Mid Ocean RidgesThermal Evolution

Joel Pierson, Glynis Jehle

Models for Ocean Plate Thermal Evolution

Half-Space Model• Cooling from the top by

conduction• Isostatic subsidence is

proportional to the square root of the sea floor age

• Plot of depth versus age1/2 is a straight line

• Half-space model significantly overestimates depth for ages >90 Ma

Plate Model• An attempt to better

represent older sea floor• Subsidence and heat flow

described using cooling conductive plate that has a constant temperature at the base

• Parameters for model: Lithosphere thickness and temperature at base (135 km thickness and 1330oC)

The relationship between depth, age and gravity in the oceans

Geophysical Journal InternationalVolume 166, Issue 2, pages 553-573, 5 JUL 2006 DOI: 10.1111/j.1365-246X.2006.03015.xhttp://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2006.03015.x/full#f1

Elevation/bathymetry

[Davis and Chapman, 2011]

Heat Flow

[Davis and Chapman, 2011]