Environmental Science Erosion! Environmental Science

Erosion Erosion The removal and transport of weathered materials by natural agents such as Caused by Glaciers Running water Gravity Wind Waves

Glaciers Mass of compacted ice and snow that moves under its own weight

Glaciers Glaciers account for about 75% of the fresh water on Earth

Glaciers can leave behind large boulders that are known as an erratic

Glacial Landforms Trough U-shaped valley, Glaciers carve U shaped valleys

Streams and Rivers Velocity - How fast the water moves Gradient - The steepness, the slope that a river or stream travels If there is a steep gradient, high velocity, and a large discharge, then Erosion will be severe! Rivers have energy to move lots of sediment, and even large boulders.

River stages affect: Velocity, Gradient, & discharge which cause Erosion

Erosion-Mass Movement The downward transportation of weathered materials by gravity Massive Landslide

Erosion-Mass Movement Creep Slump Mudflow/Earthflow Landslide/Rockslide

Fence posts leaning due to creep

Slump can cause road hazards

Mudflow in the Blue Ridge Mooreman’s Gap near Charlottesville

At the bottom of an old rock slide in N.C.

Wave Erosion The crashing of waves on a shoreline combined with storms continually shape the beach. This is a shoreline with erosion.

Wind and Waves Wind moves sand dunes at the beach and in the deserts.

Wind and Waves Wind can carve out landscapes as it carries sediment

Wind and Waves Many storms combine water and wind to cause significant erosion on landforms. Strong winds are capable of moving large amounts of sediment

Deposition: The process of dropping or depositing soil and sediments.

Types of hard stabilization Hard stabilization perpendicular to the coast within the surf zone: Jetties—protect harbor entrances Groins—designed to trap sand Hard stabilization parallel to the coast: Breakwaters—built beyond the surf zone Seawalls—built to armor the coast

Shoreline Hardening: Groin

Shoreline Hardening: Groin

Shoreline Hardening: Jetty                                           

Shoreline Hardening: Breakwater                                            Magic Island is a peninsula shooting off from Ala Moana Park. The beach is protected by a man-made breakwater that cuts off the action of the surf while allowing enough water circulation to keep the salt water fresh and clean.

Shoreline Hardening: Seawall                                                                                 Waikiki Beach from the Halekulani Hotel.