In order to grow properly, trees need an adequate period of warmth during their growing seasons; otherwise, the cell walls […] The post These Bizarre Blue Tree Rings Are Unveiling Details About Cold ...

Strange blue rings found in Scandinavian trees leave scientists perplexed - Rings hint at unusually cold summers in Norway between 1877 and 1902 ...

In the frigid landscapes of northern Norway, an unusual phenomenon etched ... Scientists have discovered that peculiar "blue rings" in wood samples reveal the aftermath of chilling volcanic ...