Can mountains grow and shrink?
Yes. Mount Everest, Earth’s highest summit, continues to rise. The 29,035-foot-high (8,850-meter-high) mountain grows about 0.16 inch (0.41 centimeters) per year. That’s because the Himalayas, the mountain range that includes Mount Everest, was formed 50 million years ago when the Eurasian and Indian plates collided. Today, the plates continue to press against each other, causing the mountains in the range to rise. Other mountains shrink. For example, Mount St. Helens, a volcano in Washington State, erupted on May 18, 1980. The mountaintop was blasted into volcanic ash, shrinking the summit height from 9,677 feet (2,950 meters) to 8,364 feet (2,550 meters).