Formation of the Boston Harbor Islands and How They Erode and Change By: Kai Bodwell

Thousands of years ago  All of Boston was covered by glaciers. The glaciers dragged till, all sorts of different sediment, into a pile creating a drumlin. When the glacier melted the drumlin was surrounded by water, called a drowned drumlin. The glacier pushed till to the side creating hills called moraine.

The drumlin is eroded.  All drumlins and other landforms are effected by the forces of erosion. There are three types of erosion. One, is erosion by water which is when the rain hits the land. Another is erosion by waves, and the last is erosion by wind.

Erosion by water  The main erosion by water is rain. The rain hits the side of the drumlin and runs down the sloped side creating a runoff. The runoff creates little creases called rill. When two or more rills join it, it becomes a gully.

Erosion by waves  The waves hit the side of the drumlin causing erosion by impact. There is also another type of erosion, called abrasion. It is when the waves drag big rocks and they cut into the sand and softer rock. The waves deposit the sand and rock forming beaches and long shore drifts. They also form spits which are similar to peninsulas.   The waves hit the side of the drumlin causing erosion by impact. There is also another type of erosion, called abrasion. It is when the waves drag big rocks and they cut into the sand and softer rock. The waves deposit the sand and rock forming beaches and long shore drifts. They also form spits which are similar to peninsulas. 

Erosion by wind  The wind carries sediments through the air and erode the soft rocks. The wind also deposit sand and other fine sediments called loess.

Landforms Created by Glaciers  The glaciers create lakes called kettle lakes that are formed when the glaciers melts then refreezes and creates an indent in the ground. Glaciers also place giant boulders in unexpected places called erratics.

This is How the Boston Harbor Looks Today