Patrick Allen 
Look at Glaciers [PDF ebook] 

Glaciers are enormous masses of ice that slowly move across the Earth’s surface. But how does something so big move on its own? And why are people concerned that glaciers might be melting more quickly? The answers to these probing questions and more can be found in this fascinating book. The book includes dazzling photographs of these icy behemoths as well as graphic organizers and annotated illustrations to aid learning.