Sio reference series 93 30 scripps institution of oceanography.
Sea floor age data.
Every once in a while the currents in the liquid core which create the earth s magnetic field reverse themselves.
It is called a geomagnetic reversal.
Shortly after the conclusion of world war ii sonar equipped vessels crisscrossed the oceans collecting ocean depth profiles of the seafloor beneath them.
The following features are shown at example depths to scale though each feature has a considerable range at which it may occur.
A digital age map of the ocean floor.
Ages for ocean floor between the oldest identified magnetic anomalies and continental crust were interpolated by estimating the ages of passive continental margin segments from geological data and published plate models.
Age of oceanic lithosphere.
When scientists studied the magnetic properties of the.
Seafloor spreading is a process that occurs at mid ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Continental shelf 300 feet continental slope 300 10 000 feet abyssal plain 10 000 feet abyssal hill 3 000 feet up from the abyssal plain seamount 6 000 feet.
Use the pointer tool to identify the age of the ocean floor moving away from the plate boundaries.
Scientists can determine the age of the seafloor by examining the changing magnetic field of our planet.
The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age.
The grids include data from all the major ocean basins as well as detailed reconstructions of back arc basins.
As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.
Youngest red is along spreading centers.
Notice that the age will appear on the sea floor age m y legend located below the map.
Click and drag the layer above the sea floor age layer.
The age at each grid node was determined by linear interpolation between adjacent isochrons in the direction of spreading.
Very little of the sea floor is older than 150 million years.
The data are described in a data and analysis note in the journal of geophysical research 1997 entitled digital isochrons of the world s ocean floor.
The survey data was used to create three dimensional relief maps of the ocean floor and by 1953 american oceanic cartographer marie tharp had created the first of several maps that revealed the presence of an underwater mountain range.
This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level.
The data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins.
Scientists use the magnetic polarity of the sea floor to determine the age.
Switch to construct mode choose the geology data library and add the plate boundary types layer to your layer list.
