Flashcards
Seismic activity beneath mid-ocean ridges
enhances the vigor/intensity of hydrothermal venting, causes some vents to die off and others to start in new places, and increases heat output from the vents.
The spacing of hydrothermal fields along ridge segments is influenced by
Permeability distribution of the ocean crust, location of fissures and faults, development of hydrothermal cells, and location of magma chambers beneath the ridges
hydrothermal vent environments
may have played a fundamental role in the origin of life, provide guids to searching for life on other planets, and are dynamic systems that rapidly change.
diking events at mid-ocean ridges
characterized by hundreds to thousands of small earthquakes, reflect extension events along the ridges, and are fundamental to formation of the oceanic crust
the fluids issuing from high temperature vents
Rapidly entrain and vigorously mix with seawater, contain high concentrations of dissolved metals, and rapidly precipitate out minerals such as pyrite (fools gold)
fast-spreading centers are characterized by
very narrow rift valleys and frequent eruptions
as seawater migrates to depth along mid-ocean ridges
they reach temps in excess of 380C, they become enriched in magmatic gases, oxygen is lost from the fluids, and they extract heat causing cooling of the surrounding rocks, which prompts cracking
Low-temperature hydrothermal flow away from spreading centers is important because
it rivals the discharge of all rivers into the ocean
The Endeavour Segment
Hosts five major hydrothermal fields, has been disturbed by multiple seismic swarm events, and hosts some of the largest chimneys known - reaching 45m in height.
Boiling is important at mid-ocean ridges because
It impacts metal deposition in the oceanic crust and in vents, bounds the upper temperature limit to life, results in fluids lower than seawater salinity, and results in fluids with increase gas concentrations
