A mechanism that counters established thinking on how the rate at which tectonic plates separate along midocean ridges
controls processes such as heat transfer in geologic materials, energy circulation, and even biological production has been revealed by a Georgia Institute of Technology, Atlanta, study.
That little-explored midocean ridge
, which is spreading slower than other known seams, runs within 350 km of the North Pole and lies at frigid depths between 4,500 and 5,000 meters.
Although Axial forms part of the global midocean ridge
, most other ridge segments do not form broad, high volcanoes, says Rachel M.
Later, lava erupting from the midocean ridge
pours over some of the fractures, coating portions of the hills with fresh volcanic rock.
Most thin areas are created at midocean ridges
and therefore lie beneath oceans, the researchers say.
The frigid temperatures at the site stand in marked contrast to the hellish conditions of the ecosystems thriving near the hydrothermal vents typically associated with midocean ridges
When lava oozes out at midocean ridges
where Earth's tectonic plates spread apart, water quickly chills the molten material as it moves across the ocean floor.
Chemical analyses of basalt drilled from the ocean floor show that in new rock being extruded from midocean ridges
, only about 15 percent of the iron atoms are ions that have a triple dose of positive charge.
The limited-circulation scenario stems from the observation that the molten rock oozing from midocean ridges
lacks much of the uranium, thorium, and other trace elements that spew from some aboveground volcanoes.
That economy makes AUVs ideal for the initial exploration of a certain area of seabed, for example, but it also enables scientists to make repeated visits and watch how features around midocean ridges
or hydrothermal vents evolve.
This [finding] illustrates just how little we know about midocean ridges
The maps suggest that open-ocean tides are spilling much energy--not all over but in hot spots, where tidal currents smash into undersea mountains and midocean ridges
that jut from the seafloor.