[pct-l] Half Dome vs Mt Whitney

[Greg Hummel]

Here's my 2 cents on this, recognizing that I'm a soft rock geologist, and know just enough about hard rocks (granite in this case) to be dangerous.


Half Dome was cut by a glacier (perhaps fractured or faulted first by stress, then the ice took away the weaker half) and is exfoliating (thin sheets breaking off) due to the unloading from being pushed up from depth, and, due to acceleration of this by the freeze-thaw cycle.


Mt Whitney, and many of the nearby peaks, are very vertically fractured and blocky.  The vertical nature of Mt Whitney undoubtedly originates in the uplift along the eastern Sierra fault. However, this too has been sculpted by glacial erosion; note the nearly vertical, rounded ice chutes on the east faces, and highly modified by the freeze-thaw cycle. Then entire Kern River gorge and plateau has seen glacial modifications.


I saw a study on Forester Pass a few years ago, that pointed out a number of near vertical faults cutting thru the  wall. Geology is always fun for backpackers and as a geologist, I sometimes find myself recognizing the beautiful complexity of what I'm walking through, if I'm lucky.


Greg Hummel



“Sometimes, I guess there just aren't enough rocks in the world” 
								― Forest Gump