Chapter 16: The Marine Environment

Shoreline Features A beach is the accumulation of sediment along the shore of a lake or ocean. Waves are constantly eroding, transporting, and depositing sediment resulting in many shoreline features.

Shoreline Features A longshore current moves parallel to the shoreline. It moves along the shore.

Shoreline Features A barrier island is a long, narrow sandbar parallel to, but separated from, the mainland. North Carolina is a state that has many barrier islands.

Shoreline Features An inlet is a division between barrier islands. A sound is a body of water that separates barrier islands from the mainland.

Shoreline Features An estuary is the area where a river or stream enters the ocean. Causes brackish water- a combination of fresh and salt water.

Shoreline Features Estuaries are important because they allow many types of shellfish and other marine life to mature in that habitat.

Protective Structures A groin is a barrier build perpendicular to the shore to trap sand. A jetty is a groin built to protect the entrance to a harbor.

Protective Structures

Protective Structures A seawall is parallel to the shore and protects the coast and property from the force of waves. Galveston, TX Right Before Hurricane Rita Hits the Coast

Beach nourishment is the addition of large quantities of sand to a beach. Very expensive. Only lasts a few years.

Changes in Sea Level Melting of glaciers and ice sheets causes global sea levels to rise. Rising sea levels can cause flooding in coastal areas. Many barrier islands in the Atlantic may be sand dunes that were flooded by rising ocean levels.

The Seafloor The deepest place in the ocean is the Mariana Trench in the Pacific Ocean.

The Seafloor The continental margin is the submerged part of a continent. It is the shallowest part of the ocean that consists of the continental shelf, continental slope, and continental rise.

The Seafloor The continental shelf is the shallowest part of a continental margin extending from the shore to the open ocean. It provides a nutrient-rich home to large numbers of fish

The Seafloor The continental slope is found after the continental shelf and it is the area where the seafloor quickly drops off towards the seafloor. It is the true edge of the continent.

The Seafloor The continental rise is the gently sloping accumulation of deposits from turbidity currents that form at the base of the continental slope.

The Seafloor The ocean basins make up 60% of the Earth’s surface. An abyssal plain is a smooth, flat, bottom part of the ocean. They are the flattest surfaces on earth.

The Seafloor A trench is a deep depression in the seafloor. Many are near chains of volcanic islands. (This is where subduction occurs)

The Seafloor The mid-ocean ridge is a chain of underwater mountains that run through the ocean basins. They are the site of volcanoes producing new ocean crust. A rift valley is the middle part of the mid ocean ridge.

The Seafloor A hydrothermal vent is a hole in the seafloor through which fluid heated by magma erupts. They are an important feature because they are the source of warm water deep in the ocean and support their own unique habitat.

The Seafloor A seamount is an underwater volcano that is higher than 1 km.

A. Continent B. Submarine Canyon K. Continental Shelf I. Volcanic Island C. Continental Slope D. Seamounts H. Midocean ridge E. Guyot J. Rift Valley G. Trench F. Abyssal Plain

The Seafloor The bottom of the seafloor is covered with marine sediments. They are composed of sediments from the land and remnants of dead sea life.