Open AccessCrustal structure of the Mid‐Atlantic ridge crest at 37° N
Author(s) -
Fowler C. M. R.
Publication year - 1976
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1976.tb07097.x
Subject(s) - geology , crust , seismology , mid atlantic ridge , seismogram , crest , mantle (geology) , ridge , upper crust , shear (geology) , geophysics , petrology , paleontology , physics , quantum mechanics
Summary. A structural model of the Mid‐Atlantic Ridge at 37° N is proposed on the basis of travel‐time data and synthetic seismograms. At the ridge axis the crust is only 3 km thick and overlies material with an anomalously low‘upper mantle’velocity of 7.2 km s −1 . Crustal thickening and the formation of layer 3 and a layer with velocity 7.2–7.3 km s −1 takes place within a few kilometres of the axis, producing a 6–7 km thick crust by less than 10 km from the axis. A normal upper mantle velocity of 8.1 km s −1 exists within 10 km of the axis. Shear waves propagate across the axis, thus precluding the existence of any sizeable magma chamber at shallow depth.