Marine Provinces

Marine Provinces

Chapter 4

Bathymetry

• Measurement of ocean depths and the charting of the shape or topography of the ocean floor

Sounding Precision Depth recorder using sonar

Side scanning sonar

• Simultaneous viewing of sea floor with a cross section of the sediments

Satellite measures sea surface using radar and correlates that to gravitational attraction of sea floor

Summary of Bathymetry Methods

1. Sounding (lead line)2. Sonar – single beam, multi-beam, side-scan3. Seismic reflection4. Satellite

Hypsographic Curve• cumulative height frequency curve for the Earth’s

surface or some part thereof. A hypsometric curve is essentially a graph that shows the proportion of land area that exists at various elevations by plotting relative area against relative

Mature Ocean Basin

• A= Rift, B= Continental margin, C= Ocean crust, D= Ocean Basin, E= Continental Crust

Submarine Canyons and Turbidity Currents

• video

A=Graded beddingB= Deep-Sea FansC= Turbidity CurrentD= Submarine Canyon

Abyssal Plain

A=continental shelf, B=abyssal plain, C=abyssal hill province, D=mid ocean ridge, E=continental slope, F=trench, G= C. Rise

G

Ocean Trench

Landward sides of ocean trenches form a volcanic arc (island arc or continental arc

Pull of subducting plate can make a back-arc spreading center

Ocean Trenches

Rift Valley Forms at diverging plates

Pillow Lava

videoYouTube - Mid Ocean Ridges, Volcanoes, and the Arctic

Hydrothermal Vents• Black Smoker at > 350⁰C• White smoker 30-350 ⁰C• Warm-water vent <30⁰C

video

• From magma (A) below, metal sulfides including lead, iron, nickel, copper, zinc and chromium spew out of black smokers (B) and precipitate out creating mineral deposits (C).

Transform boundary and fracture zones.