Switch to construct mode choose the geology data library and add the plate boundary types layer to your layer list.
Sea floor age data.
Sio reference series 93 30 scripps institution of oceanography.
Click and drag the layer above the sea floor age layer.
Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch.
Use the pointer tool to identify the age of the ocean floor moving away from the plate boundaries.
The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age.
Notice that the age will appear on the sea floor age m y legend located below the map.
Age of oceanic lithosphere.
This has happened many times throughout earth s history.
Scientists can determine the age of the seafloor by examining the changing magnetic field of our planet.
The age at each grid node was determined by linear interpolation between adjacent isochrons in the direction of spreading.
A digital age map of the ocean floor.
When scientists studied the magnetic properties of the.
The data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins.
This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level.
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.
Youngest red is along spreading centers.
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.
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.
The grids include data from all the major ocean basins as well as detailed reconstructions of back arc basins.
Shortly after the conclusion of world war ii sonar equipped vessels crisscrossed the oceans collecting ocean depth profiles of the seafloor beneath them.
Every once in a while the currents in the liquid core which create the earth s magnetic field reverse themselves.
Very little of the sea floor is older than 150 million years.
The following features are shown at example depths to scale though each feature has a considerable range at which it may occur.
It is called a geomagnetic reversal.
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.
As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.