Digital Inquiry - Coast Erosion

Last updated over 1 year ago

6 questions

VIDEO: ATCHAFALAYA BAY DELTA

See how deltas have formed at the mouths of the Atchafalaya River and Wax Lake Outlet with video created using NASA satellite images collected over 31 years. This resource provides students with the opportunity to visualize the time and spatial scale of delta formation. 

What does a delta look like? How does it form?

INTERACTIVE: DELTA

Deltas are formed when a river drops off sediments at the mouth of a river.  The link will take you to an interactive diagram about deltas. Read the text, study the image, and click the red arrows in the image to learn more.

Why do mud and silt sometimes get dropped off where a river meets the sea?

TEXT: WAVE POWER

Coastlines, where the water meets land, are constantly changing. Water is the most powerful force of weathering (breaking down) and erosion (moving away) on Earth. As water splashes and flows, it weathers rocks and erodes rock and soil. This leaves behind specific formations on rocky shores.

Tall landforms at the coastline are battered by storms which causes rock to weather and erode, with the heavy pieces deposited (dropped off) at the base. This forms a cliff, a high steep face
of rock.

When waves crash especially hard in one place, a cave opening may form. This happens often at sea level, especially where rock is softer in one place.

When a section of land sticks out into the water, the waves can batter from both sides, and instead of a cave, the opening goes clear through and an arch is formed.  An arch has some rocky land above an opening.

Sometimes, the top of the archway is so weathered it falls, this leaves a sea stack, a single formation sticking up like a candle in a cake. In these ways, the coastline is constantly being reshaped.

How do waves form cliffs, sea stacks, and arches?

INTERACTIVE: COASTAL LANDFORMS

What can waves do to rocks on coastlines?

INTERACTIVE: CHATHAM COAST

The link will take you to an interactive slideshow. Click the arrows to view the slides that show how the Chatham coast changed between 1984 and 2016. Be sure to carefully examine Slide 19.

What changes do you notice between the image in 1984 and the image in 2016? What contributed to the changes?

The shape of the coast changes due to weathering, erosion, and _______________ .
Weathering of rock by waves can form ___________ , high, steep faces of rock.
Waves can also weather rock from both sides to form ___________.
Weathering of caves or arches by waves can form _______________ , single columns of rock near the land.
Deposition, or dropping off sediments at the end of a __________, can form a delta. A delta forms when water in a river _______________. Deltas can change when more _____________  builds up.
While _______________  breaks down rocks along the coast, deposition builds up the land.