WHAT GLACIERS LEAVE BEHIND

• Glaciers are like huge mountains of moving ice. Many years ago, the   movement of glaciers across our landscapes slowly made some changes to Earth’s surface.  Ice is heavy, so when it moves it can do some damage to the ground that it is moving over. It can push rocks and soil in front of it as it moves, or it can drag them along. Since ice gradually melts with time, the glaciers end up leaving behind things that they have pushed or pulled during their travels.

• In many places on Earth, there hasn’t been any ice for many years, but there is evidence that it was once there. A moraine is a rut or indentation in the ground that is lined with small rocks and debris. It was formed by a slow- moving glacier that scraped the ground as it moved, and dropped small rocks as it melted. An erratic is a large boulder left behind after a glacier has melted. A huge stone boulder can also be called a monolith. A cirque is an area that is rounded out like a bowl or sink tub.

• Sometimes the results of the landscape transformation produced by glaciers can be amazingly scenic and beautiful. Our national parks often are home to many of these natural wonders. When land was being set aside to preserve and protect it in its natural condition, areas with amazingly sculptured landscapes were obvious choices. By including them in national parks, our government officials protected them for future generations to see.  In California’s Yosemite (Yo-Sem-it-tee) Valley is one of the best examples of how glaciers can transform a landscape. Nearly all of the lakes found in the Yosemite Valley were formed by glaciers that melted after cirques had been formed by the slow-moving giants. As the ice melted, the water settled in the bowl that had been formed rather than running off across the land. There are also many examples of erratics and moraines scattered throughout the Yosemite National Park. Visitors come to Yosemite and other national parks by the thousands to see what glaciers have left behind, and to wonder how leftovers can possibly be so picturesque.

 Name:__________________________________

Answer the following questions based on the reading passage. Don’t forget to go back to the passage whenever necessary to find or confirm   your answers.

1)  What is the main idea of this passage?

2)  What is the author’s opinion about glaciers? How do you know?

3)  What is a possible synonym for erratic?

4)  Based on the content of the passage, what do you think the word picturesque means in the last line of the passage?

5) Explain how a moraine is formed.