Age Of Sea Floor Map

This map builds on the tectonic plates map by adding seafloor age data.

Age of sea floor map.

A digital age map of the ocean floor. New sea floor map for google earth january 13 2016 in late 2014 we had a look at a map of the ocean floor published by the scripps institution of oceanography university of california san diego. 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.

Measurements of the thickness of marine sediments and absolute age determinations of such bottom material have provided additional evidence for seafloor spreading. An international scientific team recently published a new map of the ocean floor based on earth s gravity field and it is a particularly useful tool. This graphic shows several ocean floor features on a scale from 0 35 000 feet below sea level. The following features are shown at example depths to scale though each feature has a considerable range at which it may occur.

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. The age spreading rate and asymmetry at each grid node is determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Note that the youngest seafloor ages are found at the mid ocean spreading ridges where new rock is constantly coming up from under the crust to heal the rifts formed as tectonic plates move away from one another. Because of this correlation between age and subduction potential very little ocean floor is older than 125 million years and almost none of it is older than 200 million years.

A marine gravity map of the north atlantic ocean red dots show locations of earthquakes with magnitude 5 5 and they highlight the present day location of the seafloor spreading ridges and. Most new crus t forms at these mid ocean spreading ridges. Scientists use the magnetic polarity of the sea floor to determine the age. The oldest sediments so far recovered by a variety of methods including coring dredging and deep sea drilling date only to the jurassic period not exceeding about 200 million years in age.

Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. Sio reference series 93 30 scripps institution of oceanography. Therefore seafloor dating isn t that useful for studying plate motions beyond the cretaceous.