1. Free air gravity anomalies derived from radar altimetric determinations of geoid height milligals

2. Bathymetry determined from satellite radar derived gravity plus shipboard measurements

5. Free Air gravity anomaly

8. Now consider an elastic plate which bends under the load

9. The flexural parameter, a where = flexural parameter

10. Deflection vrs x, for vertical line load on infinite plate and half plate Distance, x/a (a = flexural parameter Half plate, vertical line load on edge Infinite plate, vertical line load at x =0 3  /4  /2 123450 2.0 1.6 1.2 0.8 0.4 0 -0.4

11. Bending of half plate F F

12. Outer (oceanic side) slope of trenches associated with subduction zones elastic plate model elastic-plastic model

13. Outer (oceanic side) slope of trenches associated with subduction zones elastic plate model elastic-plastic model strain stress plastic elastic

14. Venus Gravity, Topography and Geoid High correlation between gravity and topography Anomaly amplitude similar to Earth Data from Magellan spacecraft, Images from Wieczorek, 2006

15. Mars Gravity & Topography Maps Free air gravity anomaly from Mars Global Surveyor (MGS) Mars topography from MOLA on MGS Total amplitude of anomaly larger than on Earth Why?

16. Elysium volcano Isidis impact crater From Goddard Space Flight Center Gravity maps Gravity anomalies from Martian features

17. Lunar Gravity & Topography Maps Gravity data from lunar nearside from Lunar Prospector (Sugano and Heki, 2004) Topography data from Clementine Again total amplitude of free-air anomaly larger than on Earth Global map from Knopoliv et al., 1998

18. viscous fluid Temperature, degrees C 0 1300 50 100 150 200 depth, km shear stress shear strain Slope = modulus of rigidity elastic shear stress shear strain yield stress plastic elastic shear stress Slope = coeff of viscosity Viscous fluid shear strain rate