A WHIRLWIND OF GEOMORPHIC IMPACTS

Biography

Since retiring from U.K. at the end of 2020, Phillips pilots his battered 2010 Honda Civic between Croatan, North Carolina (retirement home), Lexington, and Myrtle Beach, South Carolina, home of grandchildren Caroline & Andy (and their parents). When not kayaking through the swamps and marshes, ambling through the forest, idling on the beach, or playing with the grandkids, he spends his time drinking beer, fishing, lounging in the hammock, and going to the gym. 

Research and writing continues (at a leisurely pace), mostly in the form of fieldwork in eastern N.C. connected with the activities mentioned above, or screen time on the computer when the weather is bad, the grandkids are in school, or stuck in the city. 

Submitted by jdp on Sat, 11/01/2014 - 12:21 pm

 

Hot off the press, our (myself, Dan Marion, Chad Yocum, Stephanie Mehlhope, and Jeff Olson) study of geomorphic impacts of a tornado blowdown event. You can get a copy here: https://www.researchgate.net/profile/Jonathan_Phillips4/publications

The abstract is below:

Geomorphological Impacts of a tornado disturbance in a subtropical forest.

We studied tree uprooting associated with an EF2 tornado that touched down in portions of the Ouachita Moun- tains in western Arkansas in 2009. In the severe blowdown areas all trees in the mixed shortleaf pine–hardwood forest were uprooted or broken, with no relationship between tree species or size and whether uprooting or breakage occurred. There was also no significant relationship between tree species and amount of soil displaced, and only a weak relationship between tree size and rootwad size. Uprooting resulted in a mean bioturbation rate of 205 m3 ha−1 (about 240 t ha−1). Direct transfer of wind energy via tree uprooting to geomorphic work of soil displacement was about 75 to 190 J m−2. Given the infrequency of tornadoes, this energy subsidy is minor with respect to the long-term energetics of pedogenesis and landscape evolution. However, it does represent a highly significant pulse of geomorphically-significant energy relative to other mechanical processes. Tornadoes such as that of April, 2009—not atypical for the region—are disturbances causing severe, non-selective impacts within the affected area. At a broader, landscape scale, tornadoes are highly localized disturbances, and occur infrequently within any given landform element or forest stand. Only about a third of the uproots revealed root penetration of bedrock, compared to about 90% in other areas of the Ouachita Mountains. This is attributable to the thicker colluvial soils at the study site, and is consistent with the idea that root–bedrock interaction is more likely in thinner regolith covers.