Rifts Ocean Floor

Upon his arrival at the bottom of the ocean cousteau was dumbfounded tharp s rift valley was exactly where she mapped it to be.

Rifts ocean floor. The most popular mechanism for this outward movement is sliding along the volcano ocean floor interface which consists of easily deformable sediments e g. Centennial e3 rifts beneath the ocean floor. Plate tectonics and the ocean floor bathymetry the shape of the ocean floor is largely a result of a process called plate tectonics. Rather than height of the ocean floor above a base or reference level the depth of the ocean is of interest.

The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. The discovery of ocean floor springs represents a great milestone in the scientific investigation of the earth. As one of the first women in the field of marine geophysics in the 1970s she hypothesized and then helped discover the existence of hydrothermal vents on the galápagos rift along the east pacific rise in the mid 1970s and was one the first people to see many of the strange creatures that make their home in this improbable environment. These vents are cracks in the crust of the deep ocean floor where tectonic plates pull away or push toward one another releasing hot magma that heats the cold seawater.

Kathy examining readings from some of her research instruments. Rift valleys are found both on land and at the bottom of the ocean where they are created by the process of seafloor spreading. The galapagos rift springs are described in the november 1979 issue of national. The red sea is an example of a new arm of the sea.

Kathy crane is a true adventurer. The focal mechanism for the 1975 m7 2 kalapana earthquake indicated a slip plane that was nearly horizontal with a slight dip towards at a depth consistent with the base of the volcano e g. The seafloor s permanent magnetic signatures showed that new ocean crust was created at the ridge crests and then spread outward in both directions. In this centennial episode.

With tharp s ocean floor maps in hand scientists during the 1960s formulated a revolutionary theory what is now the accepted idea of plate tectonics. The outer rocky layer of the earth includes about a dozen large sections called tectonic plates that are arranged like a spherical jig saw puzzle floating on top of the earth s hot flowing mantle. Before 1930 little was known about the ocean floor. Rift valleys differ from river valley s and glacial valley s in that they are created by tectonic activity and not the process of erosion.

This seafloor spreading hypothesis had been proposed a few years earlier by harry hess a petrologist at princeton university and robert dietz an oceanographer in the us coast and geodetic survey the federal department that made maps of the oceans and us coastlines. Volcanoes were observed to break the sea surface and this provided evidence of undersea volcanism.