Features of the Ocean Floor MID OCEAN RIDGES

Features of the Ocean Floor

MID OCEAN RIDGES • CHAINS OF SUBMARINE VOLCANIC MOUNTAINS • CREATE HYDROTHERMAL VENT ECOSYSTEMS

Mid-Ocean Ridges

Trenches • DEEPEST PARTS OF THE OCEAN • MARIANA’S TRENCH DEEPEST • 1, 580 MILES LONG • 7 -11 miles deep

Marianas Trench

SEA MOUNTS • VOLCANO THAT DOES NOT RISE ABOVE SEA LEVEL

Hot Spot • ACTIVE VOLCANIC ISLANDS • REACH ABOVE SEA LEVEL • EXAMPLE: HAWAII • creation of new island

CONTINENTAL SHELF • GENTLY SLOPING part of continent • 8% OF OCEAN • MOST BIOLOGICALLY RICH

CONTINENTAL SHELF

SUBMARINE CANYONS • DEEP GROOVES CUT INTO CONTINENTAL SLOPES • USED TO BE RIVER EDGES

CONTINENTAL SLOPE • EDGE OF ACTUAL CONTINENT • DEEP DROP OFF TO OCEAN BOTTOM

Upwelling will carry nutrients upward over corals, creating a nutrient rich environment

BIG DIFFERENCE FROM EAST TO WEST COAST

WEST COAST OF US

ACTIVE MARGINS

WEST COAST ACTIVE MARGINS Lots of Tectonic Activity & Steep Rocky Shorelines

PASSIVE MARGINS Flat Coastal Plains and Gradual Slopes

ABYSSAL PLAINS • ABOUT 10, 000 TO 13, 000 FEET • RELATIVELY FLAT area of deep ocean • COVERED BY THICK LAYERS OF SEDIMENT

SONAR • HOW WE MAP OCEAN FLOOR • measuring the length of time a sound signal takes to return. • Scientists "See" Ocean Floor via Sonar - You. Tube