As hot mantle rises it expands.
Magnetic surveys of the ocean floors reveal.
Alternating stripes of normal and reversed polarity paralleling the mid ocean ridge.
In a reconstruction of earth s geologic past the continents of africa and south america fit best along the.
Features in the seafloor layers indicating that oil and gas might be contained in the rocks include salt domes and seeps.
Magnetic surveys of the ocean floors reveal a alternating stripes of normal and reversed polarity paralleling the mid atlantic ridge.
The magnetic variation in successive bands of ocean floor parallel with mid ocean ridges is important evidence supporting the theory of.
B thin oceanic crust composed of basaltic rocks.
Magnetic surveys of the ocean floor reveal.
C that reversed polarity is rare.
To know topography and possible hiding places for submarines.
In geophysics a magnetic anomaly is a local variation in the earth s magnetic field resulting from variations in the chemistry or magnetism of the rocks.
It is suggested that the entire history of the ocean basins in terms of oceanfloor spreading is contained frozen in the oceanic crust.
Why is it so important to survey the ocean floors.
Alternating stripes of normal and reversed polarity paralleling the mid atlantic ridge.
A seismic survey may make use of both shipboad measurements and measurements from an array of ocean bottom seismometers.
Each consist of three sheets a base bathymetric map a magnetic map and a gravity map and where practicable a sediment overprint nos 1308n 17s.
Variations in the intensity and polarity of earth s magnetic field are considered to be recorded in the remanent magnetism of the igneous rocks as they solidified and cooled through the curie temperature at the crest of an oceanic ridge and subsequently.
Magnetic surveys of the ocean floor reveal.
Mapping of variation over an area is valuable in detecting structures obscured by overlying material.
Seafloor is created at mid ocean ridges and destroyed at deep ocean trenches.
Magnetic surveys of the ocean floors reveal.
The bathymetric map when combined with the other three maps serves as a base for making geological geophysical studies of the oceans bottom s crustal geophysical data for the continental shelf.
Plate tectonics states that.
Newly formed mineral grains on the ocean floor are magnetized according to the new orientation of the magnetic field.
Salt domes were created when regions in the ocean repeatedly dried out.
The concept of seafloor spreading states that.
Seafloor is created at mid ocean ridges and destroyed at deep ocean trenches.
Magnetic surveys of the ocean floors reveal alternating strips of normal and reversed polarity paralleling the mid atlantic ridge divergent boundaries are areas of.
As it expands it cools.
The concept of seafloor spreading states that.
Plate tectonics states that.