Reconstructing Historical Avalanches Using Tree Rings

Avalanche Reconstruction Using Tree Rings

A rumble, a deluge of snow, and then silence — avalanches can be deadly natural phenomena, leaving behind minimal evidence of their occurrence. However, researchers have delved into the realm of tree rings to reconstruct historical records of past avalanches.

Research Findings

By examining the wood of numerous living pine trees near a ski resort in Bulgaria, a team of scientists unearthed traces of numerous large avalanches that struck the area over a span of two centuries. This analysis not only sheds light on the frequency of potentially hazardous avalanches but also serves as valuable insight for risk management strategies and land-use planning. The results of this study were published in the journal Dendrochronologia in June.

The Pirin Mountains

Situated in southwestern Bulgaria, the Pirin Mountains host ancient forests of pine and fir trees. Some of these trees have stood tall for centuries, displaying distinct features such as steeply leaning trunks and noticeable scars like broken branches.

Damage from Avalanches

Many researchers speculate that this visible damage was caused by avalanches. The force of snow cascading downhill can inflict severe harm on large trees, potentially uprooting them. However, discerning the precise timing of an avalanche event is crucial for reconstructing a comprehensive history of these perilous occurrences.

Tree Rings Analysis

To pinpoint the timing and locations of past avalanches in the Pirin Mountains, Dr. Momchil Panayotov and Dr. Nickolay Tsvetanov, both dendrochronologists from the University of Forestry in Sofia, turned to tree rings. Trees that have experienced avalanches exhibit distinct patterns in their rings, serving as enduring records of these events. As Dr. Panayotov explains, “The survivors keep the record.”