AUTOPSY OF THE OLD MAN OF THE MOUNTAIN: HE DIED OF NATURAL CAUSES

New Hampshire’s “Old Man of the Mountain” was a naturally formed profile of a man’s face that was visible when an observer’s line of sight incorporated several overhanging blocks of rock. The profile resulted from glacial plucking, erosion, and rock falls from the quarried face of a large Roche Moutonnee. The profile measured about 23m high and weighed approximately 4500kg. The age of the Old Man is unknown, but it probably formed between the retreat of the last continental ice sheet (approximately 12,000 B.P.) and his first sighting by Native Americans.

The Old Man consisted of Jurassic Conway Granite, which is typically coarse grained, pink biotite granite. A geotechnical analysis of the Profile shows that its stability resulted from compressive cantilevering by the weight of the successive, overlying blocks where the load was at a point behind the cliff face. The center-of-gravity of the lowermost, and critical block of the profile, was located beyond the cliff face. A large cavity existed behind this block, which was open to the elements. Preventative measures were employed for decades to seal out moisture, and steel reinforcements were employed to secure the Profile’s center of mass over the cliff face. However, several geological and structural analyses suggested that the Old Man was inherently unstable, and its collapse was inevitable. On May 2nd, 2003, while hidden in the clouds, the Old Man met his unfortunate demise by tumbled down the face of Profile Mountain. Close visual examination by helicopter of the remains of the Profile showed significant grus had formed in the fracture planes, and soil had infilled voids where fractures were enlarged. Physical and chemical weathering in the uplands of the White Mountains are promoted by a hostile climate, which is characterized by high winds, ample precipitation, and vigorous freeze-thaw cycles resulting from daily temperatures that average below freezing 160 days per year. Green moss was observed where the cavity between the blocks existed, indicating excessive moisture. The boulder trail formed by the Profile’s collapse was mapped using GPS and GIS. The culmination of evidence suggests that the Old Man met his demise by the same processes that created him, and is consistent with predictions made over 30 years before.