Glacial ice can range in age from several hundred to several thousands of years old. In order to study long-term climate records, scientists drill and extract ice cores from glaciers and ice sheets. The ice cores contain information about past climate, giving scientists the ability to learn about the evolution of ice and past climates. Trapped air bubbles contain past atmospheric composition, information on temperature variations, and types of vegetation from earlier times.
Studying ice bubbles is one way for scientists to know that there have been several Ice Ages, for example. Unfortunately, glaciers have been retreating at unprecedented rates since the early twentieth century, destroying ice bubbles. This Photo Friday, view images of these information-packed glacier ice bubbles.