Explain how layers that form in ice are similar to tree rings?

Trees contain some of nature's most accurate evidence of the past. Their growth layers, appearing as rings in the cross section of the tree trunk, record evidence of floods, droughts, insect attacks, lightning strikes, and even earthquakes that occurred during the lifespan of the tree. Subtle changes in the thickness of the rings over time indicate changes in length of, or water availability during, the growing season.

Each year, a tree adds to its girth, with the new growth being called a tree ring. Tree growth depends upon local environmental conditions. In some areas the limiting factor for growth is water availability, in other areas (especially at high latitudes) it is the length of the growing season. In areas where water is limited and the amount of water varies from year to year, scientists can use tree-ring patterns to reconstruct regional patterns of drought. In areas where the length of the growing season is the limiting factor, the thickness of tree rings can indicate when growing seasons were longer (during warmer times) and when growing seasons were shorter (cooler times).

The study of the growth of tree rings is known as dendrochronology. The study of the relationship between climate and tree growth in an effort to reconstruct past climates is known as dendroclimatology.

Layers of ice and tree rings are similar in that they can both record or store data from past environmental conditions. The study of tree rings is known as dendrochronology and it involves counting and studying individual rings in the tree. Each ring represents a year or specific growing period. If the ring is smaller it means there might have been a drought or nutrients were low. A larger than average ring would represent an unusually favourable growing season. Layers of ice in an ice sheet trap information that can tell about past conditions such as climate. Just like the tree rings specific sections represent a specific period of time. Air bubbles trapped in ice provides information on past climates.