Famous composite volcanoes include Mount Fuji in Japan, Mount Cotopaxi in Ecuador, Mount Shasta and Mount Lassen in California, Mount Hood in Oregon, Mount St. Helens and Mount Rainier in Washington, Mount Pinatubo in the Philippines, and Mount Etna in Italy. Many of these volcanoes are located around the Pacific Rim.
When these composite volcanoes show signs of action, nearby towns are warned. Ash from these volcanoes can create vision and water pollution problems. The ash can be carried several hundred miles away. Mount Redoubt in Alaska once spread ash so far that air traffic in Texas was affected.
The composite volcanoes lying around the Pacific Rim are collectively known as the Ring of Fire. Composite volcanoes are also known as stratovolcanoes. Unlike flat shield volcanoes, stratovolcanoes are symmetrically shaped and can rise to 10,000 feet. Composite volcanoes are not only the most iconic and famous volcanoes on Earth, they are also the most dangerous.
Composite volcanoes are built up by the debris of previous eruptions: lava, volcanic ash and rock. For a composite volcano to reach 10,000 feet, it takes multiple eruptions over hundreds of thousands of years. Some composite volcanoes grow so tall on volcanic rubble that the pull of gravity causes landslides.