The Power of Global Metamorphism Glynis Jehle, Neil Swanson

The Power of Global MetamorphismGlynis Jehle, Neil Swanson

Oceanic Spreading Ridges

DH = 200.4 kJ/kg = 20,000 J/kgm/t=2 (sides of ridge)*h*l*r*velocityVelocity = 5 x 10-2 m/yrHeight, h = 3 x 103 m (~half of ocean crust)Length, l = 8 x 108 m (world’s ridges)r (of rock) = ~3g/cm3

Total = 4.8 x 1011 W

€

P =mt× H

Collision zones

DH = 200.4 J/g = 20,000 J/kgP = (area*h*r*H)/tArea of Himalayas and Tibeten Plateau = ~30Gkm2

Height, h = 3.5 x 104 m (amount of total thickness 70km being metamorphosed)

r (of rock) = ~3g/cm3

Time, t = 40my/3 x 107 sec per yearTotal = 5.3 x 1010 W

€

P =mt× H

Subduction

DH = 200.4 J/g = 20,000 J/kgm/t=h*l*r*velocityHeight = 100m sedimentLength = 5.5 x 107m (world’s subduction zones)r (of rock) = ~3g/cm3

Velocity = 5 x 10-2 m/yrTotal = 5.5 x 109 W

€

P =mt× H

Total energy of Metamorphism

• Oceanic spreading ridges = 4.8 x 1011 W• Collision zones = 5.3 x 1010 W• Subduction zones = 5.5 x 109 W• Total energentics of global metamorphism =

5.4 x 1011 W