In the scientific community, that doesn't wash well. Over a period of three weeks, a crew of 15 scientists drilled cores 2 meters deep, one at a time. The cores were measured, labeled and stored under the surface of the glacier to keep the ice frozen. To refine the chronology, the researchers used a technique known as electrical conductivity measurement. The method employs two tiny electrodes to get a detailed reading of the acidity of the ice.
Volcanic eruptions emit gases and minerals into the air that make precipitation more acidic.
As a result, the signatures of volcanic eruptions are recorded in ice cores. The two largest volcanic eruptions in human history occurred in the Indonesian islands in 1815 at Tambora and 1883 at Krakatau. The researchers detected the signatures of these eruptions in the Wyoming ice core, giving them new data to refine their error bar to plus or minus ten years. Recent studies suggest that glaciers in Glacier National Park in Montana and Canada will disappear within 50 years. Now that we have documented a quick climate change in the past, there is no reason not to believe it can occur in the future.