According to his measurements, around 750 cubic meters of granite fell, so he says it would have been tremendously heavy. Through the model, Maclay was able to estimate the volume and mass of rock that was lost when the Old Man of the Mountain fell, which couldn’t be calculated until now. They will also be conducting laboratory analyses of rock samples from the area to investigate chemical changes in minerals due to mildly acidic rainwater and snowmelt. Prior research has found that the cold, harsh winters and warm, wet summers in the White Mountains create conditions for efficient soil production, which may be affected by a warming climate.Īs part of the ongoing project, the researchers installed 24 sensors that record the bedrock temperature at Cannon Cliff. “The bedrock weathering processes are also significant because they are breaking down rocks on the slope into sediment, which is how soil is made,” says Maclay. “Understanding which areas of Cannon Cliff may be especially susceptible to rockfall is important given the popularity of the area as a year-round climbing and tourist destination,” he says. In his research, Maclay is studying how climate-based processes break down bedrock physically and chemically in place, which in turn loosens and frees up the bedrock for rockfall. “It’s an enormous slope of loose rocks, which serves as evidence of the efficient bedrock weathering and rockfall that has been taking place since the last ice sheet retreated, around 12,000 years ago.”

“Cannon Cliff is one of the largest cliffs in the eastern United States and it looms over a massive pile of rocky debris ranging in size from sand to boulders larger than cars,” says Maclay. Through the modern 3D model, viewers can zoom around Cannon Cliff, which is approximately one mile across and 1,000 feet high and see where the Old Man used to be located. “I’m really happy to be part of this project helping to digitally bring the Old Man back to life.” “As a New Hampshire native, I visited the Old Man many times as a child and like so many other state residents I felt a real sense of loss when it finally collapsed,” says Casana, a professor of anthropology. By applying photogrammetry, a technique akin to the way that eyes provide depth perception, Maclay was able to create a 3D model of Cannon Cliff with and without the Old Man.

Maclay processed the imagery in the Planetary Surface Processes Computing Lab led by Marisa Palucis, an assistant professor of earth sciences.

They then reconstructed the now-lost profile using original film negatives taken between 19 that documented the Old Man and surrounding area during maintenance conducted by the profile’s caretakers. As part of the research project, Maclay and collaborators Jesse Casana and Carolin Ferwerda at Dartmouth’s Spatial Archaeometry Lab performed aerial surveys of Cannon Cliff using a drone.

The old man and the seapdf