Sea Floor Age Data

A digital age map of the ocean floor.

Sea floor age data.

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. Very little of the sea floor is older than 150 million years. 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. Sio reference series 93 30 scripps institution of oceanography. 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.

Use the pointer tool to identify the age of the ocean floor moving away from the plate boundaries. 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. Click and drag the layer above the sea floor age layer. Switch to construct mode choose the geology data library and add the plate boundary types layer to your layer list.

Scientists use the magnetic polarity of the sea floor to determine the age. 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. Shortly after the conclusion of world war ii sonar equipped vessels crisscrossed the oceans collecting ocean depth profiles of the seafloor beneath them. When scientists studied the magnetic properties of the.

It is called a geomagnetic reversal. The grids include data from all the major ocean basins as well as detailed reconstructions of back arc basins. 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 data is from four companion digital models of the age age uncertainty spreading rates and spreading asymmetries of the world s ocean basins.

Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch. Notice that the age will appear on the sea floor age m y legend located below the map. Every once in a while the currents in the liquid core which create the earth s magnetic field reverse themselves. The age at each grid node was determined by linear interpolation between adjacent isochrons in the direction of spreading.

Youngest red is along spreading centers. The age spreading rate and asymmetry at each grid node is determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading.